Background: Uncertainty exists about the frequency, correlates, and clinical significance of bleeding with dual antiplatelet therapy (DAPT), particularly over an extended period in a stable population. We sought to determine the frequency and time course of bleeding with DAPT in patients with established vascular disease or risk factors only; identify correlates of bleeding; and determine whether bleeding is associated with mortality.
Methods and results: We analyzed 15 603 patients enrolled in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial, a double-blind, placebo-controlled, randomized trial comparing long-term clopidogrel 75 mg/d versus placebo; all patients received aspirin (75 to 162 mg) daily. Patients had either established stable vascular disease or multiple risk factors for vascular disease without established disease. Median follow-up was 28 months. Bleeding was assessed with the use of the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) criteria. Severe bleeding occurred in 1.7% of the clopidogrel group versus 1.3% on placebo (P=0.087); moderate bleeding occurred in 2.1% versus 1.3%, respectively (P<0.001). The risk of bleeding was greatest the first year. Patients without moderate or severe bleeding during the first year were no more likely than placebo-treated patients to have bleeding thereafter. The frequency of bleeding was similar in patients with established disease and risk factors only. In multivariable analysis, the relationship between moderate bleeding and all-cause mortality was strong (hazard ratio, 2.55; 95% confidence interval, 1.71 to 3.80; P<0.0001), along with myocardial infarction (hazard ratio, 2.92; 95% confidence interval, 2.04 to 4.18; P<0.0001) and stroke (hazard ratio, 4.20; 95% confidence interval, 3.05 to 5.77; P<0.0001).
Conclusions: In CHARISMA, there was an increased risk of bleeding with long-term clopidogrel. The incremental risk of bleeding was greatest in the first year and similar thereafter. Moderate bleeding was strongly associated with mortality. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00050817.