Since the approval of dabigatran for stroke prevention in non-valvular atrial fibrillation and for the treatment of deep vein thrombosis and pulmonary embolism, the safety profile of this anticoagulant has been brought into question. In order to assess the incidence of bleeding eventsassociated with dabigatran and warfarin in patients with acute venous thromboembolism, the authors performed a pooled analysis of RECOVER (2009) and RECOVER II (2014) studies. These two studies were randomised double-blind studies comparing warfarin with dabigatran (150 mg bid).

In this post-hoc analysis, bleeding events were classified as major bleeding events according to ISTH and TIMI criteria. Events that did not fulfill the ISTH criteria for major bleeding could be classified as clinically relevant non-major bleeding by the investigators. The incidence of any bleeding event and the incidence of the composite of major bleeding event and clinically relevant non-major bleeding events were significantly lower with dabigatran compared to warfarin.

Nevertheless, the main limitations of these results are related to patient selection in both studies: patients were quite young (68.9% were <65 years old), with no renal insufficiency (93.9% with creatinine clearance >50 mL/min). Yet, the factors known to increase bleeding risk are age >75 years and moderate kidney impairment (creatinine clearance 30-50 mL/min). Therefore, the real incidence of major bleeding events in patients at higher risk of bleeding remains unknown.

– Fanny Bonhomme