LAUSR

BACKGROUND AND AIMS Familial hypercholesterolemia (FH) is a genetic disease associated with an important risk of premature and recurrent atherosclerotic cardiovascular disease (ASCVD). Red blood cell (RBC) parameters such as cell count and hematocrit (HCT) have previously been associated with ASCVD risk in the general population. However, little is known concerning their effect in FH. The aim of the present study is to investigate the effect of the different RBC parameters on the incidence of major adverse cardiovascular events (MACE) in FH patients. METHODS In this prospective cohort study, genetically-confirmed FH patients aged between 18 and 65 years and without history of a prior ASCVD event were included. MACE included myocardial infarction, stroke, coronary revascularization, unstable angina or cardiovascular death. RESULTS A total of 482 subjects (6217 person-years of follow-up) were included in the analysis. Hemoglobin (HB), RBC count, and HCT were significant predictors of MACE risk (HR 1.04 (95% CI 1.01-1.06) p = 0.001, HR 2.69 (95% CI 1.49-4.86) p = 0.001, and HR 1.16 (95% CI 1.08-1.26) p < 0.0001, respectively) and these associations remained significant when adjusted for traditional cardiovascular risk factors. In addition, the frequency of recurrent MACE was 4-fold and 7-fold higher in the group above vs below the median for HB (p = 0.002) and RBC count (p = 0.001), respectively. CONCLUSIONS HB, RBC count and HCT were significant predictors of incident and recurring MACE in FH patients. These parameters could therefore be used to further refine the ASCVD risk prediction in this vulnerable population.