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. Keywords: Familial hypercholesterolemia, Premature coronary artery disease, Dutch Lipid Clinic Network Criteria, Correction factor, Arcus cornealis