Cost-effectiveness model of use of genetic testing as an aid in assessing the likely benefit of aspirin therapy for primary prevention of cardiovascular disease

Abstract

Background: Aspirin use for the primary prevention of cardiovascular disease (CVD) is controversial because of the need to balance the risk of major bleeding events caused by aspirin with the benefit of CVD events prevented by aspirin. The United States Preventive Services Task Force (USPSTF) proposed guidelines that use CVD risk thresholds, based on the Framingham Risk Score, to identify patients likely to benefit from aspirin use. Genetic information could be used to modify this CVD risk assessment; for example, 2 variants of the LPA gene, which encodes apolipoprotein(a), are associated with increased risk of CVD.

Objectives: To estimate the incremental cost-effectiveness of using genetic test results for 2 LPA variants to derive modified Framingham Risk Score estimates and to use these estimates to identify patients likely to benefit from aspirin use according to USPSTF guidelines for aspirin use in the primary prevention of CVD.

Methods: A cost-effectiveness model of 1 million patients representative of the US population was developed based on the association of 2 LPA variants (rs3798220 and rs10455872) with CVD. The cost of testing was estimated for patients whose 10-year CVD risk would exceed the USPSTF treatment threshold if they were to test positive for the LPA variants. Patient utility estimates for myocardial infarction and stroke, and cost estimates (using a 3.5% annual discount rate) for myocardial infarction, stroke, and gastrointestinal bleeding events were based on published estimates.

Results: Recommending aspirin to patients whose CVD risk surpassed the risk threshold when LPA information was included in their risk assessment would prevent an estimated 65 CVD events over 10 years. At a genetic test cost of $150, the incremental cost-utility of testing for LPA variants is estimated at $24,942 per quality-adjusted life-year.

Conclusions: LPA genotyping in the context of the aspirin use guidelines for primary prevention of CVD could be cost-effective.