Abstract 10530: Incidence and Electrocardiographic Predictors of Atrioventricular Conduction Recovery After Permanent Pacemaker Implantation in Transcatheter Aortic Valve Replacement

Background: High grade atrioventricular (AV) block (HGAVB) after transcatheter aortic valve replacement (TAVR) requiring permanent pacemaker implantation (PPM) is a well-established complication, but recovery of intrinsic AV conduction is not well studied. We assessed the incidence and electrocardiography (ECG) predictors of AV conduction recovery after PPM implantation post-TAVR. Methods: In this multicenter, retrospective study, consecutive patients undergoing TAVR between January 2015 to February 2019 were identified. All patients requiring PPM for HGAVB within 30 days after TAVR were included. Follow up ECGs, PPM checks, and clinic notes were reviewed to determine AV conduction recovery, defined as no need for ventricular pacing. Results: There were 533 TAVR patients, 443 with balloon expandable valves (BEV) and 90 with self-expanding valves (SEV). 5.1% of patients (n=27) required PPM for HGAVB, including 4.5% (n=20) from BEV group and 7.8% (n=7) from SEV group. Right bundle branch block (RBBB) was the most common baseline ECG finding (n=19). Mean time to PPM implant was 3.3±4.5 days. 11 patients received leadless and 16 received conventional pacemakers. At 6 months, 65% (n=13) of BEV group and none of SEV group had AV conduction recovery. BEV patients without AV conduction recovery had significantly longer baseline PR intervals compared to those with recovery (248±85 msec vs 169±22 msec; 95% CI 12.5-147.2; p=0.024). There were no significant differences in baseline QRS duration or presence of RBBB between those with and without AV conduction recovery. Conclusion: AV conduction recovery is more frequent after PPM implantation in TAVR patients receiving BEV (65%) compared to SEV (0%). Normal baseline PR intervals at baseline is associated with higher rate of AV conduction recovery among BEV patients. Temporary pacing with leadless pacemakers may be an alternative to conventional pacemakers in BEV patients without baseline first degree AV block.