Secondary Prevention Using Cholesterol-Lowering Medications in Patients with Prior Atherosclerotic Cardiovascular Disease Events: A Retrospective Cohort Analysis

Abstract

Background: Secondary prevention with lipid-lowering medications in patients with atherosclerotic cardiovascular disease (ASCVD) is known to reduce the risk of clinical events and death. Current guidelines codify recommendations for implementing secondary prevention in appropriate patients. However, in real-world practice, secondary prevention is frequently initiated only after the patient experiences a cardiovascular-related hospitalization. The impact of these delays is not well known. Objectives: To estimate the effects of delaying treatment on the risk of cardiovascular-related hospitalization and on costs for patients who meet the criteria for secondary prevention as specified in the 2013 American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults. Methods: This is a retrospective cohort analysis using Humana data. Eligible patients were categorized by treatment group: (1) patients who initiated treatment before an ASCVD-related hospitalization and (2) patients who either did not initiate treatment until after an ASCVD hospitalization or never initiated treatment. The associations between the timely initiation of cholesterol-lowering medications for secondary prevention and (1) the risk for an ASCVD hospitalization and (2) healthcare costs over one year, were estimated using multivariate regressions. Results: A total of 272 899 secondary prevention patients were identified who met study selection criteria. Early treatment was associated with significant reductions in the risk of an ASCVD hospitalization at any time following the identification of the patient’s eligibility for secondary prevention (by 33% compared to those treated late or never, P<.0001), but was significantly associated with higher total cost over the first post-index year (by US $509, P<.001). Patients whose low-density lipoprotein cholesterol (LDL-C) levels were >130 mg/dL experienced higher ASCVD hospitalization risks, and also larger risk reductions if treated before an ASCVD hospitalization compared to patients with lower LDL-C levels who were treated late or never treated. Conclusions: More widespread implementation of the treatment policies specified in the 2013 ACC/AHA Guidelines for secondary prevention should significantly reduce cardiovascular disease hospitalizations and reduce costs.