Statistical Analysis
Continuous variables were reported as mean ± standard deviation, whereas
categorical variables were expressed as percentage values. Normal
distribution of the data was tested using the Kolmogorov-Smirnov test
and categorical variables were compared using the chi-square test.
Comparisons of normally distributed continuous variables were performed
with the Student’s t-test and the Mann Whitney-U test was used for
non-parametric continuous variables. Analysis of variance (ANOVA)
followed by the Tukey correction was used to assess difference among 3
groups. The correlation between variables was examined by Pearson’s
correlation coefficient. Multiple logistic regression analyses were
performed to define risk factors of outcome variable. All potentially
relevant confounding factors were considered all together in the model.
Intraobserver variability of echocardiographic RV functional
measurements was assessed using intraclass correlation coefficients and
coefficients of variation. P value <0.05 was considered
statistically significant. Statistical analyses were performed using the
Statistical Package for the Social Sciences statistical software
(version 25; SPSS-IBM, Chicago, IL, USA).