Statistical analysis
Frequency distribution of categorical variables are reported as frequencies and percentages. Data is presented as mean (standard deviation) or median (interquartile range) where appropriate. To compare differences of echocardiographic parameters among pulmonary hypertension categories, we performed a one-way ANOVA or Kruskal-Wallis test whether it met assumptions of parametric tests or not, and a Dunn’s post hoc test was also assessed to evaluate differences among groups.