Catheter Ablation -> Ventricular Arrhythmias -> Clinical Trials / Outcomes D-PO05 - Poster Session V (ID 39) Poster

D-PO05-197 - Long-term Outcome And Mode Of Recurrence For Patients With Inducible Non-clinical Ventricular Tachycardia During Noninvasive Programmed Stimulation Performed After Ventricular Tachycardia Ablation (ID 1306)


Background: Although induction of clinical ventricular tachycardia (VT) during noninvasive programmed stimulation (NIPS) performed after VT ablation has been reported to predict >70% risk of recurrence (compared to <20% among those with no inducible VT), the significance of inducing non-clinical VT remains unclear.
Objective: To investigate the long-term outcome and mode of recurrence for patients with inducible non-clinical VT at NIPS.
Methods: We analyzed patients who underwent VT ablation between 2013 and 2016. NIPS was typically performed off antiarrhythmic drugs, median 3 (2-3) days following ablation, prior to hospital discharge. NIPS response was classified into three groups: clinical VT inducible, only non-clinical VT inducible and no VT inducible. Induced VTs were classified as clinical vs. nonclinical based on comparison to 12-lead ECG and/or ICD EGM of spontaneous episodes.
Results: Of 555 patients who underwent VT ablation, NIPS was performed in 290 (52%). Nonclinical VT was induced in 82 (28%) patients (44 with ischemic cardiomyopathy [ICM] and 38 with non-ischemic cardiomyopathy [NICM]). Interestingly, programmed stimulation at the end of ablation did not induce any VT in 42 (57%) of these 82 patients. VT recurred in 34 (41%) of the 82 patients over median follow-up 1.4 (0.2-4.0) years. In univariate Cox proportional hazard modelling, NICM (HR 2.9, 95% CI 0.16-0.70, p<0.01) was the only factor predictive of shorter time to recurrence among patients with inducible non-clinical VT. Neither cycle length of the non-clinical VT induced at NIPS nor the number of required extrastimuli predicted recurrence. The recurrent VT morphology was identical to the non-clinical VT induced during NIPS in 14 (56%) of the 25 patients with recurrent VT in whom the morphology could be compared. Recurrent VT was identical to the non-clinical VT induced at NIPS in 3 (33%) of 9 patients with ICM and 11 (69%) of 16 patients with NICM.
Conclusion: Induction of non-clinical VT during NIPS following VT ablation predicts an intermediate risk of long-term recurrence. Non-clinical VT induced at NIPS not only suggests residual arrhythmogenic substrate, but also may become a future clinical VT, particularly in patients with NICM.