Disparities in 180-day Infection Rates Following Coronary Artery Bypass Grafting and Aortic Valve Replacement.

Objective: To compare sex and racial differences in 180-day infection rates after coronary artery bypass grafting (CABG) and aortic valve replacement (AVR).

Methods: A Statewide Society of Thoracic Surgeons Adult Cardiac Surgery Database was linked to Medicare claims data to identify 8,887 beneficiaries undergoing CABG and AVR (surgical or transcatheter) between 2017 and 2021. The primary outcome was the incidence of 180-day infection. Secondary outcomes included ten infection subtypes. Multivariable logistic regression was used to evaluate the relationship between sex and race (Black versus non-Black) and infections. Two secondary analyses were conducted: (1) robustness of the primary analysis after excluding urinary tract infections "UTIs" given established sex-related differences and (2) testing a sex*race interaction.

Results: The mean (SD) age of the cohort was 74.5 (8.9) years, with 36.9% female and 4.2% Black. The infection rate was 19.6%, although varied by patient sex (female versus male: 23.7% versus 17.1%) and race (Black versus non-Black: 28.0% versus 19.2%), both p<0.0001. Differences in infection rates for females were driven by UTI, while pneumonia for Black patients. Risk-adjusted odds of infection were 1.6-fold significantly higher among female while non-significant for among Black patients. A sex*race interaction was present, with non-Black females versus non-Black males having a 1.63 higher odds of infection.

Conclusion: This multi-center study identified a 1.6-fold higher odds of infection among female patients. Non-Black female versus male patients had a 63% higher odds of infection. Transdisciplinary collaborative learning interventions should be considered to address these known disparities in infection rates.