Marbach JA, et al. - In 2,390 consecutive ST-elevation myocardial infarction (STEMI) patients referred for primary percutaneous coronary intervention and stratified based on warfarin use at baseline, researchers assessed safety and efficacy outcomes for STEMI cases on warfarin. They focused on the rate of in-hospital bleeding (a composite of major or minor bleeding) according to the thrombolysis in myocardial infarction classification, and major adverse cardiovascular events (MACE), defined as death, myocardial infarction, or stroke, as well as intracranial bleeding, cardiogenic shock, and length of stay. They noted significantly higher age (73.2 years vs 61.7 years; P < 0.01) and a higher likelihood of presenting as Killip Class IV (13.6% vs 2.7%; P < 0.01) in warfarin patients (n = 59 vs n = 2,331). In the warfarin patients and control patients, the occurrence of TIMI major/minor bleeding was seen in 30.4% and 14.2% subjects, respectively. An independent association of warfarin with an increased bleeding risk was noted following adjustment. Albeit non-significant after adjustment, an increased frequency of MACE (20.3% vs 5.9%; P < 0.01) was seen in warfarin patients.