NEW YORK (Reuters Health) – Compared to other anticoagulants or placebo, the use of dabigatran for various clinical indications is associated with an increased risk of acute coronary syndrome or myocardial infarction, according to the results of a meta-analysis reported in the Archives of Internal Medicine published online January 9. However, “Although the relative risk increase was 33%, the absolute risk increase was very small, at 0.27%,” the authors point out. Dr. Ken Uchino and Dr. Adrian V. Hernandez of the Cleveland Clinic, Ohio, explain that a large trial comparing dabigatran to warfarin in patients with atrial fibrillation originally found a small increase in the risk of MI, but this became statistically non-significant in revised results. To investigate further, the team identified seven trials comparing dabigatran to either warfarin or enoxaparin or placebo for stroke prophylaxis in AF, for prophylaxis of deep venous thrombosis, in ACS, or in acute venous thromboembolism.  The trials included a total of 39,514 patients. The rate of MI or ACS was 1.19% among patients given dabigatran compared to 0.79% among control subjects.  This difference translated to an odds ratio of 1.33 (p=0.03), the investigators report. Using the fixed-effects Mantel-Haenszel test to evaluate the effect of dabigatran on MI or ACS, they calculated that the risk difference versus control agents was only 0.27%. In discussing the results, the authors suggest that rather than directly increasing the risk of acute coronary events, dabigatran may be less cardioprotective than warfarin. A secondary outcome of the analysis was mortality, which was significantly lower in the dabigatran group at 4.83% compared to 5.02% in the control group (odds ratio 0.89; p=0.04). Drs. Uchino and Hernandez found. Summing up, they conclude, “The overall benefit and risk balance of dabigatran use appears to be favorable in patients with AF because of reduction in ischemic stroke.  However, the cardiac risk of dabigatran should be investigated further, especially if it is used in populations at high risk of MI or ACS.” The findings suggest that physicians should “retain a critical view as a powerful new drug enters clinical use on a potentially massive scale,” say the authors of a related commentary. “Only a balanced view of all high-quality data for dabigatran can permit such an assessment necessary to guide clinical decisions,” write Dr. Jeremy M. Jacobs of Hadassah-Hebrew University Medical Center and Dr. Jochanan Stessman of Hebrew University-Hadassah Medical School in Jerusalem, Israel. SOURCE: Dabigatran Association With Higher Risk of Acute Coronary Events Dabigatran: Do We Have Sufficient Data? Arch Intern Med 2012.