Coronary plaque burden, plaque characterization and their prognostic implications in familial hypercholesterolemia: A computed tomographic angiography study

Background and aims: Heterozygous familial hypercholesterolemia (FH) is associated with premature atherosclerotic cardiovascular disease. Semi-automated plaque characterization (SAPC) by coronary computed tomographic angiography (CTA) provides information regarding coronary plaque burden and plaque characterization. Our aim was to quantify and characterize the coronary plaque burden of patients with FH using SAPC analysis and to identify which factors are related to plaque burden and plaque characteristics. A second aim was to analyse the prognostic implications of these parameters.

Methods: Two hundred and fifty-nine asymptomatic individuals with molecularly determined FH were enrolled in this follow-up cohort study and underwent a coronary CTA analysed with SAPC.

Results: Mean follow-up time after coronary CTA was 3.9 ± 2 years. Mean age was 46.9 (10.7) years (130 women, 50.2%). Median plaque burden was 25.0% (19.0-29.0), non-calcified plaque burden 22.83% (17.94-26.88), calcified plaque-burden 1.12% (0.31-2.86) and CCS 8.9 (0-93). Five-year risk was independently related to plaque burden, non-calcified plaque burden, calcified plaque burden and coronary calcium score (B:3.75, 95%CI:2.92-4.58; p < 0.001, B:2.9, 95%CI:2.15-3.66; p < 0.001, B:0.75, 95%CI 0.4-1.1; p < 0.001 and B:82.2, 95%CI:49.28-115.16; p < 0.001 respectively). During follow-up, there were 15 (5.81%) nonfatal events and 1 (0.4%) fatal event. Plaque burden was significantly related to event-free survival during follow-up (HR:1.11; 95%CI:1.05-1.18; p < 0.001).

Conclusions: Coronary atherosclerosis and its qualitative components may be quantified by means of SAPC in patients with FH. Plaque burden, calcified plaque burden and non-calcified plaque burden were independently related to the estimated cardiovascular risk. Plaque burden was also related to prognosis.