Left Ventricular Activation Time Shortening With Conduction System Pacing vs Biventricular Resynchronization Therapy - LEVEL-AT

Nov 09, 2022
Font Size
A
A
A
Author/Summarized by Author:
Dharam J. Kumbhani, MD, SM, FACC
Summary Reviewer:
Deepak L. Bhatt, MD, MPH, MBA, FACC
Date Presented:
10/26/2022
Date Updated:
11/09/2022
Original Posted Date:
11/09/2022
References

Contribution To Literature:

The LEVEL-AT trial showed that ventricular synchronization achieved with conduction system pacing is noninferior to conventional BiV pacing among eligible patients.

Description:

The goal of the trial was to evaluate whether conduction system pacing would be noninferior to biventricular (BiVP) pacing.

Study Design

Patients were randomized in a 1:1 fashion to either conduction system pacing (n = 35) or BiV pacing (n = 35). BiV pacing devices were implanted according to usual practice. The preferred placement of the LV lead was posterolateral or lateral. The conduction system lead was initially placed at the His-Purkinje system. After the first month of the study, the protocol was amended to allow both strategies (His bundle pacing [HBP] or left bundle branch pacing [LBBP]) to be selected according to operator discretion. 

Only four of the patients allocated to conduction system pacing received HBP, while His pacing was pursued in 20% of patients allocated to conduction system pacing, with an implant success in 57% of patients. In 28 of 35 patients, LBBP was pursued with an implant success in 82%. There were eight crossovers from conduction system pacing to BiV pacing.

  • Total screened: 80
  • Total randomized: 70
  • Duration of follow-up: 45 days
  • Mean patient age: 66 years
  • Percentage female: 30%

Inclusion criteria:

  • Age ≥18 years
  • Symptomatic patients with heart failure on optimal medical treatment with left ventricular ejection fraction (LVEF) ≤35%
  • Wide QRS complex (left bundle branch block [LBBB] interval ≥130 ms or QRS ≥150 milliseconds in non-left branch block)
  • Indication for cardiac resynchronization therapy (CRT) due to atrioventricular (AV) block and cardiac dysfunction

Exclusion criteria:

  • Myocardial infarction
  • Unstable angina
  • Cardiac revascularization or valve surgery/intervention within 3 months before assessment

Other salient features/characteristics:

  • LBBB: 61%
  • Permanent atrial fibrillation: 8%
  • LVEF: 28%
  • Use of beta-blockers at baseline: 85%

Principal Findings:

The primary outcome, change in LV activation time from baseline on electrocardiographic imaging, for conduction system pacing vs. BiV pacing, was: -28 vs. -21 (p for noninferiority < 0.001; p for superiority = 0.24).

Secondary outcomes for conduction system pacing vs. BiV pacing:

  • Change in QRS from baseline: -53 vs. -48 msec (p = 0.23)
  • Change in LVEF at 6 months compared with baseline: 12.2% vs. 13.1% (p = 0.69)
  • Heart failure hospitalization or mortality at 6 months: 1% vs. 4% (p = 0.16)

Interpretation:

The results of this trial show that ventricular synchronization achieved with conduction system pacing is noninferior to conventional BiV pacing among eligible patients. Conduction system pacing included His-bundle pacing but was primarily via LBB pacing. This approach appears promising and will need to be tested in future trials. There appears to be a high rate of crossover to BiV pacing; in the current trial, nearly 1 in 4-5 patients required crossover.

References:

Pujol-Lopez M, Jiménez-Arjona R, Garre P, et al. Conduction System Pacing vs Biventricular Pacing in Heart Failure and Wide QRS Patients: LEVEL-AT Trial. JACC Clin Electrophysiol 2022;Oct 26:[Epub ahead of print].

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure

Keywords: Adrenergic beta-Antagonists, Arrhythmias, Cardiac, Atrial Fibrillation, Atrioventricular Block, Bundle of His, Bundle-Branch Block, Cardiac Resynchronization Therapy, Electrocardiography, Heart Failure, Pacemaker, Artificial, Stroke Volume, Ventricular Function, Left


< Back to Listings