The Magnitude of Acute Serum Creatinine Increase After Cardiac Surgery and the Risk of Chronic Kidney Disease, Progression of Kidney Disease, and Death

Study Questions:

What is the association between the magnitude of creatinine increase after cardiac surgery and the risk of incident chronic kidney disease (CKD), CKD progression, and death?


The authors identified 29,388 individuals who underwent cardiac surgery at Veterans Affairs hospitals between November 1999 and September 2005. The magnitude of creatinine increase was defined by the percent change from baseline to peak creatinine levels after cardiac surgery and categorized as none (0%), or as class I (1-24%), II (25-49%), III (50-99%), or IV (100%). Cox proportional hazard models were used to examine the association between the magnitude of creatinine increase and outcomes.


The relative hazards for outcomes increased monotonically with greater increases in creatinine levels compared with no change in creatinine levels. The relative hazards for adverse outcomes were significantly higher immediately after the creatinine increase and attenuated over time. Three months after surgery, creatinine increase classes I, II, III, and IV were associated with a greater risk of incident CKD (hazard ratios [HRs] 2.1, 4.0, 5.8, and 6.6, respectively; all p < 0.01), progression of CKD stage (HRs 2.5, 3.8, 4.4, and 8.0; all p < 0.01), and long-term mortality (HRs 1.4, 1.9, 2.8, and 5.0; all p < 0.01). At 5 years, the associations were lower in magnitude: incident CKD (HRs 1.4, 1.9, 2.3, and 2.3; all p < 0.01), CKD progression (HRs 1.5, 1.7, 1.7, and 2.4; all p < 0.01), and mortality (HRs 1.0, 1.2, 1.4, and 1.8; all p < 0.01, except class I).


The authors concluded that magnitude of creatinine increase after cardiac surgery is associated in a graded manner with an increased risk of incident CKD, CKD progression, and mortality.


This analysis suggested that the magnitude of creatinine increase after cardiac surgery was associated with an increased risk of incident CKD, progression of CKD, and death. The increase in risk of these adverse outcomes was most pronounced in the first 3-24 months of follow-up but persisted, albeit attenuated, at 5 years after surgery. These results also suggest that even a minimal increase in serum creatinine values (e.g., 1-24%) after cardiac surgery is associated with the development of long-term adverse outcomes, including mortality, progression of CKD, and incident CKD. Future research is indicated to develop strategies to prevent acute kidney injury (AKI) or long-term sequelae associated with AKI, particularly in the 3-24 months after AKI.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Follow-Up Studies, Kidney Function Tests, Biological Markers, Creatinine, Cardiac Surgical Procedures, Renal Insufficiency, Chronic

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