Abstracts
Background:
Patients with heart failure (HF) usually develop exercise intolerance. In this context, noninvasive ventilation (NIV) can help to increase physical performance.
Objective:
To undertake a systematic review and meta-analysis of randomized controlled trials that evaluated the effects of NIV on exercise tolerance in patients with HF.
Method:
Search Strategy: Articles were searched in the following databases: Physiotherapy Evidence Database (PEDro), Scientific Electronic Library Online (SciELO), and MEDLINE. Selection Criteria: This review included only randomized controlled trials involving patients with HF undergoing NIV, with or without other therapies, that used exercise tolerance as an outcome, verified by the distance travelled in the six-minute walk test (6MWT), VO2peak in the cardiopulmonary test, time spent in testing, and dyspnea. Data Collection and Analysis: The methodological quality of the studies was rated according to the PEDro scale. Data were pooled in fixed-effect meta-analysis whenever possible.
Results:
Four studies were selected. A meta-analysis including 18 participants showed that the use of NIV prior to the 6MWT promoted increased distance, [mean difference 65.29 m (95% CI 38.80 to 91.78)].
Conclusions:
The use of NIV prior to the 6MWT in patients with HF may promote increased distance. However, the limited number of studies may have compromised a more definitive conclusion on the subject.
heart disease; exercise intolerance; positive pressure
Contextualização:
Pacientes com insuficiência cardíaca (IC) usualmente desenvolvem intolerância ao exercício. Nesse contexto, a ventilação não invasiva (VNI) pode auxiliar no incremento do desempenho físico.
Objetivo:
Realizar uma revisão sistemática e metanálise de ensaios controlados randomizados que avaliaram os efeitos da VNI na tolerância ao exercício em pacientes com IC.
Método:
Para a estratégia de busca, os artigos foram pesquisados nas seguintes bases de dados: Physiotherapy Evidence Database (PEDro), Scientific Electronic Library Online (SciELO), MEDLINE. Critérios de seleção: foram incluídos somente ensaios controlados randomizados envolvendo pacientes com IC submetidos à VNI, associada ou não a outras terapias, os quais utilizaram como desfecho a tolerância ao exercício verificada pela distância percorrida no teste de caminhada de seis minutos (TC6); VO2pico no teste cardiopulmonar, tempo de permanência no teste e dispneia. Coleta de dados e análise: a qualidade metodológica dos estudos incluídos foi avaliada pela escala PEDro. Os dados foram agrupados em uma metanálise modelo fixed effect, quando possível.
Resultados:
Quatro estudos foram selecionados. Uma metanálise, incluindo 18 participantes, demonstrou que o uso de VNI prévio ao TC6 foi favorável ao aumento da distância percorrida, [diferença média 65,29m (IC95% 38,80 a 91,78)].
Conclusões:
O uso de VNI prévio ao TC6 em pacientes com IC pode promover aumento na distância percorrida. No entanto, a falta de estudos pode ter comprometido uma conclusão mais categórica sobre o assunto.
doenças cardiovasculares; intolerância ao exercício; pressão positiva
Introduction
Heart failure (HF) is a complex clinical syndrome that results from impaired ventricular
filling or ejection capacity11. Bocchi EA, Marcondes-Braga FG, Ayub-Ferreira SM, Rohde LE, Oliveira
WA, Almeida DR, et al. Sociedade Brasileira de Cardiologia. III diretriz brasileira
de insuficiência cardíaca crônica. Arq Bras Cardiol. 2009;93(1 Supl 1):1-71.
,
22. Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark
AL, et al. Clinical correlates and prognostic significance of the ventilatory
response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90.
http://dx.doi.org/10.1016/S0735-1097(97)00078-8
http://dx.doi.org/10.1016/S0735-1097(97)...
, and involvement of the left ventricle occurs
in 60% of cases in adults11. Bocchi EA, Marcondes-Braga FG, Ayub-Ferreira SM, Rohde LE, Oliveira
WA, Almeida DR, et al. Sociedade Brasileira de Cardiologia. III diretriz brasileira
de insuficiência cardíaca crônica. Arq Bras Cardiol. 2009;93(1 Supl 1):1-71. .
Exertional dyspnea, termed exercise intolerance (EI), is the main symptom of HF and is
closely linked to its pathophysiology22. Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark
AL, et al. Clinical correlates and prognostic significance of the ventilatory
response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90.
http://dx.doi.org/10.1016/S0735-1097(97)00078-8
http://dx.doi.org/10.1016/S0735-1097(97)...
.
Understanding the mechanisms of exercise intolerance is paramount in the treatment of HF
because EI directly affects the diagnosis and reflects a poor prognosis for the
patient33. Witte KK, Clark AL. Why does chronic heart failure cause
breathlessness and fatigue? Prog Cardiovasc Dis. 2007;49(5):366-84. PMid:17329182.
http://dx.doi.org/10.1016/j.pcad.2006.10.003
http://dx.doi.org/10.1016/j.pcad.2006.10...
. Those mechanisms are multifactorial
and remain poorly understood, and excessive ventilatory requirements -with predominantly
restrictive ventilatory mechanics, inspiratory muscle fatigue, exacerbated muscle
ergoreflex, accentuated sympathetic activity, or some combination of these factors - are
prominent among them33. Witte KK, Clark AL. Why does chronic heart failure cause
breathlessness and fatigue? Prog Cardiovasc Dis. 2007;49(5):366-84. PMid:17329182.
http://dx.doi.org/10.1016/j.pcad.2006.10.003
http://dx.doi.org/10.1016/j.pcad.2006.10...
. All these mechanisms
contribute to the increase in central motor command to the respiratory muscles,
withconsequent increases in perceived exertion and fatigue, similar to the results found
in skeletal muscles33. Witte KK, Clark AL. Why does chronic heart failure cause
breathlessness and fatigue? Prog Cardiovasc Dis. 2007;49(5):366-84. PMid:17329182.
http://dx.doi.org/10.1016/j.pcad.2006.10.003
http://dx.doi.org/10.1016/j.pcad.2006.10...
.
Thus, functional capacity is limited not only by cardiac factors but also by the
interaction between the cardiopulmonary and locomotor complexes44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
. Abnormal ventilatory responses, which are common in patients with
HF44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
, combine with peripheral muscle
dysfunction to reduce the patients' ability to perform daily life tasks and impair their
quality of life44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
, directly affecting their ability to perform
physical exercise. Although studies have shown direct benefits from regular physical
training in patients with HF by promoting a gradual improvement in tolerance to
effort66. Piepoli MF, Conraads V, Corrà U, Dickstein K, Francis DP, Jaarsma T,
et al. Exercise training in heart failure: from theory to practice: a consensus
document of the Heart Failure Association and the European Association for
Cardiovascular Prevention and Rehabilitation. Eur J Heart Fail. 2011;13(4):347-57.
PMid:21436360. http://dx.doi.org/10.1093/eurjhf/hfr017
http://dx.doi.org/10.1093/eurjhf/hfr017...
, increased maximal oxygen consumption
(VO2)77. Van der Meer S, Zwerink M, Van Brussel M, Van der Valk P, Wajon E,
Van der Palen J. Effect of outpatient exercise training programmes in patients with
chronic heart failure: a systematic review. Eur J Cardiovasc Prev Rehabil. 2011 [Epub
ahead of print]. PMid:21593055., and increased oxidative
capacity of the skeletal muscles88. Hambrecht R, Niebauer J, Fiehn E, Kälberer B, Offner B, Hauer K, et
al. Physical training in patients with stable chronic heart failure: effects on
cardiorespiratory fitness and ultrastructural abnormalities of leg muscles. J Am Coll
Cardiol. 1995;25(6):1239-49.
http://dx.doi.org/10.1016/0735-1097(94)00568-B
http://dx.doi.org/10.1016/0735-1097(94)0...
, the blood flow
to the respiratory muscles tends to rise significantly during exercise training because
of the redistribution of blood flow from the locomotor muscles99. Olson TP, Joyner MJ, Dietz NM, Eisenach JH, Curry TB, Johnson BD.
Effects of respiratory muscle work on blood flow distribution during exercise in
heart failure. J Physiol. 2010;588(13):2487-501. PMid:20457736 PMCid:PMC2915522.
http://dx.doi.org/10.1113/jphysiol.2009.186056
http://dx.doi.org/10.1113/jphysiol.2009....
. Consequently, reduced oxygenation of the peripheral muscles and
elevated lactate concentration occur, increasing muscle fatigue99. Olson TP, Joyner MJ, Dietz NM, Eisenach JH, Curry TB, Johnson BD.
Effects of respiratory muscle work on blood flow distribution during exercise in
heart failure. J Physiol. 2010;588(13):2487-501. PMid:20457736 PMCid:PMC2915522.
http://dx.doi.org/10.1113/jphysiol.2009.186056
http://dx.doi.org/10.1113/jphysiol.2009....
.
Accordingly, noninvasive ventilation (NIV) may reduce the respiratory work required and
increase the physical performance of such patients1010. Ribeiro JP, Chiappa GR, Callegaro CC. The contribution of
inspiratory muscles function to exercise limitation in heart failure:
pathophysiological mechanisms. Rev Bras Fisioter. 2012;16(4):261-7. PMid:22801449.
http://dx.doi.org/10.1590/S1413-35552012005000034
http://dx.doi.org/10.1590/S1413-35552012...
by increasing the oxygenation in peripheral muscle microcirculation and
improving local blood flow1111. Borghi-Silva A, Carrascosa C, Oliveira CC, Barroco AC, Berton DC,
Vilaça D, et al. Effects of respiratory muscle unloading on leg muscle oxygenation
and blood volume during high-intensity exercise in chronic heart failure. Am J
Physiol Heart Circ Physiol. 2008;294(6):2465-72. PMid:18375714.
http://dx.doi.org/10.1152/ajpheart.91520.2007
http://dx.doi.org/10.1152/ajpheart.91520...
, in addition to
possibly improving oxygenation by increasing transpulmonary pressure, which facilitates
alveolar ventilation1212. Arzt M, Schulz M, Wensel R, Montalvàn S, Blumberg FC, Riegger GA, et
al. Nocturnal continuous positive airway pressure improvesventilatory efficiency
during exercise in patients with chronic heart failure. Chest. 2005;127(3):794-802.
PMid:15764759. http://dx.doi.org/10.1378/chest.127.3.794
http://dx.doi.org/10.1378/chest.127.3.79...
. Similarly, NIV may lead
to increased intrathoracic pressure, lowers the left ventricular transmural pressure,
reducing preload and afterload, helping to improve cardiac function and providing relief
from symptoms of HF1313. Naughton MT, Rahman MA, Hara K, Floras JS, Bradley TD. Effect of
continuous positive airway pressure on intrathoracic and left ventricular transmural
pressures in patients with congestive heart failure. Circulation. 1995;91(6):1725-31.
PMid:7882480. http://dx.doi.org/10.1161/01.CIR.91.6.1725
http://dx.doi.org/10.1161/01.CIR.91.6.17...
.
Continuous positive airway pressure (CPAP and bi-level positive airway pressure
(commercially known as BiPAP), characterized by promoting constant
pressure during inspiration and expiration1414. Ho KM, Wong K. Acomparison of continuous and bilevel positive airway
pressure non-invasive ventilation in patients with acute cardiogenic pulmonary edema:
a metaanalysis. Crit Care. 2006;10(2):R49. PMid:16569254 PMCid:PMC1550921.
http://dx.doi.org/10.1186/cc4861
http://dx.doi.org/10.1186/cc4861...
,
15 15. Meduri GU. Noninvasive positive-pressure ventilation in patients
with acute respiratory failure. Clin Chest Med. 1996;17(3):513-53.
http://dx.doi.org/10.1016/S0272-5231(05)70330-0
http://dx.doi.org/10.1016/S0272-5231(05)...
or positive inspiratory and positive
pressure1616. Passarini JNS, Zambon L, Morcillo AM, Kosour C, Saad IAB. Utilização
da ventilaçãonão invasiva em edema agudo de pulmão e exacerbação da doença pulmonar
obstrutiva crônica na emergência: preditores de insucesso. Rev Bras Ter Intensiva.
2012;24(3):278-83. PMid:23917830.
http://dx.doi.org/10.1590/S0103-507X2012000300012
http://dx.doi.org/10.1590/S0103-507X2012...
,
1717. Park M, Lorenzi-Filho G, Feltrim MI, Viecili PRN, Sangean MC, Volpe
M, et al. Oxygen therapy, continuous positive airway pressure, or noninvasive bilevel
positive pressure ventilation in the treatment of acute cardiogenic pulmonary edema.
Arq Bras Cardiol. 2001;76(3):226-30.
http://dx.doi.org/10.1590/S0066-782X2001000300005
http://dx.doi.org/10.1590/S0066-782X2001...
, respectively, are known as NIV therapies.
This study aimed to conduct a systematic review with meta-analysis of controlled, randomized clinical trials that evaluated the effects of NIV on exercise tolerance in patients with HF because there is no consensus data on the outcome of these methods in exercise intolerance.
Method
The systematic review was performed according to the recommendations of the Preferred
Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)1818. Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group. Preferred
reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann
Intern Med. 2009;151(4):264-9. PMid:19622511.
http://dx.doi.org/10.7326/0003-4819-151-4-200908180-00135
http://dx.doi.org/10.7326/0003-4819-151-...
.
Inclusion criteria
This review included controlled and randomized clinical trials conducted in patients with HF, regardless of functional class and etiology. Inclusion criteria: subjects aged over 18 years of age, with no associated chronic obstructive pulmonary disease or sleep disorders, using NIV associated or not associated with other therapies, including physical exercise. The included studies had to examine exercise tolerance as a primary outcome, analyzing at least one of the following variables: distance travelled during the 6-minute walk test (6MWT), shuttle test or peak oxygen consumption (VO2 peak), maximal oxygen consumption (VO2 max), exercise time, or dyspnea. There was no language restriction for the search, and all included studies were translated when necessary and possible.
Exclusion criteria
Exclusion criteria included studies with unclear or poorly described randomization processes; unclear, inadequate or poorly described interventions; published only in abstracts.
Search strategies
The search for scientific articles was conducted by independent researchers in the
online databases MEDLINE (via OvidSP), PEDro and SciELO from the start of the
databases until June 2013 and was structured in the PICO format, an acronym that
stands for patient, intervention, control, outcome, based on the
PRISMAsearch strategy recommendations1818. Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group. Preferred
reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann
Intern Med. 2009;151(4):264-9. PMid:19622511.
http://dx.doi.org/10.7326/0003-4819-151-4-200908180-00135
http://dx.doi.org/10.7326/0003-4819-151-...
. The
search was based on words from the Medical Subject Heading Terms (MeSH) dictionary,
descriptors, and Boolean operators. The first search was conducted in the MEDLINE
database (via OvidSP) as follows: [(heart failure/ or congestive heart failure.tw)
and (CPAP ventilation.tw or continuous positive airway pressure/ or bilevel positive
airway pressure.tw or positive pressure respiration/ or no invasive ventilation/ or
CPAP) and (exercise/ or aerobic exercise/ or rehabilitation/) and (exercise
tolerance/)]. The searches in subsequent databases were adapted depending on the
database used, and the details of these adapted searches may be requested from the
authors. A manual search was conducted of the references of the articles included to
complement the search.
Selection of studies and methodological quality
Two independent assessors analyzed the search results to find potentially eligible studies. The studies were initially selected based on the title; then, the abstracts were analyzed, and only potentially eligible studies were selected. Based on the abstracts, the full papers were acquired for further selected study. In the case of disagreement between the assessors, a third assessor made the decision on the eligibility of the study in question.
The methodological quality of the selected studies was evaluated according to the PEDro scale1919. Maher CG, Sherrington C, Herbert RD, Moseley AM, Elkins M. Reliability of the PEDro scale for rating quality of randomized controlled trials. Phys Ther. 2003;83(8):713-21. PMid:12882612. . The PEDro scale comprises 11 items designed to evaluate the methodological quality - internal validity and statistical information - of randomized clinical trials. Each item satisfied, except for the first, scores one point for the overall final classification (0 to 10 points). Two experienced assessors analyzed each study independently and rated it when such a rating was not available in the PEDro database. Discrepancies between assessors were resolved by a third assessor.
Data collection and analysis
Data collection and analysis was conducted by two authors independently, and the
results were expressed as the mean and standard deviation and compared by a third
author to assess the accuracy of the data collected. A meta-analysis was conducted
regarding similarity among studies in the intervention used, patient characteristics,
and variables analyzed. A single meta-analysis was possible, and the mean and
standard deviation data of the studies included were extracted and converted into
mean differences (treatment effect) and 95% confidence intervals (95% CI). The
statistical homogeneity among studies was assessed using the I22. Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark
AL, et al. Clinical correlates and prognostic significance of the ventilatory
response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90.
http://dx.doi.org/10.1016/S0735-1097(97)00078-8
http://dx.doi.org/10.1016/S0735-1097(97)...
test value to determine whether the positive pressure used in
the CPAP group affected the response to 6MWT compared to the control/placebo. The
only possible meta-analysis was performed using a fixed effects model because
significant heterogeneity was not expected. Such meta-analysis was conducted using
the Review Manager 5.2 software. The studies that precluded conducting this type of
analysis were individually evaluated by analyzing the methodological quality and the
data reported in each study.
Results
Atotal of 235 articles were identified in the search (Figure 1), of which 88 were selected for evaluation based on the title, and their respective abstracts were reviewed. Five articles were eligible for a full review based on the abstracts, and a total of four articles met all inclusion criteria (Table 1).
The sample size of the studies included ranged from 12 to 22 subjects and involved 58
subjects in total. Comparing the treatments showed that the study by O'Donnell et
al.20 20. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
used different forms of NIV and a
control group; Lima et al.5 5. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
and Chermont et
al.4 4. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
used a control group and placebo,
respectively; whilst Wittmer et al.2121. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
applied
another form of treatment for comparison with NIV.
The evaluation of the methodological quality of the studies included is described below (Table 2).
Methodological quality
Two of the four studies selected44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
,
21 21. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
were indexed in the PEDro Scale44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
21 21. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
and had a score available in the database.
Two studies55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
were scored after reading the papers fully
and consensus among the three assessors was achieved. The assessors defined the
scores corresponding to values from 7 to 10 as high-quality studies, 5 and 6 as of
intermediate quality, and from zero to 4 as of low quality.
The scores ranged from 4 to 6 points on a 0-10 scale. All studies lost points on
items related to blinding of the patient and therapist, and only two blinded the
assessor. The minimum score of 4 points was found in one study20 20. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
, and the maximum score of 6 points was only found in the study by Lima et
al.55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
.
6-minute walk test
Three of the four studies that evaluated patients with HF subjected to NIV, with or
without exercise, evaluated the 6MWT, and all showed positive results44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
2121. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
. Wittmer et al.2121. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
compared a program of respiratory exercises associated with 30
minutes of CPAP (8 cmH2O) versus respiratory exercises
only for a period of 14 days; Chermont et al.4
4. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
compared 30 minutes of CPAP (4 to 6 cmH2O) versus
placebo prior to 6MWT, and Lima et al.5 5. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
showed
that using CPAP (10 cmH2O) for 30 minutes prior to 6MWT increased the
distance traveled compared to the control without using CPAP (Table 1).
Maximal/peak oxygen consumption and exercise time
None of the studies evaluated the VO2peak/max. The study by O´Donnell et
al.2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
was the only one that evaluated the
use of NIV during the exercise test, showing that exercise endurance in the test with
CPAP, with inspiratory pressure support, and without any noninvasive ventilatory
support (control) in randomized order was similar to the exercise endurance of the
same subjects in the test with inspiratory pressure support and CPAP, although a
difference occurred when comparing pressure support to the control.
Dyspnea
Two studies evaluated dyspnea when performing the functional capacity test55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
. The only one that showed improvement was
Lima et al.55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
, wherein patients reported a
lower sensation of dyspnea after running, having used CPAP 30 minutes before the
6MWT, compared to patients who performed the test without using CPAP, as assessed by
the Borg scale2222. Borg GAV. Psychophysical bases of perceived exertion. Med Sci Sports
Exerc. 1982;4(5):337-81. .
Effects of NIV with CPAP mode on exercise tolerance in the 6-minute walk test
Although three studies44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
21 21. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
evaluated the 6MWT, the data from only
two44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
could be grouped for analysis. The analysis
of heterogeneity resulted in an I2 2. Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark
AL, et al. Clinical correlates and prognostic significance of the ventilatory
response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90.
http://dx.doi.org/10.1016/S0735-1097(97)00078-8
http://dx.doi.org/10.1016/S0735-1097(97)...
value of
13% (p=0.28), which showed low heterogeneity between studies. The difference found
was 65.29 (from 38.80 to 91.78), with 95% CI. A greater weight was assigned to the
study by Chermont et al.44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
, corresponding to
91.9%. That result favored the use of CPAP in improving the distance travelled in the
6MWT (Figure 2).
Forest plot of the results of the meta-analysis. Comparison of intervention using positive pressure with CPAP versus a control/ sham group to test the outcome. The values shown are the average effects (difference between means) with a confidence interval of 95%. The average result was calculated using a fixed-effect model.
Discussion
Patients with HF usually exhibit dyspnea and fatigue during exercise and/or daily life
activities as their main clinical symptoms22. Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark
AL, et al. Clinical correlates and prognostic significance of the ventilatory
response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90.
http://dx.doi.org/10.1016/S0735-1097(97)00078-8
http://dx.doi.org/10.1016/S0735-1097(97)...
,
44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
. The progression of these symptoms, which link
the neurohormonal changes to declining ventricular function during the process of
myocardial and vascular remodeling and also to increasing lung congestion, promotes a
decreased level of physical activity that leads to lack of physical fitness2323. Francis GS. Pathophysiology of chronic heart failure. Am J Med.
2001;110(Suppl 7A):37S-46S.
http://dx.doi.org/10.1016/S0002-9343(98)00385-4
http://dx.doi.org/10.1016/S0002-9343(98)...
. Reduced physical fitness contributes to further
worsening of the symptoms, limitations of daily life activities, and exercise
intolerance, progressively reducing functional capacity, which leads to a frequent
clinical condition associated with high costs, disability, and high mortality rates11. Bocchi EA, Marcondes-Braga FG, Ayub-Ferreira SM, Rohde LE, Oliveira
WA, Almeida DR, et al. Sociedade Brasileira de Cardiologia. III diretriz brasileira
de insuficiência cardíaca crônica. Arq Bras Cardiol. 2009;93(1 Supl 1):1-71. .
Functional capacity has been widely evaluated in research studies and under clinical
conditions in such patients2424. Guimarães GV, Carvalho VO, Bocchi EA. Reproducibility of the
self-controlled six-minute walking test in heart failure patients. Clinics.
2008;63(2):201-6. PMid:18438574 PMCid:PMC2664221.
http://dx.doi.org/10.1590/S1807-59322008000200008
http://dx.doi.org/10.1590/S1807-59322008...
, and the 6MWT is a
simple, low-cost method of evaluating that parameter. The 6MWT test is able to reproduce
daily life activities2424. Guimarães GV, Carvalho VO, Bocchi EA. Reproducibility of the
self-controlled six-minute walking test in heart failure patients. Clinics.
2008;63(2):201-6. PMid:18438574 PMCid:PMC2664221.
http://dx.doi.org/10.1590/S1807-59322008000200008
http://dx.doi.org/10.1590/S1807-59322008...
, evaluate exercise
tolerance44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
2525. Rubim VSM, Neto CD, Romeo JLM, Montera MW. Valor prognóstico do
teste de caminhada de seis minutos na insuficiência cardíaca. Arq Bras Cardiol.
2006;86(2):120-5. PMid:16501803. http://dx.doi.org/10.1590/S0066-782X2006000200007
http://dx.doi.org/10.1590/S0066-782X2006...
, assess the degree of functional limitation,
and enable prognostic stratification2525. Rubim VSM, Neto CD, Romeo JLM, Montera MW. Valor prognóstico do
teste de caminhada de seis minutos na insuficiência cardíaca. Arq Bras Cardiol.
2006;86(2):120-5. PMid:16501803. http://dx.doi.org/10.1590/S0066-782X2006000200007
http://dx.doi.org/10.1590/S0066-782X2006...
,
2626. Bittner V, Weiner DH, Yusuf S, Rogers WJ, McIntyre KM, Bangdiwala
SI, et al. Prediction of mortality and morbidity with a 6-minute walk test in
patients with left ventricular dysfunction. SOLVD investigators. JAMA.
1993;270(14):1702-7. PMid:8411500. http://dx.doi.org/10.1001/jama.1993.03510140062030
http://dx.doi.org/10.1001/jama.1993.0351...
.
This systematic review with meta-analysis showed that the effect of a single session of
NIV with CPAP mode prior to exercise promoted an increase in functional capacity as
expressed by the increased distance traveled in the 6MWT by patients with HF44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
.
The use of NIV may be able to promote the decrease in pre- and post-load on the
ventricles, increasing the ejection fraction of the left ventricle (LV) and reducing
myocardial oxygen consumption associated with the production of carbon dioxide1313. Naughton MT, Rahman MA, Hara K, Floras JS, Bradley TD. Effect of
continuous positive airway pressure on intrathoracic and left ventricular transmural
pressures in patients with congestive heart failure. Circulation. 1995;91(6):1725-31.
PMid:7882480. http://dx.doi.org/10.1161/01.CIR.91.6.1725
http://dx.doi.org/10.1161/01.CIR.91.6.17...
,
2727. Kaye DM, Mansfield D, Naughton MT. Continuous positive airway
pressure decreases myocardial oxygen consumption in heart failure. Clin Sci.
2004;106(6):599-603. PMid:14756635.
http://dx.doi.org/10.1042/CS20030265
http://dx.doi.org/10.1042/CS20030265...
. The improvement in cardiovascular function
may be confirmed as a result of CPAP-induced increase in intrathoracic pressure, wherein
positive pressure decreases the large variations in pleural pressure. This decrease
reduces the transmural pressure of the left ventricle (LV), thus improving the
contractile performance of the heart1313. Naughton MT, Rahman MA, Hara K, Floras JS, Bradley TD. Effect of
continuous positive airway pressure on intrathoracic and left ventricular transmural
pressures in patients with congestive heart failure. Circulation. 1995;91(6):1725-31.
PMid:7882480. http://dx.doi.org/10.1161/01.CIR.91.6.1725
http://dx.doi.org/10.1161/01.CIR.91.6.17...
. NIV with
CPAP also decreases the peripheral vascular resistance, which contributes to reducing
the LV post-load. Altogether, these effects may decrease systolic blood pressure,
although the overall perfusion of peripheral tissue is high, which shows greater
cardiocirculatory efficiency1313. Naughton MT, Rahman MA, Hara K, Floras JS, Bradley TD. Effect of
continuous positive airway pressure on intrathoracic and left ventricular transmural
pressures in patients with congestive heart failure. Circulation. 1995;91(6):1725-31.
PMid:7882480. http://dx.doi.org/10.1161/01.CIR.91.6.1725
http://dx.doi.org/10.1161/01.CIR.91.6.17...
. However, the
ventilatory and hemodynamic effects of the application of a single session of NIV before
effort to increase exercise tolerance are still not fully known.
Chermont et al.4 4. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
showed that NIV with CPAP
decreased the resting heart rate (HR) and blood pressure (BP) and increased the distance
travelled during the 6MWT compared to the placebo group which is similar to the results
found by Acosta et al.2828. Acosta B, DiBenedetto R, Rahimi A, Acosta MF, Cuadra O, Van Nguyen
A, et al. Hemodynamic effects of noninvasive bilevel positive airway pressure on
patients with chronic congestive heart failure with systolic dysfunction. Chest.
2000;118(4):1004-9. PMid:11035670.
http://dx.doi.org/10.1378/chest.118.4.1004
http://dx.doi.org/10.1378/chest.118.4.10...
. Furthermore, the
authors showed an increase in peak HR during the 6MWT, showing an increase in the
chronotropic reserve, suggesting that this effect was involved in the mechanism
responsible for the increased exercise capacity, among the wide variety of responses.
Previously, Reis et al.2929. Reis MS, Sampaio LM, Lacerda D, De Oliveira LV, Pereira GB, Pantoni
CB, et al. Acute effects of different levels of continuous positive airway pressure
on cardiac autonomic modulation in chronic heart failure and chronic obstructive
pulmonary disease. Arch Med Sci. 2010;6(5):719-27. PMid:22419931.
http://dx.doi.org/10.5114/aoms.2010.17087
http://dx.doi.org/10.5114/aoms.2010.1708...
showed that the acute
effects of using CPAP, both at 5 cmH2O and at 10 cmH2O, promoted
improvement in the autonomic modulation of the HR of patients with chronic HF2929. Reis MS, Sampaio LM, Lacerda D, De Oliveira LV, Pereira GB, Pantoni
CB, et al. Acute effects of different levels of continuous positive airway pressure
on cardiac autonomic modulation in chronic heart failure and chronic obstructive
pulmonary disease. Arch Med Sci. 2010;6(5):719-27. PMid:22419931.
http://dx.doi.org/10.5114/aoms.2010.17087
http://dx.doi.org/10.5114/aoms.2010.1708...
. However, the authors failed to assess whether
the effect continued after withdrawing the NIV support.
Although Lima et al.55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
showed no significant
effects on hemodynamic parameters (HR and BP) from the prior use of positive pressure
compared to the control group at the end of the 6th minute, in the evaluation
of the double product at the end of the exercise, lower values of that physiological
property, improved SpO2, and reduced dyspnea were observed in the group of
patients who used CPAP prior to the 6MWT. That finding indicates that NIV may be able to
improve the performance of the cardiovascular and respiratory system beforehand, so that
such patients show lower cardiac work when performing the 6MWT.
Regarding the use of NIV support for a longer period, Wittmer et al.21 21. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
showed that using CPAP associated with
respiratory exercises for 14 consecutive days increased pulmonary function and the
distance travelled in the 6MWT. Positive pressure increases pulmonary compliance,
improves gas exchange, reduces respiratory effort, and reduces airflow limitation by
decreasing airway resistance in patients with HF2121. Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous
positive airway pressure on pulmonary function and exercise tolerance in patients
with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396.
http://dx.doi.org/10.1378/chest.130.1.157
http://dx.doi.org/10.1378/chest.130.1.15...
. These results corroborate the results of Yan et al.3030. Yan AT, Bradley TD, Liu PP. The role of continuous positive airway
pressure in the treatment of congestive heart failure. Chest. 2001;120(5):1675-85.
PMid:11713153. http://dx.doi.org/10.1378/chest.120.5.1675
http://dx.doi.org/10.1378/chest.120.5.16...
, showing the ability of NIV to improve the parameters of
pulmonary function and, thereby, enabling exercise to be performed more effectively3030. Yan AT, Bradley TD, Liu PP. The role of continuous positive airway
pressure in the treatment of congestive heart failure. Chest. 2001;120(5):1675-85.
PMid:11713153. http://dx.doi.org/10.1378/chest.120.5.1675
http://dx.doi.org/10.1378/chest.120.5.16...
. However, a thorough analysis was hampered by the
lack of similar studies that might have reinforced the notion that daily CPAP sessions
would be able to maintain their effect for an extended period.
The only study2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
that evaluated the use of NIV
during an exercise test showed that NIV support reduced discomfort in the lower limbs
and increased exercise resistance, with an increase of 2.8 minutes in the use of
inspiratory pressure support (PS) during the stress test compared to non-use of
ventilatory support. The authors reported that increased exercise time could be
explained by the decreased discomfort in the lower limbs, which was assessed by the Borg
scale during the use of NIV. Another possible mechanism corroborates the findings of
Borghi-Silva et al.1111. Borghi-Silva A, Carrascosa C, Oliveira CC, Barroco AC, Berton DC,
Vilaça D, et al. Effects of respiratory muscle unloading on leg muscle oxygenation
and blood volume during high-intensity exercise in chronic heart failure. Am J
Physiol Heart Circ Physiol. 2008;294(6):2465-72. PMid:18375714.
http://dx.doi.org/10.1152/ajpheart.91520.2007
http://dx.doi.org/10.1152/ajpheart.91520...
, and O'Donnell et al2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
who claimed that PS could improve peripheral
perfusion and muscle oxygenation fraction by improving cardiac output and/or by altering
regional vascular distribution. Significant improvement was observed in the time of the
ergospirometric test, 2.55 minutes on average, in the study of ten cases of HF conducted
by Azevedo et al.3131. Azevedo JCM, Carvalho ERM, Feijó LA, Oliveira FP, Menezes SLS, Murad
H. Efeitos da pressão positiva contínua nas vias aéreas na insuficiência cardíaca
crônica. Arq Bras Cardiol. 2010;95(1):115-21. PMid:20563517.
http://dx.doi.org/10.1590/S0066-782X2010005000068
http://dx.doi.org/10.1590/S0066-782X2010...
. Lower values (1.38 minute)
were observed by Steiner et al.32 32. Steiner S, Schueller PO, Schannwell CM, Hennersdorf M, Strauer BE.
Effects of continuous positive airway pressure on exercise capacity in chronic heart
failure patients without sleep apnea. J Physiol Pharmacol. 2007;58(Suppl 52):665-72.
PMid:18204181. in the use of
nocturnal CPAP (>6 h) after approximately eight months of intervention.
Functional capacity is usually measured by a cardiopulmonary exercise test that measures
exercise tolerance and helps in the diagnosis of HF3333. Guazzi M. Normalization for peak oxygen uptake increases the
prognostic power of the ventilatory response to exercise in patients with chronic
heart failure. Am Heart J. 2003;146(3):542-8.
http://dx.doi.org/10.1016/S0002-8703(03)00321-1
http://dx.doi.org/10.1016/S0002-8703(03)...
. None of the studies included in this review evaluated the
VO2max/peak, most likely because they were short-term studies. Furthermore,
no study used NIV associated with an exercise protocol, which could contribute to
increasing the VO2max/peak, which is improved by regular physical exercise,
particularly with training intensity sufficient to generate cardiovascular fitness,
especially in the relevant population11. Bocchi EA, Marcondes-Braga FG, Ayub-Ferreira SM, Rohde LE, Oliveira
WA, Almeida DR, et al. Sociedade Brasileira de Cardiologia. III diretriz brasileira
de insuficiência cardíaca crônica. Arq Bras Cardiol. 2009;93(1 Supl 1):1-71.
,
3434. Freyssin C, Verkindt C, Prieur F, Benaich P, Maunier S, Blanc P.
Cardiac rehabilitation in chronic heart failure: effect of an 8-week, high-intensity
interval training versus continuous training. Arch Phys Med Rehabil.
2012;93(8):1359-64. PMid:22446291.
http://dx.doi.org/10.1016/j.apmr.2012.03.007
http://dx.doi.org/10.1016/j.apmr.2012.03...
,
3535. McKelvie RS, Teo KK, Roberts R, McCartney N, Humen D, Montague T, et
al. Effects of exercise training in patients with heart failure: the Exercise
Rehabilitation Trial (EXERT). Am Heart J. 2002;144(1):23-30. PMid:12094184.
http://dx.doi.org/10.1067/mhj.2002.123310
http://dx.doi.org/10.1067/mhj.2002.12331...
.
Dyspnea is one of the most important variables analyzed for the diagnosis of
cardiorespiratory disease because it manifests itself when patients perform their
routine activities22. Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark
AL, et al. Clinical correlates and prognostic significance of the ventilatory
response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90.
http://dx.doi.org/10.1016/S0735-1097(97)00078-8
http://dx.doi.org/10.1016/S0735-1097(97)...
and, in more severe cases,
may progress to dyspnea at rest11. Bocchi EA, Marcondes-Braga FG, Ayub-Ferreira SM, Rohde LE, Oliveira
WA, Almeida DR, et al. Sociedade Brasileira de Cardiologia. III diretriz brasileira
de insuficiência cardíaca crônica. Arq Bras Cardiol. 2009;93(1 Supl 1):1-71. . Two studies
included in this review analyzed dyspnea55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
, and only Lima et al.5 5. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
showed that using CPAP for 30 minutes (10 cmH2O) could
decrease post-6MWT dyspnea in comparison to the group that did not undergo prior NIV. In
a non-randomized study conducted by Bussoni et al.3636. Bussoni MF, Diz NM, Guirado GN, Galera RM, Zanati SG, Matsubara BB.
Efeitos agudos de CPAP na função diastólica ventricular esquerda e tolerância ao
exercício na insuficiência cardíaca compensada. Rev Bras Ecocardiogr Imagem
Cardiovasc. 2010;23(4):33-7. , 11 patients with HF took the 6MWT before and after using CPAP (30
minutes, 10 cmH2O), and the results showed that lower dyspnea occurred at the
end of the second test. However, the small number of subjects precluded us from
confirming whether the results were reproducible when including a larger number of
participants.
Another issue requiring further study is the ideal positive pressure to promote
increased exercise tolerance. Some authors advocate a CPAP value of 10
cmH2O3737. Guilherme PPS, Reis MAS, Galas F, Park M, Franca S, Okamoto V.
Ventilação mecânica não invasiva com pressão positiva. III Consenso Brasileiro de
Ventilação Mecânica. J Bras Pneumol. 2007;33(Supl 2):S92-105. because it promotes
alveolar recruitment and effective gas exchange, whilst others advocate smaller values,
namely 6 cmH2O or the value best tolerated by patients44. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
,
38 38. Quintão M, Chermont S, Marchese L, Brandão L, Bernardez SP, Mesquita
ET, et al. Efeito agudo da pressão positiva contínua sobre a pressão de pulso na
insuficiência cardíaca crônica. Arq Bras Cardiol. 2014;102(2):181-6. PMid:24676373
PMCid:PMC3987333. because a significant improvement in cardiac
output is shown with low levels of CPAP.
Although most studies that evaluate the effect of the final positive pressure use a
value of 10 cmH2O55. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
,
3131. Azevedo JCM, Carvalho ERM, Feijó LA, Oliveira FP, Menezes SLS, Murad
H. Efeitos da pressão positiva contínua nas vias aéreas na insuficiência cardíaca
crônica. Arq Bras Cardiol. 2010;95(1):115-21. PMid:20563517.
http://dx.doi.org/10.1590/S0066-782X2010005000068
http://dx.doi.org/10.1590/S0066-782X2010...
,
3636. Bussoni MF, Diz NM, Guirado GN, Galera RM, Zanati SG, Matsubara BB.
Efeitos agudos de CPAP na função diastólica ventricular esquerda e tolerância ao
exercício na insuficiência cardíaca compensada. Rev Bras Ecocardiogr Imagem
Cardiovasc. 2010;23(4):33-7.
,
3939. Lenique F, Habis M, Lofaso F, Dubois-Randé JL, Harf A, Brochard L.
Ventilatory and hemodynamic effects of continuous positive airway pressure in left
heart failure. Am J Resp Crit Care Med. 1997;155(2):500-5. PMid:9032185.
http://dx.doi.org/10.1164/ajrccm.155.2.9032185
http://dx.doi.org/10.1164/ajrccm.155.2.9...
,
4040. Bradley TD, Logan AG, Kimoff J, Sériès F, Morrison D, Ferguson K, et
al. Continuous positive airway pressure for central sleep apnea and heart failure. N
Engl J Med. 2005;353:2025-33. PMid:16282177.
http://dx.doi.org/10.1056/NEJMoa051001
http://dx.doi.org/10.1056/NEJMoa051001...
, regardless of outcome, and although that
value is recommended by the Brazilian consensus on mechanical ventilation for patients
with acute HF3737. Guilherme PPS, Reis MAS, Galas F, Park M, Franca S, Okamoto V.
Ventilação mecânica não invasiva com pressão positiva. III Consenso Brasileiro de
Ventilação Mecânica. J Bras Pneumol. 2007;33(Supl 2):S92-105. , such recommendations are not
quite as well established for stable patients who are or who need to start practicing
physical exercise.
Accordingly, our meta-analysis showed that the CPAP values used by Chermont et al.4 4. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
(4-6 cmH2O) and Lima et al.5 5. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
(10 cmH2O) favorably promoted an
increase in the distance traveled during the 6MWT. Although the methodological quality
of the study by Chermont et al.4 4. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
(5/10) was lower
than the quality of the study by Lima et al.5
5. Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB,
et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência
cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32.
http://dx.doi.org/10.1590/S0066-782X2011005000002
http://dx.doi.org/10.1590/S0066-782X2011...
(6/10), greater weight was assigned to the results of the study by Chermont et
al.4 4. Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC.
Noninvasive ventilation with continuous positive airway pressure acutely improves
6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev.
2009;29(1):44-8. PMid:19158587.
http://dx.doi.org/10.1097/HCR.0b013e3181927858
http://dx.doi.org/10.1097/HCR.0b013e3181...
(91.9%). The authors indicated that
patients might not adapt to nor require pressures close to 10 cmH2O. Thus,
our meta-analysis suggested that lower pressures might promote favorable effects
regarding exercise tolerance, thus avoiding discomfort that often leads to a lack of
adherence to treatment.
Our findings showed that no published studies have examined the use of NIV with two
levels of pressure (only support pressure2020. O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory
assistance improves exercise endurance in stable congestive heart failure. Am J
Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589.
http://dx.doi.org/10.1164/ajrccm.160.6.9808134
http://dx.doi.org/10.1164/ajrccm.160.6.9...
) in
exercise tolerance in patients with stable HF. Such findings are most likely because
that ventilatory mode is more recent and is preferentially used in patients with the
presence of hypercapnia4141. Park M, Sangean MC, Volpe MS, Feltrim MI, Nozawa E, Leite PF, et al.
Randomized, prospective trial of oxygen, continuous positive airway pressure, and
bilevel positive airway pressure by face mask in acute cardiogenic pulmonary edema.
Crit Care Med. 2004;32(12):2407-15. PMid:15599144.
http://dx.doi.org/10.1097/01.CCM.0000147770.20400.1
http://dx.doi.org/10.1097/01.CCM.0000147...
.
Thus, the results from this meta-analysis suggest that using NIV in the CPAP mode 30 minutes before the 6MWT may increase tolerance to exercise and that a final positive pressure below 10 cmH2O may also have a beneficial effect on the increase in the distance travelled. Therefore, our results may be used as a key complement to the literature for professionals working in cardiac rehabilitation services.
Study limitations
The limitations may be described as a result of the small number of studies that could be included in the systematic review because indexed articles on this topic are scarce, which directly affected the meta-analysis.
Only two studies could be used for a single meta-analysis on the outcome distance travelled in the 6MWT, and despite their low heterogeneity and positive results in the 6MWT, these studies were of limited accuracy due to the small number of participants. Similarly, the methodological quality of studies in the PEDro Scale was intermediate to low, thus limiting a "safe" conclusion. Therefore, any effect estimates were very uncertain, and further research studies may impact such estimates, which suggests that new studies should be conducted with a larger number of patients.
Conclusion
This review with meta-analysis suggests that the use of NIV before the 6MWT in patients with HF may promote an increase in the distance travelled. However, the limited number of studies preclude a more thorough analysis of the effects of NIV on exercise tolerance in these patients.
References
-
1Bocchi EA, Marcondes-Braga FG, Ayub-Ferreira SM, Rohde LE, Oliveira WA, Almeida DR, et al. Sociedade Brasileira de Cardiologia. III diretriz brasileira de insuficiência cardíaca crônica. Arq Bras Cardiol. 2009;93(1 Supl 1):1-71.
-
2Chua TP, Ponikowski P, Harrington D, Anker SD, Webb-Peploe K, Clark AL, et al. Clinical correlates and prognostic significance of the ventilatory response to exercise in chronic heart failure. J Am Coll Cardiol. 1997;29(7):1585-90. http://dx.doi.org/10.1016/S0735-1097(97)00078-8
» http://dx.doi.org/10.1016/S0735-1097(97)00078-8 -
3Witte KK, Clark AL. Why does chronic heart failure cause breathlessness and fatigue? Prog Cardiovasc Dis. 2007;49(5):366-84. PMid:17329182. http://dx.doi.org/10.1016/j.pcad.2006.10.003
» http://dx.doi.org/10.1016/j.pcad.2006.10.003 -
4Chermont S, Quintão MM, Mesquita ET, Rocha NN, Nóbrega AC. Noninvasive ventilation with continuous positive airway pressure acutely improves 6-minute walk distance in chronic heart failure. J Cardiopulm Rehabil Prev. 2009;29(1):44-8. PMid:19158587. http://dx.doi.org/10.1097/HCR.0b013e3181927858
» http://dx.doi.org/10.1097/HCR.0b013e3181927858 -
5Lima ES, Cruz CG, Santos FC, Gomes-Neto M, Bittencourt HS, Reis FJFB, et al. Suporte ventilatório na capacidade funcional de pacientes com insuficiência cardíaca: estudo piloto. Arq Bras Cardiol. 2011;96(3):227-32. http://dx.doi.org/10.1590/S0066-782X2011005000002
» http://dx.doi.org/10.1590/S0066-782X2011005000002 -
6Piepoli MF, Conraads V, Corrà U, Dickstein K, Francis DP, Jaarsma T, et al. Exercise training in heart failure: from theory to practice: a consensus document of the Heart Failure Association and the European Association for Cardiovascular Prevention and Rehabilitation. Eur J Heart Fail. 2011;13(4):347-57. PMid:21436360. http://dx.doi.org/10.1093/eurjhf/hfr017
» http://dx.doi.org/10.1093/eurjhf/hfr017 -
7Van der Meer S, Zwerink M, Van Brussel M, Van der Valk P, Wajon E, Van der Palen J. Effect of outpatient exercise training programmes in patients with chronic heart failure: a systematic review. Eur J Cardiovasc Prev Rehabil. 2011 [Epub ahead of print]. PMid:21593055.
-
8Hambrecht R, Niebauer J, Fiehn E, Kälberer B, Offner B, Hauer K, et al. Physical training in patients with stable chronic heart failure: effects on cardiorespiratory fitness and ultrastructural abnormalities of leg muscles. J Am Coll Cardiol. 1995;25(6):1239-49. http://dx.doi.org/10.1016/0735-1097(94)00568-B
» http://dx.doi.org/10.1016/0735-1097(94)00568-B -
9Olson TP, Joyner MJ, Dietz NM, Eisenach JH, Curry TB, Johnson BD. Effects of respiratory muscle work on blood flow distribution during exercise in heart failure. J Physiol. 2010;588(13):2487-501. PMid:20457736 PMCid:PMC2915522. http://dx.doi.org/10.1113/jphysiol.2009.186056
» http://dx.doi.org/10.1113/jphysiol.2009.186056 -
10Ribeiro JP, Chiappa GR, Callegaro CC. The contribution of inspiratory muscles function to exercise limitation in heart failure: pathophysiological mechanisms. Rev Bras Fisioter. 2012;16(4):261-7. PMid:22801449. http://dx.doi.org/10.1590/S1413-35552012005000034
» http://dx.doi.org/10.1590/S1413-35552012005000034 -
11Borghi-Silva A, Carrascosa C, Oliveira CC, Barroco AC, Berton DC, Vilaça D, et al. Effects of respiratory muscle unloading on leg muscle oxygenation and blood volume during high-intensity exercise in chronic heart failure. Am J Physiol Heart Circ Physiol. 2008;294(6):2465-72. PMid:18375714. http://dx.doi.org/10.1152/ajpheart.91520.2007
» http://dx.doi.org/10.1152/ajpheart.91520.2007 -
12Arzt M, Schulz M, Wensel R, Montalvàn S, Blumberg FC, Riegger GA, et al. Nocturnal continuous positive airway pressure improvesventilatory efficiency during exercise in patients with chronic heart failure. Chest. 2005;127(3):794-802. PMid:15764759. http://dx.doi.org/10.1378/chest.127.3.794
» http://dx.doi.org/10.1378/chest.127.3.794 -
13Naughton MT, Rahman MA, Hara K, Floras JS, Bradley TD. Effect of continuous positive airway pressure on intrathoracic and left ventricular transmural pressures in patients with congestive heart failure. Circulation. 1995;91(6):1725-31. PMid:7882480. http://dx.doi.org/10.1161/01.CIR.91.6.1725
» http://dx.doi.org/10.1161/01.CIR.91.6.1725 -
14Ho KM, Wong K. Acomparison of continuous and bilevel positive airway pressure non-invasive ventilation in patients with acute cardiogenic pulmonary edema: a metaanalysis. Crit Care. 2006;10(2):R49. PMid:16569254 PMCid:PMC1550921. http://dx.doi.org/10.1186/cc4861
» http://dx.doi.org/10.1186/cc4861 -
15Meduri GU. Noninvasive positive-pressure ventilation in patients with acute respiratory failure. Clin Chest Med. 1996;17(3):513-53. http://dx.doi.org/10.1016/S0272-5231(05)70330-0
» http://dx.doi.org/10.1016/S0272-5231(05)70330-0 -
16Passarini JNS, Zambon L, Morcillo AM, Kosour C, Saad IAB. Utilização da ventilaçãonão invasiva em edema agudo de pulmão e exacerbação da doença pulmonar obstrutiva crônica na emergência: preditores de insucesso. Rev Bras Ter Intensiva. 2012;24(3):278-83. PMid:23917830. http://dx.doi.org/10.1590/S0103-507X2012000300012
» http://dx.doi.org/10.1590/S0103-507X2012000300012 -
17Park M, Lorenzi-Filho G, Feltrim MI, Viecili PRN, Sangean MC, Volpe M, et al. Oxygen therapy, continuous positive airway pressure, or noninvasive bilevel positive pressure ventilation in the treatment of acute cardiogenic pulmonary edema. Arq Bras Cardiol. 2001;76(3):226-30. http://dx.doi.org/10.1590/S0066-782X2001000300005
» http://dx.doi.org/10.1590/S0066-782X2001000300005 -
18Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann Intern Med. 2009;151(4):264-9. PMid:19622511. http://dx.doi.org/10.7326/0003-4819-151-4-200908180-00135
» http://dx.doi.org/10.7326/0003-4819-151-4-200908180-00135 -
19Maher CG, Sherrington C, Herbert RD, Moseley AM, Elkins M. Reliability of the PEDro scale for rating quality of randomized controlled trials. Phys Ther. 2003;83(8):713-21. PMid:12882612.
-
20O'Donnell DE, D'Arsigny C, Raj S, Abdollah H, Webb KA. Ventilatory assistance improves exercise endurance in stable congestive heart failure. Am J Respir Crit Care Med. 1999;160(6):1804-11. PMid:10588589. http://dx.doi.org/10.1164/ajrccm.160.6.9808134
» http://dx.doi.org/10.1164/ajrccm.160.6.9808134 -
21Wittmer VL, Simoes GM, Sogame LC, Vasquez EC. Effects of continuous positive airway pressure on pulmonary function and exercise tolerance in patients with congestive heart failure. Chest. 2006;130(1):157-63. PMid:16840396. http://dx.doi.org/10.1378/chest.130.1.157
» http://dx.doi.org/10.1378/chest.130.1.157 -
22Borg GAV. Psychophysical bases of perceived exertion. Med Sci Sports Exerc. 1982;4(5):337-81.
-
23Francis GS. Pathophysiology of chronic heart failure. Am J Med. 2001;110(Suppl 7A):37S-46S. http://dx.doi.org/10.1016/S0002-9343(98)00385-4
» http://dx.doi.org/10.1016/S0002-9343(98)00385-4 -
24Guimarães GV, Carvalho VO, Bocchi EA. Reproducibility of the self-controlled six-minute walking test in heart failure patients. Clinics. 2008;63(2):201-6. PMid:18438574 PMCid:PMC2664221. http://dx.doi.org/10.1590/S1807-59322008000200008
» http://dx.doi.org/10.1590/S1807-59322008000200008 -
25Rubim VSM, Neto CD, Romeo JLM, Montera MW. Valor prognóstico do teste de caminhada de seis minutos na insuficiência cardíaca. Arq Bras Cardiol. 2006;86(2):120-5. PMid:16501803. http://dx.doi.org/10.1590/S0066-782X2006000200007
» http://dx.doi.org/10.1590/S0066-782X2006000200007 -
26Bittner V, Weiner DH, Yusuf S, Rogers WJ, McIntyre KM, Bangdiwala SI, et al. Prediction of mortality and morbidity with a 6-minute walk test in patients with left ventricular dysfunction. SOLVD investigators. JAMA. 1993;270(14):1702-7. PMid:8411500. http://dx.doi.org/10.1001/jama.1993.03510140062030
» http://dx.doi.org/10.1001/jama.1993.03510140062030 -
27Kaye DM, Mansfield D, Naughton MT. Continuous positive airway pressure decreases myocardial oxygen consumption in heart failure. Clin Sci. 2004;106(6):599-603. PMid:14756635. http://dx.doi.org/10.1042/CS20030265
» http://dx.doi.org/10.1042/CS20030265 -
28Acosta B, DiBenedetto R, Rahimi A, Acosta MF, Cuadra O, Van Nguyen A, et al. Hemodynamic effects of noninvasive bilevel positive airway pressure on patients with chronic congestive heart failure with systolic dysfunction. Chest. 2000;118(4):1004-9. PMid:11035670. http://dx.doi.org/10.1378/chest.118.4.1004
» http://dx.doi.org/10.1378/chest.118.4.1004 -
29Reis MS, Sampaio LM, Lacerda D, De Oliveira LV, Pereira GB, Pantoni CB, et al. Acute effects of different levels of continuous positive airway pressure on cardiac autonomic modulation in chronic heart failure and chronic obstructive pulmonary disease. Arch Med Sci. 2010;6(5):719-27. PMid:22419931. http://dx.doi.org/10.5114/aoms.2010.17087
» http://dx.doi.org/10.5114/aoms.2010.17087 -
30Yan AT, Bradley TD, Liu PP. The role of continuous positive airway pressure in the treatment of congestive heart failure. Chest. 2001;120(5):1675-85. PMid:11713153. http://dx.doi.org/10.1378/chest.120.5.1675
» http://dx.doi.org/10.1378/chest.120.5.1675 -
31Azevedo JCM, Carvalho ERM, Feijó LA, Oliveira FP, Menezes SLS, Murad H. Efeitos da pressão positiva contínua nas vias aéreas na insuficiência cardíaca crônica. Arq Bras Cardiol. 2010;95(1):115-21. PMid:20563517. http://dx.doi.org/10.1590/S0066-782X2010005000068
» http://dx.doi.org/10.1590/S0066-782X2010005000068 -
32Steiner S, Schueller PO, Schannwell CM, Hennersdorf M, Strauer BE. Effects of continuous positive airway pressure on exercise capacity in chronic heart failure patients without sleep apnea. J Physiol Pharmacol. 2007;58(Suppl 52):665-72. PMid:18204181.
-
33Guazzi M. Normalization for peak oxygen uptake increases the prognostic power of the ventilatory response to exercise in patients with chronic heart failure. Am Heart J. 2003;146(3):542-8. http://dx.doi.org/10.1016/S0002-8703(03)00321-1
» http://dx.doi.org/10.1016/S0002-8703(03)00321-1 -
34Freyssin C, Verkindt C, Prieur F, Benaich P, Maunier S, Blanc P. Cardiac rehabilitation in chronic heart failure: effect of an 8-week, high-intensity interval training versus continuous training. Arch Phys Med Rehabil. 2012;93(8):1359-64. PMid:22446291. http://dx.doi.org/10.1016/j.apmr.2012.03.007
» http://dx.doi.org/10.1016/j.apmr.2012.03.007 -
35McKelvie RS, Teo KK, Roberts R, McCartney N, Humen D, Montague T, et al. Effects of exercise training in patients with heart failure: the Exercise Rehabilitation Trial (EXERT). Am Heart J. 2002;144(1):23-30. PMid:12094184. http://dx.doi.org/10.1067/mhj.2002.123310
» http://dx.doi.org/10.1067/mhj.2002.123310 -
36Bussoni MF, Diz NM, Guirado GN, Galera RM, Zanati SG, Matsubara BB. Efeitos agudos de CPAP na função diastólica ventricular esquerda e tolerância ao exercício na insuficiência cardíaca compensada. Rev Bras Ecocardiogr Imagem Cardiovasc. 2010;23(4):33-7.
-
37Guilherme PPS, Reis MAS, Galas F, Park M, Franca S, Okamoto V. Ventilação mecânica não invasiva com pressão positiva. III Consenso Brasileiro de Ventilação Mecânica. J Bras Pneumol. 2007;33(Supl 2):S92-105.
-
38Quintão M, Chermont S, Marchese L, Brandão L, Bernardez SP, Mesquita ET, et al. Efeito agudo da pressão positiva contínua sobre a pressão de pulso na insuficiência cardíaca crônica. Arq Bras Cardiol. 2014;102(2):181-6. PMid:24676373 PMCid:PMC3987333.
-
39Lenique F, Habis M, Lofaso F, Dubois-Randé JL, Harf A, Brochard L. Ventilatory and hemodynamic effects of continuous positive airway pressure in left heart failure. Am J Resp Crit Care Med. 1997;155(2):500-5. PMid:9032185. http://dx.doi.org/10.1164/ajrccm.155.2.9032185
» http://dx.doi.org/10.1164/ajrccm.155.2.9032185 -
40Bradley TD, Logan AG, Kimoff J, Sériès F, Morrison D, Ferguson K, et al. Continuous positive airway pressure for central sleep apnea and heart failure. N Engl J Med. 2005;353:2025-33. PMid:16282177. http://dx.doi.org/10.1056/NEJMoa051001
» http://dx.doi.org/10.1056/NEJMoa051001 -
41Park M, Sangean MC, Volpe MS, Feltrim MI, Nozawa E, Leite PF, et al. Randomized, prospective trial of oxygen, continuous positive airway pressure, and bilevel positive airway pressure by face mask in acute cardiogenic pulmonary edema. Crit Care Med. 2004;32(12):2407-15. PMid:15599144. http://dx.doi.org/10.1097/01.CCM.0000147770.20400.1
» http://dx.doi.org/10.1097/01.CCM.0000147770.20400.1
Publication Dates
-
Publication in this collection
12 Sept 2014 -
Date of issue
Sept-Oct 2014
History
-
Received
21 Nov 2013 -
Reviewed
17 Mar 2014 -
Accepted
31 Mar 2014