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 highintensity 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.