[The efficiency and safety of anticoagulation therapy in atrial fibrillation in Chinese].

Abstract

To determine the strength of oral anticoagulation therapy in atrial fibrillation that provides the best balance between the prevention of thromboembolism and the occurrence of bleeding complications. We studied 435 patients with atrial fibrillation who were hospitalized from 2000 to 2002 and given warfarin for prevention of thromboembolism. INR-specified rates for both ischemic and major hemorrhagic events were analyzed and the optimal levels of anticoagulation in atrial fibrillation patients determined. The average dose of warfarin was (2.77 +/- 0.83) mg and the median duration of anticoagulation is 7 months (from 1 month to 3 years). In total, there were 31 confirmed bleeding events, with major hemorrhage occurring in 5 patients. Age of the patients in the hemorrhage group is not significantly higher than that in control group (65.09 +/- 9.99 vs 62.01 +/- 12.19, P = 0.259). Chronic heart failure or hypertension increased the risk of bleeding during warfarin therapy. Multivariate analysis showed that INR >or= 3.0 is an independent risk factor for hemorrhage (OR = 3.7435, 95% CI 1.2819 - 8.9838). The risk of stroke or thromboembolism rose steeply with INR below 1.5. To achieve optimal levels of anticoagulation with the lowest risk in patients with atrial fibrillation, values of INR below 1.5 and above 3.0 should be avoided.