Background:
In the clinical trial RE-LY, dabigatran showed a better efficacy/safety profile in comparison with warfarin, but clinical trials are few representative of the real world. We aim to access if dabigatran in real-world patients with atrial fibrillation (AF) showed a better profile in comparison with warfarin, through a systematic review and meta-analysis of observational studies comparing with vitamin K antagonists.
Methods:
PubMed, Embase and Scopus databases were searched through December 2014. We include observational studies comparing dabigatran to warfarin for non-valvular AF that reported clinical events during a follow-up for dabigatran 75mg, 110 mg or 150 mg, and warfarin. We proceeded to the extraction and analysis of data for clinical thromboembolic events, bleeding and mortality. Data were pooled by meta-analysis using a random-effects model.
Results:
We selected 9 studies involving a total of 291,703 patients, 85,399 treated with dabigatran and the remaining 206,304 with warfarin. The incidence of stroke was 1.71 / 100 patient-years for dabigatran and 2.44 / 100 patient years for warfarin (relative risk [RR] 0.91, 95% CI 0.66 to 1.27, p=0.58). The major bleeding rate was 3.90 / 100 patient-years for dabigatran and 3.92 / 100 patient years for warfarin (RR 0.90; 0.78 to 1.03, p=0.11). The all-cause mortality (RR 0.81, 0.75-0.88, p<0.001) and intracranial hemorrhage (RR 0.45, from 0.27 to 0.76, p=0.002) were significantly lower in patients treated with dabigatran in comparison to those treated with warfarin. There were no significant differences in risk of myocardial infarction (RR 0.55; 0.29 to 1.07, p=0.08), total hemorrhage (RR 1.00; 0.57 to 1.77, p=0.99), and gastro-intestinal bleeding (RR 1.14; 0.78 to 1.69, p=0.50).
Conclusions:
In this combined analysis of observational studies of real world, dabigatran compared to warfarin was associated with a similar risk of stroke, myocardial infarction, major bleeding, total bleeding and gastrointestinal bleeding, and a lower risk of intracranial hemorrhage and mortality.
Letter by Machado-Alba et al Regarding Article, “Rivaroxaban Versus Dabigatran or Warfarin in Real-World Studies of Stroke Prevention in Atrial Fibrillation: Systematic Review and Meta-Analysis”
