Regionalization of Care for Acute Type A Aortic Dissection: Utilizing Mixed Methods Toward Bottom-Up Health System Interventions in Emergent Surgical Care

Acute Type A aortic dissection (ATAAD) is a life-threatening event that carries a mortality rate of 15-30% even with emergent surgical intervention. Patients with ATAAD face operative mortality rates that exhibit a striking difference according to providing center experience, with those treated at high-volume aortic centers afforded a 10% or greater survival benefit compared to those treated at low-volume centers. And yet, 48% of ATAAD patients undergo surgery at low-volume centers. This is despite a robust U.S. study demonstrating that the delay inherent to interfacility transfer to high-volume centers does not offset a 7.2% absolute risk reduction in operative mortality. What’s more, one third of patients who incur the potential risk associated with interfacility transfer are transferred to low-volume centers. Consequently, contemporary guidelines published by the American College of Cardiology and the American Heart Association (2022) recommend the transfer of stable ATAAD patients from low- to high-volume centers. However, current transfer patterns deviate from these recommendations. The proposed research will utilize mixed methods health services research to improve the care of patients with ATAAD by defining parameters that optimize the regionalization of care and informing targeted interventions to increase the frequency of appropriate interfacility transfer to high-volume aortic centers. Quantitative analysis of state-level administrative claims databases and emergency medical transport services electronic medical records will be used to define the population distribution in the current level of regionalization of care for ATAAD and measure the transport time and case volume thresholds that optimize the survival benefit of interfacility transfer of ATAAD patients from no- or low-volume to high-volume aortic centers. Qualitative analysis will be employed to identify facilitators of and barriers to the regionalization of care for ATAAD through semi-structured interview of emergency medicine and cardiac surgery providers. This work will establish optimal parameters for the safe regionalization of care for ATAAD, characterize geographically granular facilitators of appropriate interfacility transfer, and ultimately improve survival rates for ATAAD patients. The knowledge that emerges from this work will inform an implementation science proposal to design and test a targeted intervention to regionalize emergent, specialized surgical care, improving patient outcomes, reducing complications, and lowering healthcare costs. By performing this work, Dr. Sabatino will receive mentored training in mixed methodology inclusive of quantitative statistical analysis, interview conduct and qualitative analysis, geospatial analysis, and the clinical science of cardiac and thoracic aortic surgery, facilitating her development into an independent surgeon-scientist and a leader in cardiac surgery. Project Number: 1F32HL179865-01 | Fiscal Year: 2025 | NIH Institute/Center: National Heart Lung and Blood Institute (NHLBI) | Principal Investigator: Marlena Sabatino | Institution: MASSACHUSETTS GENERAL HOSPITAL, BOSTON, MA | Award Amount: $97,040 | Activity Code: F32 | Study Section: Special Emphasis Panel[ZRG1 F16-K (20)] View on NIH RePORTER: https://reporter.nih.gov/project-details/1F32HL17986501