Effects of Statin Intensity and Adherence on the Long-Term Prognosis After Acute Ischemic Stroke

Background and Purpose— Statin is an established treatment for secondary prevention after ischemic stroke. However, the effects of statin intensity and adherence on the long-term prognosis after acute stroke are not well known. Methods— This retrospective cohort study using a nationwide health insurance claim data in South Korea included patients admitted with acute ischemic stroke between 2002 and 2012. Statin adherence and intensity were determined from the prescription data for a period of 1 year after the index stroke. The primary outcome was a composite of recurrent stroke, myocardial infarction, and all-cause mortality. We performed multivariate Cox proportional regression analyses. Results— We included 8001 patients with acute ischemic stroke. During the mean follow-up period of 4.69±2.72 years, 2284 patients developed a primary outcome. Compared with patients with no statin, adjusted hazard ratios (95% confidence interval) were 0.74 (0.64–0.84) for good adherence, 0.93 (0.79–1.09) for intermediate adherence, and 1.07 (0.95–1.20) for poor adherence to statin. Among the 1712 patients with good adherence, risk of adverse events was lower in patients with high-intensity statin (adjusted hazard ratio [95% confidence interval], 0.48 [0.24–0.96]) compared with those with low-intensity statin. Neither good adherence nor high intensity of statin was associated with an increased risk of hemorrhagic stroke. Conclusions— After acute ischemic stroke, high-intensity statin therapy with good adherence was significantly associated with a lower risk of adverse events.