Outcomes of transcatheter vs. isolated surgical aortic valve replacement in mediastinal radiation-associated severe aortic stenosis
Authors: Nauffal V , Bay C , Shah P , Sobieszczyk P , Kaneko T , O'Gara P , Nohria A 
Published: November 2020

Abstract

Introduction
Mediastinal radiation can lead to long-term cardiac sequelae, including aortic valve disease. Surgical aortic valve replacement (SAVR) is associated with poor outcomes in this population. Transcatheter aortic valve replacement (TAVR) now provides an alternative treatment strategy that may improve outcomes.

Purpose
To compare 30-day outcomes after TAVR vs. isolated SAVR for radiation-associated severe symptomatic aortic stenosis using the Society of Thoracic Surgery (STS) National Adult Cardiac Surgery Database.

Methods
We evaluated 1,668 TAVR and 2,611 isolated SAVR patients enrolled in the STS national database from July 2011 through December 2018. A propensity score for TAVR vs. SAVR was derived using a non-parsimonious logistic regression model that included 29 pre-operative variables and was used to generate a 1:1 matched cohort (NTotal=1,560). 30-day outcomes in TAVR vs. SAVR patients were compared in the matched cohort using conditional logistic regression. We also tested for temporal trends in 30-day mortality separately for TAVR and SAVR in the matched cohort, adjusted for potential confounders, to see if outcomes varied across the study period.

Results
In the propensity-matched cohort, baseline demographics, comorbidities and preoperative characteristics were balanced between the TAVR and SAVR groups. The mean age was 73.3 years and 75% were females in each group. In the propensity-matched cohort, TAVR was associated with significantly reduced 30-day all-cause [OR=0.50 (0.30–0.84), p=0.01] and cardiovascular mortality as compared to SAVR [OR=0.33 (0.14–0.78), p=0.01]. Similarly, post-operative complications occurred less in the TAVR group except for stroke/transient ischemic attack (TIA) [OR=3.17 (1.27–7.93), p=0.01] and pacemaker implantation [OR=1.71 (1.21–2.44), p=0.003] which were significantly higher with TAVR (Figure 1A). While, 30-day mortality associated with both procedures improved over the course of the study, the trend was only statistically significant in the TAVR group following adjustment for potential confounders. TAVR was consistently associated with better survival than SAVR in the matched cohort across the study period (Figure 1B).

Conclusion
Our findings suggest that TAVR is a safe alternative to SAVR for radiation-associated severe symptomatic aortic stenosis and is associated with lower 30-day mortality and post-operative complications. The risk of stroke/TIA and pacemaker implantation is higher with TAVR and should be considered when choosing therapy. Additional prospective studies to validate our findings and evaluate long-term outcomes are needed to further guide clinical decision making in this population.
Figure 1

Funding Acknowledgement
Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Funding to support acquisition of the data from the Society of Thoracic Surgery was obtained from discretionary funds available to Dr. Anju Nohria from the Cardiovascular Medicine Division.