Cost-effectiveness analysis of 30-month vs 12-month dual antiplatelet therapy with clopidogrel and aspirin after drug-eluting stents in patients with acute coronary syndrome.

Continuation of dual antiplatelet therapy (DAPT) beyond 1 year reduces late stent thrombosis and ischemic events after drug-eluting stents (DES) but increases risk of bleeding. We hypothesized that extending DAPT from 12 months to 30 months in patients with acute coronary syndrome (ACS) after DES is cost-effective. A lifelong decision-analytic model was designed to simulate 2 antiplatelet strategies in event-free ACS patients who had completed 12-month DAPT after DES: aspirin monotherapy (75-162 mg daily) and continuation of DAPT (clopidogrel 75 mg daily plus aspirin 75-162 mg daily) for 18 months. Clinical event rates, direct medical costs, and quality-adjusted life-years (QALYs) gained were the primary outcomes from the US healthcare provider perspective. Base-case results showed DAPT continuation gained higher QALYs (8.1769 vs 8.1582 QALYs) at lower cost (USD42 982 vs USD44 063). One-way sensitivity analysis found that base-case QALYs were sensitive to odds ratio (OR) of cardiovascular death with DAPT continuation and base-case cost was sensitive to OR of nonfatal stroke with DAPT continuation. DAPT continuation remained cost-effective when the ORs of nonfatal stroke and cardiovascular death were below 1.241 and 1.188, respectively. In probabilistic sensitivity analysis, DAPT continuation was the preferred strategy in 74.75% of 10 000 Monte Carlo simulations at willingness-to-pay threshold of 50 000 USD/QALYs. Continuation of DAPT appears to be cost-effective in ACS patients who were event-free for 12-month DAPT after DES. The cost-effectiveness of DAPT for 30 months was highly subject to the OR of nonfatal stroke and OR of death with DAPT continuation.