Abdominal Compared With Coronary Artery Calcification and Incident Cardiovascular Events and Mortality in Black Adults

BACKGROUND: Black adults show heightened cardiovascular risk compared with other groups despite comparable or lower coronary artery calcium (CAC) scores, indicating potential cardiovascular risk underestimation by CAC. Abdominal aortic calcification (AAC), preceding CAC, may predict cardiovascular events better in Black adults who are prone to early atherosclerotic cardiovascular disease and excess events at low CAC scores. METHODS: We included 2551 participants from the JHS (Jackson Heart Study) visit 2 examination (2005-2008) without cardiovascular disease, followed through 2016. Cox regression estimated hazard ratios for incident cardiovascular events defined as a composite of myocardial infarction, stroke, heart failure, and all-cause mortality. The predictive value of CAC and AAC, when added to the American College of Cardiology/American Heart Association cardiovascular risk algorithm (pool cohort equation), was assessed. RESULTS: Mean age was 57±10 years; 66% were women. Over a follow-up period of 12.6 years, 287 (11.3%) cardiovascular events and 360 (14.1%) mortality cases were observed. Adjusting for demographic and clinical variables, each 2-fold increase in CAC and AAC was associated with cardiovascular events (CAC: hazard ratio, 1.10 [95% CI, 1.06-1.13]; AAC: hazard ratio, 1.10 [95% CI, 1.06-1.13]) and all-cause mortality CAC: hazard ratio, 1.04 [95% CI, 1.01-1.08]; AAC: hazard ratio, 1.05 [95% CI, 1.01-1.08]). The incremental value of CAC (0.17 [95% CI, 0.08-0.23]) and AAC (0.15 [95% CI, 0.07-0.29]) to the pool cohort equation by net reclassification index was comparable. Notably, 45% of participants with 0 CAC showed some degree of AAC. Each 2-fold increase in AAC was associated with an increased risk of cardiovascular events (hazard ratio, 1.07 [95% CI, 1.01-1.19]) but not all-cause mortality among participants with 0 CAC. CONCLUSIONS: AAC is comparable to CAC in predicting cardiovascular events and all-cause mortality among Black adults, potentially valuable when CAC is absent.