Effect of baseline VT inducibility on acute success and VT recurrences
PVS was performed at the end of the procedure in 129 patients (80.6%). In the remaining 31 patients PVS was not performed at the discretion of the operator because of perceived risk of hemodynamic inestabilization or previous baseline non-inducibility. Overall acute success rate of the procedure in patients with baseline VT inducibility (groups 2 and 3) and considering non-inducibility of any sustained VT was 66% (76% for group 2 and 60% for group 3, p=0.068). The clinical VT was still inducible in 6.2% of patients (4.5% and 7.7% for groups 2 and 3, respectively) and any non-clinical VT/pleomorphic/polymorphic VT or VF was present in 17.8% of patients at the end of the procedure (4.5% and 26.9% for groups 2 and 3, respectively).
Overall survival free of VT recurrence after a single procedure was 71,1% with a median follow-up of 38.5 months (IQR 16.8-63.2). There were significant differences in survival free of VT recurrence among groups depending on baseline VT inducibility: 94.4% for group 1; 84.9% for group 2 and 58% for group 3, Log-rank p<0.0001 for overall comparison, Log-rank p=0.001 for comparison between group 2 and 3 (figure 2A). Repeat procedures were performed in 31 patients (mean 1.25±0.58 procedures per patient) with an overall survival free of VT recurrence that increased to 85.6% after the last procedure with a median follow-up of 29.5 months (IQR 38.9-54.4). Group 1 survival free of VT recurrence after the last procedure remained stable at 94.4% but increased for patients in group 2 (94.3%) and group 3 (78.7%).