Statistical analysis Categorical baseline characteristics, expressed as numbers and percentages, will be compared using the chi-square test. Continuous variables, expressed as mean and standard deviation (SD), will be compared using the 2-tailed t test and analysis of variance if normally distributed or by means of the Kruskal-Wallis method if not normally distributed. A composite end-point of MACE will be used (cardiac death, non-fatal infarction, unstable angina). Cumulative event rates as a function of time were obtained by means of the Kaplan-Meier method. Event curves of MACE will be compared using the log-rank test. Cox regression analysis will be used to identify associations between clinical characteristics and CTCA variables and outcome. Univariate and multivariate analyses will be performed to identify potential predictors. In the multivariate analysis will be included only variables which were significant at univariate analysis. Hazard ratios will be calculated with 95% confidence intervals as an estimate of the risk associated with a particular variable. Statistical analyses will be performed using Excel 2007 software (Microsoft, United States), MedCalc software (version 8.0, United States), STATA software (version 10, United States), SPSS software (version 12.0, United States). p values <0.05 will be considered statistically significant.