Prasugrel was associated with a significant increase in the rate of bleeding, notably TIMI (Thrombolysis In Myocardial Infarction) major hemorrhage, which was ob- served in 2.4% of patients taking prasugrel and in 1.8% of patients taking clopidogrel (HR for prasugrel versus clopi- was associated with a significant increase in fatal bleeding compared with clopidogrel (0.4% versus 0.1%; P 0.002). From the standpoint of safety, prasugrel was associated with an increase of 35 TIMI major and non coronary artery graft bypass (CABG) bleeds (number needed to harm 167).7 Also, greater rates of life-threatening bleed- ing were evident in the prasugrel group than in the clopidogrel group: 1.4% versus 0.9%, respectively (HR for patients who underwent CABG, TIMI major bleeding through 15 months was also greater with prasugrel than with clopidogrel (13.4% versus 3.2%, respectively; HR for net clinical benefit in the TRITON TIMI 38 study dem- onstrated a primary efficacy and safety endpoint rate of 13.9% in the clopidogrel group versus 12.2% in the P 0.004). A post hoc analysis suggested there were 3 subgroups of ACS patients who did not have a favorable net clinical benefit (defined as the rate of death due to any cause, nonfatal MI, nonfatal stroke, or non CABG-related nonfatal TIMI major bleeding) from the use of prasugrel or who had net harm: Patients with a history of stroke or transient ischemic attack before enrollment had net harm from prasugrel (HR: 1.54; no net benefit from prasugrel (HR: 0.99; 95% CI: 0.81 to 1.21; P 0.92); and patients with a body weight of 60 kg had no net benefit from prasugrel (HR: 1.03; 95% CI: 0.69 to 1.53; P 0.89). 