Short term clinical outcomes and analysis of risk factors for pacemaker implantation: a single center experience of self-expandable TAVI valves.

Objectives: Transcatheter aortic valve implantation is a recognized treatment for patients with severe aortic stenosis at all risk groups. However, permanent pacemaker rates remain high for self expandable transcatheter valves and permanent pacemaker implantation has been associated with increased morbidity. In this analysis we aim to evaluate short term clinical outcomes post self expandable transcatheter aortic valve implantation and determine risk factors for permanent pacemaker implantation.

Methods: 88 patients with severe aortic stenosis with transcatheter aortic valve implantation performed between the year 2016-2018 were retrospectively analyzed. Outcomes of interest included 1- year all cause mortality, 30-day major adverse cardiovascular events, permanent pacemaker and paravalvular leak rates. Survival analysis was performed with Kaplan Meier analysis and risk factors for survival and permanent pacemaker rates were identified with log rank test and regression analysis.

Results: The mean age of the cohort was 80.3 +/- 6.9 years. The mean STS score was 9.25. The 30 day all-cause mortality was 5.7% and 1-year all cause mortality was 16.7%. 80 patients had transfemoral transcatheter aortic valve implantation, and a majority of the patients (85.2%) were implanted with Corevalve Evolut R device. The device success rate was 88.6%. Multivariate analysis identified concomitant severe coronary artery disease (OR = 18.2 +/- 0.9; P = 0.002), pre transcatheter aortic valve implantation atrial fibrillation (OR = 8.6 +/- 0.91; P = 0.02) and post procedural disabling stroke (OR = 32.6 +/- 1.35; P = 0.01) as risk factors for 1-year mortality. The 30-day pacemaker rate was 17.6%. The presence of right bundle branch block (OR 11.1 +/- 0.86; P = 0.005), non-coronary cusp implantation depth (OR = 1.34 +/- 0.15; P = 0.05) and a non coronary cusp implantation depth / membranous septal length ratio of more than 50% were associated with post procedural pacemaker implantation (OR = 29.9 +/- 1.72; P = 0.05). Among the 15 patients with post procedural pacemaker implantation, 40% were found to be non-pacemaker dependent at 1 year.

Conclusion: Short term outcomes of transcatheter aortic valve implantation in severe aortic stenosis patients are promising. Pacemaker rates remain high. More studies are needed to evaluate the factors that influence pacemaker rates and dependence to further improve transcatheter aortic valve implantation outcomes.