Left bundle-branch block induced by transcatheter aortic valve implantation increases risk of death.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a novel therapy for treatment of severe aortic stenosis. Although 30% to 50% of patients develop new left bundle-branch block (LBBB), its effect on clinical outcome is unclear. METHODS AND
RESULTS: Data were collected in a multicenter registry encompassing TAVI patients from 2005 until 2010. The all-cause mortality rate at follow-up was compared between patients who did and did not develop new LBBB. Of 679 patients analyzed, 387 (57.0%) underwent TAVI with the Medtronic CoreValve System and 292 (43.0%) with the Edwards SAPIEN valve. A total of 233 patients (34.3%) developed new LBBB. Median follow-up was 449.5 (interquartile range, 174-834) days in patients with and 450 (interquartile range, 253-725) days in patients without LBBB (P=0.90). All-cause mortality was 37.8% (n=88) in patients with LBBB and 24.0% (n=107) in patients without LBBB (P=0.002). By multivariate regression analysis, independent predictors of all-cause mortality were TAVI-induced LBBB (hazard ratio [HR], 1.54; confidence interval [CI], 1.12-2.10), chronic obstructive lung disease (HR, 1.56; CI, 1.15-2.10), female sex (HR, 1.39; CI, 1.04-1.85), left ventricular ejection fraction ≤50% (HR, 1.38; CI, 1.02-1.86), and baseline creatinine (HR, 1.32; CI, 1.19-1.43). LBBB was more frequent after implantation of the Medtronic CoreValve System than after Edwards SAPIEN implantation (51.1% and 12.0%, respectively; P<0.001), but device type did not influence the mortality risk of TAVI-induced LBBB.
CONCLUSIONS: All-cause mortality after TAVI is higher in patients who develop LBBB than in patients who do not. TAVI-induced LBBB is an independent predictor of mortality.