Coronary artery calcium among patients with heterozygous familial hypercholesterolaemia.

Aims: We aimed to determine if coronary artery calcium (CAC) is associated with cardiovascular disease (CVD) events, defined as CVD-related death, unstable angina, myocardial infarction, or staged revascularization among patients with heterozygous familial hypercholesterolaemia (HeFH) under primary prevention settings.

Methods and results: Data of patients with FH admitted to Kanazawa University Hospital between 2000 and 2020, who underwent CAC measurement and were followed up (n = 622, male = 306, mean age = 54 years), were retrospectively reviewed. Risk factors for CVD events were determined using the Cox proportional hazard model. The median follow-up duration was 13.2 years (interquartile range: 9.8-18.4 years). We observed 132 CVD events during the follow-up period. The event rate per 1000 person-years for CAC scores of 0 [n = 283 (45.5%)], 1-100 [n = 260 (41.8%)], and >100 [n = 79 (12.7%)] was 1.2, 17.0, and 78.8, respectively. Log (CAC score + 1) was a significant predictor of the occurrence of CVD events (hazard ratio: 3.24; 95% confidence interval: 1.68-4.80; P < 0.0001) in the multivariate Cox regression analysis, independent of other factors. The risk discrimination of CVD events was enhanced by adding CAC information to other conventional risk factors (C-statistics: 0.833-0.934; P < 0.0001).

Conclusion: The CAC score helps in further risk stratification in patients with HeFH.