Predictors of pacing-induced cardiomyopathy in patients undergoing AV nodal ablation: insights from a Delphi process and retrospective cohort study.

Abstract

Aims: Pacing-induced cardiomyopathy (PICM) is a recognized complication of pace-and-ablate therapy. Early identification of patients at risk may allow tailored strategies, including upfront biventricular or conduction system pacing.

Purpose: This study aimed to identify predictors of PICM in patients undergoing pace-and-ablate therapy, combining expert consensus with clinical validation.

Methods and results: A three-round Delphi process involving 12 electrophysiologists prioritized candidate predictors of PICM. Consecutive patients undergoing atrioventricular node ablation with non-cardiac resynchronization therapy (CRT) devices at Liverpool Heart and Chest Hospital (2015-2019) were retrospectively analysed. The primary endpoint was PICM, defined as ≥10% reduction in left ventricular ejection fraction (LVEF) to <50%, adjudicated by two independent cardiologists. Cox regression was used to identify independent predictors. The Delphi process prioritized baseline LVEF, intrinsic and paced QRS duration, RV lead position, and key comorbidities. Among 658 ablation patients, 323 (median age 76 years, 67% female) had non-CRT devices. Over a median follow-up of 192 days (IQR, 63-1003 days), 33 patients (9.8%) developed PICM. In multivariable analysis, RV free wall vs. septal lead position [hazard ratio (HR) 4.896, 95% confidence interval (CI) 1.263-18.973, P = 0.022], intrinsic QRS duration (HR 1.247 per 10 ms, 95% CI 1.064-1.462, P = 0.006), independently predicted PICM. Exploratory analyses suggested that higher intrinsic QRS duration was associated with increased PICM risk; however, these findings were based on a small number of events and should be interpreted with caution.

Conclusion: Intrinsic QRS duration and free wall RV lead position independently predict PICM in pace-and-ablate patients. These findings support early risk stratification and may guide personalized pacing strategies.