Left Bundle Branch Block Induced by Transcatheter Aortic Valve Implantation Increases Risk of Death

Study Questions:

What is the clinical outcome of new left bundle branch block (LBBB) that develops during transcatheter aortic valve implantation (TAVI)?

Methods:

The investigators collected data including all-cause mortality rate from a multicenter registry encompassing TAVI patients from 2005 up to 2010. The investigators compared the all-cause mortality rate at follow-up between patients who did and did not develop new LBBB. Of 679 patients analyzed, 57.0% (n = 387) underwent TAVI with the Medtronic CoreValve System (MCS) and 43.0% (n = 292) with the Edwards SAPIEN (ES) valve.

Results:

A total of 233 patients (34.3%) developed new LBBB. The median follow-up period was 449.5 (174-834) days in patients with and 450 (253-725) days in patients without LBBB (p = 0.90). The investigators found that all-cause mortality was 37.8% (n = 88) in patients with and 24.0% (n = 107) in patients without LBBB (p = 0.002). Using multivariate regression analysis, the study authors found that independent predictors of all-cause mortality were: TAVI-induced LBBB (hazard ratio [HR], 1.54; confidence interval [CI], 1.12-2.10), left ventricular ejection fraction ≤50% (HR, 1.38; CI, 1.04-1.85), chronic obstructive lung disease (HR, 1.54; CI, 1.13-2.09), female gender (HR, 1.38; CI, 1.04-1.85), and baseline creatinine (HR, 1.32; CI, 1.19-1.43). LBBB was more frequent after implantation of MCS than after ES (51.1% and 12.0%, respectively, p < 0.001), but device type did not influence mortality risk of TAVI-induced LBBB.

Conclusions:

The investigators concluded that all-cause mortality after TAVI is higher in patients who develop LBBB than in patients who do not, suggesting that TAVI-induced LBBB is an independent predictor of mortality.

Perspective:

LBBB with TAVI is inevitable because of the accompanying calcification of the conduction system in aortic valve disease. This study suggests that LBBB is an important biomarker of mortality following TAVI. The approach to this finding would be firstly, to take care in implantation of the valve particularly with the CoreValve system, and this may require careful imaging (JACC Cardiovasc Imaging 2012;5:441-55) and deployment. Secondly, studies are required to determine whether cardiac resynchronization therapy in those with LBBB after TAVI will reduce mortality risk associated with TAVI.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Valvular Heart Disease, Implantable Devices, EP Basic Science, Cardiac Surgery and Arrhythmias, Cardiac Surgery and CHD & Pediatrics, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Congenital Heart Disease, CHD & Pediatrics and Arrhythmias, CHD & Pediatrics and Quality Improvement, Acute Heart Failure, Heart Failure and Cardiac Biomarkers

Keywords: Heart Valve Prosthesis, Follow-Up Studies, Multivariate Analysis, Heart Defects, Congenital, Ventricular Function, Left, Calcinosis, Creatinine, Electrocardiography, Motor Vehicles, Cardiac Resynchronization Therapy, Incidence, Registries, Pulmonary Disease, Chronic Obstructive, Biological Markers, Heart Failure, Heart Valve Diseases, Bundle-Branch Block, Stroke Volume, Confidence Intervals, Regression Analysis


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