Ventricular Duration Map Area as a Valuable and Effective Target for VT Ablation End Point in Ischemic Cardiomyopathy: The VEDUM FREEDOM Study

Background: Ventricular electrogram duration map (VEDUM) is a new approach for the identification of the arrhythmogenic substrate critical for ventricular tachycardia (VT), and it is based on the evaluation of the prolonged bipolar electrograms. Our aim is to evaluate the prognostic role of the VEDUM area in patients with VT and ischemic cardiomyopathy. Methods: We enrolled all patients with ischemic cardiomyopathy who underwent VT ablation in 2 different centers. After isthmus transection for VT inducible, the procedure was aimed at noninducibility of any VT plus substrate modification. For each patient, we retrospectively analyzed the amount of the VEDUM area covered during catheter ablation. The primary outcome included any recurrence of sustained VT. Results: Seventy-one patients (mean age: 69.9±8.9 years; males 93%) were enrolled. The mean size of the VEDUM area was 14.6±10.3 cm2, and it was visualized in a low voltage area in 65 (91.6%) patients. A deceleration zone and late potentials were recorded inside the VEDUM area in 71.8% and 73.2%, respectively. During a mean follow-up of 24.4±13.9 months, the primary outcome occurred in 18 (25.4%) cases; the arrhythmia free-survival was significantly lower in patients with ablation of at least 75% of the VEDUM area (VEDUM <50%: 57.5%; 50% <75%: 76%; VEDUM >75%: 89.5%; log-rank P value: 0.047). The ablation of at least 50% of the VEDUM area (hazard ratio, 0.374 [0.147-0.947]; P value, 0.038) and the VT inducibility (hazard ratio, 4.087 [1.341-12.450]; P value, 0.013) represented the only predictors of VT recurrence. Conclusions: VEDUM area ablation represented a new target for catheter ablation of VT in patients with ischemic cardiomyopathy.