Po-03-070 ripple-vt study: multicentre, prospective evaluation of ventricular tachycardia substrate ablation by targeting scar channel entrances to eliminate latest scar potentials without direct ablation

Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction. Better defining this arrhythmic substrate could help improve outcome and reduce ablation burden. We tested the hypothesis that limiting ablation within post-infarct scar to the entrances of functional channels within the scar can reduce VT recurrence. Patients undergoing catheter ablation for recurrent implantable defibrillator (ICD) therapy for post-infarct VT were recruited at 5 centres. 3D Ripple maps of the left ventricle were collected on CARTO™ using a Pentaray™ catheter. Ablation was delivered sequentially to areas exhibiting earliest Ripple bars within scar. Successful ablation of a Ripple channel entrances was defined as loss of the latest potentials within scar without their direct ablation. The primary outcome measure was sustained VT episodes as documented by device interrogations at 1yr and was compared with VT episodes in the year pre-ablation. 50 pts were recruited (mean LVEF 32.9±9.5%.) and 37pts (74%) had loss of latest SPs without direct ablation. There were 3 deaths and 7 recurrences during 1 yr follow up. 45 pts completed 1 yr follow up and their pre-ablation VT burden significantly reduced from 41.6±12.5 to 4.4±2.6 (p<0.001) per patient, as did the shock burden from 2.4±0.5 to 0.13±0.1(p<0.001). The patients not reaching the channel entrance block endpoint, required more extensive ablation 39.9±6.1 vs 25.7±4.2 mins (p=0.001) and had similar recurrence rates 2 (18%) vs 5 (15%) p>0.05. Figure 1 summarizes findings. Scar channel entrance ablation is feasible using Ripple Mapping and can be an alternative to more extensive substrate modification techniques.