Long-term cardiac outcomes of conduction system pacing upgrade in patient with generator replacement indication and heart failure
摘要
This study aimed to investigate the potential efficacy and safety of conduction system pacing (CSP) upgrades in patients indicated for elective replacement (ERI) with a left ventricular ejection fraction (LVEF) of less than 50% including those with heart failure with mildly reduced ejection fraction (HFmrEF).
MethodsThis observational, retrospective cohort study included all patients with an LVEF < 50% who had a right ventricular pacing percentage of ≥ 40% prior to pulse generator replacement from January 2018 to October 2021. Cardiac performance and lead outcomes were compared across different LVEF groups based on whether they received CSP upgrades.
ResultsA total of 60 patients were enrolled in this study, comprising 29 patients who successfully underwent CSP upgrades (29/32, 90.46%) and 31 patients who declined the upgrades. Comparable improvements in LVEF (9.00 ± 5.90% vs. 5.90 ± 3.72%, P = 0.325) and LVEDD (2.80 ± 1.95 mm vs. 3.10 ± 2.60 mm, P = 0.835) were noted in patients with HFmrEF. However, the final LVEF (53.50 ± 6.06 vs. 40.10 ± 10.20, P = 0.031) and LVEDD (48.60 ± 4.79 vs. 55.67 ± 9.80, P = 0.040) were more favorable in patients with HFmrEF compared to those with heart failure with reduced ejection fraction (HFrEF). In patients who declined CSP upgrades, NYHA grade (2.92 ± 0.79 vs. 2.75 ± 0.45, P = 0.010) and LVEF (29.50 ± 8.19% vs. 32.92 ± 5.25%, P = 0.018) decreased in patients with HFrEF, while comparable reductions in LVEF (45.84 ± 3.00% vs. 39.89 ± 10.83%, P = 0.001) and LVEDD (55.86 ± 9.62 mm vs. 50.11 ± 6.26 mm, P = 0.044) were observed in patients with HFmrEF. No complications, including thrombosis, infection, lead dislodgement, perforation, or stroke, were reported. The pacing threshold (1.25 ± 0.45 V vs. 1.57 ± 0.55 V, P = 0.129) did not differ significantly between patients with CSP upgrades and those without, following a follow-up period of 40.57 ± 8.21 months.
ConclusionCSP upgrade during pulse generator replacement for battery depletion was associated with improved cardiac performances in patients with LVEF less than 50%. The final cardiac performance in patients with HFmrEF is more favorable. Larger-scale randomized controlled studies are therefore necessary to validate these findings, confirm the efficacy of CSP upgrade, and establish its optimal timing.