Prognostic value of cystatin С in pulmonary embolism

BACKGROUND. Standard criteria allow diagnosing AKI within hours to days. The use of biomarkers is a promising approach for early diagnosis and prognosis of AKI. THE AIM: to study the capabilities of serum cystatin C (CYS) in the early diagnosis and prognosis of AKI and associated hospital mortality, the risk of 30-day death in pulmonary embolism (PE). PATIENTS (MATERILS) AND METHODS. 98 patients with suspected PE were included; patients were excluded if the diagnosis was not confirmed. CYS was determined on admission, the difference between the determined CYS and the estimated CYS corresponding to a glomerular filtration rate (GFR) of 75 ml/min/1.73 m2 (CYSdiff) and the difference between the GFR by CYS and the GFR by creatinine (eGFRdiff) were calculated. RESULTS. AKI was diagnosed in 13 of 63 patients with PE (men – 36(57 %), age – 67(12) years). In 7(54 %) cases, AKI was detected against the background of chronic kidney disease (CKD), in 6(46 %) – first-onset AKI. CYS>2.55 μg/ ml predicted AKI (sensitivity – 70 %, specificity – 62 %; AUC=0,70; p=0,01) and AKI in CKD patients (sensitivity – 86 %, specificity – 62 %; AUC=0,78; p=0,001). CYSdiff>1,62 μg/ml predicted AKI (sensitivity – 69 %, specificity – 68 %; AUC=0,70; p=0,01). 5 patients (9 %) died in hospital. Mortality was higher in AKI (χ2 =5.8; p=0,02). CYS, CYSdiff did not predict hospital mortality, while CYS>2,17 μg/ml (sensitivity – 70 %, specificity – 70 %; AUC=0,76; p=0,0001) and CYSdiff>1,22 μg/ml (sensitivity – 70 %, specificity – 70 %; AUC=0.77; p0,05). CONCLUSION. The results of the study confirm the effectiveness of CYS in the early diagnosis and prediction of AKI, including cases associated with CKD. The accuracy of prediction can be improved using CYSdiff. CYS does not predict in-hospital mortality but is associated with a high risk of 30-day death in PE.