Left bundle branch area pacing vs right ventricular pacing for atrioventricular block: the MELOS RELOADED study

Area of Science:

• Cardiovascular Medicine
• Electrophysiology
• Cardiac Pacing

Background:

• Left bundle branch area pacing (LBBAP) offers physiological ventricular activation, potentially benefiting patients with atrioventricular block (AVB).
• The long-term mortality impact of LBBAP versus traditional right ventricular pacing (RVP) in AVB patients requires clarification.

Purpose of the Study:

• To compare long-term survival between AVB patients undergoing LBBAP and RVP.
• To identify mortality predictors within the LBBAP cohort.

Main Methods:

• Registry-based study (MELOS RELOADED) including 3382 AVB patients with preserved left ventricular ejection fraction (LVEF >40%) and significant ventricular pacing (>20%).
• 1:1 propensity score matching between LBBAP and RVP groups.
• Kaplan-Meier survival analysis and multivariable Cox proportional hazards models.

Main Results:

• LBBAP demonstrated an 11.8% absolute survival advantage at 4 years (P < .001).
• LBBAP was a significant predictor of reduced mortality (Hazard Ratio: 0.53; P < .001).
• Independent predictors of increased mortality in LBBAP patients included lack of confirmed left bundle branch capture (HR 1.85), lower percentage of ventricular pacing, and advanced age.

Conclusions:

• This study provides the first large-scale evidence of a long-term survival benefit associated with LBBAP in AVB patients.
• LBBAP is a viable pacing strategy for AVB patients with preserved/mildly reduced LVEF, pending randomized trial data.
• Confirmation of successful left bundle branch capture during LBBAP is recommended for optimizing patient outcomes.