Development of New-Onset or Progressive Atrial Fibrillation in Patients With Permanent HIS Bundle Pacing Versus Right Ventricular Pacing: Results From the RUSH HBP Registry

Background

Conventional right ventricular pacing (RVP) has been associated with an increased incidence of atrial fibrillation (AF). We sought to compare the occurrence of new‐onset AF and assessed AF disease progression during long‐term follow‐up between His bundle pacing (HBP) and RVP.

Methods and Results

We included patients undergoing initial dual‐chamber pacemaker implants at Rush University Medical Center between January 1, 2016, and June 30, 2019. A total of 360 patients were evaluated, and 225 patients (HBP, n=105; RVP, n=120) were included in the study. Among the 148 patients (HBP, n=72; RVP, n=76) with no history of AF, HBP demonstrated a lower risk of new‐onset AF (adjusted hazard ratio [HR], 0.53; 95% CI, 0.28–0.99; P=0.046) compared with traditional RVP. This benefit was observed with His or RVP burden exceeding 20% (HR, 0.29; 95% CI, 0.13–0.64; P=0.002), ≥40% (HR, 0.31; P=0.007), ≥60% (HR, 0.35; P=0.015), and ≥80% (HR, 0.40; P=0.038). There was no difference with His or RV pacing burden <20% (HR, 0.613; 95% CI, 0.213–1.864; P=0.404). In patients with a prior history of AF, there was no difference in AF progression (P=0.715); however, in a subgroup of patients with a pacing burden ≥40%, HBP demonstrated a trend toward a lower risk of AF progression (HR, 0.19; 95% CI, 0.03–1.16; P=0.072).

Conclusions

HBP demonstrated a lower risk of new‐onset AF compared with RVP, which was primarily observed at a higher pacing burden.

Pros and Cons of Left Bundle Branch Pacing: A Single-Center Experience

BACKGROUND

Left bundle branch pacing (LBBP) has recently emerged as a promising alternative modality for conduction system pacing. However, limited real-world data exists on the advantages and complications associated with LBBP. We analyzed the Rush conduction system pacing registry on LBBP to assess the success rates and complications associated with LBBP.

METHODS

All patients with an indication for permanent pacemaker or cardiac resynchronization therapy that underwent LBBP for various reasons from June 2018 to April 2020 were included in the analysis.

RESULTS

A total of 57 of 59 patients underwent successful LBBP (success rate 97%). The average follow-up duration was 6.2±5 months. The implanted devices included 38 dual-chamber pacemakers, 17 cardiac resynchronization therapy defibrillators, and 2 cardiac resynchronization therapy pacing systems. The most common reason for performing LBBP was a high His-Bundle pacing threshold (n=23) at implant. The mean LBBP capture threshold at implant was 0.62±0.21 V at 0.4 ms which remained stable during follow-up at 0.65±0.68 V at 0.4ms. In 21 patients with cardiomyopathy, there was a significant improvement in left ventricle ejection fraction from 30±11% to 42±15%. A total of 7 lead-related complications (12.3%) were noted in the follow-up period. Three patients (5.3%) required lead revision during the follow-up period. Interventricular septal perforation occurred (as late sequela) after 2 weeks in one patient.

CONCLUSIONS

LBBP can be achieved with a high success rate and low capture thresholds. Left ventricular dysfunction improved significantly during follow-up. Lead-related complications were relatively common occurring in 12.3% of initially successful implants. Lead revision was required in 3 (5%) of patients.

Permanent His Bundle Pacing: A programming and troubleshooting guide

Permanent His Bundle Pacing (HBP) has recently gained popularity. However, implanting physicians and those who perform the device checks must invest in additional education in order to accurately program these devices, identify changes in morphology and perform troubleshooting to help achieve the best outcomes for the patients. This paper reviews key aspects of HBP and provides the educational tools for successful HBP follow-up and troubleshooting.

Clinical Outcomes of Selective Versus Nonselective His Bundle Pacing

OBJECTIVES

The aim of the study was to evaluate the clinical outcomes of nonselective (NS) His bundle pacing (HBP) compared with selective (S) HBP.

BACKGROUND

HBP is the most physiologic form of ventricular pacing. NS-HBP results in right ventricular septal pre-excitation due to fusion with myocardial capture in addition to His bundle capture resulting in widened QRS duration compared with S-HBP wherein there is exclusive His bundle capture and conduction.

METHODS

The Geisinger and Rush University HBP registries comprise 640 patients who underwent successful HBP. Our study population included 350 consecutive patients treated with HBP for bradyarrhythmic indications who demonstrated ≥20% ventricular pacing burden 3 months post-implantation. Patients were categorized into S-HBP or NS-HBP based on QRS morphology (NS-HBP n = 232; S-HBP n = 118) at the programmed output at the 3-month follow-up. The primary analysis outcome was a combined endpoint of all-cause mortality or heart failure hospitalization.

RESULTS

The NS-HBP group had a higher number of men (64% vs. 50%; p = 0.01), higher incidence of infranodal atrioventricular block (40% vs. 9%; p < 0.01), ischemic cardiomyopathy (24% vs. 14%; p = 0.03), and permanent atrial fibrillation (18% vs. 8%; p = 0.01). The primary endpoint occurred in 81 of 232 patients (35%) in the NS-HBP group compared with 23 of 118 patients (19%) in the S-HBP group (hazard ratio: 1.38; 95% confidence interval: 0.87 to 2.20; p = 0.17). Subgroup analyses of patients at greatest risk (higher pacing burden or lower left ventricular ejection fraction) revealed no incremental risk with NS-HBP.

CONCLUSIONS

NS-HBP was associated with similar outcomes of death or heart failure hospitalization when compared with S-HBP. Multicenter risk-matched clinical studies are needed to confirm these findings.