Factors predicting and having an impact on the need for a permanent pacemaker after CoreValve prosthesis implantation using the new Accutrak delivery catheter system

Abstract

Objectives: The purpose of this study was to evaluate the need for a permanent pacemaker after transcatheter aortic valve implantation with the CoreValve prosthesis (Medtronic, Inc., Minneapolis, Minnesota) using the new Accutrak delivery system (Medtronic, Inc.).

Background: The need for a permanent pacemaker is a recognized complication after transcatheter aortic valve implantation with the CoreValve prosthesis.

Methods: Between April 23, 2008 and May 31, 2011, 195 consecutive patients with symptomatic aortic valve stenosis underwent transcatheter aortic valve implantation using the self-expanding CoreValve prosthesis. In 124 patients, the traditional delivery system was used, and in 71 patients, the Accutrak delivery system was used.

Results: There were no significant differences in baseline electrocardiographic characteristics between the traditional system and the Accutrak patients: PR interval: 153 ± 46 mm versus 165 ± 30 mm, p = 0.12; left bundle branch block: 22 (20.2%) versus 8 (12.7%), p = 0.21; right bundle branch block: 21 (19.3%) versus 8 (12.7%), p = 0.26. The depth of the prosthesis in the left ventricular outflow tract was greater with the traditional system than with the Accutrak system (9.6 ± 3.2 mm vs. 6.4 ± 3 mm, p < 0.001) and the need for a permanent pacemaker was higher with traditional system than with Accutrak (35.1% vs. 14.3%, p = 0.003). The predictors of the need for a pacemaker were the depth of the prosthesis in the left ventricular outflow tract (hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 1.08 to 1.34, p < 0.001), pre-existing right bundle branch block (HR: 3.5, 95% CI: 1.68 to 7.29, p = 0.001), and use of the traditional system (HR: 27, 95% CI: 2.81 to 257, p = 0.004).

Conclusions: The new Accutrak delivery system was associated with less deep prosthesis implantation in the left ventricular outflow tract, which could be related to the lower rate of permanent pacemaker requirement.