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.