PAM-VT 2 Study: Long-Term Scar Evolution and Ablation Lesion Assessment by Late Gadolinium Enhancement Cardiac Magnetic Resonance After Ventricular Tachycardia Ablation

doi:10.1161/circulationaha.125.074748

Arrhythmias & electrophysiologyCohort study

PAM-VT 2 Study: Long-Term Scar Evolution and Ablation Lesion Assessment by Late Gadolinium Enhancement Cardiac Magnetic Resonance After Ventricular Tachycardia Ablation

CirculationPublished 2 Mar 2026

Prospective cohort study
serial postablation late gadolinium enhancement cardiac magnetic resonance (LGE-CMR)

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Authors' conclusion

Postablation LGE-CMR reveals durable changes in scar characteristics, with early scar evaluation at 3 to 6 months strongly associated with long-term VT recurrence.

Study context

Population: Patients with structural heart disease undergoing first substrate-based ventricular tachycardia (VT) ablation, March 2019–July 2020 (mean age 65.2±9.8 years; men 95.8%; ischemic heart disease 83%; LVEF 34.5±10.4%)
Participants: 51 patients

Exposure: Pre vs CMR-1 vs CMR-2
Outcome: Long-term evolution of scar and ablation lesions on serial postablation LGE-CMR

Main finding

As reported in the abstract

Scar evolution on serial LGE-CMR

Group	Core scar mass	Border zone	Conducting channels
Pre	12.2±1.5 g	25.3±1.8 g	mean 2.4±0.2/median 2 [IQR 1-3]
CMR-1	19.8±1.6 g	20.8±2.0 g	mean 1.4±0.2/median 1 [IQR 0-1]
CMR-2	remained stable	16.7±2.1 g	mean 1.6±1.0/median 1 [IQR 0-1]

Core scar mass increased significantly from baseline to CMR-1: P < 0.01
Border zone decreased significantly over time: P < 0.01
Conducting channels decreased significantly after ablation, persisting at CMR-2: P < 0.001

Observational data: associations, not effects.

Further findings

Outcome	Lower risk with ≥2 conducting channels at CMR-1 ←→ Higher risk with ≥2 conducting channels at CMR-1	HR (95% CI)	P value
VT recurrence by ≥2 conducting channels persisting at CMR-1 · recurrence 75.6 vs 19.5%		4.1 (2.4–12.1)	P = 0.012
	0.050.21520Hazard ratio (log scale)

LV volume

Premean 160.8 mLSE 7.6

CMR-1mean 156.7 mLSE 8.1

CMR-2mean 131.8 mLSE 8.6

LV volume — Significant reduction in LV volume at CMR-2: <0.01

VT recurrence · median follow-up 3.1 years

VT recurrence: 29.4%
Number of conducting channels at CMR-1 and their relative reduction from baseline related to VT recurrence

Original publication

PAM-VT 2 Study: Long-Term Scar Evolution and Ablation Lesion Assessment by Late Gadolinium Enhancement Cardiac Magnetic Resonance After Ventricular Tachycardia Ablation. Circulation. Published 2 March 2026. doi:10.1161/circulationaha.125.074748

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Summarised from the published abstract; every number is checked against it