Prognostic value of the coronary artery calcium score in suspected coronary artery disease: a study of 644 symptomatic patients

AIM: The long-term value of coronary artery calcium (CAC) scanning has not been studied extensively in symptomatic patients, but was evaluated by us in 644 consecutive patients referred for stable chest pain. METHODS: We excluded patients with a history of cardiovascular disease and with a CAC score of zero. CAC scanning was done with a 16-row MDCT scanner. Endpoints were: (a) overall mortality, (b) mortality or non-fatal myocardial infarction and (c) the composite of mortality, myocardial infarction or coronary revascularisation. Revascularisations within 1 year following CAC scanning were not considered. RESULTS: The mean age of the 320 women and 324 men was 63 years. Follow-up was over 8 years. There were 58 mortalities, while 22 patients suffered non-fatal myocardial infarction and 24 underwent coronary revascularisation, providing 104 combined endpoints. Cumulative 8‑year survival was 95% with CAC score <100, 90% in patients with CAC score >100 and <400, and 82% with CAC score ≥400 Agatston units. Risk of mortality with a CAC score >100 and ≥400 units was 2.6 [95% confidence interval (CI) 1.23–5.54], and 4.6 (95% CI 2.1–9.47) respectively. After correction for clinical risk factors, CAC score remained independently associated with increased risk of cardiac events. CONCLUSIONS: Risk increased with increasing CAC score. Patients with CAC >100 or ≥400 Agatston units were at increased risk of major adverse cardiac events and are eligible for preventive measures. CAC scanning provided incremental prognostic information to guide the choice of diagnostic and therapeutic options in many subjects evaluated for chest pain.