LAUSR

BACKGROUND High-grade atrioventricular block (H-AVB) is a well-described in-hospital complication of transcatheter aortic valve replacement (TAVR). Delayed high-grade atrioventricular block (DH-AVB) has not been systematically studied among outpatients post-TAVR, using latest-generation TAVR technology and in the early post-TAVR discharge era. OBJECTIVES The purpose of this study was to assess utility of ambulatory event monitoring (AEM) in identifying post-TAVR DH-AVB and associated risk factors. METHODS Patients without pre-existing pacing device undergoing TAVR at the University of Colorado Hospital from October 2016 to March 2018, and who did not require permanent pacemaker implantation pre-discharge, were discharged with 30-day AEM to assess for DH-AVB (≥2 days post-TAVR). Clinical and follow-up data were collected and compared among those without incident H-AVB. RESULTS Among 150 consecutive TAVR patients without a prior pacing device, 18 (12%) developed H-AVB necessitating permanent pacemaker <2 days post-TAVR, 1 died pre-discharge, and 13 declined AEM; 118 had 30-day AEM data. DH-AVB occurred in 12 (10% of AEM patients, 8% of total cohort) a median of 6 days (range 3 to 24 days) post-TAVR. DH-AVB versus non-AVB patients were more likely to have hypertension and right bundle branch block (RBBB). Sensitivity and specificity of RBBB in predicting DH-AVB was 27% and 94%, respectively. CONCLUSIONS DH-AVB is an underappreciated complication of TAVR among patients without pre-procedure pacing devices, occurring at rates similar to in-hospital, acute post-TAVR H-AVB. RBBB is a risk factor for DH-AVB but has poor sensitivity, and other predictors remain unclear. In this single-center analysis, AEM was helpful in expeditious identification and treatment of 10% of post-TAVR outpatients. Prospective study is needed to clarify incidence, risk factors, and patient selection for outpatient monitoring.