Conduction System Pacing vs Right Ventricular Pacing in Preserved or Mildly Reduced Ejection Fraction: A
Abdalhakim Shubietah1, Mohamed Saad Rakab2, Elsayed Balbaa3
1Department of Medicine, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
Insights
Conduction system pacing (CSP) significantly lowers pacing-induced cardiomyopathy and heart failure hospitalizations compared to right ventricular pacing (RVP) in patients with preserved or mildly reduced ejection fraction. While CSP shows benefits, it involves longer procedure times.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Observational studies on conduction system pacing (CSP) versus right ventricular pacing (RVP) show mixed results regarding patient outcomes.
- Patients with preserved or mildly reduced left ventricular ejection fraction (LVEF) requiring permanent pacing are the focus of this comparison.
Purpose of the Study:
- To compare the efficacy and safety of CSP versus RVP in randomized controlled trials (RCTs).
- To evaluate the impact of CSP on pacing-induced cardiomyopathy (PICM), heart failure hospitalizations (HFH), and left ventricular function.
Main Methods:
- A meta-analysis of RCTs comparing CSP modalities with RVP was conducted.
- Databases were searched through February 24, 2026, with outcomes pooled using random-effects models.
Main Results:
- CSP significantly reduced PICM (4.6% vs 16.2%) and HFH (3.3% vs 9.1%) compared to RVP.
- CSP improved LVEF and shortened paced QRS duration but had lower pacing success rates and longer procedural/fluoroscopy times.
Conclusions:
- CSP is a viable preventive strategy for patients with preserved or mildly reduced LVEF anticipated to require substantial ventricular pacing.
- CSP demonstrates superior outcomes in reducing PICM and HFH, alongside better preservation of LV function compared to RVP.
Background:
Evidence, largely observational, has been mixed on whether conduction system pacing (CSP) improves outcomes over conventional right ventricular pacing (RVP). This meta-analysis compared the efficacy and safety of CSP vs RVP in randomised controlled trials (RCTs) of patients with preserved or mildly reduced left ventricular ejection fraction (LVEF) who require permanent pacing.
Methods:
We analysed RCTs comparing different CSP modalities with RVP. Databases were searched through February 24, 2026. Outcomes were pooled using random-effects models for risk ratios (RRs) and mean differences (MDs).
Results:
Fifteen RCTs (n = 1466; mean baseline left ventricular ejection fraction (LVEF) = 59.4 ± 7.0%) showed lower pacing-induced cardiomyopathy (PICM) with CSP vs RVP (4.6% vs 16.2%; RR 0.34, 95% CI 0.19-0.60) and lower heart failure hospitalisation (HFH) (3.3% vs 9.1%; RR 0.34, 95% CI 0.17-0.70), with no difference in all-cause mortality. CSP shortened paced QRS duration (MD -30.10 ms, 95% CI -35.46 to -24.74 ms) and improved LVEF (MD +2.96%, 95% CI 1.18%-4.73%), but had lower pacing success (93.6% vs 99.5%; RR 0.95, 95% CI 0.91-0.99) and worse procedural metrics (procedure time MD +32.44 min, 95% CI 21.22-43.67 min; fluoroscopy time MD +5.27 min, 95% CI 3.89-6.65 min; radiation dose MD +24.91 mGy, 95% CI 10.27-39.55 mGy).
Conclusions:
In RCTs of predominantly preserved or mildly reduced LVEF requiring permanent pacing, CSP reduced PICM and HFH and preserved left ventricular function more effectively than RVP, but with longer procedural and fluoroscopy times. CSP is a reasonable preventive strategy when substantial ventricular pacing is anticipated in this population.
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