Endocrine Abstracts

Background: Cardiovascular disease (CVD) risk in familial hypercholesterolaemia (FH) is driven by cumulative exposure to high low-density lipoprotein cholesterol (LDL-C) levels. Previously, LDL-C burden has been loosely approximated using the cholesterol year score (CYS) based on two LDL-C readings only. We aimed to determine whether a more sophisticated LDL-C burden score based on serial LDL-C measurements, could more accurately predict major atherosclerotic cardiovascular events (MACE) in FH patients.

Methods: A retrospective longitudinal study was conducting using data from patients followed-up at a tertiary-centre lipid clinic. Area under the curve (AUC) was determined to represent cumulative LDL-C burden using all available LDL-C values for individual patients. The primary outcome was MACE. AUC_{[LDL-C burden]}, CYS and other clinical factors were investigated for their role in predicting MACE using receiver operator characteristics (ROC) and Kaplan-Meier analyses. Sub-analyses were performed among subgroups based on age.

Results: Seventy patients (male 55.7%, mean age 56.8±17.7) were included, of which 14 suffered a MACE during the follow-up period. Patients with MACE had significantly higher AUC_{[LDL-C burden]} compared to those without MACE (P<0.05). However, this was only the case for younger patients (P<0.01 for patients <60 yr vs P=0.27 for patients >60 yr). This pattern was supported by Kaplan-Meier analysis. Area under the ROC curve analysis showed that the CYS tool (AUC=0.696) is as valid at predicting MACE as AUC_{[LDL-C burden]} (AUC=0.685).

Conclusions: Cumulative LDL-C burden is associated with MACE development in FH patients, particularly in patients under the age of 60. The CYS tool is as effective at predicting CVD as using serial LDL-C values after diagnosis to represent LDL-C burden.