Application of biological markers of kidney injury for prognosis of long-term adverse outcomes in patients with ST-segment elevation myocardial infarction

Objective: To study the prognostic significance of serum NGAL (sNGAL) and cystatin C in the acute phase of ST-segment elevation myocardial infarction (STEMI) in the late disease period. Material and Methods: 357 patients with STEMI, admitted to hospital within 24 h of symptom onset, were included in the study. Serum creatinine levels with the calculation of glomerular filtration rate (GFR) using the MDRD as well as levels of sNGAL and cystatin C were measured on day 1 and 12–14. Results: All patients were divided into 2 groups according to their estimated GFR: with and without renal dysfunction (RD), defined as a decrease of GFR < 60 ml/min/1.73 m2. Within 3 years of follow-up, the composite endpoint (CEP) were assessed (CEP – death + non-fatal cardiovascular events). The ROC curve analysis was used to determine the thresholds for every biomarker, involved in the CEP development: NGAL (≥ 1.25 ng / ml) and cystatin C (≥ 1.9 mg / l). On day 12–14 of hospitalization elevated NGAL ≥ 1.25 ng / mL was associated with a 3-fold increased risk for adverse cardio vascular events in a 3-year follow up after STEMI; whereas, elevated cystatin C ≥ 1.9 mg/l – with a 2-fold increased risk for the CEP, and signs of RD, found in patients before the discharge from the hospital, – with a 1.5-fold increased cardiovascular risk. The model considering an increase of NGAL over 1.25 ng / l has the highest prognostic value, while the models based on the levels of cystatin C and GFR are of equal prognostic value. Conclusion: The most promising issue in the prognosis of long-term adverse outcomes in patients with STEMI may be considered the assessment of RD using new biomarkers such as sNGAL.