As the first new oral anticoagulant since warfarin, dabigatran (Pradaxa, Boehringer-Ingelheim) has been subject to intense concerns over its safety and efficacy in a real-world population. Last November an FDA investigation found no indication that bleeding rates for dabigatran were any higher than bleeding rates for warfarin. A new study from Scandinavia, published in the Journal of the American College of Cardiology (see note at bottom of story), provides more real-world information that helps to confirm the safety and efficacy of the new drug.
Using data from the Danish Registry of Medicinal Product Statistics, researchers compared 4978 patients treated with dabigatran to 8936 matched patients who received warfarin. They found similar rates of stroke or systemic embolism and major bleeding with dabigatran and warfarin. In addition, mortality, intracranial bleeding, pulmonary embolism,and myocardial infarction were significantly lower in the dabigatran-treated group.
Here are the adjusted hazard ratios (and 95% confidence intervals) for dabigatran 110 mg and 150 mg, respectively, compared with warfarin:
- Stroke: 0.73 (0.53 -1.00), 1.18 (0.85 – 1.64)
- Systemic embolism: 0.60 (0.19 – 1.60), 1.00 (0.26 – 3.35)
- Death: 0.79 (0.65 – 0.95), 0.57 (0.40 – 0.80)
- MI: 0.30 (0.18 – 0.49), 0.40 (0.21 – 0.70)
- Pulmonary embolism: 0.33 (0.12 – 0.74), 0.24 (0.06 – 0.72)
- Intracranial bleeding: 0.24 (0.08 – 0.56), 0.08 (0.01 – 0.40)
- Major bleeding: 0.82 (0.59 -1.12), 0.77 (0.51 – 1.13)
The authors concluded that ”previous concerns about an excess of bleeding events or myocardial infarction amongst dabigatran treated patients were not evident in this propensity-matched comparison against warfarin in a large post-approval registry study.” However, they noted one limitation of their study: The Danish AF patients included in the study were at lower risk and had a lower event rate than the patients studied in the pivotal RE-LY randomized trial of dabigatran.
Note to readers: This study is now available on Science Direct and the manuscript has been posted on CardioSource. Due to technical problems the article will be published online in the Journal of the American College of Cardiology website on Wednesday, April 10.