In the 2019 ESC/EAS guidelines for the management of dyslipidaemias, coronary artery calcium (CAC) score assessment may be considered as a risk modifier. It seems that CAC score is often very low in patients younger than 45 with severe familial hypercholesterolaemia (FH).

We assessed the relationship between CAC score and FH.

Analysis was based on patients consecutively referred to a Department of Preventive Cardiology and having a CAC score assessed (n=1402). FH was diagnosed using the modified version of the Dutch Lipid Clinic Network (DLCN). LDL-C was corrected for patients under statin or ezetimibe using dose- and statin- or ezetimibe-specific correction factors. FH was considered as definite, probable, possible or unlikely for a total >8, equal to 6–8, 3–5 or <3 points, respectively.

DLCN score was assessed in 1157 patients. CAC score was significantly associated with DLCN score: 21%, 29%, 18%, and 32% of the patients with FH (DLCN score for definite or probable FH; n=38) versus 39%, 29%, 18% and 14% of the patients without FH (DLCN score for possible or unlikely FH; n=1119) had a CAC score equal to 0, 1-100, 101-400 and >400, respectively (P=0.009). Factors independently associated with a CAC>400 were age, male gender, diabetes mellitus, hypertension, lipid-lowering treatment and definite or probable FH. Among patients with FH<45 years, CAC was>0 for 40% of patients. Among patients with FH, 11% had premature CVD and 68% were treated. Mean corrected LDL-C was 9.8mmol/L (±2.3) and 4.1mmol/L (±1.3) in patients with and without FH, respectively (P<0.0001). None of the patients with FH reached the LDL-C goal. In patients with FH that were not treated, 67% had a CAC>0 (25%, 17% and 25% with a CAC equal to 1-100, 101-400 and >400, respectively).

In patients with definite or probable FH, CAC may refine CV risk assessment and may be helpful in discussions about treatment strategies.