Statins After Ischemic Stroke in the Oldest: A Cohort Study Using the Clinical Practice Research Datalink Database

Abstract

Background and Purpose: Statins are frequently initiated in patients aged 80 years and older after an ischemic stroke, even though evidence on prevention of recurrent cardiovascular disease is scarce. In this study, we seek evidence for statin prescription in the oldest old. Methods: We performed a retrospective cohort study in patients aged 65 years and older hospitalized for a first ischemic stroke between 1999 and 2016 without statin prescriptions in the year before hospitalization using the Clinical Practice Research Datalink. The age group 65 to 80 years was included to compare our results to current evidence on statin efficacy. The primary outcome was a composite of recurrent stroke, myocardial infarction, and cardiovascular mortality. The secondary outcome was all-cause mortality. A time-varying Cox model was used to account for statin prescription over time. We compared at least 2 years of statin prescription time with untreated and <2 years of prescription time. Analyses were adjusted for potential confounders. The number needed to treat was calculated based on the adjusted hazard ratios and corrected for deaths during the first 2 years of follow-up. Results: Five thousand nine hundred ten patients, aged 65 years and older were included, of whom 3157 were 80 years and older. Two years of statin prescription in patients aged 80 years and older resulted in both a lower risk of the composite end point (adjusted hazard ratio, 0.80 [95% CI, 0.62-1.02]) and all-cause mortality (adjusted hazard ratio, 0.67 [95% CI, 0.57-0.80]). After correction for the mortality of 23.9% of the patients during the first 2 years, the number needed to treat was 64 for the primary outcome during a median follow-up of 3.9 years and 19 for all-cause mortality. Conclusions: Statins initiated in patients aged 80 and older, discharged home after hospitalization for an ischemic stroke are associated with a reduction in cardiovascular events.