Abstract 13416: Evaluation of Risk Factors for Pacemaker After Tavr Among Patients With a Pre-Existing Right Bundle Branch Block

Background:Pacemaker implantation (PMI) remains a common complication after TAVR. While a pre-existing right bundle branch block (RBBB) is consistently the strongest reported risk factor for PMI, most patients with a RBBB will not require PMI after TAVR.Objective:To identify factors associated with a higher risk of PMI after TAVR among patients with pre-existing RBBB.Methods:We identified all patients at a single institution undergoing first-time TAVR with a balloon-expandable prosthesis without a pre-existing pacemaker or ICD, and pre-existing RBBB (defined as RBBB morphology with QRS >=110ms) from December 2013 to December 2020 (n=219). We evaluated the univariate association for numerous clinical, EKG, imaging, and procedural characteristics with PMI. We included all factors with p=<0.10 in a logistic regression model to assess for independent associations with PMI in the original cohort and 1000 bootstrapped samples.Results:A history of syncope, body mass index, calcium channel blocker use, baseline PR interval, and prosthesis oversizing >16% were associated with PMI on univariate analysis. When included in a logistic regression model, syncope (OR 3.2, 95%CI: 1.1-8.8, p=0.027) and oversizing (OR 3.1, 95% CI: 1.4-6.8, p=0.005) remained independently associated with PMI. These findings were consistent in the bootstrapped samples. Those with both factors (n=4) had a PMI rate of 75% which was higher compared to those with one or neither (43% and 22%, respectively; p<0.001).Conclusion:Among those with pre-existing RBBB, a history of syncope and prosthesis oversizing >16% were independently associated with a higher risk of PMI. These findings warrant external validation.