Risk Differences in Secondary Prevention Patients Who Present With Acute Coronary Syndrome and Implications of Guideline-Directed Cholesterol Management

The 2018 American College of Cardiology/American Heart Association cholesterol guidelines for secondary prevention identified a group of “very high risk” (VHR) patients, those with multiple major atherosclerotic cardiovascular disease (ASCVD) events or 1 major ASCVD event with multiple high-risk features. A second group, “high risk” (HR), was defined as patients without any of the risk features in the VHR group. The incidence and relative risk differences of these 2 groups in a nontrial population has not been well characterized. Using the Northwestern Medicine Enterprise Data Warehouse, we compared the incidence of VHR and HR patients as well as their relative risk for cardiovascular morbidity and mortality in a single-center, large, academic, retrospective cohort study. Total 1,483 patients with acute coronary events from January 2014 to December 2016 were risk stratified into VHR and HR groups. International Classification of Diseases versions 9 and 10 were used to assess for composite events of unstable angina pectoris, non-ST elevation myocardial infarction, or ST-elevation myocardial infarction, ischemic stroke, or all-cause death with a median follow-up of 3.3 years. VHR patients were found to have 87 ± 5.4 composite events per 1,000 patient-years compared with HR patients who had 33 ± 5.1 events per 1,000 patient-years (p <0.001). VHR group had increased risk of future events as compared to the HR group (multivariable adjusted hazard ratio 1.66 [1.01 to 2.74], p = 0.047). In conclusion, these results support the stratification of patients into the VHR and HR risk groups for secondary prevention.