Objectives

This study sought to evaluate the association and burden of coronary artery calcium (CAC) with long-term, cause-specific mortality across the spectrum of baseline risk.

Background

Although CAC is a known predictor of short-term, all-cause mortality, data on long-term and cause-specific mortality are inadequate.

Methods

The CAC Consortium cohort is a multicenter cohort of 66,636 participants without coronary heart disease (CHD) who underwent CAC testing. The following risk factors (RFs) were considered: 1) current cigarette smoking; 2) dyslipidemia; 3) diabetes mellitus; 4) hypertension; and 5) family history of CHD.

Results

During the 12.5-years median follow-up, 3,158 (4.7%) deaths occurred; 32% were cardiovascular disease (CVD) deaths. Participants with CAC scores ≥400 had a significantly increased risk for CHD and CVD mortality (hazard ratio [HR]: 5.44; 95% confidence interval [CI]: 3.88 to 7.62; and HR: 4.15; 95% CI: 3.29 to 5.22, respectively) compared with CAC of 0. Participants with ≥3 RFs had a smaller increased risk for CHD and CVD mortality (HR: 2.09; 95% CI: 1.52 to 2.85; and HR: 1.84; 95% CI: 1.46 to 2.31, respectively) compared with those without RFs. Across RF strata, CAC added prognostic information. For example, participants without RFs but with CAC ≥400 had significantly higher all-cause, non-CVD, CVD, and CHD mortality rates compared with participants with ≥3 RFs and CAC of 0.

Conclusions

Across the spectrum of RF burden, a higher CAC score was strongly associated with long-term, all-cause mortality and a greater proportion of deaths due to CVD and CHD. Absence of CAC identified people with a low risk over 12 years of follow-up, with most deaths being non-CVD in nature, regardless of RF burden.

Background and aims

South Asian (SA) ethnicity is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). However, the implications of considering SA ethnicity as a "risk-enhancing factor" per recent American College of Cardiology/American Heart Association guidelines are not fully understood.

Methods

We used data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, a community-based cohort study of individuals of SA ancestry living in the US. The Pooled Cohort Equations were used to estimate 10-year ASCVD risk. Metabolic risk factors and coronary artery calcium (CAC) scores were assessed.

Results

Among 1114 MASALA participants included (median age 56 years, 48% women), 28% were already using a statin at baseline, 25% had prevalent diabetes, and 59% qualified for 10-year ASCVD risk assessment for statin allocation purposes. The prevalence of low, borderline, intermediate, and high estimated ASCVD risk was 65%, 11%, 20% and 5%, respectively. Among participants at intermediate risk, 30% had CAC = 0 and 37% had CAC>100, while among participants at borderline risk, 54% had CAC = 0 and 13% had CAC>100. Systematic consideration of intermediate and, particularly, of borderline risk individuals as statin candidates would enrich the statin-consideration group with CAC = 0 participants up to 35%. Prediabetes and abdominal obesity were highly prevalent across all estimated risk strata, including among those with CAC = 0.

Conclusions

Our findings suggest that systematic consideration of borderline risk SAs as statin candidates might result in considerable overtreatment, and further risk assessment with CAC may help better personalize statin allocation in these individuals. Early, aggressive lifestyle interventions aimed at reducing the risk of incident diabetes should be strongly recommended in US SAs, particularly among those considered candidates for statin therapy for primary prevention. Longitudinal studies are needed to confirm the favorable prognosis of CAC = 0 in SAs.