Mitral valve repair in the United States: Single-center versus multicenter surgeons’ risk-adjusted outcomes

Abstract

Objectives

Health care consolidation may force cardiac surgeons to operate at multiple centers. Few data exist as to this phenomenon's effect upon patients' quality of care as measured by risk-adjusted outcome (RAO) rates. We sought to compare mitral valve repair (MVr) RAO rates between surgeons operating at multiple centers (MC) versus single-centers (SC); and for MC surgeons, to compare MVr RAO rates between their primary and secondary centers.

Methods

The 2011-2019 Society of Thoracic Surgeons Adult Cardiac Surgery Database's MVr records were analyzed. MC surgeons performed MVr procedures at ≥2 centers within a year; each MC surgeon's greatest MVr volume (“primary”) center was identified. Applying the Society of Thoracic Surgeons−approved 2018 isolated-MVr risk models, study end points included risk-adjusted 30-day major morbidity or mortality (MMM; determined by operative death, dialysis, stroke, prolonged ventilation, mediastinitis, or repeat procedure) and risk-adjusted prolonged length of stay (pLOS). The impacts of surgeon's and hospital's MVr and total cardiac surgery volumes were evaluated.

Results

Compared with MC surgeons, SC surgeons had lower risk-adjusted MMM (odds ratio [OR], 1.170; P < .001). After adjusting for surgeon and center volumes, this finding persisted (OR, 1.141; P = .0155). MC surgeons experienced lower risk-adjusted MMM at their primary versus secondary centers (OR, 1.269; P < .001); this finding was partially attributable to center-based volume variations (OR, 1.130; P = .098). No SC versus MC surgeon risk-adjusted pLOS differences were found; however, regional risk-adjusted pLOS differences persisted.

Conclusions

Compared with SC surgeons, reallocating surgeons’ caseload across multiple centers has a statistically significant, negative impact on their MVr RAO rates.