Characterization of the phrenic nerve course within the epicardial substrate of patients with nonischemic cardiomyopathy and ventricular tachycardia

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION Catheter ablation outcomes for drug-resistant ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) are suboptimal when compared to ischemic cardiomyopathy. We aimed to analyse the long-term efficacy and safety of percutaneous catheter ablation in this subset of patients. METHODS Single-center observational retrospective registry including consecutive NICM patients who underwent catheter ablation for drug-resistant VT during a 10-year period. The efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. Independent predictors of VT recurrence were assessed by Cox regression. RESULTS In a population of 68 patients, most were male (85%), mean left ventricular ejection fraction (LVEF) was 34 ± 12%, and mean age was 58 ± 15 years. All patients had an implantable cardioverter-defibrillator. Twenty-six (38%) patients underwent epicardial ablation (table 1). Over a median follow-up of 3 years (IQR 1-8), 41% (n = 31) patients had VT recurrence and 28% died (n = 19). Multivariate survival analysis identified LVEF (HR= 0.98; 95%CI 0.92-0.99, p = 0.046) and VT storm at presentation (HR = 2.38; 95%CI 1.04-5.46, p = 0.041) as independent predictors of VT recurrence. The yearly rates of VT recurrence and overall mortality were 21%/year and 10%/year, respectively. No patients died at 30-days post-procedure, and mean hospital length of stay was 5 ± 6 days. The complication rate was 7% (n = 5, table 1), mostly in patients undergoing epicardial ablation (4 vs 1 in endocardial ablation, P = 0.046). CONCLUSION LVEF and VT storm at presentation were independent predictors of VT recurrence in NICM patients after catheter ablation. While clinical outcomes can be improved with further technical and scientific development, a tailored endocardial/epicardial approach was safe, with low overall number of complications and no 30-days mortality. Abstract Figure.

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Abstract 16668: Long-term Outcomes After Endo-epicardial Catheter Ablation of Ventricular Tachycardia in Nonischemic Cardiomyopathy

Circulation ◽

10.1161/circ.132.suppl_3.16668 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Erica S Zado ◽

Pasquale Santangeli ◽

Francis E Marchlinski

Keyword(s):

Ventricular Tachycardia ◽

Catheter Ablation ◽

Substantial Improvement ◽

Nonischemic Cardiomyopathy ◽

Term Outcome ◽

Long Term Outcome ◽

Linear Ablation ◽

Long Term Follow Up

Introduction: Endo-epicardial catheter ablation of ventricular tachycardia (VT) in patients (pts) with nonischemic cardiomyopathy (NICM) has been reported to have satisfactory results at the short- and mid-term follow-up. We sought to determine the outcomes at the long-term follow-up of endo-epicardial ablation of VT in NICM. Hypothesis: Catheter ablation provides satisfactory long term outcome Methods: We prospectively enrolled 128 pts (age 59±13 years, 116 [91%] males) with NICM who underwent endo-epicardial radiofrequency catheter ablation at our Institution. After substrate mapping, all critical sites for the clinical or induced VT(s), identified with activation, entrainment or pace-mapping, together with late, split and fractionated potentials were targeted with focal and/or linear ablation. The procedural endpoint was noninducibility of sustained monomorphic VT. Pts were followed with ICD interrogation. Results: A total of 108 (73%) pts had idiopathic dilated NICM. The remaining 20 (14%) pts had hypertrophic CM (n=11), suspected inflammatory CM (n=6), or valvular CM (n=3). The mean LV ejection fraction was 33±15%. After a mean follow-up of 19 months (max 97 months), a total of 36 (28%) pts died and 17 (13%) underwent heart transplant. Cumulative survival free from any recurrent VT was 53% (68/128 patients) (Figure A). In the remaining 60 (47%) patients with VT recurrences, catheter ablation still resulted in a significant beneficial clinical impact on VT burden, with 25/60 (42%) having only isolated (1-2) VT episodes over follow-up, and a striking reduction of VT storm in the remaining pts (Figure B). Conclusions: In patients with NICM and VT, endo-epicardial substrate-based ablation is effective in achieving long-term freedom from any VT in 53% of patients, with a substantial improvement in VT burden in many of the remaining patients.

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