P11 Coronary artery disease prevalence by computed tomography coronary angiography in patients with familial hypercholesterolaemia

Introduction Early studies of patients with familial hypercholesterolemia (FH) reported mostly on high prevalence and incidence of clinical coronary artery disease (CAD) events. Little data exists on the prevalence of subclinical CAD in the computed tomography coronary angiography (CTCA) era. Methods As part of a wider quality improvement project on appropriateness of CTCA at a tertiary centre in London, we documented core demographics, symptoms, CTCA findings and outcomes in patients with FH undergoing CTCA between 2015–2019. All patients underwent CT calcium scoring (Agatston) and CTCA. CAD presence was defined as having at least mild plaques (>25% stenosis). Results We identified 42 patients with FH and a CTCA (22 men; mean age 49.5 ± 10.6 years). Of these, 23 (54.8%) were mutation positive and 24 (57.1%) were asymptomatic. Additional cardiac risk factors included hypertension (n=5; 11.9%), type 2 diabetes mellitus (n=2, 4.76%), current cigarette smokers (n=8, 19.0%) and a family history of CAD (n=36, 85.7%). Mean LDL was 4.13 mmol/L ± 1.70 mmol/L with mean BMI of 24.6kg/m2. The average Agatston calcium score was 112, equating to a mean age/sex adjusted percentile of 44.7%. CAD was identified in 22 (52.4%) patients, and the majority had plaque in the LAD (LMS = 4; LCx = 7; LAD = 19 and RCA = 13). Conclusion Among a highly selected population with FH, we confirm a high prevalence of CAD identified by CTCA. Larger studies are needed to confirm true prevalence in an unselected population and whether knowing this information helps guide preventive or therapeutic measures.