Dabigatran for stroke prevention in atrial fibrillation

Summary

Dabigatran is a novel direct thrombin inhibitor that has recently been approved for primary and secondary stroke prevention and prevention of systemic embolism in patients with atrial fibrillation. In the pivotal RE-LY study, dabigatran 110 mg BID was demonstrated to be associated with a stroke rate similar to that observed with warfarin (INR target 2.0 to 3.0), but with a lower rate of major haemorrhage. Dabigatran administered at a dose of 150 mg BID was significantly more effective in stroke prevention than warfarin and showed a similar rate of major hemorrhages. Of note, both dosages resulted in an approximately 60–70% relative risk reduction of haemorrhagic stroke. The dosage of 110 mg BID should be preferably used in patients aged 75–80 years or older as the rate of extracranial bleeding events tends to increase with dabigatran 150 mg BID above this age limit. In RE-LY, myocardial infarcts occurred at a very low incidence. There were numerically more myocardial infarcts in dabigatran-treated patients than in warfarin patients; however, other myocardial ischaemic events were similar in the three treatment arms.

Zusammenfassung

Dabigatran ist ein neuer direkter Thrombininhibitor, der unlängst für die primäre und sekundäre Schlaganfallsprävention bei Patienten mit Vorhofflimmern zugelassen wurde. In der entscheidenden Zulassungsstudie, der RE-LY Studie, war Dabigatran in einer Dosierung von 110 mg zweimal täglich mit einer Schlaganfallsrate assoziiert, die derjenigen von Vitamin-K-Antagonisten ähnlich war. Es traten aber signifikant weniger schwerwiegende Blutungen auf. In der höheren Dosierung von Dabigatran 150 mg zweimal täglich zeigte sich eine signifikant niedrigere Schlaganfallsinzidenz als unter Warfarin bei vergleichbarem Blutungsrisiko. Beide Dosierungen waren mit einer 60–70%igen Reduktion des Risikos eines hämorrhagischen Schlaganfalls assoziiert verglichen mit der Vitamin-K-Antagonisten-Therapie. Die niedrigere Dabigatrandosierung sollte bei Patienten im Alter über 75–80 Jahren präferiert werden, da die höhere Dosierung mit einer altersabhängigen Zunahme extrakranieller Blutungen assoziiert war. In RE-LY wurden numerisch mehr Myokardinfarkte in den Dabigatran-behandelten Patienten beobachtet, jedoch war der Unterschied nicht statistisch signifikant. Andere Myokard-ischämische Ereignisse waren in allen Gruppen vergleichbar häufig aufgetreten.

Keywords

Atrial fibrillation - anticoagulation - stroke - dabigatran - warfarin

Schlüsselwörter

Vorhofflimmern - Antikoagulation - Schlaganfall - Dabigatran - Warfarin

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