Higher Statin Adherence Associated with Lower Mortality in Veterans with Atherosclerotic Cardiovascular Disease
BACKGROUND:
Recently updated 2018 American College of Cardiology and American Heart Association cholesterol treatment guidelines continue to recommend statins as the main treatment for patients with atherosclerotic cardiovascular disease (ASCVD) – and emphasize the importance of tracking adherence in follow-up. However, previous research shows that as many as a third of high-risk patients prescribed statins discontinue statin therapy, with most of the discontinuations attributable to patient preference and not drug side effects. This retrospective cohort analysis sought to determine whether statin adherence is associated with mortality in stable patients with atherosclerotic cardiovascular disease. Investigators identified all VA outpatients with established ASCVD, defined as coronary artery disease (CAD), cerebrovascular disease, or peripheral artery disease (PAD) that was diagnosed between 1/1/13 and 4/1/14 (n=347,104). The primary outcome was all-cause mortality adjusted for demographic and clinical characteristics, and adherence to other cardiac medications. Other outcomes were 1-year mortality, and 1-year hospitalization for ischemic heart disease or ischemic stroke.
FINDINGS:
- Higher statin adherence was associated with lower mortality in a national sample of Veterans with atherosclerotic cardiovascular disease. Also, ischemic heart disease or stroke hospitalizations in the VA healthcare system were more frequent in Veterans who were less adherent to statins.
- Overall, statin adherence in this cohort on a stable statin intensity was high (88%).
- Veterans on moderate-intensity statin therapy were more adherent than Veterans on high-intensity statin therapy.
- Veterans with PAD and cerebrovascular disease were less adherent than those with CAD.
- Women and minority groups were less adherent to statin therapy, with adherence lowest among black patients.
- Younger and older patients were less adherent, compared with adults aged 65-74.
IMPLICATIONS:
- Findings suggest a substantial opportunity for improvement in the secondary prevention of ASCVD through optimization of statin adherence – an important metric that should be carefully tracked.
LIMITATIONS:
- Investigators could not fully account for residual confounding that may explain the association between low adherence to statins and mortality. In addition, they were unable to determine the cause of death, or hospitalizations outside VA.
AUTHOR/FUNDING INFORMATION:
Dr. Heidenreich leads MedSafe QUERI: Optimizing Appropriate Use of Medications for Veterans, and is part of HSR&D's Center for Innovation to Implementation (Ci2i), and Dr. Virani is part of HSR&D's Center for Innovations in Quality, Effectiveness and Safety (IQuESt). Dr. Virani was supported by an HSR&D Career Development Award.
Rodriguez F, Maron D, Knowles J, Virani S, Lin S, and Heidenreich P. Association of Statin Adherence with Mortality in Patients with Atherosclerotic Cardiovascular Disease. JAMA Cardiology. February 13, 2019; Epub ahead of print.
