Abstract
BACKGROUND: Ten-year and lifetime cardiovascular risk assessment algorithms have been adopted into atherosclerotic cardiovascular disease (ASCVD) prevention guidelines, but these prediction models are not based on South Asian populations and may underestimate the risk in Indians, Pakistanis, Bangladeshis, Nepali, and Sri Lankans in the United States. Little is known about ASCVD risk prediction and intermediate endpoints such as subclinical atherosclerosis in US individuals of South Asian ancestry. METHODS AND RESULTS: South Asians (n=893) from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study who were 40 to 79 years and free of ASCVD were included. Ten-year ASCVD predicted risk was calculated using the 2013 Pooled Cohort Equations. Lifetime predicted risk was based on risk factor burden. Baseline levels of subclinical atherosclerosis (coronary artery calcium [CAC] and carotid intima media thickness [CIMT]) were compared across 10-year and lifetime risk strata: (1) high (≥7.5%) 10-year and low (<7.5%) 10-year risk; (2) high (≥39%) lifetime and low (<39%) lifetime risk. South Asian men and women with high 10-year predicted risk had a significantly greater CAC burden than those with low 10-year risk. South Asians with high lifetime predicted risk had a significantly increased odds for CAC higher than 0 (odds ratio: men 1.97; 95% CI, 1.2 to 3.2; women 3.14; 95% CI, 1.5, 6.6). Associations between risk strata and CIMT were also present. CONCLUSION: This study is the first to provide evidence that contemporary ASCVD risk assessment algorithms derived from non-Hispanic white and African-American samples can successfully identify substantial differences in atherosclerotic burden in US South Asians.