Predictors of worsening renal function after computed tomography coronary angiography: assessed by cystatin C.
BACKGROUND
An increase in cystatin C (CyC) of ≥10% for 24 hours may predict contrast-induced nephropathy and worse outcomes in patients with renal dysfunction undergoing invasive coronary angiography.


OBJECTIVE
We investigated the changes in CyC in patients with preserved renal function referred for contrast-enhanced coronary computed tomography angiography (CTA).


METHODS
We studied 151 patients undergoing CTA with 70 mL of iopamidol. Serum creatinine and CyC, a sensitive measure of renal dysfunction, shown to be associated with adverse outcomes, were measured 1 day and 1 week after CTA, respectively. The percentage change in CyC (%CyC) was determined and evaluated in comparison to fluid intake.


RESULTS
The patients were dichotomized into 2 groups: 47 patients had ≥10% increase in CyC 1 day after CTA (group A) and 104 did not (group B). The percentage of diabetic patients, hemoglobin A1c (HbA1c), and the CyC levels at 1 week were significantly greater, and the oral fluid volume was significantly lower in group A than in group B. The %CyC inversely correlated with oral fluid volume (r = -0.80, P < 0.0001) and positively with HbA1c (r = 0.38, P < 0.001). Multiple regression analysis showed that oral fluid intake (β = -0.796, P < 0.0001) and HbA1c (β = 0.128, P = 0.007) are independent predictors for %CyC of ≥10%.


CONCLUSIONS
Frequency of CyC elevation was strongly related to hydration after the study and also weakly related to HbA1c. Sufficient oral fluid intake (oral fluid volume/kg ≥ 20 mL/kg) is crucial, particularly for poorly controlled diabetic patients referred for CTA even though they show preserved renal function.
Department of Cardiology, Kami-iida Dai-ichi General Hospital, 2-70 Kami-iida, Kita-machi, Kita-ku, Nagoya, 462-0802, Japan.
Hirohiko
H
Ando
Satoshi
S
Isobe
Tetsuya
T
Amano
Takashi
T
Yamada
Hiroko
H
Ohtsubo
Miyuki
M
Yuba
Hideki
H
Ishii
Toyoaki
T
Murohara
D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000453:epidemiology*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015897:Comorbidity; D003287:Contrast Media; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D055316:Cystatin C / Q000097:blood*; D005260:Female; D006801:Humans; D007479:Iopamidol; D007564:Japan / Q000453:epidemiology; D007674:Kidney Diseases; D007677:Kidney Function Tests; D008297:Male; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
D015415:Biomarkers; D003287:Contrast Media; D055316:Cystatin C; D007479:Iopamidol