Left bundle branch area vs biventricular pacing for cardiac resynchronization therapy: the LEFT-BUNDLE-CRT trial
Óscar Cano1,2,3, Víctor Pérez-Roselló4, Andrea Di Marco3,5,6
1Department of Cardiology, Hospital Universitario y Politécnico La Fe, Planta 4-Torre F, Av. Fernando Abril Martorell, 106, Valencia 46026, Spain.
Insights
Left-bundle branch area pacing (LBBAP) was not found to be non-inferior to biventricular pacing (BiVP) for cardiac resynchronization therapy (CRT). Both LBBAP-CRT and BiVP-CRT demonstrated high patient response rates and similar clinical outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Conduction system pacing offers an alternative to biventricular pacing (BiVP) for cardiac resynchronization therapy (CRT).
- Left-bundle branch area pacing (LBBAP) is a novel conduction system pacing technique.
- Assessing LBBAP's efficacy against BiVP in CRT is crucial.
Purpose of the Study:
- To evaluate if left-bundle branch area pacing (LBBAP) is non-inferior to biventricular pacing (BiVP) for cardiac resynchronization therapy (CRT).
- To compare CRT response rates between LBBAP-CRT and BiVP-CRT in eligible patients.
Main Methods:
- A multi-center, randomized, non-inferiority trial (left-bundle CRT trial) was conducted.
- Patients with CRT indications and left-bundle branch block were randomized to BiVP-CRT or LBBAP-CRT.
- The primary endpoint was a positive CRT response at 6 months, defined by clinical composite score improvement or ≥15% reduction in left ventricular end-systolic volume.
Main Results:
- The study included 176 patients randomized to BiVP-CRT (n=84) or LBBAP-CRT (n=92).
- In intention-to-treat analysis, 94.6% of BiVP-CRT patients and 89.7% of LBBAP-CRT patients achieved the primary endpoint, not meeting non-inferiority.
- Secondary outcomes, adverse events, and heart failure hospitalization rates were similar between the groups.
Conclusions:
- Left-bundle branch area pacing-cardiac resynchronization therapy (LBBAP-CRT) was not non-inferior to biventricular pacing-cardiac resynchronization therapy (BiVP-CRT) in CRT candidates with typical LBBB.
- Both LBBAP-CRT and BiVP-CRT demonstrated high response rates and comparable clinical outcomes.
- Further research may explore optimal patient selection for LBBAP.
Background And Aims:
Conduction system pacing has emerged as an alternative to biventricular pacing (BiVP) for cardiac resynchronization therapy (CRT). The left-bundle CRT trial evaluated whether left-bundle branch area pacing (LBBAP) is non-inferior to BiVP in patients eligible for CRT.
Methods:
The left-bundle CRT trial was a multi-centre, randomized, investigator-initiated, and non-inferiority study. Patients with guideline-based CRT indications and left-bundle branch block per Strauss criteria were randomized to BiVP-CRT or LBBAP-CRT. The primary endpoint was the proportion of patients with a positive CRT response at 6-months, defined as either an improved clinical composite score (CCS) or a ≥15% reduction in left ventricular end-systolic volume. The non-inferiority margin was the lower bound of the 95% confidence interval (CI) and was set at 10%. Patients were followed for 12-months; secondary endpoints included echocardiographic, clinical, and quality-of-life outcomes.
Results:
The baseline characteristics of the 176 patients randomized to BiVP-CRT (n=84) or LBBAP-CRT (n=92) were similar, except for a wider intrinsic QRS in the LBBAP group: median 172 ms [IQR 158-184] vs. 165 ms [152-180]; P=0.04. Crossovers occurred in 26 patients (14.9%). In the intention-to-treat analysis, the primary endpoint was achieved in 94.6% of BiVP-CRT and 89.7% of LBBAP-CRT patients (RR 0.95; 95% CI 0.88-1.02), not meeting non-inferiority. CCS improved in 77% and 68% of patients randomized to BiVP-CRT and LBBAP-CRT, respectively and 85% and 79% had a ≥15% reduction in left ventricular end-systolic volume. Rates of adverse events and heart failure hospitalization were similar between groups.
Conclusions:
In CRT candidates with typical LBBB, LBBAP-CRT was not shown to be non-inferior to BiVP-CRT. Both strategies yielded high response rates and similar clinical outcomes.
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