Introduction Permanent pacemaker implantation (PPM) following transcatheter aortic valve implantation (TAVI) is a recognised complication. However, the higher pacing rate post CoreValve TAVI compared to SAVR (33% vs 8%) is a cause for concern. Several factors including pre-existing bundle branch block (BBB), larger valve size, post dilatation and low implantation have been shown to independently impact on an increased risk of PPM requirement. Depth of CoreValve implantation below the aortic annulus can result in compression of conduction tissue and heart block and is therefore an important predictor of PPM requirement. A modified delivery catheter (ACCUTRAK) was introduced to address this by providing more controlled release of the prosthesis, preventing low implantation, thereby reducing the pacing rate. We evaluated the pacing rate in our cohort of patients (pts) and the effect of the new Accutrak catheter on the pacing rate.
Methods TAVI was performed in 91 patients, mean age (82.9 years). The trans-femoral route (72 patients), the left subclavian route (15 patients) and direct aortic approach (4 patients) was used with a consistently high valve deployment strategy of 3–5 mm below the aortic annulus. 46 patients had TAVI with pre-Accutrak catheter and 35 patients with the Accutrak catheter. Procedural outcomes were analysed (Abstract 043 table 1) with detailed evaluation of pre-TAVI PPM, pre-procedure ECG, annulus size, pre-dilatation balloon size, CoreValve size, and post-dilatation in the two different groups.
Results 81 patients of the 91 had no pre-existing PPM. CoreValve prosthesis was deployed high, 3–5 mm, below aortic annulus. Factors previously identified as predictors of PPM requirement post TAVI, were similar in both groups (Abstract 043 table 2). A total of eight patients required a new PPM with a pacing rate post TAVI of 9.8%. There were 5 PPM implantations in the pre-Accutrak group and 3 in the Accutrak group. In the pre-Accutrak ppm group, 2 patients had sinus rhythm (SR) plus LBBB,1 AF and LBBB,1SR with RBBB and 1SR. In the Accutrak PPM group (3 patients) 2 had SR with RBBB and 1 with SR and 1st degree heart block. There was no significant difference in the pacing rate between the pre-Accutrak (10.9%) and post-Accutrak (8.6%) groups (p=1.0) in this matched cohort.
Conclusion The pacing rate was 9.8% post CoreValve TAVI, which is significantly lower compared to previous estimates. The reduction in pacing rate was due to a successful high deployment strategy and was independent of the Accutrak delivery system. Although the Accutrak catheter has modified CoreValve deployment, it appears to have had little impact on the pacing rate in our cohort. Further evaluation is required to establish whether the Accutrak delivery catheter facilitates a lower pacing rate in middle to low CoreValve implanting centres. We advocate a high CoreValve deployment strategy to ensure a lower pacing rate.
- Transcatheter aortic valve implantation
- permanent pacemakers
- new delivery catheter