Follow-up
All patients included had a clinical follow-up after the procedure until hospital discharge. Then, patients were followed in the arrhythmia clinic every 6 months and whenever considered necessary. All patients with a previous ICD were included in a remote monitoring program.
Statistical Analysis
Data are presented as mean ± standard deviation or median and interquartile range (IQR) for continuous variables. Discrete variables are presented as percentage and were compared using Chi-square test while continuous variables were compared using either the t- Student test or analysis of varianze (ANOVA) as appropriate. VT recurrence free survival was calculated using the Kaplan–Meier method with differences between groups compared with the log-rank test. Time-to-event was defined as time from procedure to occurrence of outcome event. Death from any cause within the follow-up period was considered for mortality analysis and was censored at date of death for VT recurrence endpoint. To identify predictors of VT recurrence and death univariate and multivariate Cox proportional hazards models were used. For multivariate analysis, variables traditionally associated with VT recurrences and with a P value ≤ 0.15 in the univariate analysis were included in the model. HR and 95% confidence intervals (CI) from the Cox model were reported. Two-tailed P values < 0.05 were considered statistically significant. All analyses were performed by using SPSS (IBM SPSS Statistics, Version 22.0, Armonk, New York, USA).