Ablation Index as a predictor of long-term efficacy in premature ventricular complex ablation: A regional target value analysis

BACKGROUND The effectiveness of radiofrequency catheter ablation (RFCA) in atrial tachyarrhythmias correlates with lesion transmurality. Ablation Index (AI) is an index that incorporates contact force, time, and radiofrequency power simultaneously and is able to predict lesion size and outcomes in RFCA of atrial fibrillation. OBJECTIVE The purpose of this study was to assess whether AI could be an acute and long-term success predictor in RFCA of premature ventricular complexes (PVCs). METHODS One hundred forty-five patients with idiopathic outflow tract PVCs undergoing RFCA were retrospectively enrolled. The maximum and maximum AI values were calculated for each ablation site. Acute and 6-month outcomes were analyzed. Patients were divided into 3 outcome subgroups-success, acute failure, and 6-month failure-and the maximum and mean AI values were compared. RESULTS Acute and 6-month success rates were 95% and 77%, respectively. The maximum and mean AI values were statistically higher in the success group (median of the maximum AI 630 [IQR 561-742]; median of the mean AI 489 [IQR 411-560]) than in the acute failure group (median of the maximum AI 487 [IQR 445-583]; median of the mean AI 372 [IQR 332-434]; P < .0001 for both) and the 6-month failure group (median of the maximum AI 519 [IQR 476-568]; median of the mean AI 410 [IQR 368-472]; P < .0001 for both). Both maximum and mean AI values were confirmed to be statistically higher in the success group than in the failure/6-month failure group (P = .001 and P = .04, respectively) and right ventricular free wall (P = .007 and P = .01, respectively) PVC origin subgroups. CONCLUSION Our data support the concept that AI could be a long-term success predictor in RFCA of PVCs. However, further prospective studies are required to assess the feasibility of the AI-guided PVC ablation approach.