Predictors for Permanent Pacing After Transcatheter Aortic Valve Implantation

Background: Transcatheter aortic valve implantation (TAVI) is a new treatment strategy for patients with symptomatic aortic stenosis who are high risk for traditional surgical aortic valve replacement. The incidence of conduction system abnormalities after the procedure is significant. We examine our experience with Core Valve TAVI focusing on electrocardiographic changes found pre-, peri-, and postintervention. Methods: During 2007-08 we undertook 33 cases utilizing the Core Valve revalving system (Core Valve, Paris, France). Assessment of ECGs, with particular reference to the PR and QRS duration, was made daily during each patient's hospital stay. Results: Patients were aged 81.7 +/- 6.7 years and the majority were male (57%). Baseline cardiac rhythm was sinus (n = 28, 80%); atrial fibrillation (n = 6, 18%) or ventricular paced (n = 1, 3%). Following Core Valve implantation, prolongation of both the PR interval and QRS duration was seen. Preprocedural PR interval was 193.5 +/- 38.7 ms and QRS interval preprocedure was 115.3 +/- 24.8 ms. PR interval increased after the procedure by 23.5 +/- 23.9 ms and peaked at day 4 with a mean increase of 66.1 +/- 72.7 ms. QRS duration increased by a mean of 30.6 +/- 26.1 ms postprocedure and remained stable thereafter during the remaining hospital stay. The need for PPM insertion was partially predicted by pre-procedural QRS morphology: patients with pre-existing right bundle branch block had an 83% chance of requiring a permanent pacemaker (P < 0.01 OR 28 95%CI 2.4-326.7); those with LBBB had a 33% chance of requiring a pacemaker (P = ns OR 2.3 95%CI 0.2-34.9). Patients undergoing the procedure later in our experience showed a decreased incidence of pacing (P = 0.046 OR 0.36 95% CI 0.07-1.82). Pre-procedural annulus measurements also predicted the requirement for pacing with larger annulus sizes more likely to require a pacemaker (P = 0.044 OR 3.3 95% Cl 0.63-17.6). The requirement for pacing was not predicted by age, baseline PR interval or gender. Requirement for pacing overall was 32% with an additional 13% having had a pacemaker inserted prior to the TAVI. Conclusion: Core Valve insertion was associated with an increase in PR interval and QRS duration. PR interval continued to rise during admission, peaking on Day 4 post procedure, making a prolonged period of monitoring highly desirable. There was a significant requirement for permanent pacing, which was predicted by pre-procedural QRS morphology, annulus measurement, and the learning curve. (C) 2010 Wiley-Liss, Inc.