Significance of coronary artery calcification for predicting major adverse cardiovascular events: results from the NADESICO study in Japan.

Background: We aimed to determine the usefulness and sex differences of assessment of coronary artery calcification (CAC) with cardiovascular risk factors and major adverse cardiovascular events (MACE) in Japanese patients.

Methods: In a nationwide, multicenter, prospective cohort study, 1187 patients with suspected coronary artery disease who underwent coronary computed tomography were enrolled. MACE included cardiovascular death, myocardial infarction, stroke, revascularization, and hospitalization for unstable angina, heart failure, or aortic disease. The concordance (C)-statistics were used to assess the relationships among the Suita risk score, CAC score, and incident MACE, with emphasis on sex differences.

Results: The final analysis included 982 patients (mean age, 64.7 ± 6.6 years; male patients, 53.9 %). MACE developed in 65 male and 21 female patients during a median follow-up of 1480 days. The C-statistics calculated using Suita score for MACE were 0.650, 0.633, and 0.569 in overall, male, and female patients, respectively. In overall patients, the C-statistic significantly increased in combined models of Agatston CAC scores of ≥100, 200, 300, or 400 and the Suita score. In each sex, the C-statistics significantly increased in the model that added an Agatston CAC score of ≥100 and ≥200 (+0.049 and +0.057) in male patients, and ≥400 (+0.119) in females, respectively.

Conclusions: Adding assessment of Agatston CAC scores to Suita score was useful to improve the predictive ability for future MACE in Japanese patients. Agatston CAC scores of ≥100 or 200 in male and ≥400 in female patients in addition to Suita score improved the MACE risk prediction.