Association between coronary artery calcium and all-cause mortality: A large single-center retrospective cohort study

OBJECTIVE: Previous studies have revealed that coronary artery calcium is related to cardiovascular diseases and mortality. However, most studies have been conducted in Western countries and have excluded patients with pre-existing heart disease. We investigated the association between coronary artery calcium (CAC) and all-cause mortality in an Asian cohort and in subgroups stratified by age, sex, smoking, obesity, diabetes, cardiovascular disease, blood pressure, and biochemical parameters. METHODS: We conducted a retrospective cohort study on 4529 health examinees who underwent multidetector computed tomography in a tertiary medical center in Taiwan between 2011 and 2016. The mean follow-up was 3.5 years. Cox regression was used to estimate the relative hazards of death. Stratified analyses were performed. RESULTS: The all-cause mortality rates were 2.94, 4.88, 17.6, and 33.1 per 1000 person-years for CAC scores of 0, 1–100, 101–400, and >400, respectively. The multivariable adjusted hazard ratios (95% confidence intervals [CIs]) for all-cause mortality were 0.95 (0.53, 1.72), 1.87 (0.89, 3.90), and 3.05 (1.46, 6.39) for CAC scores of 1–100, 101–400, and >400, respectively, relative to a CAC score of 0. Compared with CAC ≤ 400, the HRs (95% CIs) for CAC > 400 were 6.46 (2.44, 17.15) and 1.94 (1.00, 3.76) in younger and older adults, respectively, indicating that age was a moderating variable (p = 0.02). CONCLUSION: High CAC scores were associated with increased all-cause mortality. Although older adult patients had higher risks of death, the relative risk of death for patients with CAC > 400 was more prominent in people younger than 65 years.