Novel Anatomic Predictors of New Persistent Left Bundle Branch Block after Evolut Transcatheter Aortic Valve Implantation

ABSTRACT New persistent left bundle branch block(NP-LBBB) has been associated with adverse outcomes after TAVI but few predictors thus far reported. We sought to identify predictors of NP-LBBB after TAVI with EvolutR/PRO(ER/EP). From 1/2016 to 4/2019, 544 patients from 2 centers underwent TAVI with Evolut(54%ER, 46%EP) for severe native aortic stenosis. Patients with prior LBBB and pacemaker were excluded. Aortic root analysis was performed using 3Mensio Valves Software and membranous septal length(MSL) was determined using the standard coronal view. Clinical, anatomic and procedural characteristics of 396 Evolut were analyzed and predictors of NP-LBBB were identified. Valve Academic Research Consortium-2 outcomes were reported. At discharge, NP-LBBB was seen in 76(19.2%) patients. NP-LBBB in Evolut was associated with implant depth at left coronary cusp(p=0.004) and 34mm ER(p=0.026). Independent predictors of NP-LBBB in Evolut were shorter MSL(OR=0.82 per mm septum,95%CI=0.68-0.98,p=0.030), left ventricular outflow tract(LVOT) eccentricity(OR=1.04 per%,95%CI=1.01-1.06,p=0.002), implant depth at non-coronary cusp(NCC)(OR=1.28 per mm ventricular,95%CI=1.11-1.48,p=0.001) and annular perimeter oversizing≥20%(OR=2.38, 95%CI=1.20-4.72, p=0.013). On ROC curve analysis, MSL≤6.5mm, NCC depth≥3mm and LVOT eccentricity≥35% were optimal threshold values to predict NP-LBBB. In Conclusion, shorter MSL, LVOT eccentricity, annular oversizing and deeper implant depth are novel predictors of NP-LBBB in Evolut TAVI. Pre-procedural CT assessment of aortic root anatomy may help identify patients at risk for NP-LBBB. In such patients, modifying procedural factors such as higher implant and less annular oversizing may reduce the risk of NP-LBBB. Further evaluation of our hypothesis is warranted.