Extreme Atherosclerotic Cardiovascular Disease (ASCVD) Risk Recognition.

Purpose Of Review: To distinguish extreme and very high atherosclerotic cardiovascular disease (ASCVD) event risk based on prospective epidemiological studies and clinical trial results.

Recent Findings: Clinical practice guidelines have categorized patients with either a history of one or more "clinical ASCVD" events or "coronary heart disease (CHD) risk equivalency" to be at "very high risk" for a recurrence or a first event, respectively. A 20% or greater 10-year ASCVD risk for a composite 3-point "major" atherosclerotic cardiovascular event (MACE) of non-fatal myocardial infarction (MI), non-fatal stroke, or cardiovascular death can serve as an arbitrary definition of those at "very high risk." Exclusion of stroke may underestimate risk of "hard" endpoint 10-year ASCVD risk and addition of other potential endpoints, e.g., hospital admission for unstable angina or revascularization, a 5-point composite MACE, may overinflate the risk definitions and categorization. "Extreme" risk, a descriptor for even higher morbidity and mortality potential, defines a 30% or greater 10-year 3-point MACE (ASCVD) risk. In prospective, epidemiological studies and randomized clinical trial (RCT) participants with an initial acute coronary syndrome (ACS) within several months of entry into the study meet the inclusion criteria assignment for extreme risk. In survivors beyond the first year of an ASCVD event, "extreme" risk persists when one or more comorbidities are present, including diabetes, heart failure (HF), stage 3 or higher chronic kidney disease (CKD), familial hypercholesterolemia (FH), and poorly controlled major risk factors such as hypertension and persistent tobaccoism. "Extreme" risk particularly applies to those with progressive or multiple clinical ASCVD events in the same artery, same arterial bed, or polyvascular sites, including unstable angina and transient ischemic events. Identifying asymptomatic individuals with extensive subclinical ASCVD at "extreme" risk is a challenge, as risk engine assessment may not be adequate; individuals with genetic FH or those with diabetes and Agatston coronary artery calcification (CAC) scores greater than 1000 exemplify such threatening settings and opportunities for aggressive primary prevention. Heterogeneity exists among individuals at risk for clinical ASCVD events; identifying those at "extreme" risk, a more ominous ASCVD category, associated with greater morbidity and mortality, should prompt the most effective global cardiometabolic risk reduction.