Competing Cardiovascular Outcomes Associated With Subclinical Atherosclerosis (from the Multi-Ethnic Study of Atherosclerosis)

Subclinical atherosclerosis measured by coronary artery calcium (CAC) is associated with increased risk for multiple cardiovascular disease (CVD) outcomes and non-CVD death simultaneously. The aim of this study was to determine the competing risks of specific CVD events and non-CVD death associated with varying burdens of subclinical atherosclerosis. A total of 3,095 men and 3,486 women from the Multi-Ethnic Study of Atherosclerosis (MESA), aged 45 to 84 years, from 4 ethnic groups were included. Participants were stratified by CAC score (0, 1 to 99, and ≥100). Competing Cox models were used to determine competing cumulative incidences and hazard ratios within a group (e.g., those with CAC scores ≥100) and hazard ratios for specific events between groups (e.g., CAC score ≥100 vs 0). Risks were compared for specific CVD events and also against non-CVD death. In women, during a mean follow-up period of 7.1 years, the hazard ratios for any CVD event compared with a non-CVD death occurring first for CAC score 0 and CAC score ≥100 were 1.40 (95% confidence interval 0.97 to 2.04) and 3.07 (95% confidence interval 2.02 to 4.67), respectively. Coronary heart disease was the most common first CVD event type at all levels of CAC, and coronary heart disease rates were 9.5% versus 1.6% (hazard ratio 6.24, 95% confidence interval 3.99 to 9.75) for women with CAC scores ≥100 compared with CAC scores of 0. Similar results were observed in men. In conclusion, at all levels of CAC, coronary heart disease was the most common first CVD event, and this analysis represents a novel approach to understanding the temporal sequence of cardiovascular events associated with atherosclerosis.