OBJECTIVES

Monotherapy of either aspirin or clopidogrel is recommended for long-term use after discontinuation of dual-antiplatelet therapy (DAPT) for acute coronary syndrome (ACS) management after percutaneous coronary intervention (PCI). The current study evaluated the cost-effectiveness of clopidogrel versus aspirin after 12-month DAPT in ACS patients who underwent PCI in China.

METHODS

A two-part model was developed to estimate the cost-effectiveness of clopidogrel as compared with aspirin. The short-term part was a decision-tree that included health states such as “myocardial infarction (MI)”, “stroke”, “MI and stroke”, “cardiovascular death”, and “death from other causes” , with a treatment horizon of 1 year (base-case), 2 years or 3 years after 12-month DAPT. Major bleeding was included. The long-term (lifetime) part was a Markov model that included different health states such as “MI”, “post MI”, “stroke”, “post stroke”, and “death”. Drug acquisition cost and other direct medical costs were based on pricing records, literature and expert panels. Clinical outcomes and utilities were based on literature. The model calculated quality-adjusted life years (QALYs) and total medical costs per patient. Sensitivity analyses were conducted.

RESULTS

In the base-case scenario (administrating clopidogrel or aspirin for 1 year after 12-month DAPT), the average total medical costs of the clopidogrel and aspirin arms were ¥12,590 and ¥10,642 while average QALYs were 9.7341 and 9.6894 years, respectively. The Incremental cost of ¥43,593/QALY was lower than recommended cost-effectiveness threshold (3xGDP/capita, ¥161,940). Both one-way sensitivity analysis and probabilistic sensitivity analysis confirmed the robustness of the results. Results in other scenarios (clopidogrel or aspirin for 2 or 3 years after 12-month DAPT) also indicated that clopidogrel was more cost-effective than aspirin for ACS patients after 12-month DAPT.

CONCLUSIONS

Compared with aspirin, clopidogrel monotherapy up to 3 years after 12-month DAPT was more cost-effective among ACS patients who underwent PCI in China.