Predictors of long-term ventricular tachyarrhythmia recurrence after combined endo-epicardial ablation in patients with structural heart disease

Abstract

Purpose. To identify predictors of ventricular tachycardia (VT) recurrence after endo-epicardial ablation in patients with structural heart disease.Methods. A prospective observational study included 39 patients with structural heart disease and indications for catheter ablation of ventricular tachyarrhythmia. Endo- and epicardial electroanatomical mapping of the ventricular myocardium and ablation of abnormal electrical activity areas were performed. Clinical, ECG characteristics, and voltage maps of bipolar potentials (limits of scar detection <0.5 mV, normal activity >1.5 mV) and unipolar signals (limits <5.0 and >9.0 mV, respectively) on endo- and epicardial surfaces were evaluated. Intraprocedurally, the procedure was considered effective when no VT was inducible; partially effective - when only clinical VT(s) was/were non-inducible. Scheduled patient visits or remote monitoring were performed at 6, 12 and 24 months, and then annually.Results. The mean age of the patients was 49.5±15.7 years (34 men and 5 women). VT recurrences at 6 months were more often detected in non-ischemic cardiomyopathy patients, in subjects with non-paroxysmal atrial fibrillation (42.9% vs. 7.4%), with a lower VT-QRS amplitude in lead III (0.6 [0.4;1.07] versus 1.28 [0.99; 1.53] mV), and when epicardial “scar” area prevailed over endocardial, P<0.05 for all listed parameters. At 12-months, VT recurrence was more common in patients with partially effective ablation (33.3% vs. 5.0% in patients with effective ablation, P=0.02). The presence of electrical storm at the time of ablation was independently associated with recurrences (HR 4.32; 95% CI: 1.06-17.48; P=0.04).Conclusion. In a heterogeneous group of patients, clinical and electrophysiological factors associated with VT recurrence have been identified at various follow-up periods after endo-epicardial ablation. Electrical storm ablation is an independent predictor of VT recurrence in the long-term, up to 5 years of follow-up.