Trends in Successful Ablation Sites and Outcomes of Ablation for Idiopathic Outflow Tract Ventricular Arrhythmias

Abstract

This study sought to examine clinical characteristics of procedural and long-term outcomes in patients undergoing catheter ablation (CA) of outflow tract ventricular arrhythmias (OT-VAs) over 16 years. CA is an effective treatment strategy for OT-VAs. Patients undergoing CA for OT-VAs from 1999 to 2015 were divided into 3 periods: 1999 to 2004 (early), 2005 to 2010 (middle), and 2011 to 2015 (recent). Successful ablation site (right ventricular OT, aortic cusps/left ventricular OT, or coronary venous system/epicardium), VA morphology (right bundle branch block or left bundle branch block), and acute and clinical success rates were assessed. Six hundred eighty-two patients (336 female) were included (early: n=97; middle: n=204; recent: n=381). Over time there was increase in use of irrigated ablation catheters and electroanatomic mapping, and more VAs were ablated from the aortic cusp/left ventricular OT or coronary venous system/epicardium (14% vs. 45% vs. 56%; p<0.0001). Acute procedural success was achieved in 585 patients (86%) and was similar between groups (82% vs. 84% vs. 88%; p=0.27). Clinical success was also similar between groups (86% vs. 87% vs. 88%; p=0.94), but more patients in earlier periods required repeat ablation (18% vs. 17% vs. 9%; p=0.02). Overall complication rate was 2% (similar between groups). Over a 16-year period there was an increase in patients undergoing CA for OT-VTs, with more ablations performed at non-right ventricular outflow tract locations using electroanatomic mapping and irrigated-tip catheters. Over time, single procedure success has improved and complications have remained limited.