Left vs. Normal QRS Axis During Left Bundle Branch Block Induced by Transcatheter Aortic Valve Replacement: 3-Year...

Area of Science:

• Cardiology
• Interventional Cardiology
• Cardiac Electrophysiology

Background:

• The clinical significance of left QRS axis deviation (LAD) in patients developing new-onset left bundle branch block (LBBB) following transcatheter aortic valve replacement (TAVR) is not well-defined.
• Understanding this specific subgroup is crucial for optimizing post-procedural management.

Purpose of the Study:

• To investigate the clinical impact and long-term outcomes of new-onset LBBB with LAD (LBBB _LAD) compared to LBBB with a normal QRS axis (LBBB _NA) after TAVR.
• To identify predictors of LBBB _LAD and its association with adverse clinical events.

Main Methods:

• A retrospective analysis of 254 patients who experienced new-onset LBBB post-TAVR.
• Comparison of clinical and echocardiographic outcomes between LBBB _LAD (QRS axis <-30°) and LBBB _NA groups at 3-year follow-up.
• Multivariable analysis to determine independent predictors of LBBB _LAD and permanent pacemaker implantation (PPI).

Main Results:

• 38% of patients (96/254) developed LBBB _LAD, predicted by a more leftward preprocedural QRS axis.
• No significant differences in all-cause death, cardiovascular death, or heart failure rehospitalization between groups at 3 years.
• LBBB _LAD was associated with a significantly higher incidence of PPI (16% vs. 6%, P=0.02) and was an independent predictor of PPI (HR 2.46, P=0.04).

Conclusions:

• Post-TAVR LBBB _LAD necessitates a higher rate of permanent pacemaker implantation compared to LBBB _NA.
• LBBB _LAD does not appear to be associated with increased mortality or heart failure events at 3-year follow-up.
• Enhanced and prolonged rhythm monitoring should be considered for patients with post-TAVR LBBB _LAD.