Risk Factors for High Grade AV Block post-Trans-Catheter Aortic Valve Implantation (TAVI) Using the Medtronic CoreValve™

Abstract

Background: High grade AV block (HGAVB) is a known complication of TAVI using the Medtronic CoreValve™. We aimed to identify risk factors for persistent HGAVB following CoreValve™ implantation. Methods: We retrospectively analysed peri-operative characteristics of 61 consecutive patients between November 2008 and March 2012 for predictors of persistent HGAVB. HGAVB was defined as type 2 second-degree AV block, 2:1 AV block, or third-degree AV block. Risk factors were determined with binary logistic regression using the following input variables: age, pre-procedural PR & QRS intervals, valvuloplasty balloon:annulus ratio, device size:annulus ratio and occurrence of any intra-procedural HGAVB. Statistical analysis was performed using the SPSS 20.0 statistical program. Results: Fifty-four patients (mean age 82 ± 5 years, 65% male) were analysed (seven patients with pre-existing pacemakers were excluded). Prior to TAVI, nine patients had first-degree AV block (17%), two had left bundle branch block (4%), four had right bundle branch block (7%), and three had a non-specific intra-ventricular conduction delay (6%). Fourteen patients (26%)developed persistent HGAVB post-CoreValve™ insertion, thirteen of whom survived to pacemaker implantation. In 12/14 the onset of HGAVB was within seven days of the index procedure. Intra-procedural HGAVB was the only significant predictor of persistent HGAVB following TAVI with CoreValve™ (OR 38.9, 95% CI 1.3–153.4, p < 0.05). Conclusion: One in four patients can be expected to develop persistent HGAVB, usually within seven days of CoreValve™ implantation. Intra-procedural HGAVB is a significant predictor of persistent HGAVB and suggests the need for an appropriate period of monitoring.