Association between Statins Prescribed for Primary and Secondary Prevention and Major Adverse Cardiac Events among Older Adults with Frailty: A Systematic Review

Background Statins reduce the risk of major adverse cardiovascular events (MACE), however their clinical benefit for primary and secondary prevention among older adults with frailty is uncertain. This systematic review investigates whether statins prescribed for primary and secondary prevention are associated with reduced MACE among adults aged ≥ 65 years with frailty. Methods We conducted a systematic review of studies published between 1 January 1952 and 1 January 2019 in the MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library and International Pharmaceutical Abstracts databases. Studies that investigated the effect of statins on MACE among adults ≥ 65 years of age with a validated frailty assessment were included. Data were extracted from the papers as per a prepublished protocol, PROSPERO: CRD42019127486. Risk of bias was assessed using the Cochrane Risk of Bias in Non-Randomised Studies of Interventions tool. Results Six cohort studies fulfilled the inclusion criteria; there were no randomised clinical trials. Among studies evaluating the association between statins for primary and secondary prevention and mortality, one study found statins were associated with reduced mortality (hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.37–0.93), while another study found they were not (HR 0.81, 95% CI 0.61–1.08). Furthermore, one study of statins used for secondary prevention found they were associated with reduced mortality (HR 0.28, 95% CI 0.21–0.39). No studies investigated the effect of statins for primary prevention or the effect of statins on the frequency of MACE. Conclusion This review identified only observational evidence that among older people with frailty, statins are associated with reduced mortality when prescribed for secondary prevention, and an absence of evidence evaluating statin therapy for primary prevention. Randomised trial data are needed to better inform the use of statins among older adults living with frailty.