Abstract T P71: Risk Of Ischemic Stroke During Periods Of Warfarin Discontinuation For Surgical Procedures: A Longitudinal Study Of 4060 Patients With Atrial Fibrillation

Abstract

BACKGROUND: The risk of ischemic stroke during periods of warfarin discontinuation for surgical procedures is recognized nut not well characterized. We performed this study to quantitate the risk of ischemic stroke associated with strial fibrillation during periods of warfarin discontinuation. METHODS: We evaluated the association of warfarin discontinuation for procedure with the incidence of ischemic stroke using pooled repeated measures and Cox proportional hazards analyses during follow-up after adjusting for age, gender, obesity, diabetes mellitus, hypercholesterolemia, cigarette smoking, and study period in a cohort of A total of 4060 patients were randomized into the AFFIRM study. Patients enrolled in the study had AF plus at least one other risk factor for stroke or death: age >65 yrs, systemic hypertension, diabetes mellitus, congestive heart failure, transient ischemic attack, prior stroke, left atrium 50+ mm, left ventricular fractional shortening <25%, or left ventricular ejection fraction <40%. RESULTS: Warfarin discontinuation for procedure occurred in 17 (0.5%) of the 11,116 person observations with a mean follow-up period of 9.9+/-1.0 years. The rate of ischemic stroke was higher among participant with warfarin discontinuation (17 of 3313 person observations versus 209 of 36505 person observations, p=0.047). Warfarin discontinuation was associated with an increased risk for ischemic stroke (relative risk [RR], 2.2; 95% CI, 0.5 to 9.3). among the 11,802 person observations after adjusting for potential confounders. CONCLUSIONS: The risk associated with discontinuation of warfarin for procedures must be recognized and considered in the risk benefit analysis of any procedure.