The “Coming of Age” of Coronary Calcium Score?

Age Factors; Atherosclerosis; Calcium

“A man is as old as his arteries”

Thomas Sydenham (English physician, 1624-1689)

The use of coronary artery calcium (CAC) score to guide the primary prevention of atherosclerosis and its manifestations has grown in popularity in recent years. Its advantages over the current paradigm of risk-factor-based calculators include better discrimination and greater predictive power, with the promise of better treatment decisions and timely implementation of personalized preventive measures.¹-³

CAC results are usually expressed as an absolute value and as a percentile among individuals of the same age and sex. Importantly, conveying this information to patients seems to improve their adherence to lifestyle modifications and pharmacological therapy.⁴ One of the ways developed for making patients understand their risk is the concept of vascular age. Quite simply, an individual’s vascular age assessed by CAC score is the average age at which people of the same sex have a similar degree of coronary calcification. So, if a person’s vascular age is higher than their chronological age, this indicates a higher risk of cardiovascular events than one would suppose. For instance, a 50-year-old female smoker with a vascular age of 70 may realize that she needs to take preventive measures to reduce her risk. Conversely, when vascular age is lower than chronological age, it suggests a lower risk compared to their age group.⁵ Although vascular age provides a clear and relatable way to communicate cardiovascular risk to patients, it should be noted that it might convey the false notion that atherosclerosis is part of the natural aging process. It is not. Nevertheless, despite this imprecision, its clinical usefulness remains.

In this issue of ABC, an interesting study sought to assess the impact of using vascular age to reclassify the risk of 150 asymptomatic white men undergoing CAC scores.⁶ Replacing chronological age with vascular age in the North American Pooled Cohort Equation resulted in the reclassification of two-thirds of the subjects (31% upward and 36% downward). In the absence of clinical events to assess the appropriateness of this reclassification, the authors used CAC score progression on a second scan (performed almost 8 years later, on average) as a surrogate. Unlike baseline risk scores, vascular age was significantly correlated with CAC progression over time.

This study illustrates one of the potential applications of vascular age (i.e., to be used instead of chronological age when calculating risk scores). Also, it supports the notion that the CAC score outperforms current guideline-supported calculators in assessing cardiovascular risk. However, several limitations should also be acknowledged. Using a CAC-based parameter such as vascular age to predict CAC progression is, to some degree, a self-fulfilling promise since baseline CAC is probably the best predictor of CAC progression over time.⁷ Another important caveat is the absence of data on lipid-lowering medication at baseline and during the inter-scan period. Statins are known to increase CAC scores in some patients through a mechanism that probably involves “stabilization” of pre-existing plaques with concurrent calcification.⁸ So, CAC progression may be desirable in certain circumstances, which is one reason why the interpretation of post-statin repeat scans is troublesome.

Despite these limitations, this study reminds us of the potential benefits of assessing subclinical atherosclerosis with CAC score and possible ways of integrating this information with our current clinical practice of estimating risk with calculators. Several ongoing large randomized trials will soon tell us whether we should keep using CAC only in selected cases (when the benefit of pharmacological therapy is uncertain) or if this new approach should become standard. Stay tuned!

Referências

• ¹
  Wong ND. Evolution of Coronary Calcium Screening for Assessment of Atherosclerotic Cardiovascular Disease Risk and Role in Preventive Cardiology. Curr Atheroscler Rep. 2022;24(12):949-57. doi: 10.1007/s11883-022-01073-z.
  » https://doi.org/10.1007/s11883-022-01073-z
• ²
  Bettencourt N, Mendes L, Fontes JP, Matos P, Ferreira C, Botelho A, et al. Consensus Document on Chronic Coronary Syndrome Assessment and Risk Stratification in Portugal: A Position Paper Statement from the [Portuguese Society of Cardiology’s] Working Groups on Nuclear Cardiology, Magnetic Resonance and Cardiac Computed Tomography, Echocardiography, and Exercise Physiology and Cardiac Rehabilitation. Rev Port Cardiol. 2022;41(3):241-51. doi: 10.1016/j.repc.2020.10.009.
  » https://doi.org/10.1016/j.repc.2020.10.009
• ³
  Valério RS, Generoso G, Fernandes JL, Nasir K, Hong JC, Bittencourt MS. Cost-Effectiveness of Using the Coronary Artery Calcium Score in Guiding Therapeutic Decisions in Primary Prevention in the Brazilian Population. Arq Bras Cardiol. 2022;118(6):1126-31. doi: 10.36660/abc.20210347.
  » https://doi.org/10.36660/abc.20210347
• ⁴
  Gupta A, Lau E, Varshney R, Hulten EA, Cheezum M, Bittencourt MS, et al. The Identification of Calcified Coronary Plaque Is Associated with Initiation and Continuation of Pharmacological and Lifestyle Preventive Therapies: A Systematic Review and Meta-Analysis. JACC Cardiovasc Imaging. 2017;10(8):833-42. doi: 10.1016/j.jcmg.2017.01.030.
  » https://doi.org/10.1016/j.jcmg.2017.01.030
• ⁵
  McClelland RL, Nasir K, Budoff M, Blumenthal RS, Kronmal RA. Arterial Age as a Function of Coronary Artery Calcium (from the Multi-Ethnic Study of Atherosclerosis [MESA]). Am J Cardiol. 2009;103(1):59-63. doi: 10.1016/j.amjcard.2008.08.031.
  » https://doi.org/10.1016/j.amjcard.2008.08.031
• ⁶
  Polli I, Bruscato NM, Da Luz PL, Freitas DDM, Almeida AO, Carli W, et al. Determination of Vascular Age in Men Using the Coronary Calcium Score and its Impact on Restratification of Cardiovascular Risk. DOI: https://doi.org/10.36660/abc.20230253 Arq Bras Cardiol. 2023; 120(10):e20230253.
  » https://doi.org/10.36660/abc.20230253
• ⁷
  Erbel R, Lehmann N, Churzidse S, Rauwolf M, Mahabadi AA, Möhlenkamp S, et al. Progression of Coronary Artery Calcification Seems to be Inevitable, but Predictable - Results of the Heinz Nixdorf Recall (HNR) study. Eur Heart J. 2014;35(42):2960-71. doi: 10.1093/eurheartj/ehu288.
  » https://doi.org/10.1093/eurheartj/ehu288
• ⁸
  Puri R, Nicholls SJ, Shao M, Kataoka Y, Uno K, Kapadia SR, et al. Impact of Statins on Serial Coronary Calcification During Atheroma Progression and Regression. J Am Coll Cardiol. 2015;65(13):1273-82. doi: 10.1016/j.jacc.2015.01.036.
  » https://doi.org/10.1016/j.jacc.2015.01.036

• Short editorial related to the article: Determination of Vascular Age in Men Using the Coronary Calcium Score and its Impact on Restratification of Cardiovascular Risk

Publication Dates

• Publication in this collection
  24 Nov 2023
• Date of issue
  Nov 2023

History

• Received
  11 Oct 2023
• Reviewed
  18 Oct 2023
• Accepted
  18 Oct 2023