Abstract Body (Do not enter title and authors here): Background: Transcatheter aortic valve replacement (TAVR) is rapidly becoming commonplace for severe symptomatic aortic stenosis (AS). As amyloidosis is becoming more frequently diagnosed, its association with aortic stenosis is coming to light. Cardiac amyloidosis has been historically associated with significant morbidity and mortality. Since many amyloidosis patients may have aortic stenosis, we aimed to assess outcomes in these individuals undergoing TAVR.

Hypothesis: Patients with severe aortic stenosis (AS) and concurrent cardiac amyloidosis have worse clinical outcomes compared to those with severe AS alone. Given the increased prevalence of AS among patients with cardiac amyloidosis, would initiating tafamidis therapy prior to transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR) improve outcomes in this population?

Methods: We utilized the National Inpatient Sample from 2016-2019 to identify 217,575 hospitalized adults who underwent TAVR for AS. These hospitalizations were further stratified based on the presence of Amyloidosis. A multivariate regression model was used to adjust for confounders and analyze the variables.

Results: Of those who underwent TAVR, 245 had amyloidosis. In-hospital mortality was higher in those with amyloidosis (3.1% vs 1.4%; p=0.001). Figure 1 shows the Forrest plot for multivariate analysis of periprocedural complications when adjusted for patient demographics, comorbidities, and hospital characteristics. When adjusted similarly, TAVR patients with amyloidosis had longer length of stay (LOS) by 1.2 days (p<0.001) and had additional hospital costs (HC) of $43,160 (p<0.001).

Conclusion: TAVR patients who had amyloidosis had significantly worse outcomes in terms of AKI, cardiogenic shock, pneumonia, and atrial fibrillation. There was a trend towards worse outcomes for mortality, LOS, and HC, ventricular tachycardia, vascular complications, intubation, and atrial flutter but was not statistically significant. Some limitations of the study include lack of outpatient follow-up and lower statistical power due to small sample size of amyloidosis patients. Amyloidosis is typically underdiagnosed which could result in their misclassification. While inpatient outcomes seem to be worse in those with amyloidosis. Outpatient follow-up is needed to identify whether this population sees the long-term benefits from TAVR as those without amyloidosis.