Coronary Artery Calcium Dispersion and Cause-Specific Mortality

Area of Science:

• Cardiology
• Preventive Medicine
• Medical Imaging

Background:

• Coronary artery calcium (CAC) scoring is crucial for assessing subclinical atherosclerosis and refining cardiovascular risk stratification.
• Existing research suggests that specific CAC characteristics, such as vessel involvement, volume, and density, differentially influence risk.
• The impact of CAC dispersion, defined by the number of calcified vessels or CAC phenotype, on cause-specific mortality requires further investigation.

Purpose of the Study:

• To evaluate the association between CAC dispersion, encompassing the number of calcified vessels and CAC phenotype (diffuse vs. concentrated), and cause-specific mortality.
• To determine if CAC dispersion provides incremental prognostic information beyond the overall CAC score.

Main Methods:

• Retrospective analysis of the CAC Consortium cohort (n=28,147) with CAC > 0, excluding individuals with pre-existing coronary heart disease (CHD).
• Calculation of CAC area, density, and phenotype using the index of diffusion.
• Statistical assessment of the relationship between CAC characteristics and cause-specific mortality, controlling for overall CAC score.

Main Results:

• Increasing numbers of calcified vessels (dispersion) showed a graded increase in all-cause, cardiovascular disease (CVD), and CHD-specific mortality.
• A diffuse CAC phenotype, compared to a concentrated phenotype among those with multi-vessel involvement, was associated with higher CVD-specific mortality and trends toward higher all-cause and CHD-specific mortality.
• Diffuse CAC was characterized by less dense calcifications, larger CAC area, and involvement of multiple coronary vessels.

Conclusions:

• CAC dispersion, both in terms of the number of calcified vessels and the diffuse phenotype, is a significant independent predictor of increased all-cause, CVD, and CHD mortality.
• These findings highlight the prognostic importance of evaluating the spatial distribution and pattern of coronary calcifications beyond the total CAC score.