Incidence and Predictors of Pacemaker Implantation in Patients Undergoing Transcatheter Aortic Valve Replacement.

Background: Transcatheter aortic valve replacement (TAVR) has emerged as an alternative treatment for patients with symptomatic aortic stenosis who are at high risk for surgical aortic valve replacement. The development of conduction abnormalities is a major complication in the postprocedural period of TAVR.

Objectives: The objective of this study was to investigate the development of postprocedural conduction abnormalities and the requirement of permanent pacemaker (PPM) implantation in patients undergoing TAVR.

Methods: Data from 137 consecutive patients who underwent TAVR (Edwards SAPIEN valve, Edwards Lifesciences, Irvine, CA, USA) between June 2008 and October 2012 were reviewed. Patients with prior history of PPM (n = 27) were excluded. The role of various predictors for pacemaker implantation after TAVR, including the valve index (calculated as [valve size/left ventricular outflow tract diameter] × 100) was investigated.

Results: A total of 31/110 (28.2%) patients required implantation of a PPM after TAVR. The median time to implantation of a PPM was 5 days after the procedure. The development of postprocedural complete heart block was the most common indication for implantation of a PPM (16/31; 51.6%). On multivariate analysis, the presence of preexisting right bundle branch block (RBBB) was found to be a strong predictor of PPM implantation after TAVR (adjusted odds ratio: 4.87; 95% confidence interval: 1.29-18.46, P = 0.020). Using the receiver operated curve analysis, a cut-off value of valve index of 128 was found to be a strong predictor for PPM implantation with a sensitivity of 73% and specificity of 61% (c statistic = 0.68).

Conclusions: This study identified the presence of prior RBBB and a valve index of 128 as important risk factors for PPM implantation after TAVR. A larger implanted valve size relative to left ventricular outflow tract diameter leads to a greater compression of the intrinsic conduction system, increasing the need for pacemaker placement.