COMPLETE ATRIOVENTRICULAR BLOCK FOLLOWING SURGICAL VALVE REPLACEMENT: ARE PATIENTS STILL PACED AT 1 YEAR FOLLOW-UP?

Abstract

Complete atrioventricular (AV) block after valve replacement often recovers in many cases few days after surgery. However, 3% will require the implantation of a permanent pacemaker (PP) for postoperative AV block. We aim to assess the recovery of complete AV block twelve months after PP implantation following surgical valve replacement and to determine which clinical factors predict long term pacing requirement. We retrospectively reviewed all 3092 patients operated for isolated aortic and/or mitral valve replacement in our institution from 2006 -2018. Overall, 137 (4.4%) patients required a PP for postoperative complete AV block. Preoperative EKGs and pacemaker interrogation at 12 months were reviewed. Mean age at surgery was 69.7 ± 10.2 years and 57% were female. Mean ejection fraction was 54.6 ± 12.3%. Preoperative baseline EKG showed sinus rhythm (n=111), atrial fibrillation (n=24), first-degree AV block (n=24), left bundle branch block (n=20) and right bundle branch block (n=16). Forty-eight (35%) patients had a previous sternotomy. Fifty-two patients had aortic valve replacement, 54 patients had mitral valve replacement and 31 had bivalvular procedure. Forty-four patients had a concomitant tricuspid annuloplasty. Cardio-pulmonary bypass mean time was 113.5 ± 47 minutes and mean cross-clamp time was 84.5 ± 40 minutes. All patients received their PP within 30 days of the initial surgery (mean time: 7,2 ± 4,49 days postop). Single-chamber, dual-chamber and biventricular devices we implanted in respectively 31, 90 and 16 patients. Mean and median % of ventricular pacing at 12 months follow-up was respectively 55.5% , 43.5 % and 70%. One patient died in-hospital and three within one year (2 were pacemaker dependent), none had conduction disorder preop. Overall survival at 6 years was 78%. The majority of patients who required a PP after surgery for AV block are still paced (RV paced) twelve months after aortic or mitral valve replacement. Redo surgery and preop left bundle branch block are risk factors for permanent complete AV block.View Large Image Figure ViewerDownload Hi-res image Download (PPT)