Chang, Su Min

Backgrounds: Role of coronary artery calcium score (CACS) in acute chest pain patients is currently not well defined. The objective of this study was to investigate the prognostic value of CACS obtained by noncontrast electrocardiogram-gated CT in acute chest pain patients suspected for cardiac origin in emergency department. Methods: We search Pubmed, Embase, Cochrane databases for longitudinal studies of CACS in acute chest pain patients without known coronary artery disease (CAD) in emergency department which reported major adverse cardiovascular events (MACE), consisting of death, nonfatal myocardial infarction (NFMI), revascularization or stroke. Pooled annualized event rate, risk ratios and 95% confidence intervals (CI) were analyzed. A random-effect, generic inverse variance model was used. Result: Eight studies evaluated 3556 patients (mean age = 51 years, 47% men) with the pooled prevalence of hypertension, diabetes mellitus, dyslipidemia and smoking of 42%, 16%, 33% and 33% respectively. During a median follow-up of 5 months (range 1-60 months, 37234 patient-months), the overall pooled MACE rate was 7.6%/y. The pooled event rate of MACE for CACS=0 versus CACS>0 was 0.8%/y (13 events in 18874 patient-months) versus 14.6%/y (224 events in 18360 patient-months). The pooled risk ratio with CACS=0 was 0.04 (95% CI: 0.02-0.07, p<0.001) for MACE compared to CACS>0. The sensitivity, specificity, positive and negative predictive value, positive and negative likelihood ratio of CACS for MACE was 94.5%, 64.1%, 15.8%, 99.4%, 2.63 and 0.09 respectively. The heterogeneity among studies was low with an I 2 of 13%. Conclusion: In acute-chest-pain patients without known CAD presenting to emergency department, MACE was rare in those with CACS=0. Zero CACS by noncontrast electrocardiogram-gated CT in this population has high negative predictive value (>99%) for subsequent cardiac events.