Social disadvantage, coronary artery calcium, and their interplay in the prediction of atherosclerotic cardiovascular disease events

BACKGROUND AND AIMS

Social determinants of health (SDOH) are key for the identification of populations at increased risk of atherosclerotic cardiovascular disease (ASCVD). However, whether at the individual level SDOH improve current ASCVD risk prediction paradigms beyond traditional risk factors and the coronary artery calcium (CAC) score, is unknown. We evaluated the interplay between CAC and SDOH in ASCVD risk prediction.

METHODS

MESA is a prospective study of US adults free of clinical ASCVD at baseline. We used an SDOH index inclusive of 14 determinants from 5 domains. The index ranged 0-1 and was divided into quartiles, with higher ones representing worse SDOH. Cox regression was used to evaluate the adjusted associations between CAC, SDOH, their interplay, and ASCVD events. The C-statistic was computed to assess improvement in risk discrimination for prediction of ASCVD events.

RESULTS

We included 6479 MESA participants (50% with CAC = 0, 24% CAC>100). ASCVD incidence increased with increasing CAC scores across SDOH quartiles. The lowest incidence was noted in those with CAC = 0 and favourable SDOH (2/1000 person-years) and highest in those with CAC>100 and most unfavourable SDOH (20.6/1000 person-years). While CAC was strongly associated with ASCVD across SDOH quartiles, SDOH was weakly associated with ASCVD across CAC strata. CAC improved the discriminatory ability of all prediction models beyond traditional risk factors, the improvement in C-statistic ranging +0.02 - +0.05. Improvements with SDOH were smaller, and were none on top of CAC.

CONCLUSIONS

CAC improves ASCVD risk stratification across the spectrum of social vulnerability, while SDOH fail to improve risk prediction beyond traditional RFs and CAC.

Role of coronary artery calcium score in the primary prevention of cardiovascular disease

First developed in 1990, the Agatston coronary artery calcium (CAC) score is an international guideline-endorsed decision aid for further risk assessment and personalized management in the primary prevention of atherosclerotic cardiovascular disease. This review discusses key international studies that have informed this 30 year journey, from an initial coronary plaque screening paradigm to its current role informing personalized shared decision making. Special attention is paid to the prognostic value of a CAC score of zero (the so called "power of zero"), which, in a context of low estimated risk thresholds for the consideration of preventive therapy with statins in current guidelines, may be used to de-risk individuals and thereby inform the safe delay or avoidance of certain preventive therapies. We also evaluate current recommendations for CAC scoring in clinical practice guidelines around the world, and past and prevailing barriers for its use in routine patient care. Finally, we discuss emerging approaches in this field, with a focus on the potential role of CAC informing not only the personalized allocation of statins and aspirin in the general population, but also of other risk-reduction therapies in special populations, such as individuals with diabetes and people with severe hypercholesterolemia.