Ischemic Event Rates in Very-High-Risk Adults

Background: The 2018 American Heart Association/American College of Cardiology (AHA/ACC) cholesterol guideline includes recommendations for intensive lipid-lowering therapy in patients at very high risk for atherosclerotic cardiovascular disease (ASCVD) events. Objectives: This study sought to estimate event rates among adults with a history of ASCVD who met and did not meet the definition of very high risk in the 2018 AHA/ACC cholesterol guideline. Methods: Data from U.S. adults with health insurance in the MarketScan database who had a history of ASCVD on January 1, 2016 (n = 27,775) were analyzed. Very high risk for ASCVD events was defined as a history of ≥2 major ASCVD events or 1 event and ≥2 high-risk conditions. Patients were followed through December 31, 2017, for ASCVD events, including myocardial infarction, ischemic stroke, and major adverse limb events. Results: Overall, 15,366 patients (55.3%) with ASCVD met the definition of very high risk. Among patients with and without very high risk, the ASCVD event rate per 1,000 person-years was 53.1 (95% confidence interval [CI]: 50.1 to 56.1) and 17.0 (95% CI: 15.2 to 18.9), respectively. Among patients with ≥2 major ASCVD events and with 1 event and ≥2 high-risk conditions, the ASCVD event rate per 1,000 person-years was 89.8 (95% CI: 82.2 to 98.0) and 41.3 (95% CI: 38.3 to 44.4), respectively. The age- and sex-adjusted hazard ratios for ASCVD events among patients with very high risk, overall, with ≥2 major ASCVD events and with 1 event and ≥2 high-risk conditions versus those without very high risk were 2.98 (95% CI: 2.63 to 3.37), 4.89 (95% CI: 4.22 to 5.66), and 2.33 (95% CI: 2.04 to 2.66), respectively. Conclusions: The 2018 AHA/ACC cholesterol guideline directs intensive lipid-lowering therapy to adults with a very high ASCVD event rate.