Comparing Conduction System Pacing to Biventricular Upgrade in Pacemaker-Induced Cardiomyopathy: A Retrospective Observational Study.

Background/

Objectives

Pacemaker-induced cardiomyopathy (PICM) develops in up to 30% of patients with chronic right ventricular pacing. While biventricular (BIV) upgrade is the conventional strategy, conduction system pacing (CSP) offers a physiologic alternative recently endorsed by the 2025 ESC/EHRA Consensus Statement. However, comparative evidence in PICM is limited. Therefore, we aimed to compare outcomes of PICM patients undergoing CSP versus BIV upgrade.

Methods

This retrospective analysis included consecutive PICM patients who were upgraded to CSP or BIV between 2022 and 2024 at a single, experienced center. Follow-up averaged >19 months. Clinical outcomes, lead performance, echocardiographic parameters, complications, and quality of life (QoL) were evaluated.

Results

Sixty-three patients were included (CSP: 26; BIV: 37). Mean age and sex distribution were similar; both groups had wide paced QRS complexes and a high ventricular pacing burden. Baseline left ventricular ejection fraction (LVEF) was lower in BIV patients (29 ± 7% vs. 35 ± 6%, p = 0.01). Procedure duration was comparable, but fluoroscopy was shorter with CSP. QRS duration narrowed significantly in both groups (CSP: 163 ± 28→132 ± 12 ms; BIV: 171 ± 23→140 ± 18 ms; both p < 0.05). During follow-up, LVEF improved (CSP: 41 ± 8%; p = 0.008; BIV: 39 ± 8%, p = 0.0001), as did NYHA class, with no significant intergroup differences. The rates of heart failure hospitalization, all-cause mortality, and QoL were similar. Notably, 34.6% of CSP patients retained their existing generator, suggesting procedural and economic benefits.

Conclusions

CSP is a feasible and potentially cost-efficient alternative to BIV upgrade in PICM, with comparable improvements in ventricular function, symptoms, and clinical outcomes. Larger prospective trials are warranted.