A Cost-Effectiveness Analysis of Combination Antiplatelet Therapy for High-Risk Acute Coronary Syndromes: Clopidogrel plus Aspirin versus Aspirin Alone

Although clopidogrel plus aspirin is more effective than aspirin alone in preventing subsequent vascular events in patients with unstable angina, the cost-effectiveness of this combination has yet to be examined in this high-risk population.To determine the cost-effectiveness of clopidogrel plus aspirin compared with aspirin alone.Cost-utility analysis.Published literature.Patients with unstable angina and electrocardiographic changes or non-Q-wave myocardial infarction. time horizon: Lifetime.Societal.Combination therapy with clopidogrel, 75 mg/d, plus aspirin, 325 mg/d, for 1 year, followed by aspirin monotherapy, was compared with lifelong aspirin therapy, 325 mg/d.Lifetime costs, life expectancy in quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio.Patients treated with aspirin alone lived 9.51 QALYs after their initial event and incurred expenses of 127,700 dollars; the addition of clopidogrel increased life expectancy to 9.61 QALYs and costs to 129,300 dollars. The incremental cost-effectiveness ratio for clopidogrel plus aspirin compared with aspirin alone was 15,400 dollars per QALY.The analysis of 1 year of therapy was robust to all sensitivity analyses. In the probabilistic sensitivity analysis, fewer than 3% of simulations resulted in cost-effectiveness ratios over 50,000 dollars per QALY. The cost-effectiveness of longer combination therapy depends critically on the balance of thrombotic event rates, durable efficacy, and the increased bleeding rate in patients taking clopidogrel.This analysis may not apply to patients with severe heart failure, those undergoing long-term anticoagulant therapy, those recently managed with revascularization, or those undergoing short-term treatment with glycoprotein IIb/IIIa inhibitors.In patients with high-risk acute coronary syndromes, 1 year of therapy with clopidogrel plus aspirin results in greater life expectancy than aspirin alone, at a cost within the traditional limits of cost-effectiveness. The durable efficacy of clopidogrel relative to the risk for hemorrhage should be further explored before more protracted therapy can be recommended.