Acute and Chronic Kidney Disease and Cardiovascular Mortality After Major Surgery

Abstract

Objective: The aim of the study was to determine the long-term cardiovascular-specific mortality in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) after major surgery.

Background: In surgical patients, pre-existing CKD and postoperative AKI are associated with increases in all-cause mortality.

Methods: In a single-center cohort of 51,457 adult surgical patients undergoing major inpatient surgery, long-term cardiovascular-specific mortality was modeled using a multivariable subdistributional hazards model while treating any other cause of death as a competing risk and accounting for the progression to end-stage renal disease (ESRD) after discharge. Pre-existing CKD and ESRD, and postoperative AKI were the main independent predictors.

Results: Before the admission, 4% and 8% of the cohort had pre-existing ESRD and CKD not requiring renal replacement therapy, respectively. During hospitalization, 39% developed AKI. At 10-year follow-up, adjusted cardiovascular-specific mortality estimates were 6%, 11%, 12%, 19%, and 27% for patients with no kidney disease, AKI with no CKD, CKD with no AKI, AKI with CKD, and ESRD, respectively (P < 0.001). This association remained after excluding 916 patients who progressed to ESRD after discharge, although it was significantly amplified among them. Compared with patients having no kidney disease, adjusted hazard ratios for cardiovascular mortality were significantly higher among patients with kidney disease, ranging from 1.95 (95% confidence interval, 1.80-2.11) for patients with de novo AKI to 5.70 (95% confidence interval, 5.00-6.49) for patients with pre-existing ESRD.

Conclusions: Both AKI and CKD were associated with higher long-term cardiovascular-specific mortality compared with patients having no kidney disease.

Figure 1

Adjusted cumulative incidence curves for progression to end stage renal disease (A) by kidney disease status (B) by severity stages (adjusted for age, gender, ethnicity, Charlson comorbidity index, emergent surgery status, surgery type, and admission day hemoglobin level as described in Methods). All groups with acute or chronic kidney disease have significantly higher hazards ratios compared to no known kidney disease group with p<0.001.

Figure 2

Adjusted cumulative incidence curves for cardiovascular-specific mortality by kidney disease status (adjusted for age, gender, ethnicity, Charlson comorbidity index, emergent surgery status, surgery type, and admission day hemoglobin level as described in Methods). All groups with acute or chronic kidney disease have significantly higher hazards ratios compared to no known kidney disease group with p<0.001.

Figure 3

Adjusted cumulative incidence curves for cardiovascular mortality by kidney disease status after stratification by age and gender (A) Male, aged<50 years (B) Female, aged<50 years (C) Male, aged 50 to 64 years (D) Female, aged 50 to 64 years (E) Male, aged ≥ 65 years (F) Female, aged ≥ 65 years. All groups with acute or chronic kidney disease have significantly higher hazards ratios compared to no known kidney disease group within each strata with p<0.001 except for CKD with no AKI group for females with age between 50 and 64 years and males with age<50 years which have p<0.05.