Feasibility and Safety of Permanent Left Bundle Branch Pacing in Patients With Conduction Disorders Following Prosthetic Cardiac Valves

Long-term outcomes of left bundle branch area pacing compared with right ventricular pacing in TAVI patients

BACKGROUND

New-onset permanent pacemaker implantation (PPMI) is still a common complication after transcatheter aortic valve implantation (TAVI) with adverse clinical outcomes.

OBJECTIVE

The purpose of this study was to investigate whether left bundle branch area pacing (LBBAP) improves long-term clinical results compared with traditional right ventricular pacing (RVP) in patients requiring PPMI after TAVI.

METHODS

A total of 237 consecutive patients undergoing RVP (N = 117) or LBBAP (N = 120) after TAVI were retrospectively included. Long-term outcomes, including all-cause death, heart failure rehospitalization (HFH), and left ventricular ejection fraction (LVEF) change compared to baseline, were obtained until 5 years post-TAVI.

RESULTS

The mean age of the overall population was 74 years, with a mean surgical risk score of 4.4%. The paced QRS duration was significantly longer in the RVP group compared with the LBBAP group (151 ± 18 vs 122 ± 12 ms; P < .001). No difference was found between the 2 groups in all-cause death (13.7% vs 13.3%; adjusted hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.37-1.58; P = .466) or the composite endpoint of death and HFH (29.9% vs 19.2%; adjusted HR, 1.22; 95% CI, 0.70-2.13; P = .476); however, the risk of HFH was significantly higher in the RVP group at 5 years after TAVI (21.4% vs 7.5%; adjusted HR, 2.26; 95% CI, 1.01-5.08; P = .048). There was greater improvement of LVEF over time in the LBBAP group (P = .046 for LVEF changes over time between groups).

CONCLUSIONS

LBBAP improved long-term clinical outcomes compared with RVP in patients undergoing PPMI after TAVI in terms of less HFH and better LVEF improvement.

Left bundle branch area pacing using a lumenless lead: A systematic literature review and meta-analysis

BACKGROUND

Although left bundle branch area pacing (LBBAP) has been shown to be a feasible option for delivering physiological pacing, data are largely limited to single-center reports. The aim of this analysis was to systematically assess the safety and efficacy of LBBAP with the Model 3830 lead among primarily bradycardia patients.

METHODS AND RESULTS

PubMed, Embase, Cochrane Library, and Google Scholar were searched for full-text articles on LBBAP using the SelectSecure Model 3830 lumenless lead. Rates and means were estimated using random- and mixed-effects models. Of 3395 articles, 53 met inclusion criteria, representing 6061 patients undergoing an implant attempt. Average patient age was 68.1 years (95% CI: 66.6, 69.6) and 53.1% were male (95% CI: 50.5%, 55.7%). The average implant success rate among bradycardia-indicated patients was 92.7% (95% CI: 89.5%, 94.9%). The overall estimated procedural adverse event rate was 2.5% (95% CI: 1.1%, 5.4%). The estimated septal perforation rate at implant was 1.6% (95% CI: 1.0%, 2.6%) with no adverse clinical sequelae reported. Pacing thresholds were low at implant (0.67 V [95% CI: 0.64, 0.70]) and remained stable through 12 months (0.76 V [95% CI: 0.72, 0.80]). Among bradycardia-indicated patients, LVEF remained stable from baseline to post-implant (59.5% [95% CI: 57.9%, 61.1%] vs. 60.1% [95% CI: 58.5%, 61.7%]).

CONCLUSION

This meta-analysis including 6061 patients implanted with a Model 3830 lead for LBBAP found an average implant success rate of 92.7% and a procedural adverse event rate of 2.5% with stable electrical parameters and LVEF post-implant.

Left bundle branch area pacing in mildly reduced heart failure: A systematic literature review and meta-analysis

Cardiac resynchronization therapy (CRT) strategy for heart failure with mildly reduced ejection fraction (HFmrEF) is controversial. Left bundle branch area pacing (LBBAP) is an emerging pacing modality and an alternative option to CRT. This analysis aimed to perform a systematic review of the literature and meta-analysis on the impact of the LBBAP strategy in HFmrEF, with left ventricular ejection fraction (LVEF) between 35% and 50%. PubMed, Embase, and Cochrane Library were searched for full-text articles on LBBAP from inception to July 17, 2022. The outcomes of interest were QRS duration and LVEF at baseline and follow-up in mid-range heart failure. Data were extracted and summarized. A random-effect model incorporating the potential heterogeneity was used to synthesize the results. Out of 1065 articles, 8 met the inclusion criteria for 211 mid-range heart failure patients with an implant LBBAP across the 16 centers. The average implant success rate with lumenless pacing lead use was 91.3%, and 19 complications were reported among all 211 enrolled patients. During the average follow-up of 9.1 months, the average LVEF was 39.8% at baseline and 50.5% at follow-up (MD: 10.90%, 95% CI: 6.56-15.23, p < .01). Average QRS duration was 152.6 ms at baseline and 119.3 ms at follow-up (MD: -34.51 ms, 95% CI: -60.00 to -9.02, p < .01). LBBAP could significantly reduce QRS duration and improve systolic function in a patient with LVEF between 35% and 50%. Application of LBBAP as a CRT strategy for HFmrEF may be a viable option.

Conduction system pacing in prosthetic heart valves

BACKGROUND

There has been increasing interest in physiologic pacing techniques that directly activate the specialized conduction system. We aimed to assess outcomes of conduction system pacing (CSP) in patients with prosthetic heart valves.

METHODS

This systematic review was performed according to PRISMA guidelines. Freeman-Tukey double arcsine transformation with the random-effect model was used to summarize the data. Outcomes studied were 1) implant success (defined as ability to recruit the His-Purkinje system or the distal Purkinje system); (2) lead parameters at implant and follow-up; and (3) procedure-related complications.

RESULTS

This systematic review of 7 studies included 267 unique patients in whom CSP was attempted with either HBP or LBBAP for pacing indications after a prosthetic valve. HBP was attempted in 38% (n = 108), while LBBAP in 62% (n = 175) patients. The overall success rate of CSP was 87%, while in patients post-TAVR, the overall success rate was 83.2%. In the subgroup analysis, LBBAP had a significant higher overall success rate compared to HBP (94.3% vs. 76.5%, p _interaction = 0.02) and post-TAVR patients (94.3 vs. 66.9%, p _interaction < 0.01), respectively. The LBBAP thresholds were significantly lower compared to HBP both at implant (0.67 ± 0.4 @ 0.44 ms vs. 1.35 ± 1 @ 0.85 ms, p _interaction < 0.01) and at a mean follow-up of 12.4 ± 8 months (0.73 ± 0.1 @ 0.44 ms vs. 1.39 ± 1 @ 0.85 ms, p _interaction < 0.01), respectively.

CONCLUSION

CSP is safe and feasible in patients with a prosthetic valve, with a significantly higher success rate and superior lead parameters with LBBAP than HBP, especially in patients post-TAVR.