Protected ventricular tachycardia ablation in severe LV dysfunction: acute safety and efficacy in the real world

Background Patients with severely impaired left ventricular ejection fraction (LVEF) undergoing catheter ablation for ventricular tachycardia (VT) are at high risk of procedure-related acute haemodynamic decompensation. Temporary mechanical circulatory support (percutaneous left ventricular assist devices [pLVAD]) may help to stabilise haemodynamics and improve procedural safety. Purpose To evaluate the acute safety and efficacy of protected VT ablation (pVTA) supported by pLVAD in patients with severely reduced LVEF. Methods Consecutive patients with structural heart disease and severely impaired LVEF ≤30% who underwent pVTA using pLVAD (Impella CP SmartAssist at maximum possible flow level throughout the procedure) within the last 12 months at a single tertiary referral centre were retrospectively analysed. Substrate and functional mapping were performed in all patients. Activation mapping was performed if VT was haemodynamically tolerated. The primary endpoint was acute procedural safety, including death or major complications (cardiogenic shock, thromboembolic events, access-site complications, major bleeding, pericardial tamponade, intensive care unit admissions, sepsis). The secondary endpoint was non-inducibility of any sustained VT by programmed ventricular stimulation at the end of the procedure. Results Nine patients underwent pVTA with pLVAD support: mean age 68±7 years, 100% male; ischaemic 89%, non-ischaemic cardiomyopathy 11%; peripheral arterial disease (PAD) 22%. Mean LVEF was 23±6%. All patients were internal cardiac defibrillator carriers. Mean procedure duration was 256±44 minutes; mean fluoroscopy time was 25±6 minutes. The pLVAD could be weaned in all patients immediately after the procedure. A total of 18 VT morphologies were inducible. Activation mapping was successfully performed in 8/18 VTs (44%). In two patients, no VT was inducible. After ablation, 18/18 (100%) VTs were non-inducible. The primary endpoint occurred in two patients (22%): vascular access-site complications 2/9 (22%), cardiogenic shock and death 1/9 (11%). One patient had a bleeding complication due to failure of the vascular closure device, which was treated by intravascular balloon occlusion. This patient later developed cardiogenic shock due to pneumogenic sepsis and died. One patient experienced major bleeding at the access site after complicated placement of the pLVAD due to severe PAD, which was managed conservatively. Conclusions In patients with severely reduced LVEF, pVTA is feasible and results in high procedural efficacy, but may lead to major complications, mainly related to pLVAD access sites. These findings support the selective use of pLVAD in high-risk VT ablation to facilitate mapping and ablation. However, aside from improved acute procedural success, long-term data do not show a significant benefit of pLVAD usage.