Background: The aim of this study was to compare the management and prognosis of major bleeding in patients treated with dabigatran or warfarin.
Methods and results: Two independent investigators reviewed bleeding reports from 1034 individuals with 1121 major bleeds enrolled in 5 phase III trials comparing dabigatran with warfarin in 27 419 patients treated for 6 to 36 months. Patients with major bleeds on dabigatran (n=627 of 16 755) were older, had lower creatinine clearance, and more frequently used aspirin or non-steroid anti-inflammatory agents than those on warfarin (n=407 of 10 002). The 30-day mortality after the first major bleed tended to be lower in the dabigatran group (9.1%) than in the warfarin group (13.0%; pooled odds ratio, 0.68; 95% confidence interval, 0.46-1.01; P=0.057). After adjustment for sex, age, weight, renal function, and concomitant antithrombotic therapy, the pooled odds ratio for 30-day mortality with dabigatran versus warfarin was 0.66 (95% confidence interval, 0.44-1.00; P=0.051). Major bleeds in dabigatran patients were more frequently treated with blood transfusions (423/696, 61%) than bleeds in warfarin patients (175/425, 42%; P<0.001) but less frequently with plasma (dabigatran, 19.8%; warfarin, 30.2%; P<0.001). Patients who experienced a bleed had shorter stays in the intensive care unit if they had previously received dabigatran (mean 1.6 nights) compared with those who had received warfarin (mean 2.7 nights; P=0.01).
Conclusions: Patients who experienced major bleeding on dabigatran required more red cell transfusions but received less plasma, required a shorter stay in intensive care, and had a trend to lower mortality compared with those who had major bleeding on warfarin.
Keywords: anticoagulants; atrial fibrillation; hemorrhage; mortality; venous thrombosis.