Familial Hypercholesterolemia and Cardiovascular Outcomes Amongst Younger Patients Undergoing Coronary Bypass Surgery

Background: Familial hypercholesterolemia (FH) is an under-recognised but common genetic condition resulting in elevated levels of low-density lipoprotein cholesterol (LDL-C) and a high risk of premature coronary disease. The prevalence of FH among younger patients undergoing coronary bypass surgery is unknown, as is their post-surgical prognosis.

Method: This was a retrospective analysis of younger patients (aged <60 years) undergoing coronary bypass surgery at an Australian tertiary hospital between 2008 and 2022. A Dutch Lipid Clinical Network Score was calculated to determine the presence of underlying FH for each patient. Outcomes were FH prevalence, pre-surgical attainment of guideline-based secondary prevention LDL-C targets and post-surgical major adverse cardiovascular events.

Results: Overall, 590 eligible patients (mean age 53.7 years, 85.6% male) were followed over a median of 7.9 years (interquartile range 4.7-12.1). Eighty (80; 13.6%) patients were categorised as 'FH', 249 (42.2%) 'possible FH' and 261 (44.2%) 'non-FH'. Compared to the non-FH group, patients with FH were less likely to achieve target LDL-C <1.8 mmol/L (15 [18.8%] vs 119 [45.6%]; p<0.001) and had higher rates of adverse cardiovascular events in the years following surgery (adjusted odds ratio 2.52; 95% confidence interval 1.0-6.4; p<0.001).

Conclusions: FH is highly prevalent among younger patients undergoing coronary bypass surgery. These patients are less likely to achieve adequate LDL reduction and are at higher risk of further adverse events. Detection and appropriate treatment of FH prior to bypass surgery should be a clinical priority.