From the Guidelines
A coronary artery calcium (CAC) score is not recommended after a heart attack because it provides limited additional value in managing established coronary artery disease, and instead, focus should be on optimal medical therapy and lifestyle modifications to reduce morbidity, mortality, and improve quality of life. The primary goal after a heart attack is to prevent another cardiovascular event, and this can be achieved through evidence-based medical therapy and lifestyle changes. According to the most recent guidelines, patients who have had a myocardial infarction should aim to achieve low-density lipoprotein cholesterol (LDL-C) levels of < 55 mg/dL (< 1.4 mmol/L) through the use of high-intensity statins, such as atorvastatin or rosuvastatin, and lifestyle modifications, including a healthy diet and regular physical activity 1.
The use of a CAC score is most valuable in individuals without known coronary disease as a risk stratification tool to guide preventive therapy decisions, not for patients who have already experienced a cardiac event. In fact, a study published in the Journal of Internal Medicine found that a CAC score of 0 is associated with a highly favorable prognosis, with low cardiac risk defined as <1% annually for cardiac death or MI, and an annual mortality rate of <0.5% even in patients with possible CAD symptoms 1. However, once a patient has had a heart attack, their risk profile is already established, and the focus should shift to secondary prevention.
Key components of post-heart attack care include:
- Optimal medical therapy with aspirin, a high-intensity statin, a beta-blocker, and an ACE inhibitor or ARB
- Additional medications, such as a P2Y12 inhibitor, if a stent was received
- Regular follow-up with cardiology and cardiac rehabilitation
- Lifestyle modifications, including smoking cessation, a heart-healthy diet, and regular exercise
- Monitoring for symptoms and controlling other atherosclerosis risk factors, such as hypertension, diabetes, and obesity. By prioritizing these evidence-based strategies, patients can reduce their risk of another cardiovascular event and improve their overall quality of life.
From the Research
Coronary Artery Calcium Score After Heart Attack
- The coronary artery calcium (CAC) score is a useful noninvasive assessment of coronary artery disease and is associated with an increased risk of major adverse cardiovascular and cerebrovascular events (MACE) 2.
- A high CAC score is significantly associated with MACE in patients with acute myocardial infarction (AMI) 3.
- CAC scoring has emerged as a widely available, consistent, and reproducible means of assessing risk for major cardiovascular outcomes, especially useful in asymptomatic people for planning primary prevention interventions 4.
- The use of CAC testing appears to be optimal when used in selected patients who are at intermediate or borderline risk of atherosclerotic cardiovascular disease (ASCVD) as a sequential decision aid after initial quantitative risk assessment and consideration of individual patient risk-enhancing factors 5.
Clinical Outcomes
- Clinical outcomes were worse in AMI patients with a high CAC score than in those with a low-intermediate CAC score 3.
- A high CAC score was significantly associated with MACE in multivariate analysis 3.
- The absence of CAC is associated with low risk of cardiovascular events compared with any CAC > 0 in both asymptomatic and symptomatic population without coronary artery disease 2.
Risk Assessment
- CAC testing can meaningfully reclassify risk and can support improved targeting of drug therapy to patients most likely to benefit 5.
- The result of the CAC test can be helpful to clarify whether the patient's true risk is high enough to justify initiation of primary prevention medications, such as statins or aspirin 5.
- CAC testing should be used selectively in patients who are at intermediate risk of ASCVD, when there is persistent uncertainty after performing standard risk assessment using traditional risk factors in a risk score, and after consideration of additional individual risk-enhancing factors 5.