Neutralizing the adverse prognosis of coronary artery calcium

Same evidence, varying viewpoints: Three questions illustrating important differences between United States and European cholesterol guideline recommendations

In 2018, the AHA/ACC Multisociety Guideline on the Management of Blood Cholesterol was released. Less than one year later, the 2019 ESC/EAS Dyslipidemia Guideline was published. While both provide important recommendations for managing atherosclerotic cardiovascular disease (ASCVD) risk through lipid management, differences exist. Prior to the publication of both guidelines, important randomized clinical trial data emerged on non-statin lipid lowering therapy and ASCVD risk reduction. To illustrate important differences in guideline recommendations, we use this data to help answer three key questions: 1) Are ASCVD event rates similar in high-risk primary and stable secondary prevention? 2) Does imaging evidence of subclinical atherosclerosis justify aggressive use of statin and non-statin therapy (if needed) to reduce LDL-C levels below 55 ​mg/dL as recommended in the European Guideline? 3) Do LDL-C levels below 70 ​mg/dL achieve a large absolute risk reduction in secondary ASCVD prevention? The US guideline prioritizes both the added efficacy and cost implications of non-statin therapy, which limits intensive therapy to individuals with the highest risk of ASCVD. The European approach broadens the eligibility criteria by incorporating goals of therapy in both primary and secondary prevention. The current cost and access constraints of healthcare worldwide, especially amidst a COVID-19 pandemic, makes the European recommendations more challenging to implement. By restricting non-statin therapy to a subgroup of high- and, in particular, very high-risk individuals, the US guideline provides primary and secondary ASCVD prevention recommendations that are more affordable and attainable. Ultimately, finding a common ground for both guidelines rests on our ability to design trials that assess cost-effectiveness in addition to efficacy and safety.

Screening low-risk individuals for coronary artery disease

A large proportion of cardiovascular events occur in individuals classified by traditional risk factors as "low-risk." Efforts to improve early detection of coronary artery disease among low-risk individuals, or to improve risk assessment, might be justified by this large population burden. The most promising tests for improving risk assessment, or early detection, include the coronary artery calcium (CAC) score, the ankle-brachial index (ABI), and the high-sensitivity C-reactive protein (hsCRP). Data regarding the role of additional testing in low-risk populations to improve early detection or to enhance risk assessment are sparse but suggest that CAC and ABI may be helpful for improving risk classification and detecting the higher-risk people from among those at lower risk. However, in the absence of clinical trials in this patient population, such as has recently been proposed, we do not recommend routine use of any additional testing or screening in low-risk individuals at this time.