Point-by-point versus multisite electrode mapping in VT ablation: does freedom from VT recurrences depend on mapping catheter? An observational study.

PURPOSE: This study was conducted with the purpose of determining whether or not the potential technical advantages of multi-electrode mapping catheters in catheter ablation (CA) of ventricular tachycardia (VT) result in any relevant clinical benefit for VT patients.

METHODS: A single-center VT study, having taken place from 2012 to 2014 using a standard 3.5-mm catheter (Thermocool SF® group 1) and from 2014 to 2016 using a 1-mm multi-electrode-mapping catheter (PentaRay® group 2), was conducted. The endpoint was the complete elimination of late potentials (LPs), local abnormal ventricular activities (LAVA), and VT non-inducibility. Follow-up consisted of device interrogation to monitor for VT recurrence.

RESULTS: Out of 74 VT patients aged 64.5 ± 12.0 years (66 male [89.2%], 56 with ICM [75.7%], and 18 with NICM [24.3%)]), 48 patients (64.9%) were investigated in group 1 and 26 (35.1%) in group 2. Using the multi-point acquisition approach, a tendency to require less mapping time (group 1 65.2 ± 37.6 min, group 2 55.6 ± 34.4 min, p ns) was determined. During 12-month follow-up, 57 patients had freedom from VT recurrences (79.2%). The result was insignificant between the groups (38 patients (79.2%) in group 1 and 19 patients (73.1%) in group 2).

CONCLUSIONS: In a single-center observational study, both conventional and high-density mapping approaches in VT patients are comparable in terms of procedure duration and outcome. Mapping time when using a multi-electrode catheter seems to have the tendency of being shorter. We should be encouraged to recruit more patients comparing the benefit of different catheter types.