Abstract Body (Do not enter title and authors here): Background:
Transcatheter Aortic Valve Replacement (TAVR) is often performed in the cardiology catheterization suite. Although rare, instances of annular rupture, cardiac arrest, and coronary occlusion may occur requiring institution of emergent extracorporeal life support (ECLS). This study aims to examine the risk factors for complications requiring ECLS during TAVR procedures to identify patients who may benefit from having procedures performed in hybrid operating rooms.

Methods:
Data from the Transcatheter Valve Therapy registry for our institution was obtained on patients (n=4908) who underwent TAVR between November 2012 and July 2023. Univariable logistic regression was performed to compare relevant covariates in those requiring intraoperative ECLS (n=23) to the rest of the patient cohort (n=4885). All-cause mortality during the follow-up period was compared to assess the impact of emergent intraoperative ECLS.

Results:
The patients requiring ECLS experienced significantly higher all-cause mortality (69.6% versus 28.8%, p<0.001) with median follow up of 2 years (Table 1). Female sex (p=0.013) and smaller annulus size (p=0.007) were significant independent risk factors for complications requiring emergent intraoperative ECLS based on univariable logistic regression (Table 2). Patients requiring ECLS had significantly smaller annulus sizes (21.0-23.2 mm) compared to the uncomplicated cohort (22.0-25.8 mm). Of the patients requiring ECLS, 11 cases (47.8%) were due to annular/ventricular rupture while 4 cases (17.4%) resulted from valve embolization. Of note, valve type (self-expanding versus balloon expandable), annular calcification, and porcelain aorta were not found to be significant risk factors.

Conclusions:
In this large volume single-center retrospective cohort study, female sex and smaller aortic annular size significantly increased the risk of complications necessitating ECLS support during TAVR procedures. Our study represents the first to identify independent risk factors for catastrophic complications during TAVR procedures. Patients with these high-risk profiles should have their TAVR procedures performed in the hybrid operating room with cardiopulmonary bypass on immediate standby.