Digital Twin Guided Ventricular Tachycardia Ablation: Design and Rationale of the APOLO‐VT Trial

BACKGROUND: VT ablation reduces arrhythmic burden and ICD therapies, yet VT recurrence remains common. A key limitation is incomplete identification and durable elimination of the slow-conduction substrate. Structural imaging and ECGi provide complementary information but are not routinely integrated into a workflow-ready ablation strategy. OBJECTIVE: APOLO-VT aims to evaluate the feasibility, safety, and clinical impact of an integrated multimodal mapping workflow combining noninvasive structural and functional substrate characterization using ECGi with invasive EAM to support VT ablation targeting and verification. METHODS: APOLO-VT is an interventional, prospective, single-center investigation enrolling 60 adults with structural heart disease undergoing VT ablation. Scar/border-zone characterization will be derived from LGE-CMR (or CT when contraindicated) and integrated with ECGi maps and invasive EAM. Noninvasively defined targets will be ablated, followed by S3-paced ECGi remapping; persistent deceleration zones will prompt additional ablation. If the S3-paced ECGi map is free of deceleration zones, programmed stimulation and an invasive S3-paced map will be performed to confirm endpoint achievement. Follow-up will be 12 months. RESULTS: The primary endpoint is VT recurrence at 12 months. Secondary endpoints include acute non-inducibility, procedural efficiency, safety outcomes, mortality, and mechanistic concordance analyses. CONCLUSIONS: APOLO-VT will provide prospective feasibility, safety, mechanistic, and exploratory outcome data on a standardized noninvasive-to-invasive multimodal strategy with iterative post-ablation functional noninvasive reassessment.