S. T. Kim1, Z. Tran1, V. Dobaria1, C. Pan1, P. Benharash1 1David Geffen School Of Medicine, University Of California At Los Angeles, Los Angeles, CA, USA
Introduction: Safety-net hospitals (SNH) care for a high proportion of uninsured/underinsured patients with the mission of improving access to care within the community. Patients in this setting may lack access to adequate longitudinal care such as anticoagulation monitoring following mechanical heart valve operations. The present study characterized the association of SNH with utilization of mechanical valves in aortic valve replacement (AVR). Additionally, we evaluated the impact of mechanical aortic valve utilization on readmissions and stroke at high-burdened SNH centers.
Methods: The Nationwide Readmissions Database was queried for all isolated AVR from 2016-2018. Hospitals were divided into quartiles based on annual volume of Medicaid and uninsured admissions, with the highest quartile defined as SNH. Mixed-effects multivariable regression was used to determine factors associated with mechanical valve use at a center-level. Among patients at SNH, multivariable regressions were used to determine associations between prosthesis type and outcomes of interest including in-hospital mortality, index length of stay, costs, 90-day readmissions and stroke at readmission.
Results: Of an estimated 135,930 AVR patients included in analysis, 15.9% underwent operations at SNH. Patients at SNH were younger (62 vs 64 years, P<0.001) and more frequently received mechanical valves (21.9% vs 18.1%, P<0.001) compared to patients at non-SNH, despite a similar burden of comorbidities as measured by the Elixhauser comorbidity index (4.9 vs 4.9, P=0.12). Hospital safety net status, female sex and preexisting peripheral vascular disease were among factors associated with increased odds of mechanical valve use (C-statistic=0.73), while increasing age, preexisting liver disease and coagulopathy showed decreased odds (Table). Among patients at SNH, recipients of mechanical valves had higher rates of 90-day readmissions (14.9% vs 13.0%, P<0.001) and stroke at readmission (0.7% vs 0.2%, P<0.001) compared to recipients of biological prostheses. After adjustment, mechanical valve use was still associated with higher odds of readmission at 90-days (AOR 1.20, 95%CI:1.04–1.39) and stroke at readmission (AOR 3.48, 95%CI:1.87–6.46) compared to bioprosthetic valves, despite similar in-hospital mortality, costs and length of stay.
Conclusion: Hospital safety-net status is associated with increased odds of mechanical valve use over biologic prostheses. However, mechanical valves are also associated with increased readmissions and stroke for patients undergoing AVR in this setting. These findings may help to highlight socioeconomic barriers that may prevent adequate access to follow-up care following aortic valve replacement.
