Abstract Body (Do not enter title and authors here): Introduction: Substrate mapping may offer a safer alternative to VT mapping by avoiding prolonged episodes of VT during catheter ablation. However, VT induction to gauge procedural efficacy is still routinely attempted following substrate ablation, thereby exposing patients to potentially unnecessary hemodynamic risk.

Objective: To assess the feasibility and efficacy of VT ablation without any attempted VT induction.

Methods: Patients with ICDs who underwent VT ablation between August 2020 and May 2023 were assessed retrospectively. Ablation and induction strategies were at the operators’ discretion. Patients with or without attempted VT induction were compared with respect to 6-month VT burden reduction using univariable linear regression; and the 1-year incidence of recurrent VT, heart transplant or death using multivariable Cox regression.

Results: Eighty-nine consecutive patients (median age 68 years, 89% male, 51% infarct-related cardiomyopathy, mean LVEF 38%) were followed for a median of 16 months after VT ablation. VT induction was attempted in 63% of patients. The median (IQR) reduction in VT burden was similar in the induction and non-induction groups (96% [0%, 100%] vs. 100% [93%, 100%], p = 0.20). There was no difference between induction and non-induction groups in the 1-year incidence of recurrent VT, heart transplant or death (62% vs. 42%, HR 1.26, 95% CI 0.61-2.62, p=0.54) after adjusting for cardiomyopathy type, VT storm, pre-ablation cardiac CT/MRI, baseline creatinine, pre-ablation VT burden and the presence of NYHA Class III-IV heart failure symptoms.

Conclusion: In a single-center study of 89 consecutive VT ablations, a non-induction strategy was equally effective to an induction strategy in reducing 6-month VT burden and 1-year risk of VT recurrence, transplant or death. Our findings suggest that VT induction, recognized as a risk factor for hemodynamic compromise, may be avoided in some patients without sacrificing procedural efficacy.