The cost‐effectiveness of coronary calcium score‐guided statin therapy initiation for Australians with family histories of premature coronary artery disease

Abstract

Objectives: To compare the cost‐effectiveness of coronary artery calcium (CAC) score‐guided statin therapy criteria and American College of Cardiology/American Heart Association (ACC/AHA) guidelines (10‐year pooled cohort equation [PCE] risk ≥ 7.5%) with selection according to Australian guidelines (5‐year absolute cardiovascular disease risk [ACVDR] ≥ 10%), for people with family histories of premature coronary artery disease.

Study design, setting: Markov microsimulation state transition model based on data from the Coronary Artery calcium score: Use to Guide management of Hereditary Coronary Artery Disease (CAUGHT‐CAD) trial and transition probabilities derived from published statin prescribing and adherence outcomes and clinical data.

Participants: 1083 people with family histories of premature coronary artery disease but no symptomatic cardiovascular disease.

Main outcome measures: Relative cost‐effectiveness over fifteen years, from the perspective of the Australian health care system, compared with usual care (Australian guidelines), assessed as incremental cost‐effectiveness ratios (ICERs), with a notional willingness‐to‐pay threshold of $50 000 per quality‐adjusted life‐year (QALY) gained.

Results: Applying the Australian guidelines, 77 people were eligible for statin therapy (7.1%); with ACVDR 5‐year risk ≥ 2% and CAC score > 0, 496 people (46%); with ACVDR 5‐year risk ≥ 2% and CAC score ≥ 100, 155 people (14%); and with the ACC/AHA guidelines, 256 people (24%). The ICERs for CAC‐guided selection were $33 108 (CAC ≥ 100) and $53 028 per QALY gained (CAC > 0); the ACC/AHA guidelines approach (ICER, $909 241 per QALY gained) was not cost‐effective. CAC score‐guided selection (CAC ≥ 100) was cost‐effective for people with 5‐year ACVDR of at least 5%.

Conclusion: Expanding the number of people at low to intermediate CVD risk eligible for statin therapy should selectively target people with subclinical atherosclerosis identified by CAC screening. This approach can be more cost‐effective than simply lowering treatment eligibility thresholds.