Efficacy and safety of catheter ablation of VT using the QDOT Micro catheter: a propensity-matched dual-center comparison with the thermocool SmartTouch catheter

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is an increasingly used treatment option for patients with recurrent ventricular tachycardia (VT) or electrical storm (ES). The QDOT Micro (QDOT) Catheter (Biosense Webster) is a novel radiofrequency ablation catheter that was found to allow rapid and effective pulmonary vein isolation among patients with atrial fibrillation. There is no published data on the safety and efficacy of catheter ablation for VT using the QDOT catheter, and few data allow a direct comparison of different technologies in this setting. Purpose to assess outcomes of CA for VT among patients with structural heart disease using the QDOT catheter, and compare them to those observed with the Thermocool Smarttouch (TC-ST, Biosense Webster) catheter. Methods we conducted a dual-center, observational, prospective study enrolling patients with structural heart disease and recurrent VT/ES undergoing catheter ablation with the QDOT catheter. For comparison, we performed a 1:1 propensity score matching to identify patients who underwent VT CA with the TC-ST catheter, using the nearest neighbor method. Propensity score was based on gender, age, etiology of structural heart disease, left ventricular ejection fraction, electrical storm, and number of previous CAs for VT. The primary efficacy outcome was freedom from recurrent VT, as assessed by implantable defibrillator (ICD) interrogation; the primary safety outcome was in-hospital complications. Results Forty propensity-matched patients were included in the analysis (QDOT, n=20; TC-ST, n=20); baseline clinical characteristics are resumed in Table. After a median follow-up of 7 months, survival free from any recurrent VT measured 74 (95% CI, 57-97)% and 69 (95% CI, 51-93)% in the QDOT and TC-ST groups, respectively (log-rank p=0.54, Figure A), while survival free from ICD shocks was 95 (95% CI, 86-100)% versus 84 (95% CI, 69-100)% (log-rank p=0.26, Figure B). There were no major complications in the QDOT group, while three patients (15%) in the TC-ST had a primary safety event (p=0.23; femoral pseudoaneurysm, n=1; cardiac tamponade, n=1; aortic cusp perforation, n=1). Conclusion In a cohort of patients with structural heart disease and recurrent VT or ES, the novel QDOT ablation catheter had similar efficacy and safety compared to the TC-ST catheter. Interestingly, no major procedural complications were observed with the QDOT catheter, suggesting that this device may be safe even in most challenging patients.