Role of mechanical circulatory support in VT ablation procedures: data from the German PROTECT VT registry
Authors: Wakili R , Bogossian H , Falagkari A , Guckel D , Kupusovic J , Sommer P , Vacanti G , Zarse M , Luik A , Sohns C 
Published: May 2024

Abstract

Introduction
Ventricular tachycardia (VT) ablation in patients with progressed heart failure (HF) is known to be complex and associated with a high periprocedural risk and mortality, in part due due to hemodynamic instability during ongoingVTs. Use of mechanical circulatory support (MCS) systems has been already implemented in complex high-risk percutaneous coronary intervention (CHIP-PCI) workflows. Use and benefit of MCS in VT ablation is still under debate. MCS protected VT ablation (proVT-A) might be associated with improved clinical outcomebut potentially comes along with an increased risk of periprocedural complications. Based on data of four German high-volume centers we aimed to analyze retrospective data on patient characteristics and impact of proVT-A with respect to safety and mid-term efficacy.

Methods
All patients undergoing proVT-A as a primary approach from four German EP centers were included in the analysis. Use of MCS in bailout scenariosin VT ablation were not included. Patient characteristics, procedural parameters and clinical outcome were evaluated. The primary endpoint was a combined endpoint of VT/VF recurrence and all-cause death.

Results
41 patients who underwent proVT-A were included. Mean age was 64±11a, 92% of patients were male (38/41), 65% (27/41) suffered from ischemic cardiomyopathy, mean left ventricular ejection fraction was 33±13%,76% (31/41) of patients presented with a documented hemodynamically not tolerated VT, mean PAAIN-ESD score was 13±7, and 46% (19/41) had a history of a previous VT ablation w/o MCS. During proVT-A procedure at least one VT was inducible and mappable in 35 patients (85%). Acute procedural success was 85%, with only n=6 patients remaining inducible for VT. Mean procedure duration was 245±46min. With respect to periprocedural safety (30days)a total of n=12 relevant procedural complications were reported in 8 patients. This included n=5 vascular access complications, of which n=3 requiring transfusion or surgery. One case of periprocedural death was reported 6h post proVT-A due to PEA. Three patients developed pericardial effusion, one requiring drainage. Freedom from VT/VF was 78% (n=9 VT/VF recurrences) after a mean follow-up (FU) of 15±14 months (figure 1A). Death of any cause occurred in n=9 patients (figure 1B). In summary, after a mean FU of 15±14 months n=16 patients (39%) met the combined endpoint of VT/VF recurrence and all-cause death (figure 1C).

Conclusion
Patients enrolled in the German PROTECT VT Registry had significant cardiovascular comorbidities and therefore represent a high-risk population for VT ablation. Use of MCS was feasible, comparably safe, associated with high procedural and promising long-term success rate. These results highlight the need for larger registries and future prospective trials evaluating the potential benefit of proVT-A in selected patients. Further, it should be aimed for optimization of periprocedural vascular access site management.