Background: 

The prognostic value of noninvasive programmed ventricular stimulation (NIPS) to predict recurrences of ventricular tachycardia (VT) is under discussion. Optimal endpoints of VT ablation are not well defined and optimal timepoint of NIPS is unknown. The goal of this study was to evaluate the ability of noninvasive programmed stimulation (NIPS) after ventricular tachycardia (VT) ablation to identify patients at high risk of recurrence.

Methods: 

Between January 2018 and February 2022 consecutive patients with VT and structural heart disease undergoing ablation were included. In total, 421 patients were included. Of them, 72 (17%) had clinical VT still inducible at the end of the procedure and 10 (2%) had spontaneous VT recurrence. Of the remaining, 99 underwent NIPS through their implanted ICDs after a mean of 2.2 ± 3.1 days after ablation. At at least 2 drive cycles lengths (500 and 400ms) single, double, triple and quadruple right ventricular extrastimuli were delivered to refractoriness. Clinical VT was defined by comparison with 12-lead electrocardiograms and stored ICD electrograms from spontaneous VT episodes. Patients were followed for mean 4.8 ± 2.3 years. 

Results: 

76 (76%) of all patients had ischemic cardiomyopathy (ICM), 23 (23%) patients had non-ischemic cardiomyopathy (NICM). 75 patients (75%) had no VT inducible at NIPS, 20 (20%) had only non-clinical VT inducible and only 4 patients (4%) still had clinical VT inducible. Overall, VT-free survival was 55% with higher VT recurrence rates among NICM patients (58% vs. 42%; log-rank p=0.005). Patients with inducible VT at NIPS had markedly decreased VT-free survival compared to those with VT non-inducibility (62% vs. 39%; p=0.050). Those patients with inducible clinical VT had the highest risk for VT recurrences (100%). 

Conclusions: 

In patients after VT ablation and structural heart disease NIPS can be a considered to further stratify the risk of VT recurrences. If clinical CT is inducible with NIPS early repeat ablation may be considered because recurrence rates are high.