Mid-Term Cardiac Outcomes in Prosthetic Valve Surgery and HF Patients Across EF After CSP

Objective Clinical outcomes of conduction system pacing (CSP) in patients with prosthetic valve surgery (PVS) and heart failure (HF) remain unclear. This study evaluated the feasibility, safety, and clinical impact of CSP in this population. Methods Consecutive patients with atrioventricular block post-PVS and HF history undergoing CSP from January 2018 to December 2022 were enrolled. Exclusions included prior pacemaker implantation, biventricular pacing, or ventricular pacing <40%. Outcomes were assessed by left ventricular ejection fraction (LVEF) categories: reduced (HFrEF, LVEF <= 40%), mildly reduced (HFmrEF, 41%-49%), and preserved (HFpEF, >= 50%). Results CSP succeeded in 90/96 patients (93.75%): 34 HFrEF (37.78%), 11 HFmrEF (12.22%), and 45 HFpEF (50.00%). All cohorts showed improved left ventricular end-diastolic diameter (LVEDD) (HFrEF: 56.35 +/- 10.01 vs. 60.76 +/- 8.36 mm, p < 0.001; HFmrEF: 52.54 +/- 5.01 vs. 56.73 +/- 4.10 mm, p = 0.017; HFpEF: 48.07 +/- 4.22 vs. 48.80 +/- 3.99 mm, p = 0.035). The HFrEF cohort demonstrated significant improvements in LVEF (44.15 +/- 12.23% vs. 31.26 +/- 5.98%, p < 0.001), left atrial diameter (50.12 +/- 13.91 vs. 54.00 +/- 17.14 mm, p = 0.006), and New York Heart Association class (2.63 +/- 0.85 vs. 3.13 +/- 0.78, p = 0.002). No deterioration occurred in HFmrEF/HFpEF. Complete LVEF/LVEDD normalization was achieved in 26.47% of HFrEF patients (9/34), with absence of rheumatic heart disease (RHD) as an independent predictor (HR = 8.851, 95% CI 1.336-58.646, p = 0.024). Over 25.49 +/- 9.4 months, no cardiac perforation, thrombosis, pacemaker-induced cardiomyopathy (PICM), or infections occurred. Conclusions CSP is feasible and safe, promoting cardiac reverse remodeling and mitigating PICM risk in PVS patients with HF across LVEF categories. Over 25% of HFrEF patients achieved complete normalization, predicted by non-RHD etiology.