Intraprocedural high-degree atrioventricular block or complete heart block in transcatheter aortic valve replacement recipients with no prior intraventricular conduction disturbances

Background Conduction disturbances are the most frequent complication of transcatheter aortic valve replacement (TAVR). However, no data exists regarding the outcomes of intraprocedural high-degree atrioventricular block (HAVB) or complete heart block (CHB) in patients without previous conduction disturbances. Objectives The aim of this study was to evaluate the outcomes of intraprocedural-HAVB/CHB in patients without previous intraventricular conduction disturbances. Methods The occurrence of intraprocedural-HAVB/CHB was assessed in 676 consecutive patients undergoing TAVR, and two groups were established according to its duration: persistent-HAVB/CHB (PHAVB/CHB) and transient-HAVB/CHB (THAVB/CHB), not present at the end of the procedure. Results Intraprocedural-HAVB/CHB occurred in 50 patients (7.4%), being persistent in 32 (64.0%), and transient in 18 (36.0%). The use of Medtronic Corevalve Revalving System (MCRS) and a greater oversizing of the valve increased the risk of intraprocedural-HAVB/CHB (p < 0.001). Permanent pacemaker implantation (PPI) was more frequent in the PHAVB/CHB than in the THAVB/CHB group (96.9% vs. 33.3%; p < 0.001). At 1-month follow-up, the PHAVB/CHB group showed a 98% ventricular pacing rate (VPR) compared to 16% in the THAVB/CHB group (p < 0.001), and similar VPR were observed at 1-year follow-up (98% vs. 37%, p < 0.001). Left ventricular ejection fraction (LVEF) decreased at 1-year follow-up in patients with PHAVB/CHB (-3.9 +/- 1.8%, p = 0.003). Conclusions In TAVR recipients with no prior intraventricular conduction disturbances, intraprocedural-HAVB/CHB occurred in 7.4% of cases. HAVB/CHB was persistent in most cases and determined a high rate of PPI post-TAVR. Very high VPR at 1- and 12-month follow-up were observed, which in turn was associated with a negative effect on LVEF. These results support early PPI and close follow-up in patients developing intraprocedural-PHAVB/CHB.