Long-term benefit of first-line peri-implantable cardioverter-defibrillator implant ventricular tachycardia-substrate ablation in secondary prevention patients.

Abstract

This study assessed the benefit of peri-implantable cardioverter-defibrillator implant ventricular tachycardia (VT)-substrate ablation in patients with structural heart disease (SHD). Patients with SHD and indication for secondary prevention ICD implant were prospectively included. Patients presenting with incessant and/or slow VT or frequent (≥2) VT episodes who underwent peri-ICD VT-substrate ablation (the scar dechannelling technique) were compared with those who received ICD alone and did not meet ablation criteria. The primary endpoint was any sustained VT/ICD therapy during follow-up. Of 206 patients included (43.2% non-ischaemic), 70 were assigned to ablation and 136 received ICD implant alone. During a mean follow-up of 45.6 ± 24.7 months, the primary endpoint was more frequent in the non-ablation group (47.1 vs. 22.9%; P< 0.0001). Higher VT recurrence-free survival rate [log-rank P= 0.001; HR = 0.42 (0.24-0.73), P= 0.002] and ICD shock-free survival rate [log-rank P= 0.007; HR = 0.36 (0.17-0.78); P = 0.01] were observed in the ablation group. Higher relative risk reduction was observed in ischaemic [HR = 0.38 (0.18-0.83); P = 0.015] vs. non-ischaemic patients [HR = 0.49 (0.23-1.01); P = 0.08]. Patients with left ventricular ejection fraction (LVEF) <35% showed no differences in VT recurrence between treatment groups (log-rank P = 0.213) although VT burden during follow-up was lower in the ablation group [median (interquartile range) 1 (1-3) vs. 4 (1-10) VT episodes; P = 0.05]. First-line peri-ICD implant VT-substrate ablation was associated with decreased VT recurrence and ICD shocks during long-term follow-up in patients with SHD and indication for secondary prevention ICD implant, especially in ischaemic patients. In patients with LVEF <35%, no benefit was observed in terms of VT recurrence-free survival, although VT burden during follow-up was lower in the ablation group.