Left bundle branch area pacing versus endocardial resynchronization in patients with heart failure.

Left bundle branch area pacing (LBBAP) and endocardial resynchronization (Endo-CRT) are alternatives to biventricular pacing for cardiac resynchronization therapy (CRT). To compare the outcomes of LBBAP versus Endo-CRT using conventional pacing leads. Patients with heart failure (HF) undergoing CRT with LBBAP or Endo-CRT were included. The primary efficacy outcome was a composite of HF-related hospitalization and all-cause mortality. The primary safety outcome was any procedure-related complication. Secondary outcomes included procedural characteristics, electrocardiographic, and echocardiographic parameters. A total of 223 patients (LBBAP n = 197, Endo-CRT n = 26; mean age 69 ± 10.3 years, 32.3% female) were included. Patients in the LBBAP group had lower NYHA class, shorter preprocedural QRS durations (161 [142-183] vs. 180 [170-203] msec, p < .001), and a lower preprocedural spironolactone use (57.4% vs. 84.6%, p = .009) than patients in the Endo-CRT group. Fluoroscopy time was significantly shorter in patients undergoing LBBAP (11.4 [7.2-20] vs. 23 [14.2-34.5] min; p < .001). There was no significant difference in the primary efficacy outcome between both groups (Cox proportional HR 1.21, 95% CI 0.635-2.31; p = .56). During follow-up, patients undergoing LBBAP had a lower incidence of stroke than patients in the Endo-CRT group (0% vs. 11.5%, p = .001). Postprocedural LVEF (35% [25-45] vs. 40% [20-55]; p = .307) and change in LVEF (7% [0-20] vs. 11% [2-18]; p = .384) were similar between the LBBAP and the Endo-CRT groups, respectively. LBBAP and Endo-CRT using conventional leads are associated with similar mortality and HF-related hospitalization, as well as improvements in LVEF. Endo-CRT is associated with longer fluoroscopy times and a higher risk of stroke.

Diaz JC ，Bastidas O ，Aristizabal J ，Marin J ，Niño C ，Moreno S ，Ruiz LM ，Caceres M ，Jaraba E ，Cabanillas N ，Duque M ... -  《-》

Biventricular endocardial pacing and left bundle branch area pacing for cardiac resynchronization: Mechanistic insights from electrocardiographic imaging, acute hemodynamic response, and magnetic resonance imaging.

Biventricular endocardial pacing (BiV-endo) has demonstrated superior cardiac resynchronization compared to conventional biventricular epicardial pacing (BiV-epi). Left bundle branch area pacing (LBBAP) may also achieve effective cardiac resynchronization therapy (CRT). The purpose of this study was to compare the acute electrical and hemodynamic effects of BiV-epi, BiV-endo, and LBBAP delivered from the LV endocardium and to assess how myocardial scar affects response. Eleven patients with heart failure and indications for CRT underwent a temporary pacing study with electrocardiographic imaging (ECGi) and hemodynamic assessment. BiV-endo was delivered by stimulation of the left ventricular (LV) lateral wall, and LBBAP was delivered by stimulation of the LV septum, at the site of a Purkinje potential. LV activation time (LVAT-95), LV dyssynchrony index (LVDI), biventricular activation time (BIVAT-90), and biventricular dyssynchrony index (BIVDI) were calculated. Myocardial scar was assessed using magnetic resonance imaging (MRI). The protocol was completed in 10 patients. Compared to BiV-epi (LVAT-95: 79.2 ± 13.1 ms; LVDI: 26.6 ± 3.4 ms) LV resynchronization was superior during BiV-endo (LVAT-95: 48.5 ± 14.9 ms; P = .001; LVDI: 16.6 ± 6.4 ms; P = .002) and LBBAP (LVAT-95: 48.9 ± 12.5 ms; P = .001; LVDI: 15.3 ± 3.4 ms; P = .001). Biventricular resynchronization was similarly superior during BiV-endo and LBBAP vs BiV-epi (BIVAT-90 and BIVDI; P <.05). The rate of acute hemodynamic responders was higher during BiV-endo (90%) and LBBAP (70%) vs BiV-epi (50%). The benefits of LBBAP (but not BiV-endo) on LV resynchronization were attenuated when septal scar was present in a subset of 8 patients who underwent MRI. Our findings suggest superior electrical resynchronization and a higher proportion of acute hemodynamic responders during BiV-endo and LBBAP compared to BiV-epi. Electrical resynchronization was similar between BiV-endo and LBBAP; however, septal scar seemed to attenuate response to LBBAP.

Elliott MK ，Strocchi M ，Sieniewicz BJ ，Sidhu B ，Mehta V ，Wijesuriya N ，Behar JM ，Thorpe A ，Martic D ，Wong T ，Niederer S ，Rinaldi CA ... -  《-》

Left bundle branch area pacing for atrioventricular block and mild to moderately reduced left ventricular systolic function.

The clinical efficacy of left bundle branch area pacing (LBBAP) has not been fully elucidated in patients with atrioventricular block and mild to moderately reduced left ventricular ejection fraction (LVEF). This study evaluated the impact of LBBAP on patients with an LVEF of ≤50% and dependent on ventricular pacing. Thirty-seven patients with atrioventricular block underwent successful LBBAP. All patients had a reduced LVEF of 36%-50% and underwent pacemaker implantation. Ventricular pacing was performed using the LBBAP alone throughout the follow-up period. Clinical outcomes, including death from any cause, fatal ventricular arrhythmias, hospitalization for heart failure, and echocardiographic improvements after 1 year, were assessed. Thirty-three (89%) patients were free from the composite endpoint during a median follow-up of 36 months, whereas four patients experienced noncardiovascular deaths or hospitalization for heart failure. No fatal ventricular arrhythmias occurred. LVEF was improved using LBBAP from 42.6 ± 4.7% to 52.1 ± 9.1% (p < .001). LVEF normalization (>50%) was achieved in 64.5% of patients, while in 11 patients LVEF remained stable demonstrating no deterioration (from 42.5 ± 4.7% to 42.4 ± 6.3%). Nonischemic cardiomyopathy (odds ratio, 21.52; 95% confidence interval, 1.96-236.45) and Pre-existing bundle branch block (odds ratio, 11.79; 95% confidence interval, 1.11-125.75) were independent preoperative predictors of LVEF normalization using LBBAP. LBBAP significantly improved cardiac systolic dysfunction without causing fatal ventricular arrhythmias. Moreover, LBBAP may provide a promising alternative to biventricular pacing in patients with atrioventricular block and a reduced LVEF of 36%-50%.

Kato H ，Sato T ，Shimeno K ，Mito S ，Nishida T ，Soejima K ... -  《-》

His bundle pacing versus left bundle branch area pacing in patients undergoing atrioventricular node ablation: A prospective and comparative study.

Pacemaker implantation combined with atrioventricular node ablation (AVNA) is a well-established strategy for uncontrolled atrial arrhythmias. Limited data are available regarding His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in this setting. To compare the outcomes of HBP and LBBAP in patients undergoing pacemaker implantation combined with AVN in routine clinical practice. We prospectively included all patients who underwent AVNA after successful conduction system pacing (CSP) in two hospitals between September 2017 and May 2023. The primary outcome was the 1-year composite of first episode of heart failure hospitalization, symptomatic atrioventricular node reconduction requiring a second AVNA procedure, lead revision or death from any cause. A total of 164 patients underwent AVNA following successful CSP (68 HBP and 96 LBBAP). Mean pacemaker implantation and AVNA procedure times were shorter in the LBBAP group than the HBP group (46±18 vs 59±23min; P<0.001 and 31±12 vs 43±22min, respectively; P<0.001). Complete atrioventricular block was more frequently obtained in the LBBAP group (88/96 patients [92%] vs 54/68 patients [79%]; P=0.04). One-year freedom from the composite outcome was more frequent in the LBBAP group (89.7% vs 72.9%; hazard ratio 0.32, 95% confidence interval 0.14-0.72; P=0.01). The strategy was similarly effective in both groups with a significant improvement in NYHA class and left ventricular ejection fraction. A secondary pacing threshold elevation >1V occurred only in the HBP group (11%). In this prospective, comparative study, LBBAP provided better 1-year outcomes than HBP.

Chaumont C ，Azincot M ，Savouré A ，Auquier N ，Hamoud RA ，Popescu E ，Viart G ，Mirolo A ，Eltchaninoff H ，Anselme F ... -  《-》

Cardiac resynchronization therapy guided by interventricular conduction delay: How to choose between biventricular pacing or conduction system pacing.

Biventricular pacing (BIV) is the gold standard for cardiac resynchronization therapy (CRT). Thirty percent of patients do not respond to CRT. Conduction system pacing (CSP) represents a viable alternative. Interventricular conduction delay (IVCD), as electrical desynchrony marker, is a CRT response predictor. The aim of this study was to determine the incidence of CRT responders by selecting the best approach between BIV and CPS based on intraoperative IVCD measurement in patients with HFrEF and LBBB. Ninety-six patients were randomly assigned in a 1:1 ratio to either a standard BIV group(control group, CG) or a group where the CRT approach was determined based on IVCD evaluation(study group, SG). If the right ventricular sensed electrogram (RVs)-left ventricular sensed electrogram (LVs) interval was ≥100 ms, the lead was left in its original position; otherwise, the LV lead was removed, and CSP was performed instead. Clinical, EKG, and echocardiographic features have been assessed pre- and 6 months post-implant. Echocardiographic and clinical responder were evaluated. Thirty-seven percent of patients in the SG underwent CSP, as the operative algorithm. The incidence of CRT responders was significantly higher in the SG (echocardiographic criterion: 92.5% vs. 69.8%, p:.009; clinical criterion 87.5% vs. 62.8%, p:.014). The SG showed a significantly greater difference in EF between pre- and post-implant as well as reduced end-diastolic and systolic volumes. Univariate and multivariate regression analysis indicated that enrollment in the SG was the only factor associated with CRT response. Intraoperative assessment of IVCD could help determine the optimal CRT approach between BIV and CSP, leading to a significant improvement in the rate of CRT responders.

Marallo C ，Landra F ，Taddeucci S ，Collantoni M ，Martini L ，Lunghetti S ，Pagliaro A ，Menci D ，Baiocchi C ，Fineschi M ，Santoro A ... -  《-》