Purpose: This study examines the efficacy of warfarin in preventing ischemic stroke due to paroxysmal atrial fibrillation (PAF) after coronary artery bypass grafting (CABG).
Methods: Postoperative PAF occurred in 151(33.5%) of 447 patients undergoing conventional CABG. The patients were divided into two groups: group I consisting of 93 patients administered two types of antiplatelet agents and group II consisting of 58 patients treated with a single antiplatelet agent and warfarin. We compared the two groups in terms of CHADS2 score, incidence of ischemic stroke, and independent risk for stroke associated with post-CABG PAF.
Results: The group I CHADS2 score (2.24 ±1.67) was significantly lower than the group II score (2.64 ± 1.22), p = 0.0452. However, 12 patients in group I (12.9%) suffered postoperative ischemic stroke, a rate significantly higher than that of group II (1 patient, 1.7%; p = 0.0173). Any recurrence of PAF or atrial fibrillation with bradycardia was assessed at the time of stroke onset. Logistic regression analysis showed that the absence of warfarin therapy constituted a risk factor for post-CABG stroke associated with PAF (Odds 13.04, p = 0.027).
Conclusion: Warfarin therapy administered concomitantly with an antiplatelet agent dramatically reduced the incidence of ischemic stroke associated with postoperative PAF.