Value of Left Ventricular Low Voltage Area and Ejection Fraction in Predicting End-Stage Heart Failure Outcomes After Ventricular Tachycardia Ablation in Patients With Non-Ischemic Cardiomyopathy

Abstract

BACKGROUND: Patients with nonischemic cardiomyopathy (NICM) and ventricular tachycardia are at increased risk for adverse HF outcomes, and abnormal left ventricular (LV) substrate identified by endocardial unipolar and bipolar low-voltage areas (LVAs) may aid in risk stratification. This study assessed the association of LV unipolar and bipolar LVAs with end-stage HF outcomes in patients with NICM undergoing ventricular tachycardia ablation. METHODS: Patients with NICM and LV ejection fraction (EF) <50% undergoing ventricular tachycardia ablation from 2019 to 2023 were included. Endocardial voltage mapping defined confluent (>2 cm 2 ) unipolar LVAs as <8.27 mV and bipolar LVAs as <1.5 mV during sinus or paced rhythm. End-stage HF outcomes included HF death, LV assist device implantation, or heart transplant. Multivariable Cox proportional hazards regression analysis assessed associations between unipolar/bipolar LVAs and end-stage HF outcomes. RESULTS: One hundred eleven patients with NICM (mean age, 64.6±9.8 years; 81.1% male; mean LVEF, 33.8±11.7%) were included. During a median follow-up of 28.1 months (interquartile range, 18–46), 28 (25.2%) patients experienced end-stage HF outcomes. Unipolar LVA (hazard ratio, 1.03 per 1% increase [95% CI, 1.01–1.05]; P =0.002) and LVEF (hazard ratio, 1.04 per 1% decrease [95% CI, 1.00–1.09]; P =0.03) were independently associated with higher end-stage HF risk, while bipolar LVA was not (hazard ratio, 0.98, 1% increase [95% CI, 0.96–1.01]; P =0.25). A 3-point risk score based on the Youden index, unipolar LVA ≥70% (2 points), 35% to 70% (1 point), and LVEF ≤25% (1 point), had 82.1% sensitivity and 77.1% specificity for predicting end-stage HF in scores ≥2. CONCLUSIONS: In patients with NICM undergoing ventricular tachycardia ablation, unipolar LVA and LVEF are independent predictors of end-stage HF outcomes. Integrating these predictors yields a prognostic score to identify patients at the highest risk of end-stage HF outcomes.