Impact of Centralized Care at Aortic Centers on Aortic Dissection Outcomes: A 20-Year Analysis of U.S. Hospitals

BACKGROUND Over the past thirty years in the United States, hospitals have increasingly become incorporated into hospital systems, leading to organized care with more complex cases being managed at large urban-teaching hospitals. Over a similar period, changes in intervention guidelines for Aortic Dissection have occurred, with continually growing options for endovascular, minimally-invasive treatment. Given these dynamic changes, we examined trends in Aortic Dissection hospitalizations, intervention approaches, and hospital characteristics over past twenty-years to elucidate the effect of centralized care on outcomes. METHODS We identified all patients presenting with aortic dissection, both ascending and descending, (ICD-9-CM: 441.0; ICD-10-CM: I71.0) in the NIS between 2000-2021. We then examined the utilization of open repair, endovascular and complex-endovascular repair, as well as nonoperative/medical management. Stratified by hospital setting (urban-teaching, urban-nonteaching, and rural), we analyzed trends of interventions and in-hospital mortality over time. If an operation was performed, we were able to discern between ascending/arch or descending aorta after the 2017 ICD revision. RESULTS 553,030 patients with aortic dissection were identified. The number of inpatients in the US with aortic dissections has increased, with an incidence of 26.7 cases/100k in 2000 to 47.2 cases/100k in 2020 (p<0.01). Overall, including all hospital settings, aortic dissections were less frequently managed nonoperatively (2000-2021: 83%-71%) and more frequently managed endovascularly (Figure), with 85% of all descending and 16% of all ascending/arch aortic dissections undergoing TEVAR in 2021. Over time, aortic dissections have increasingly been managed at urban-teaching hospitals (2000-2021: 72%-92%;p<0.01). Since 2016, urban-teaching hospitals more frequently intervened on aortic dissections compared to their rural counterparts (21% vs. 6%;p<0.01), despite having similar rates of failed medical management (9.8% vs. 8.2%;p=0.30). Finally, comparing the last 5-years, urban-teaching hospitals have lower mortality rates when managing aortic dissection versus their rural counterparts (10.9% vs 11.7%, OR=1.10;p=0.02) and if managed operatively, there was a lower associated risk of mortality at urban-teaching hospitals compared to urban-nonteaching hospitals (12.5% vs. 17.3%, OR=1.46;p<0.01). CONCLUSION Both aortic dissection hospitalizations and interventions have significantly increased over the past two decades in the US. The growth of large hospital systems and their absorption of smaller hospitals into integrated primary through quaternary care centers has resulted in an increase in “regionalization” of care, in which complex cases are transferred to larger urban teaching centers. Our analysis suggests there is a mortality benefit from the centralization of aortic care to tertiary/urban-teaching centers, though further research into this question is required.