Association of Kidney Function With Inpatient Mortality and Morbidity After Cardiac Surgery.

Background: Contemporary population-based data examining the rates of cardiac surgery and the relationship between non-dialysis-requiring chronic kidney disease (CKD) and postoperative outcomes in cardiac surgery are limited. Methods: We identified hospital admissions for cardiac surgical procedures in adults from 2010-2019 in the United States. The primary exposure was kidney disease, categorized as CKD stage G3, CKD stages G4 or G5, and end-stage kidney disease (ESKD). The primary outcome was in-hospital mortality. We evaluated the association between CKD stage and in-hospital-mortality by using multivariable logistic regression. We calculated the annual national incidence of cardiac surgical procedures by CKD stage by incorporating data from the United States Census Bureau. Results: We identified an estimated 2,772,081 admissions during which patients aged 18 years or older underwent cardiac surgical procedures. The incidence of cardiac surgical procedures was 1.1, 1.0, and 13.0 per 1000 person-years among patients with normal or nearly normal kidney function, non-dialysis-requiring kidney disease, and ESKD, respectively. In-hospital mortality was 2.2%, 3.7%, 6.7%, and 8.8% among patients with normal or nearly normal kidney function, CKD stage G3, CKD stages G4 or G5, and ESKD, respectively. In adjusted analyses, patients with CKD stage G3, CKD stage G4 or G5, and ESKD experienced absolute risks of in-hospital mortality that were 0.6% (95% CI, 0.5%-0.7%), 2.2% (95% CI, 1.8%-2.6%), and 4.4% (95% CI, 4.0%-4.8%) higher, respectively, than in patients with normal or nearly normal kidney function. Conclusions: In the United States, advanced stages of CKD are associated with an increased incidence of cardiac surgical procedures, as well as high adjusted risks of in-hospital mortality.