Long-term outcomes of aortic root operations in the United States among Medicare beneficiaries

Abstract

Objective: The best method of aortic root repair in older patients remains unknown given a lack of comparative effectiveness of long-term outcomes data. The objective of this study was to compare long-term outcomes of different surgical approaches for aortic root repair in Medicare patients using The Society of Thoracic Surgeons Adult Cardiac Surgery Database-Centers for Medicare & Medicaid Services-linked data.

Methods: A retrospective cohort study was performed by querying the Society of Thoracic Surgeons Adult Cardiac Surgery Database for patients aged 65 years or more who underwent elective aortic root repair with or without aortic valve replacement. Primary long-term end points were mortality, any stroke, and aortic valve reintervention. Short-term outcomes and long-term survival were compared among each root repair strategy. Additional risk factors for mortality after aortic root repair were assessed with a multivariable Cox proportional hazards model.

Results: A total of 4173 patients aged 65 years or more underwent elective aortic root repair. Patients were stratified by operative strategy: mechanical Bentall, stented bioprosthetic Bentall, stentless bioprosthetic Bentall, or valve-sparing root replacement. Mean follow-up was 5.0 (±4.6) years. Relative to mechanical Bentall, stented bioprosthetic Bentall (adjusted hazard ratio, 0.80; confidence interval, 0.66-0.97) and stentless bioprosthetic Bentall (adjusted hazard ratio, 0.70; confidence interval, 0.59-0.84) were associated with better long-term survival. In addition, stentless bioprosthetic Bentall (adjusted hazard ratio, 0.64; confidence interval, 0.47-0.80) and valve-sparing root replacement (adjusted hazard ratio, 0.51; confidence interval, 0.29-0.90) were associated with lower long-term risk of stroke. Aortic valve reintervention risk was 2-fold higher after valve-sparing root replacement compared with other operative strategies.

Conclusions: In the Medicare population, there was poorer late survival and greater late stroke risk for patients undergoing mechanical Bentall and a higher rate of reintervention for valve-sparing root replacement. Bioprosthetic Bentall may be the procedure of choice in older patients undergoing aortic root repair, particularly in the era of transcatheter aortic valve replacement.

Keywords: aortic root; aortic surgery; elderly; root replacement.