Discordance between 10-year cardiovascular risk estimates using the ACC/AHA 2013 estimator and coronary artery calcium in individuals from 5 racial/ethnic groups: Comparing MASALA and MESA

Abstract

Background and aims: South Asian (SA) individuals are thought to represent a group that is at high-risk for atherosclerotic cardiovascular disease (ASCVD). However, the performance of the Pooled Cohort Equations (PCE) remains uncertain in SAs living in the US. We aimed to study the interplay between predicted 10-year ASCVD risk and coronary artery calcium (CAC) in SAs compared to other racial/ethnic groups.

Methods: We studied 536 SAs from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, and 2073 Non-Hispanic Whites (NHWs), 1514 African Americans (AAs), 1254 Hispanics, and 671 Chinese Americans (CAs) from the Multi-Ethnic Study of Atherosclerosis (MESA) who were not currently on statins. We used logistic regression models to assess the association between race/ethnicity and CAC within each ASCVD risk stratum.

Results: SAs at low and at intermediate estimated ASCVD risk were more likely to have CAC = 0 compared to NHWs, while SAs at high risk had a similar CAC burden to NHWs. For example, intermediate-risk SAs had a 73% higher odds of CAC = 0 compared to NHWs (95% 1.00-2.99), while high-risk SAs were equally likely to have CAC = 0 (OR 0.95, 95% CI 0.65-1.38) and CAC >100 (OR 0.86, 95% CI 0.61-1.22).

Conclusions: Our results suggest that the extent of ASCVD risk overestimation using the PCEs may be even greater among SAs considered at low and intermediate risk than among NHWs. Studies with incident ASCVD events are required to validate and/or recalibrate current ASCVD risk prediction tools in this group.

Keywords: Atherosclerosis; Cardiovascular disease; Coronary artery calcium; Race/ethnicity; Risk; South Asian.

Figure 1.

Flowchart diagram demonstrating inclusion/exclusion criteria in each cohort to derive the final study population We excluded participants older than 80 years and those already taking statins. To allow direct comparisons between the two studies, MASALA participants aged <45 years were also excluded from the analysis as the minimum age of MESA participants at enrollment was 45 years. Finally, individuals with missing information on any of the variables used by the 2013 ACC/AHA PCE were excluded.

Figure 2.

Distribution of categories. (A) Distribution of low (<5%), intermediate (5 to 7.5%) and high (≥7.5%) 10-year estimated ASCVD risk categories by racial/ethnic group. (B) Distribution of clinically relevant coronary artery calcium categories (0, 1 – 100, >100), by racial/ethnic group. (C) Distribution of clinically relevant coronary artery calcium categories (0, 1 – 100, >100), by racial/ethnic group and ASCVD risk categories. Data are presented as percentages. AA = African American; CA = Chinese American; NHW = Non-Hispanic White; SA = South Asian; ASCVD = atherosclerotic cardiovascular risk disease; CAC = coronary artery calcium.