Long-term survival after ischemic stroke in patients with atrial fibrillation

Abstract

While the short-term impact of atrial fibrillation-related stroke has been well studied, surprisingly little is known about its long-term effect on survival. We followed 13,559 patients with atrial fibrillation for a median of 6 years, identifying ischemic strokes through computerized databases and validating 1,025 events. Stroke severity was determined from hospital records. We compared survival of stroke patients with comparator nonstroke patients (matched for age, sex, race, comorbid conditions, and time of entry into the cohort) using proportional hazard models controlling for warfarin use and compared survival by degree of discharge deficit. Median survival after stroke was 1.8 years compared with 5.7 years for matched nonstroke comparators (hazard ratio [HR] 2.8, 95% confidence interval [CI] 2.5-3.2). This increased risk of all-cause death persisted even after restricting the analysis to the 576 stroke patients who survived 6 months after the initial stroke event (HR 2.0, 95% CI 1.7-2.5, adjusting for warfarin use). Risk of death was strongly associated with stroke severity: HR 2.9 (95% CI 2.3-3.5) for strokes resulting in major deficits and HR 8.3 (95% CI 5.2-13.2) for strokes resulting in severe deficits compared with matched comparators without stroke. Ischemic stroke approximately triples the mortality rate in patients with atrial fibrillation. This effect persists well beyond the immediate period poststroke and is strongly associated with disability after stroke. Stroke prevention by anticoagulation has even greater beneficial effects on survival than usually considered when focusing solely on 30-day mortality rates.