The anticoagulant dabigatran is associated with an
increased risk for myocardial infarction or acute coronary syndrome in a wide
range of patients when compared with other medicines, according to a study
published online in the Archives of Internal Medicine.
Originally FDA-approved in 2010 for the prevention of
stroke and systemic embolism in those with nonvalvular atrial fibrillation,
dabigatran etexilate (Pradaxa, Boehringer Ingelheim) was
later compared with warfarin in a 2-year safety and efficacy study of 18,000
patients with atrial fibrillation. Although the trial reported a decrease in
stroke and systemic embolism for patients receiving dabigatran, there also was
an increased risk for MI.
In 2011, Ken Uchino, MD, and Adrian V.
Hernandez, MD, PhD, of the Cleveland Clinic in Ohio, reviewed PubMed,
Scopus and Web of Science for randomized controlled trials of dabigatran in
which MI or acute coronary syndrome were reported as secondary outcomes.
Seven trials were selected for the meta-analysis —
comprising 30,514 participants — including three studies in short-term
venous thrombosis, two studies of stroke prophylaxis in atrial
fibrillation, one study in acute venous thromboembolism and one study in acute
coronary syndrome. Compared against control groups administering warfarin,
enoxaparin or placebo, dabigatran was associated with a higher risk for MI or
acute coronary syndrome (dabigatran, 237 of 20,000 [1.19%] vs. control, 83 of
10,514 [0.79%]; OR=1.33; 95% CI, 1.03-1.71).
Despite its increased risk for MI and acute coronary
syndrome, according to the study, dabigatran was associated with a lower
mortality than control group (dabigatran, 945 of 19,555 [4.83%] vs. control,
524 of 10,444 [5.02%]; OR=0.89; 95% CI, 0.80-0.99). Given this information, the
researchers said although dabigatran might not directly increase MI risk, it
may lack the beneficial effects that warfarin and aspirin display in MI
“The overall benefit and risk balance of dabigatran
use appears to be favorable in patients with [atrial fibrillation] because of
reduction in ischemic stroke,” the researchers said. “However, the
cardiac risk of dabigatran should be investigated further, especially if it is
used in populations at high risk of MI or [acute coronary syndrome].”
Disclosure: The researchers report no relevant