Neutrophil Gelatinase-Associated Lipocalin for the Assessment of Reversible versus Persistent Renal Tubular Damage in ST-Segment Myocardial Infarction Patients

Background: Most studies investigated the value of neutrophil gelatinase-associated lipocalin (NGAL) as a marker of renal tubular injury only at a single time point. We investigated the possible utilization of NGAL level dynamics for the identification of different renal injury patterns in ST-elevation myocardial infarction (STEMI) patients. Methods: Blood samples for plasma NGAL in 132 STEMI patients were drawn immediately before and 24 h following primary coronary intervention. Abnormal elevation of NGAL levels was defined using the cardiac surgery-associated NGAL score with NGAL levels ≥100 ng/mL suggesting renal tubular damage. According to NGAL levels at 0 and 24 h, patients were stratified into 3 groups: no tubular damage (NGAL <100 ng/mL in both exams), reversible tubular damage (NGAL >100 ng/mL at 0 h but <100 ng/mL at 24 h), and persistent tubular damage (NGAL >100 ng/mL at both 0 and 24 h). Results: Mean age was 62 ± 13 years, and 78% were men. Of these patients, 29/132 (22%) demonstrated reversible tubular damage, and 36/132 (27%) persistent tubular damage. Only 13/132 patients (10%) progressed to clinical acute kidney injury during hospitalization, all of whom had persistent tubular injury. In multivariate regression model, symptom duration was independently associated with persistent tubular damage, both as continues variable (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.04; p = 0.04) and for symptom duration >360 min (OR 2.66, 95% CI 1.07-6.63; p = 0.03). Conclusions: Renal tubular damage is common among STEMI patients. Dynamic NGAL measurement may differentiate between reversible and persistent tubular damage. Further trials are needed in order to assess the complex cardiorenal interactions.