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).