Lipoprotein(a): An underrecognized genetic risk factor for malignant coronary artery disease in young Indians

Abstract

Malignant coronary artery disease (CAD) refers to a severe and extensive atherosclerotic process involving multiple coronary arteries in young individuals (aged <45 years in men and <50 years in women) with a low or no burden of established risk factors. Indians, in general, develop acute myocardial infarction (AMI) about 10 years earlier; AMI rates are threefold to fivefold higher in young Indians than in other populations. Although established CAD risk factors have a predictive value, they do not fully account for the excessive burden of CAD in young Indians. Lipoprotein(a) (Lp(a)) is increasingly recognized as the strongest known genetic risk factor for premature CAD, with high levels observed in Indians with malignant CAD. High Lp(a) levels confer a twofold to threefold risk of CAD-a risk similar to that of established risk factors, including diabetes. South Asians have the second highest Lp(a) levels and the highest risk of AMI from the elevated levels, more than double the risk observed in people of European descent. Approximately 25% of Indians and other South Asians have elevated Lp(a) levels (≥50 mg/dl), rendering Lp(a) a risk factor of great importance, similar to or surpassing diabetes. Lp(a) measurement is ready for clinical use and should be an essential part of all CAD research in Indians.

Keywords: ASCVD risk enhancing factor; Acute coronary syndrome; Acute myocardial infarction; Cardiovascular disease; Coronary artery disease; Indians; Lipoprotein(a); Lp(a)-years; Malignant coronary artery disease; Mendelian randomization; Standardized mortality ratio.

Fig. 1

Age-adjusted odds ratio for 10-yr CAD incidence of in South Asians compared with whites after adjustments for risk factors in the UK. CAD = coronary artery disease.