Cystatin C and glomerular filtration rate in the cardiac surgery with cardiopulmonary bypass.
OBJECTIVE
The aim of this study was to compare cystatin C versus creatinine as a marker for acute kidney injury in patients submitted to cardiac surgery with cardiopulmonary bypass.


METHODS
Fifty consecutive patients submitted to coronary artery bypass grafting were studied. Renal function was evaluated by serum cystatin C and creatinine. Blood samples were obtained from each patient at three time points: before operation, and on the first and fifth postoperative days. Glomerular filtration rate (GFR) was calculated by Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Larsson (Cys-GFR) formulas.


RESULTS
Creatinine and GFR by CG and MDRD formulas did not show statistical difference between study times. After renal injury from surgery, there was an increase in cystatin C on the 1st and 5th day after surgery, being significantly different on the 5th postoperative (P<0.01). The GFR by Larson formula was higher in the preoperative time (105.2 +/- 41.0 ml/min) than in the 5th postoperative day (89.5+/- 31.5 ml/min; P<0.012).


CONCLUSIONS
The cystatin C and the Cys-GFR showed significant changes after cardiac surgery when compared with the creatinine and respective GFR calculated by the Cockcroft-Gault and MDRD formulas.
Felicio
Marcello Laneza
ML
Department of Cardiovascular Surgery, FMB - UNESP, Botucatu - SP, Brazil. felicio@fmb.unesp.br
Andrade
Rubens Ramos de
RR
Castiglia
Yara Marcondes Machado
YM
Silva
Marcos Augusto de Moraes
MA
Vianna
Pedro Thadeu Galvão
PT
Martins
Antonio Sergio
AS
D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D013997:Time Factors
D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine