Abstract 16093: Hemodynamic Implications of Transseptal Access for Ventricular Tachycardia Ablation in Patients With Left Ventricular Assist Devices

Abstract

Introduction: Ventricular tachycardia (VT) is common in patients with left ventricular assist devices (LVAD), and catheter ablation can be an effective treatment strategy. Although transseptal approach for LV mapping and ablation is often preferred, iatrogenic atrial septal defect (ASD) after transseptal access may theoretically result in clinically significant right-to-left shunting. The short- and long-term implications of transseptal puncture, including hemodynamic changes in LVAD patients, remain uncertain. Methods and Results: From 2013-2023, 15 LVAD patients (age 68.5±12 years; 2 women) underwent 18 VT ablation procedures with single transseptal access for LV ablation without ASD closure afterwards. Clinical VT was eliminated in 83%. No patients had prior PFO/ASD; Mean RVSP was 45mmHg, 6 (40%) had pulmonary hypertension, and 8 (53.3%) had moderate or severe RV dysfunction. All patients had previously failed at least 1 antiarrhythmic drug (amiodarone 100%; sotalol 33%; mexiletine 94%). Procedural complications occurred in 3 procedures (all related to vascular access, none directly related to transseptal access; 1 patient with interrupted IVC requiring transhepatic access had bleeding due to transection of intercostal artery requiring arterial embolization). Post-procedure echocardiograms (n=14; mean time to echo 90±116 days) showed no intra-cardiac shunting or persistent ASD. Right heart catheterization (pre: n=12; post: n=8, at mean follow-up 187±243 days) showed similar pre- and post-ablation RA pressures (11.6 vs 14.9 mmHg, p =0.24) and wedge pressures (14.9 vs 20.4 mmHg, p =0.8) with absence of significant shunting based on pre- and post-ablation arterial (95.2% vs 97.7%, p =0.06) and PA oxygen saturations (56.5% vs 51.3%, p =0.29). No episodes of clinically significant hypoxia occurred after ablation. Conclusion: Transseptal access for VT ablation can be safely performed in LVAD patients and is unlikely to result in clinically or hemodynamically significant residual shunting over long-term follow-up. Therefore, empiric ASD closure after transseptal access in all LVAD patients is likely unnecessary.