"Dabigatran versus Warfarin in Patients with Mechanical Heart Valves".The New England Journal of Medicine. 2013. 369(13):1206-1214.PubMed•Full text•PDF

Clinical Question

Is dabigatran an effective and safe alternative to warfarin in patients with mechanical heart valves?

Bottom Line

In patients with mechanical heart valves, dabigatran was less effective than warfarin and was associated with a higher risk of both thromboembolic and bleeding complications.

Major Points

Guidelines

Current guidelines do not recommend dabigatran and other novel oral anticoagulants for patients with mechanical heart valves, generally favoring vitamin K antagonist therapy.

Design

Prospective, randomized, phase 2, open-label trial with blinded endpoint adjudication, comparing dabigatran to warfarin in patients with mechanical heart valves.

Population

Patients between the ages of 18 and 75 years who had either recent (within 7 days) or past (at least 3 months prior) aortic or mitral mechanical valve replacement.

Interventions

Patients were randomized to receive dabigatran or warfarin in a 2:1 ratio. Dabigatran dose was selected based on renal function and adjusted for plasma levels, whereas warfarin dose was adjusted targeting an INR of 2 to 3 or 2.5 to 3.5.

Outcomes

The primary endpoint was the trough plasma level of dabigatran, with secondary endpoints including stroke, systemic embolism, valve thrombosis, and major bleeding events.

Criticisms

The trial was stopped early due to excess thromboembolic and bleeding events in the dabigatran group, which may have caused an underestimation of long-term efficacy and safety.

Funding

The trial was funded by Boehringer Ingelheim.

Further Reading

Full details of the study design and results are available in the published article by The New England Journal of Medicine and additional supplementary material.