Genetic testing in patients with acute coronary syndrome undergoing percutaneous coronary intervention: a cost‐effectiveness analysis

Background: The CYP2C19 genotype is a predictor of adverse cardiovascular events in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) treated with clopidogrel. Objectives: We aimed to evaluate the cost‐effectiveness of a CYP2C19*2 genotype‐guided strategy of antiplatelet therapy in ACS patients undergoing PCI, compared with two ‘no testing’ strategies (empiric clopidogrel or prasugrel). Methods: We developed a Markov model to compare three strategies. The model captured adverse cardiovascular events and antiplatelet‐related complications. Costs were expressed in 2010 US dollars and estimated using diagnosis‐related group codes and Medicare reimbursement rates. The net wholesale price for prasugrel was estimated as $5.45 per day. A generic estimate for clopidogrel of $1.00 per day was used and genetic testing was assumed to cost $500. Results: Base case analyses demonstrated little difference between treatment strategies. The genetic testing‐guided strategy yielded the most QALYs and was the least costly. Over 15 months, total costs were $18 lower with a gain of 0.004 QALY in the genotype‐guided strategy compared with empiric clopidogrel, and $899 lower with a gain of 0.0005 QALY compared with empiric prasugrel. The strongest predictor of the preferred strategy was the relative risk of thrombotic events in carriers compared with wild‐type individuals treated with clopidogrel. Above a 47% increased risk, a genotype‐guided strategy was the dominant strategy. Above a clopidogrel cost of $3.96 per day, genetic testing was no longer dominant but remained cost‐effective. Conclusions: Among ACS patients undergoing PCI, a genotype‐guided strategy yields similar outcomes to empiric approaches to treatment, but is marginally less costly and more effective.