Long-term sex differences in atherosclerotic cardiovascular disease in individuals with heterozygous familial hypercholesterolaemia in Spain: a study using data from SAFEHEART, a nationwide, multicentre, prospective cohort study

Abstract

Background: Sex differences in atherosclerotic cardiovascular disease (ASCVD) in familial hypercholesterolaemia have been reported but are not fully established. We aimed to assess sex differences in the risk of ASCVD and life-time burden of ASCVD in patients with heterozygous familial hypercholesterolaemia.

Methods: SAFEHEART is a nationwide, multicentre, long-term prospective cohort study conducted in 25 tertiary care hospitals and one regional hospital in Spain. Participants in the SAFEHEART study aged 18 years or older with genetically confirmed familial hypercholesterolaemia were included in our analysis. Data were obtained between Jan 26, 2004, and Nov 30, 2022. ASCVD and age at onset were documented at enrolment and at follow-up. Our aim was to investigate the differences by sex in the risk and burden of ASCVD in patients with heterozygous familial hypercholesterolaemia, over the study follow-up and over the life course. The SAFEHEART study is registered with ClinicalTrials.gov, NCT02693548.

Findings: Of the 5262 participants in SAFEHEART at the time of analysis, 3506 (1898 [54·1%] female and 1608 [45·9%] male participants) met the inclusion criteria and were included in the current study. Mean age was 46·1 years (SD 15·5) and median follow-up was 10·3 years (IQR 6·4-13·0). Mean on-treatment LDL-cholesterol at follow-up was 3·1 mmol/L (SD 1·4) in females and 3·0 mmol/L (1·5) in males. LDL-cholesterol reductions over time were similar in both sexes (1·39 mmol/L [95% CI 1·30-1·47] absolute reduction in females vs 1·39 mmol/L [1·29-1·48] in males; p=0·98). At enrolment, 130 (6·8%) females and 304 (18·9%) males (p<0·0001) had cardiovascular disease. During follow-up, 134 (7·1%) females and 222 (13·8%) males (p<0·0001) had incident cardiovascular events. Median age at first ASCVD event (mostly due to coronary artery disease) was 61·6 years (IQR 50·0-71·4) in females and 50·6 years (42·0-58·6) in males (p<0·0001). The adjusted hazard ratio for ASCVD in males compared with females during follow-up was 1·90 (95% CI 1·49-2·42) and for cardiovascular death was 1·74 (1·11-2·73). Major adverse cardiovascular disease event (MACE)-free survival from birth was lower in males than females (hazard ratio 3·52 [95% CI 2·98-4·16]; p<0·0001). Median MACE-free survival time was 90·1 years (95% CI 86·5-not estimable) in females and 71·0 years (69·2-74·6) in males. The age at which 25% of female participants have had a MACE event was 74·9 years, this figure was 55·5 years in male participants.

Interpretation: Our findings suggest that the burden and risk of ASCVD are markedly lower in females than males with familial hypercholesterolaemia. The impact of sex needs to be considered to improve risk stratification and personalised management in patients with heterozygous familial hypercholesterolaemia.

Funding: Fundación Hipercolesterolemia Familiar, the Instituto de Salud Carlos III, and Next Generation EU funds from the Recovery and Resilience Mechanism Program.

Translation: For the Spanish translation of the abstract see Supplementary Materials section.