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- Azza A. Elmandouh,
- Mahmoud Elbadry,
- Ahmed El-Sherif and
- Hossam Sherif, MD
Acute kidney injury (AKI) is a frequent finding in critically ill patients and can be diagnosed early by renal biomarker. These biomarkers have led to concepts like ‘subclinical AKI’ and ‘renal angina’, which are biomarker-guided and describe the clinical condition, characterized by positive biomarker and negative creatinine findings. The performance of urinary L-FABP which is a 14-kDa protein expressed in proximal tubular epithelial cells as an early detection marker of AKI has shown promise in various clinical settings. Determination of the renal resistive index (RI) by Doppler sonography has also been suggested as a means of diagnosing acute tubular necrosis.
The aim of our work is prospective assessment of the clinical biomarker L-FABP and the renal artery duplex for early prediction of renal angina in patients scheduled for coronary angiography.
The present study was conducted on 40 patients admitted to the ICU Critical Care Department, Cairo University Hospitals scheduled for coronary angiography. Different risk factors for AKI were evaluated, including: Patients with diabetes mellitus, hypertensions, dyslipidemia, smoking, ischemic heart disease and the number of diseased coronary arteries. The L-FABP and the renal artery duplex were studied for early prediction of renal angina before and after coronary angiography.
After coronary angiography mean serum creatinine was increased (p value < 0.006) but still not beyond the critical value. Again the mean creatinine clearance was reduced in our patients after usage of contrast (p value < 0.000). Mean L-FABP significantly increased 4 hours after coronary angiography and the sensitivity of L-FABP to CIN is 41% and specificity is 76% (with an AUC-ROC of 0.55).The mean RRI was significantly increased after angiography but Pulsaticity before and after coronary angiography show no statistically significant difference. The sensitivity of RRI to CIN is 69% and specificity is 48% (with an AUC-ROC of 0.56).
This study highlighted the importance of urinary L-FABP levels and RRI in early detection of renal angina associated with contrast administration earlier than serum creatinine. The RI is more sensitive to CIN (69%) while the L-FABP is more specific (76%).