Platelet parameters may not be related to new-onset atrial fibrillation after coronary bypass surgery

Dear Editor,

I read with great interest the retrospective study of Demirel et al., which investigated the existence of a seasonal relationship between platelet count and mean platelet volume (MPV) values and the risk of postoperative atrial fibrillation in patients who underwent coronary artery bypass graft (CABG) surgery in spring and autumn¹. They found preoperative MPV and platelet mass index (PMI) values to be significantly higher in patients who operated in the autumn months compared to the spring months and observed a significant relationship between PMI and postoperative atrial fibrillation. I would like to emphasize the existence of some factors that may have negatively affected the platelet parameters in the results of this study.

Although the authors suggested that platelet parameters are related to the pathogenesis of inflammation, MPV measurement methodology has not been standardized to date, and therefore it is not recommended to use MPV values for diagnosis or prognosis, especially in acquired diseases². The main factors that directly affect MPV measurement standardization are the time from blood collection to MPV measurement, the anticoagulant used in MPV measurement, and the devices used in MPV measurement³–⁸. Ethylenediaminetetraacetic acid (EDTA) is the most commonly used anticoagulant in complete blood counts, and contact with EDTA in the blood tube causes platelets to rapidly swell, increase their diameter, and develop into podocytes³. This diameter increase in platelets can increase up to 30% in the first 5 min and 40–45% in the first 2 h³. In studies using EDTA, an MPV increase of 2–50% has been reported³,⁵. The use of other anticoagulants also causes an increase in MPV⁴,⁹. Lancé et al. aimed to standardize the time from blood collection to MPV measurement and found the optimal MPV measurement time to be 60 and 120 min after blood collection, respectively, based on the use of sodium citrate and dipotassium EDTA as anticoagulants⁴,⁹. Differences in blood analyzers used in measurement also cause deviations in MPV values of up to 40%⁵–⁸. Since PMI is a parameter obtained by calculation as a result of multiplying MPV and platelet count, any standardization problem that affects MPV values directly affects PMI values. The fact that no methodology for MPV measurement was defined in the study of Demirel et al. significantly negatively affects the reliability of the measured MPV and calculated PMI results. Likewise, the fact that the study was conducted retrospectively made it impossible to rule out preanalytical and analytical errors, and this is an unacceptable situation for MPV studies¹⁰.

Contrary to the authors’ claim, another important point that should be emphasized is that MPV values are related to platelet production, not platelet function. The gold-standard measurement of platelet function is performed by light transmission platelet aggregometry performed in platelet-rich plasma¹¹, and in studies using this technique, no correlation was found between all platelet parameters, including MPV and PMI, and platelet aggregation responses to aggregation-stimulating agents¹²,¹³.

As a result, preoperative MPV and PMI values may not be associated with seasonal changes and postoperative atrial fibrillation in patients undergoing CABG surgery.

• Funding:

  none.

REFERENCES

• ¹
  Demirel A, Engin M, Toktas F, Özsin KK, As AK, Aydın U, et al. Relationship between platelet-related parameters and new-onset atrial fibrillation after coronary bypass surgery. Rev Assoc Med Bras (1992). 2024;70(5):e20240076. https://doi.org/10.1590/1806-9282.20240076
  » https://doi.org/10.1590/1806-9282.20240076
• ²
  Noris P, Melazzini F, Balduini CL. New roles for mean platelet volume measurement in the clinical practice? Platelets. 2016;27(7):607-12. https://doi.org/10.1080/09537104.2016.1224828
  » https://doi.org/10.1080/09537104.2016.1224828
• ³
  Jackson SR, Carter JM. Platelet volume: laboratory measurement and clinical application. Blood Rev. 1993;7(2):104-13. https://doi.org/10.1016/s0268-960x(05)80020-7
  » https://doi.org/10.1016/s0268-960x(05)80020-7
• ⁴
  Lancé MD, Sloep M, Henskens YM, Marcus MA. Mean platelet volume as a diagnostic marker for cardiovascular disease: drawbacks of preanalytical conditions and measuring techniques. Clin Appl Thromb Hemost. 2012;18(6):561-8. https://doi.org/10.1177/1076029612458147
  » https://doi.org/10.1177/1076029612458147
• ⁵
  Beyan C, Beyan E. Were the measurements standardized sufficiently in published studies about mean platelet volume? Blood Coagul Fibrinolysis. 2017;28(3):234-6. https://doi.org/10.1097/MBC.0000000000000586
  » https://doi.org/10.1097/MBC.0000000000000586
• ⁶
  Lippi G, Pavesi F, Pipitone S. Evaluation of mean platelet volume with four hematological analyzers: harmonization is still an unresolved issue. Blood Coagul Fibrinolysis. 2015;26(2):235-7. https://doi.org/10.1097/MBC.0000000000000220
  » https://doi.org/10.1097/MBC.0000000000000220
• ⁷
  Latger-Cannard V, Hoarau M, Salignac S, Baumgart D, Nurden P, Lecompte T. Mean platelet volume: comparison of three analysers towards standardization of platelet morphological phenotype. Int J Lab Hematol. 2012;34(3):300-10. https://doi.org/10.1111/j.1751-553X.2011.01396.x
  » https://doi.org/10.1111/j.1751-553X.2011.01396.x
• ⁸
  Hoffmann JJ. Reference range of mean platelet volume. Thromb Res. 2012;129(4):534-5. https://doi.org/10.1016/j.thromres.2011.11.012
  » https://doi.org/10.1016/j.thromres.2011.11.012
• ⁹
  Lancé MD, Oerle R, Henskens YM, Marcus MA. Do we need time adjusted mean platelet volume measurements? Lab Hematol. 2010;16(3):28-31. https://doi.org/10.1532/LH96.10011
  » https://doi.org/10.1532/LH96.10011
• ¹⁰
  Harrison P, Goodall AH. Studies on mean platelet volume (MPV) - new editorial policy. Platelets. 2016;27(7):605-6. https://doi.org/10.1080/09537104.2016.1225467
  » https://doi.org/10.1080/09537104.2016.1225467
• ¹¹
  Paniccia R, Priora R, Liotta AA, Abbate R. Platelet function tests: a comparative review. Vasc Health Risk Manag. 2015;11:133-48. https://doi.org/10.2147/VHRM.S44469
  » https://doi.org/10.2147/VHRM.S44469
• ¹²
  Ho CH, Chan IH. The influence of time of storage, temperature of storage, platelet number in platelet-rich plasma, packed cell, mean platelet volume, hemoglobin concentration, age, and sex on platelet aggregation test. Ann Hematol. 1995;71(3):129-33. https://doi.org/10.1007/BF01702648
  » https://doi.org/10.1007/BF01702648
• ¹³
  Beyan C, Kaptan K, Ifran A. Platelet count, mean platelet volume, platelet distribution width, and plateletcrit do not correlate with optical platelet aggregation responses in healthy volunteers. J Thromb Thrombolysis. 2006;22(3):161-4. https://doi.org/10.1007/s11239-006-9014-7
  » https://doi.org/10.1007/s11239-006-9014-7

Publication Dates

• Publication in this collection
  16 Sept 2024
• Date of issue
  2024

History

• Received
  22 May 2024
• Accepted
  13 June 2024