Under-Recognised and Underestimated: The Cardiovascular Health Burden of Familial Hypercholesterolaemia

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.

Prevalence of familial hypercholesterolemia in premature coronary artery disease patients admitted to a tertiary care hospital in North India

Aims

The prevalence of premature coronary artery disease (CAD) in India is two to three times more than other ethnic groups. Untreated heterozygous familial hypercholesterolemia (FH) is one of the important causes for premature CAD. As the age advances, these patients without treatment have 100 times increased risk of cardiovascular (CV) mortality resulting from myocardial infarction (MI). Recent evidence suggests that one in 250 individuals may be affected by FH (nearly 40 million people globally). It is indicated that the true global prevalence of FH is underestimated. The true prevalence of FH in India remains unknown.

Methods

A total of 635 patients with premature CAD were assessed for FH using the Dutch Lipid Clinical Network (DLCN) criteria. Based on scores, patients were diagnosed as definite, probable, possible, or no FH. Other CV risk factors known to cause CAD such as smoking, diabetes mellitus, and hypertension were also recorded.

Results

Of total 635 patients, 25 (4%) were diagnosed as definite, 70 (11%) as probable, 238 (37%) as possible, and 302 (48%) without FH, suggesting the prevalence of potential (definite + probable) FH of about 15% in the North Indian population. FH is more common in younger patients, and they have lesser incidence of common CV risk factors such as diabetes, hypertension, and smoking than the younger MI patients without FH (26.32% vs.42.59%; 17.89% vs.29.44%; 22.11% vs.40.74%).

Conclusion

FH prevalence is high among patients with premature CAD admitted to a cardiac unit. To detect patients with FH, routine screening with simple criteria such as family history of premature CAD combined with hypercholesterolemia, and a DLCN criteria score >5 may be effectively used.