Risk Factors for Postoperative Pacemaker Implantation After Rapid Deployment Aortic Valve Replacement: Results from the RADAR Registry.

Introduction: Rapid deployment aortic valve replacement has been recently introduced in clinical practice. Different studies have reported a significant reduction in surgical times with excellent hemodynamic profiles and short-term results. However, an increase in permanent pacemaker requirements compared with conventional aortic valve replacement has been described. Nevertheless, risk factors for postoperative pacemaker implantation are not well known. The aim of this study is to report our early outcomes with rapid deployment aortic valve replacement within the RADAR Registry, especially focusing on risk factors for postoperative pacemaker implantation.

Methods: Between April 2012 and January 2016, 164 patients undergoing isolated or combined aortic valve replacement with Edwards INTUITY Elite (Edwards Lifesciences, Irvine, CA, USA) were included in the RADAR Registry. Pre-, intra- and postoperative clinical data results and complications were recorded, especially focusing on risk factors for the development of postoperative complete or high-grade AV block requiring pacemaker implantation. Patients were followed up for up to 1 year with evaluation of clinical and echocardiographic outcomes.

Results: A total of 164 consecutive patients were included in this study, where 128 patients (78.05%) had an isolated aortic valve replacement (group 1) and 36 (21.95%) a concomitant procedure (group 2). The surgical approach was ministernotomy in 61 patients (37.20%) and median sternotomy in 100 patients (60.98%). Complications with valve implantation were observed in three patients. Postoperative complete or high-degree AV block requiring a permanent pacemaker implantation developed in ten patients (6.9%). Seven patients died in-hospital (4.27%). No significant differences between groups were found in terms of stroke, postoperative infection, mortality, atrial fibrillation and postoperative atrioventricular block. Seven patients presented acute renal impairment (5.51%) in group 1 versus seven patients (20%) in group 2 (p = 0.007). In multivariate analysis, low weight and preoperative arrhythmia (atrial fibrillation, bifascicular block, left bundle branch block) emerged as risk factors for postoperative AV block requiring a pacer. In median follow-up of 1 year, seven (4.27%) patients died, and no cases of structural valve deterioration or endocarditis were observed. Significant patient-prosthesis mismatch was found in seven (4.27%) patients.

Conclusion: Initial experience with rapid deployment aortic valve replacement in the RADAR Registry demonstrates low rates of implantation complications and good perioperative and 1-year clinical and echocardiographic outcomes. Incidence of postoperative AV block requiring a pacer correlated with low weight and preoperative arrythmias (atrial fibrillation, bifascicular block and left bundle branch block). Avoidance of oversizing and careful consideration of implantation of this technology in patients with pre-existing arrythmias could minimize the risk for postoperative pacemaker implantation.