September 14, 2023Open Access

Left bundle branch pacing preserved left ventricular myocardial work in patients with bradycardia

Q: What is the clinical evidence from this study?

Study design: Observational. Population: Symptomatic bradyarrhythmia (n=96). Intervention: Left bundle branch pacing (LBBP) vs. Right ventricular pacing (RVP) and non-selective His-bundle pacing (NS-HBP). Primary outcome: Global myocardial work efficiency (GWE) (p=<0.001).

Q: What does this research mean for the field?

Left bundle branch pacing preserves left ventricular global myocardial work efficiency (91.4% vs 80.9%) compared to right ventricular pacing in patients with bradycardia. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

Key Result

Left bundle branch pacing preserved left ventricular global myocardial work efficiency (91.4% vs 80.9%) compared to right ventricular pacing in patients with bradycardia.

Study Design

Type

Observational (n=96)

Multicenter

Structured PICO

Does left bundle branch pacing improve left ventricular myocardial work and mechanical synchrony compared to right ventricular pacing and non-selective His-bundle pacing in patients with bradycardia?

Population

96 subjects, including 86 patients with symptomatic bradyarrhythmia (sinus nodal dysfunction and atrioventricular block) and normal LV systolic function (LVEF ≥50%), and 10 control subjects without pacemakers. Mean age 74, 51% male. Exclusions: HF with LVEF <50% due to severe valvular heart disease or cardiomyopathy, permanent atrial fibrillation, left bundle branch block, end-stage renal disease, and malignancy with expected lifespan <1 year.

Intervention

Left bundle branch pacing (LBBP) (n=46) for symptomatic bradyarrhythmia

Comparator

Non-selective His-bundle pacing (NS-HBP) (n=24), right ventricular pacing (RVP) (n=16), and control subjects without pacemakers (n=10)

Outcome

Left ventricular myocardial work (MW) parameters including global MW index (GWI), global constructive work (GCW), global wasted work (GWW), and global MW efficiency (GWE) at 6-month follow-upsurrogate

Left bundle branch pacing preserves left ventricular myocardial work and mechanical synchrony better than right ventricular pacing and non-selective His-bundle pacing in patients with bradycardia.

Main Result

Absolute Event Rate: 91.4% vs 80.9%

p-value: p=<0.001

Limitations

Single-center prospective study with small sample size
Speckle tracking echocardiography study only at implant and 6-month follow-up
Differentiation between LBBP and LVSP is inconclusive
Echocardiographic images during non-selective LBBP with or without anodal capture were not distinguished
Worse GWW and GWE estimations during NS-HBP might be attributed to partial right ventricular myocardial capture
Individually regional LV myocardial work was not further evaluated

Abstract

Background Left bundle branch pacing (LBBP) is an emerging physiological pacing modality. Left ventricular (LV) myocardial work (MW) incorporates afterload and LV global longitudinal strain to estimate global and segmental myocardial contractility. However, the effect of LBBP on LV MW remains unknown. This study aimed to evaluate the impact of LBBP on LV MW in patients receiving pacemaker for bradyarrhythmia. Methods We prospectively enrolled 70 bradycardia patients with normal LV systolic function receiving LBBP ( n = 46) and non-selective His-bundle pacing (NS-HBP) ( n = 24). For comparative analysis, patients receiving right ventricular pacing (RVP) ( n = 16) and control subjects ( n = 10) were enrolled. Two-dimensional speckle tracking echocardiography was performed. The LV pressure-strain loop was non-invasively constructed to assess global LV MW. Results After 6-month follow-up, LBBP group (with 40% ventricular pacing during 6 months) had shorter peak strain dispersion (PSD) compared with RVP group, and higher LV global longitudinal strain compared with RVP group and NS-HBP group, but had no difference in left intraventricular mechanical dyssynchrony, including septal-to-posterior wall motion delay and PSD, compared with NS-HBP group. During ventricular pacing, LBBP group had higher global MW index (GWI) (2,189 ± 527 vs. 1,493 ± 799 mmHg%, P = 0.002), higher global constructive work (GCW) (2,921 ± 771 vs. 2,203 ± 866 mmHg%, P = 0.009), lower global wasted work (GWW) (211 ± 161 vs. 484 ± 281 mmHg%, P 0.001) and higher global MW efficiency (GWE) (91.4 ± 5.0 vs. 80.9 ± 8.3%, P 0.001) compared with RVP group, and had lower GWW (211 ± 161 vs. 406 ± 234 mmHg%, P 0.001) and higher GWE (91.4 ± 5.0 vs. 86.4 ± 8.1%, P 0.001) compared with NS-HBP group. Conclusions In this study we found that in patients with mid-term (6-month) high ventricular pacing burden (40%), LBBP preserved more LV MW compared with NS-HBP and RVP. Further studies are warranted to assess the association between LV MW and long-term clinical outcomes in LBBP with high ventricular pacing burden.

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Cite This Study

Chen et al. (Thu,) conducted a observational in Symptomatic bradyarrhythmia (n=96). Left bundle branch pacing (LBBP) vs. Right ventricular pacing (RVP) and non-selective His-bundle pacing (NS-HBP) was evaluated on Global myocardial work efficiency (GWE) (p=<0.001). Left bundle branch pacing preserved left ventricular global myocardial work efficiency (91.4% vs 80.9%) compared to right ventricular pacing in patients with bradycardia.

synapsesocial.com/papers/6a15a9479b87f33fc69fbe06 https://doi.org/https://doi.org/10.3389/fcvm.2023.1201841

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