Upgrade to his bundle pacing in pacing-dependent patients referred for pulse generator change: Feasibility and intermediate term follow up

Effectiveness of bundle of His pacing for cardiac resynchronization therapy in patients with heart failure combined with wide QRS complex: a meta-analysis

OBJECTIVE

To evaluate systematically the feasibility and effectiveness of His Bundle Pacing (HBP) for cardiac resynchronization therapy.

METHODS

A comprehensive search was conducted in PubMed, EMbase, WOS, Cochrane Library, Medline, and SinoMed for studies published between December 2003 and December 2023. Primary clinical outcomes included implantation success, QRS wave duration, pacing threshold, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), New York Heart Association (NYHA) cardiac function class, and complications. Data were extracted and summarized, and meta-analysis was performed by Revman 5.3 software.

RESULTS

Fourteen studies involving a total of 555 patients were included. The overall success rate for HBP implantation was 83.2% (462/555). Compared to baseline values, QRS duration was significantly reduced (MD=48.29, 95% CI: 45.20 to 51.38, P<0.01, I2=85%), LVEF was significantly increased (MD=-13.62, 95% CI: -15.46 to -11.79, P<0.01, I2=74%), LVEDD was smaller (MD=5.83, 95% CI: 4.44-7.22, P<0.01, I2=78.2%), and NYHA showed significant improvement (MD=1.24, 95% CI: 1.14-1.35, P<0.01, I2=97.2%). At follow-up, pacing threshold increased (MD=-0.28, 95% CI: -0.43 to -0.12, P<0.01, I2=0%), and pacing impedance decreased (MD=51.62, 95% CI: 23.67 to 79.56, P<0.01, I2=56%).

CONCLUSION

HBP is effective for cardiac resynchronization therapy. HBP significantly reduces QRS duration and improves LVEF in heart failure patients.

Cardiovascular imaging in conduction system pacing: What does the clinician need?

Permanent pacemakers are used for symptomatic bradycardia and biventricular pacing (BVP)-cardiac resynchronization therapy (BVP-CRT) is established for heart failure (HF) patients traditionally. According to guidelines, patients' selection for CRT is based on QRS duration (QRSd) and morphology by surface electrocardiogram (ECG). Cardiovascular imaging techniques evaluate cardiac structure and function as well as identify pathophysiological substrate changes including the presence of scar. Cardiovascular imaging helps by improving the selection of candidates, guiding left ventricular (LV) lead placement, and optimization devices during the follow-up. Conduction system pacing (CSP) includes His bundle pacing (HBP) and left bundle branch pacing (LBBP) which is screwed into the interventricular septum. CSP maintains and restores ventricular synchrony in patients with native narrow QRSd and left bundle branch block (LBBB), respectively. LBBP is more feasible than HBP due to a wider target area. This review highlights the role of multimodality cardiovascular imaging including fluoroscopy, echocardiography, cardiac magnetic resonance (CMR), myocardial scintigraphy, and computed tomography (CT) in the pre-procedure assessment for CSP, better selection for CSP candidates, the guidance of CSP lead implantation, and the optimization of devices programming after the procedure. We also compare the different characteristics of multimodality imaging and discuss their potential roles in future CSP implantation.

Upgrading right ventricular pacemakers to biventricular pacing or conduction system pacing: a systematic review and meta-analysis

Guidelines recommend patients undergoing a first pacemaker implant who have even mild left ventricular (LV) impairment should receive biventricular or conduction system pacing (CSP). There is no corresponding recommendation for patients who already have a pacemaker. We conducted a meta-analysis of randomized controlled trials (RCTs) and observational studies assessing device upgrades. The primary outcome was the echocardiographic change in LV ejection fraction (LVEF). Six RCTs (randomizing 161 patients) and 47 observational studies (2644 patients) assessing the efficacy of upgrade to biventricular pacing were eligible for analysis. Eight observational studies recruiting 217 patients of CSP upgrade were also eligible. Fourteen additional studies contributed data on complications (25 412 patients). Randomized controlled trials of biventricular pacing upgrade showed LVEF improvement of +8.4% from 35.5% and observational studies: +8.4% from 25.7%. Observational studies of left bundle branch area pacing upgrade showed +11.1% improvement from 39.0% and observational studies of His bundle pacing upgrade showed +12.7% improvement from 36.0%. New York Heart Association class decreased by -0.4, -0.8, -1.0, and -1.2, respectively. Randomized controlled trials of biventricular upgrade found improvement in Minnesota Heart Failure Score (-6.9 points) and peak oxygen uptake (+1.1 mL/kg/min). This was also seen in observational studies of biventricular upgrades (-19.67 points and +2.63 mL/kg/min, respectively). In studies of the biventricular upgrade, complication rates averaged 2% for pneumothorax, 1.4% for tamponade, and 3.7% for infection over 24 months of mean follow-up. Lead-related complications occurred in 3.3% of biventricular upgrades and 1.8% of CSP upgrades. Randomized controlled trials show significant physiological and symptomatic benefits of upgrading pacemakers to biventricular pacing. Observational studies show similar effects between biventricular pacing upgrade and CSP upgrade.

Feasibility and safety of both His bundle pacing and left bundle branch area pacing in atrial fibrillation patients: intermediate term follow-up

PURPOSE

His bundle pacing (HBP) improves heart failure (HF) in atrial fibrillation (AF) pacing-dependent patients with a potential for a progressively increased threshold. HBP with right ventricular pacing (RVP) as a backup is always the preferred choice; however, RVP may induce HF. His Purkinje system pacing (HPSP) includes HBP and left bundle branch area pacing (LBBAP). LBBAP maintains left ventricular synchrony but has not been proven to be safe over the long term. We assessed the feasibility and safety of both HBP and LBBAP in AF pacing-dependent patients and compared the parameters of both leads at baseline and at the 6-month follow-up.

METHODS

A total of 16 AF patients in our center, who successfully attempted both HBP and LBBAP, were prospectively enrolled unless only one of these treatment statuses was attained. The electrocardiogram characteristics, leading parameters, echocardiography results, and clinical outcomes were assessed.

RESULTS

Thirteen out of 16 patients achieved both HBP and LBBAP successfully in the same AF pacing-dependent patients. In symptomatic HF patients with preserved left ventricular ejection fraction (LVEF) (n = 10), the left ventricular end-diastolic diameter (LVEDD) was reduced from 51.8 ± 4.4 to 48.3 ± 3.1 mm (p = 0.01) with the use of diuretics, either reduced or stopped (n = 7). During the follow-up, one patient in the group without HF had an increased HBP threshold and developed HF symptoms. His HF symptoms disappeared when switched into LBBAP mode. Another patient in the group with HF got his LVEF elevated by HBP for 3 months by utilizing left bundle branch block(LBBB)correction and continued to increase when switched into LBBAP for another 3 months due to an increased HBP correction threshold. The average unipolar pacing threshold of LBBAP was lower than that of HBP. No perforation or dislodgement occurred in our study.

CONCLUSION

Both HBP and LBBAP could be attempted successfully in the same AF patients when one of the two modes could be adopted and switched according to the clinical feasibility. Compared with HBP, LBBAP yielded better and more stable parameters but showed comparable effects during the 6-month follow-up.

The clinical utility of direct His-bundle pacing in patients with heart failure and permanent atrial fibrillation

In patients with significantly impaired left ventricle function permanent atrial fibrillation (AF) often coexists with symptoms of heart failure. Based on various studies, it is assumed that in patients with heart failure in functional class III and IV AF occurs in 40-50% of patients. AF adversely affects cardiac hemodynamics, and its harmfulness increases particularly in the failing heart. The lack of mechanical function of the left atrium, the usually fast ventricular rate and the irregular sequence of ventricular contraction constitute the spectrum of harmful effects of this arrhythmia. Therefore, the only way to address the underlying problem of AF, which is irregular ventricular rhythm, is to pace the ventricles and to slow or block the AV conduction. Classic, right ventricular pacing is contraindicated in this population as it promotes the abovementioned disorders by initiating additional dyssynchrony of left ventricular contraction with reduction of its contractility and aggravation of AF-related mitral regurgitation. The possibility of direct His bundle pacing (DHBP) significantly extended the clinical armamentarium of cardiac pacing. The restoration of the physiological electrical activation could significantly contribute to echocardiographic and clinical improvement. With time and the development of dedicated tools for direct His bundle pacing the success rate of implantations became more than 90% and the acceptable pacing thresholds under 2.0 V (1 ms) could be achieved in most patients. This contributed to the broader clinical application of DHBP in different patient' groups with various pacing indications. The authors of the paper discuss different electrocardiographic and clinical indications for DHBP.

Cardiac resynchronization performed by LBBaP-CRT in patients with cardiac insufficiency and left bundle branch block

OBJECTIVE

To evaluate the efficacy and safety of left bundle branch area pacing (LBBaP) in patients with heart failure and left bundle branch block (LBBB), and to compare the clinical effects with traditional cardiac resynchronization therapy (CRT).

METHODS

Thirty-two patients with dilated cardiomyopathy complicated by cardiac insufficiency and left bundle branch block were divided into CRT group and LBBaP group. Parameters including pacing threshold, R-wave amplitude, pacing impedance and operation time, and X-ray exposure time were recorded. The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) were examined by echocardiography. The changes of QRS complex before and after operation were compared.

RESULTS

Compared with CRT group, the LBBaP group spent less time on total operation time and X-ray exposure time and had stable electrode parameters including pacing threshold, R-wave amplitude, and lead impedance after 12-month follow-up. In addition, LBBaP can achieve narrow QRS complex (117.15 ± 9.91) ms immediately than that in CRT group (130.32 ± 12.41) ms. The change of QRS between LBBaP is (50.30 ± 23.79) ms and CRT group is (33.15 ± 20.22) ms. After 6 months' follow-up in LBBaP group, EF was higher than that before operation. Followed up for 12 months after operation, EF and LVEDD in LBBaP group were significantly improved compared with those before operation.

CONCLUSION

Left bundle branch area pacing is a safe and effective resynchronization method for patients with cardiac insufficiency and asynchronization, which can achieve same clinical effects to CRT.

Efficacy and safety of left bundle branch area pacing versus right ventricular apex pacing in patients with atrioventricular block: study protocol for a randomised controlled trial

INTRODUCTION

Left bundle branch area pacing (LBBaP) is a relatively new approach for physiologic pacing. A limited number of retrospective clinical studies, featuring small sample sizes, have shown that compared with right ventricular apex pacing (RVAP), the QRS duration of postoperative ECG in LBBaP patients is narrower and the cardiac systolic function is improved. However, there have been no randomised controlled trials (RCTs) evaluating the efficacy and safety of LBBaP in patients with atrioventricular block (AVB). Therefore, the current study intends to address the paucity in RCT data evaluating LBBaP versus RVAP in AVB patients.

ANALYSIS AND METHODS

This study is a single-centre, randomised controlled superiority trial to be conducted at the Cardiac Centre of Beijing Anzhen Hospital. From January 2021 to December 2023, 210 consecutive AVB patients meeting the inclusion criteria and receiving pacemaker implantation will be enrolled. Participants will be randomly divided into an experimental group (LBBaP) and a control group (RVAP) at a 1:1 ratio. The primary outcome is left ventricular ejection fraction (LVEF), which will be assessed by echocardiography. The secondary outcomes in this study are synchrony of left ventricular systole, NT-proBNP, LVEDD, the 6-min walk distance, quality of life (SF-36 scale), all-cause mortality, cardiovascular death events, rehospitalisation rate and major complication rate.

ETHICS AND DISSEMINATION

This study was approved by the Medical Ethics Committee of Beijing Anzhen Hospital (No. 2020021X). The results of the trial will be presented at national and international conferences. We hypothesise that compared with RVAP, LBBaP will be superior for treating patients with AVB. This trial will provide evidence-based suggestion for the majority of electrophysiologists in pacing implantation.

TRIAL REGISTRATION

ChiCTR2000034335.

Feasibility and Outcomes of Upgrading to Left Bundle Branch Pacing in Patients With Pacing-Induced Cardiomyopathy and Infranodal Atrioventricular Block

His bundle pacing (HBP) can reverse left ventricular (LV) remodeling in patients with right ventricular (RV) pacing-induced cardimyopathy (PICM) but may be unable to correct infranodal atrioventricular block (AVB). Left bundle branch pacing (LBBP) results in rapid LV activation and may be able to reliably pace beyond the site of AVB. Our study was conducted to assess the feasibility, safety, and outcomes of permanent LBBP in infranodal AVB and PICM patients. Patients with infranodal AVB and PICM who underwent LBBP for cardiac resynchronization therapy (CRT) were included. Clinical evaluation and echocardiographic and electrocardiographic assessments were recorded at baseline and follow-up. Permanent LBBP upgrade was successful in 19 of 20 patients with a median follow-up duration of 12 months. QRS duration (QRSd) increased from 139.3 ± 28.0 ms at baseline to 176.2 ± 21.4 ms (P < 0.001) with right ventricular pacing (RVP) and was shortened to 120.9 ± 15.2 ms after LBBP (P < 0.001). The mean LBBP threshold was 0.7 ± 0.3 V at 0.4 ms at implant and remained stable during follow-up. The left ventricular ejection fraction (LVEF) increased from 36.3% ± 6.5% to 51.9% ± 13.0% (P < 0.001) with left ventricular end-systolic volume (LVESV) reduced from 180.1 ± 43.5 to 136.8 ± 36.7 ml (P < 0.001) during last follow-up. LBBP paced beyond the site of block, which results in a low pacing threshold with a high success rate in infranodal AVB patients. LBBP improved LV function with stable parameters over the 12 months, making it a reasonable alternative to cardiac resynchronization pacing via a coronary sinus lead in infranodal AVB and PICM patients.

Efficacy of upgrading to left bundle branch pacing in patients with heart failure after right ventricular pacing

BACKGROUND

Chronic right ventricular (RV) pacing is associated with an increased incidence of heart failure and mortality. Left bundle branch (LBB) pacing could produce near-physiological electrical activation and mechanical synchrony. We aimed to report the effects of upgrading to LBB pacing in heart failure patients after chronic RV pacing.

METHODS

The indications included pacing-induced cardiomyopathy (PICM) in Group 1 and heart failure after RV pacing with left ventricular ejection fraction (LVEF) ≥ 50% in Group 2. LBB pacing was achieved by penetrating the pacing lead to the subendocardium of left-sided interventricular septum through the venous access. Left ventricular activation time (LVAT) was measured from the pacing stimulus to the ascending peak of lead V5 or V6. All patients underwent clinical and echocardiographic evaluations before and after upgrading.

RESULTS

Totally 27 patients (13 in Group 1 and 14 in Group 2) were consecutively enrolled. The mean follow-up time after upgrade was 10.4 ± 6.1 months. Paced QRS duration was significantly shortened from 174.1 ± 15.8 milliseconds to 116.6 ± 11.7 milliseconds (p < .0001). The mean LVAT was 83.2 ± 11.7 milliseconds. LVEF increased from 40.3 ± 5.2% before upgrading to 48.1 ± 9.5% at follow-up in patients with PICM. Serum N-terminal probrain natriuretic peptide levels decreased and New York Heart Association classification improved in both groups. No upgrade-related complications were observed.

CONCLUSIONS

Upgrading to LBB pacing was feasible and effective with improved cardiac function in heart failure patients with both reduced and preserved LVEF after RV pacing.

His bundle pacing for cardiac resynchronization therapy: a systematic literature review and meta-analysis

BACKGROUND

Permanent His bundle pacing has been to shown to be an alternative for the patients with CRT indications and more recently has been evaluated for feasibility as a first-line strategy. Data on His bundle pacing (HBP) for cardiac resynchronization therapy are largely limited to small single-center reports, and clinical benefits and risks have not been systematically examined. The purpose of this study was to systematically review published studies of HBP for cardiac resynchronization therapy and evaluate the feasibility and efficacy of the therapy.

METHODS

PubMed, Cochrane Library, Embase, CNKI, and WANFANG databases were searched up to December 2019 to identify relevant studies. Clinical outcomes of interest include implant success rate; Q wave, R wave, and S wave QRS duration; pacing thresholds; left ventricular ejection fraction (LVEF); left ventricular end-diastolic dimension (LVEDD); and New York Heart Association (NYHA) status, complications, and mortality. Extract and summarize the data. Using Revman5.3 software to perform the meta-analysis.

RESULTS

A total of 13 studies involving 503 patients were included. The average implant success rate was 79.8% (95% CI 72.4-87.2%). Permanent HBP resulted in a significant narrow of mean QRS duration from 165.5 ± 8.7 to 122.9 ± 12.0 ms (MD = 43.5, 95%Cl: 36.34 ~ 50.56, p < 0.001). A trend of increase was observed in capture thresholds at follow-up compared with that in the baseline threshold (MD = - 0.24, 95% Cl: - 0.38 ~ - 0.10, p = 0.001). Average NYHA functional class (MD = 1.2, 95% CI: 1.09 ~ 1.31, p < 0.001), LVEF (MD = - 12.60, 95% Cl: - 14.32 ~ - 10.87, p < 0.001), LVEDD (MD = 4.30, 95% Cl: 3.05 ~ 5.55, p < 0.001) significantly improved at > 3 months follow-up compared with that of the baseline (p < 0.001). Ten studies reported safety information and the most commonly reported complication was the increase in HB capture threshold.

CONCLUSIONS

HBP is feasible with a reasonable success rate in patients requiring CRT. HBP could achieve significant narrow of QRS duration and improve left ventricular function during follow-up. Randomized controlled trials are needed to further assess the efficacy of HBP compared with that of biventricular pacing (BVP) in achieving CRT. Graphical abstract Schematic representation of detecting ofloxacin (OFL) by differential pulse voltammetry approach based on the laser modified glassy carbon electrode (LGCE), which increased the active functional groups and surface area compared to GCE.

His Bundle Pacing in Heart Failure-Concept and Current Data

PURPOSE OF REVIEW

His bundle pacing (HBP) has continued to emerge as a viable alternative to both right ventricular pacing (RVP) and cardiac resynchronization therapy. In recent years, a considerable amount of research has been published with regard to using HBP to treat congestive heart failure (CHF) and this article presents a concise yet comprehensive review of this literature.

RECENT FINDINGS

Studies have demonstrated that HBP is useful for CHF patients who are non-responders to biventricular pacing (BiVP) or have a history of previously failed coronary sinus lead placement, right/left bundle branch block cardiomyopathy, or pacing-induced cardiomyopathy. Additionally, HBP is useful in patients with an indication for pacing who are expected to have a RVP burden exceeding 20%. The theoretical benefit of utilizing the native His Purkinje system to excite cardiac tissue is appealing as it can result in true cardiac resynchronization. Limited studies have shown its benefit in reducing heart failure symptoms and improving cardiac function. Larger randomized clinical trials and further investments into developing better technologies are highly desired to make its clinical use sustainable in the long run.

Recent approaches to His-Purkinje system pacing

OBJECTIVE

Physiologic cardiac pacing is a novel technique which has been largely popularized in recent decades. His bundle pacing (HBP) has been long considered the most physiologic pacing method; however, with the widespread implementation of this method, its disadvantages have become apparent. In this context, left bundle branch pacing (LBBP)-directly engaged in the His-Purkinje system-has been foreseen as the best pacing method to mimic physiologic activation patterns. This review aimed to summarize recent approaches to physiologic cardiac pacing.

DATA SOURCES

This review included fully peer reviewed publications up to July 2018, found in the PubMed database using the keywords "His bundle branch pacing," "right ventricular pacing," and "physiologic pacing."

STUDY SELECTION

All selected articles were in English, with no restriction on study design.

RESULTS

The HBP has been studied worldwide, and is currently considered the most physiologic pacing method. However, it has disadvantages, such as high pacing threshold, unsatisfactory sensing and long procedure times, among others. Although LBBP is theoretically superior to HBP, the clinical relevance of this difference remains under debate, as few large randomized clinical trials with LBBP have been published.

CONCLUSIONS

Although HBP indeed appears to be the most physiologic pacing method, it has certain shortcomings, such as high pacing threshold, difficult implantation due to specific anatomic features, and others. Further studies are required to clarify the clinical significance of LBBP.

Adverse Consequences of Right Ventricular Apical Pacing and Novel Strategies to Optimize Left Ventricular Systolic and Diastolic Function

Several studies have focused on the deleterious consequences of Right Ventricular Apical (RVA) pacing on Left Ventricular (LV) function, mediated by pacing-induced ventricular dyssyn-chrony. Therapeutic strategies to reduce the detrimental consequences of RVA pacing have been pro-posed, that includes upgrading of RVA pacing to Cardiac Resynchronization Therapy (CRT), alterna-tive Right Ventricular (RV) pacing sites, minimal ventricular pacing strategies, as well as atrial-based pacing. In developing countries, single chamber RV pacing still constitutes a majority of cases of permanent pacing, and assessment of the optimal RV pacing site is of paramount importance. In chronically-paced patients, it is crucial to maintain as close and normal LV physiological function as possible, by minimizing ventricular dyssynchrony, reducing the chances for heart failure and other complications to develop. This review provides an analysis of the deleterious immediate and long-term consequences of RVA pacing, and the most recent available evidence regarding improvements in pacing options and strategies to optimize LV diastolic and systolic function. Furthermore, the place of advanced echocardiography in the identification of patients with pacing-induced LV dysfunction, the potential role of a new predictor of LV dysfunction in RV-paced subjects, and the long- term out-comes of patients with RV septal pacing will be explored

Permanent His bundle pacing in heart failure patients: A systematic review and meta-analysis

BACKGROUND

Cardiac resynchronization therapy (CRT) is the standard-of-care therapy for the patients with heart failure and left ventricular (LV) dyssynchrony. However, approximately 30% of the patients show no response. Recent studies have shown that His bundle pacing (HBP) could be an alternative for the patients with CRT indications. The purpose of this study was to evaluate the efficacy of HBP in patients with heart failure.

METHODS

We searched PubMed and Embase databases for studies evaluating HBP in patients with heart failure and LV dyssynchrony. The successful rate of implantation, QRS duration, pacing threshold, LV function at baseline and follow-up, and mortality rates were extracted and summarized.

RESULTS

Eleven studies including 494 patients were included in this analysis. The overall successful rate for implantation was 82.4%. The main indications for HBP were CRT candidates and cardiomyopathy with atrial fibrillation undergoing atrioventricular node ablation. Permanent HBP resulted in narrow QRS duration of 116.3 ± 13.9 ms after implantation. LV functions, including echocardiographic parameters and clinical outcomes, significantly improved at follow-up (P < 0.001). However, there was a trend of increased capture and bundle branch block correction thresholds at follow-up compared to baseline (P = 0.01 and 0.02, respectively). During a mean follow-up of 23.7 months, 5.9% of the patients experienced heart failure-related hospitalization and the mortality rate was 9.1%.

CONCLUSION

Permanent HBP has shown promising results for heart failure patients in small observational studies. Randomized controlled trials are needed to assess the efficacy of HBP in these patients.

Updates on His bundle pacing: The road more traveled lately

His bundle pacing (HBP) has continued to evolve over the past decade and has started to become a global phenomenon. Evidence is mounting of its clinical benefits as compared to both right ventricular and left ventricular pacing. In this paper, we review recent data in support of His bundle pacing and some of the challenges facing us as we advocate its increasing role in clinical practice.