Predictors for new-onset complete heart block after transcatheter aortic valve implantation.

OBJECTIVES: The aim of this study was to identify risk factors for new-onset atrioventricular (AV) block requiring pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI).

BACKGROUND: High-grade AV block and consecutive PM implantation are frequent complications following TAVI.

METHODS: For logistic regression analysis, we included 159 patients (mean age: 81 +/- 6 years, EuroSCORE: 22 +/- 13%) who underwent TAVI (n = 116 transfemoral, n = 4 via subclavian artery, n = 37 transapical, n = 2 transaortic) between June 2007 and January 2009 and who had no previously implanted PM.

RESULTS: Thirty-five patients (22%) developed new-onset post-operative AV block with the need of PM implantation. Logistic regression revealed a 2-fold increased risk for new-onset AV block in patients in whom a large valve is implanted in a small annulus (32% pacemaker implantations, odds ratio [OR]: 2.378, p = NS), a 4-fold increased risk with the implantation of the CoreValve (Medtronic, Minneapolis, Minnesota) versus the Edwards Sapien valve (Edwards Lifesciences, Irvine, California) (27% pacemaker implantations, OR: 3.781, p = NS), and a 5-fold increased risk for patients who exhibit an AV block episode instantly during the implantation procedure (49% pacemaker implantations, OR: 4.819, p = 0.001). Pre-existing ECG alterations were not identified as risk factors for AV block after transcatheter aortic valve implantation.

CONCLUSIONS: We assume that conduction tissue impairment is provoked by mechanical compression with large prostheses in smaller annuli or in the larger area of the CoreValve covering the outflow tract and may appear instantly during the implantation procedure. Continuous post-operative electrocardiogram monitoring should be performed for at least 3 days in all patients after TAVI procedures and until discharge in patients with increased risk for this complication.