Abstract 2467: Stentless Aortic Valve Replacement Increased the Requirement for Permanent Pacemaker

BACKGROUND: Stentless aortic valve prosthesis are thought to provide a superior hemodynamic profile compared to mechanical or other tissue valve replacements. Unlike other aortic valve prostheses, stentless valves are most commonly implanted in the subcoronary position, potentially resulting in the placement of sutures in the atrio-ventricular node of the heart’s conduction system. We assessed the incidence of permanent pacemaker insertion following aortic valve replacement. METHODS: We performed a retrospective cohort analysis of all patients who underwent aortic valve replacement at the University of Alberta Hospital between January 1996 and December 2004. The primary outcome was heart block requiring permanent pacemaker insertion. Binary logistic regression analysis was performed to assess the influence of a number of factors on the requirement for permanent pacemaker insertion. RESULTS: In total, 1,451 patients underwent aortic valve replacement (69% male, age 17–92). Permanent pacemaker insertion was required in 32 (5.0%) of 644 patients receiving mechanical valves and in 24 (4.4%) of 543 patients who had a stented tissue aortic valve replacement. In contrast, 27 (10.2%) of 264 patients who had a stentless bioprosthetic valves implanted developed heart block necessitating permanent pacemaker insertion (P = 0.02). Logistic regression demonstrated that implantation of a stentless tissue valve and postoperative inotropic support were the only two significant predictors of the development of heart block following aortic valve replacement. CONCLUSIONS: Aortic valve replacement with a stentless valve prosthesis increases the risk of heart block and the requirement for permanent cardiac pacing.