Post-Myocardial Infarction Bleeding Risk Examined
Risk of hospital admission for bleeding increases with number of antithrombotic drugs
MONDAY, Dec. 14 (HealthDay News) -- For patients receiving antithrombotic drugs post heart attack, the risk of hospitalization for bleeding increases as the number of drugs increases, according to a study in the Dec. 12 issue of The Lancet.
Rikke Sorensen, M.D., of Copenhagen University Hospital Gentofte in Denmark, and colleagues analyzed 40,812 patients hospitalized with a first-time myocardial infarction between 2000 and 2005. The subjects were grouped by their prescribed antithrombotic drugs: monotherapy with aspirin, clopidogrel, or vitamin K antagonist; dual therapy with aspirin plus clopidogrel, aspirin plus vitamin K antagonist, or clopidogrel plus vitamin K antagonist; or triple therapy including all three. The researchers assessed the risk of hospital admission for bleeding and other outcomes for each regimen.
The researchers found the incidence of yearly bleeding for the medications to be as follows: aspirin, 2.6 percent; clopidogrel, 4.6 percent; vitamin K antagonist, 4.3 percent; aspirin plus clopidogrel, 3.7 percent; aspirin plus vitamin K antagonist, 5.1 percent; clopidogrel plus vitamin K antagonist, 12.3 percent; and triple therapy, 12 percent. Using aspirin as the referent, the hazard ratios for bleeding for the medications were: clopidogrel, 1.33; vitamin K antagonist, 1.23; aspirin plus clopidogrel, 1.47; aspirin plus vitamin K antagonist, 1.84; clopidogrel plus vitamin K antagonist, 3.52; and for triple therapy, 4.05.
"In patients with myocardial infarction, risk of hospital admission for bleeding increased with the number of antithrombotic drugs used. Treatment with triple therapy or dual therapy with clopidogrel plus vitamin K antagonist should be prescribed only after thorough individual risk assessment," the authors write.