Statistical analysis
The Kolmogorov-Smirnov test was used to verify the normal distribution
of continuous variables. Variables with normal distribution were
described by means and standard deviations and compared by paired
Student’s t-test. For comparison of the mean LVEF after 6 months between
the groups, the unpaired t test was performed. Non-parametric variables
were described as medians and interquartile range and compared with the
the Wilcoxon test. Categorical data were presented as the number of
patients and percentage of the total sample and were compared by the
Fisher’s exact test. The overall survival was calculated by the
Kaplan-Meier method and the log-rank test was used to compare the
survival curves. A value of P <0.05 was considered as
statistically significant. To identify the variables that are
independently predictive of overall mortality, a subsequent stepwise
multivariate analysis using Cox’s regression model was performed,
including variables that had a predictive value of P-value <
0.10 in the univariate analysis of overall survival (log-rank test). The
Statistical Package for the Social Sciences (SPSS) version 20.0 was used
for the analysis of all data.