2.6. Statistical Analysis
REGRESSION
The sample size was calculated with an expected incidence of GLS reduction of 20% with the use of AC and an expected reduction to 10% with the addition of ivabradine [Descriptive statistics such as frequency tables and medians (Q1–Q3) were used to describe quantitative and qualitative data. The Kolmogorov–Smirnov test was used to assess the normality of the data. Most parameters were non-normally distributed, so non-parametric statistical analyses were chosen. The Fisher exact test assessed differences between treatment groups and categorical clinical parameters. The Mann–Whitney U test evaluated differences between treatment groups and continuous parameters. The Wilcoxon signed-rank test was used to compare baseline clinical parameter values with the same parameter values at different time points. The univariate logistic regression model was used to evaluate the odds ratio of ivabradine administration. A two-tailed 