Letter by Hifumi et al regarding article, "Management and outcomes of major bleeding during treatment with dabigatran or warfarin".

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. CLINICAL TRIAL REGISTRATION URL http://www.ClinicalTrials.gov. Unique identifiers: NCT00262600, NCT00291330, NCT00680186, NCT00329238 and NCT00558259.