Statistical Analysis
SPSS 16.0 statistical analysis software was used for statistical analysis. All continuous data were expressed as mean ± standard deviation (±S). Paired data following a normal distribution were analyzed using t-tests, while independent samples were analyzed using independent sample t-tests. Binary logistic regression analysis was performed to select valuable S and Sr parameters for detecting viable myocardium. Receiver operating characteristic (ROC) curves were used to calculate the area under the curve (AUC) and determine the optimal cutoff points, sensitivity, specificity, and accuracy for diagnosing viable myocardium. Chi-square test was used for intergroup comparison of rates. A p-value ≤0.05 was considered statistically significant, with a significance level of α=0.05.
Additional methods can be found in SI Appendix, SI Materials and Methods.