Elevated neutrophil gelatinase-associated lipocalin levels before contrast media administration among ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention.

Background Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein released by renal tubular cells upon nephrotoxic or ischemic events and is considered an early marker of tubular damage. We aimed to demonstrate the presence of early renal injury detected by elevated NGAL levels taken before contrast administration in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). Patients and methods We prospectively included 88 patients with STEMI treated with PCI. Blood samples for plasma NGAL were drawn immediately before PCI (baseline NGAL; NGAL1) and 24 h after PCI (NGAL2). Abnormal elevations in NGAL levels were defined using the cardiac surgery associated NGAL score (NGAL score) with NGAL levels at least 100 ng/ml, suggesting renal tubular damage. Patients were also assessed for the dynamics between NGAL2 and NGAL1 levels. Results The mean age of the patients was 62 +/- 13 years and 78% were men. A total of 50/88 (56%) patients had baseline NGAL level of at least 100, suggesting possible tubular damage before PCI. Only 10 patients progressed to clinical acute kidney injury during hospitalization, all of whom had baseline NGAL level of at least 100 (P < 0.001). Among patients with baseline NGAL at least 100, 28/50 (56%) showed a decrease in the NGAL level within 24 h, whereas only 9/50 (18%) showed an elevation in the NGAL level. In contrast, only 7/38 (19%) patients with baseline NGAL level less than 100 showed an elevation in NGAL levels within 24 h. Conclusion Elevated NGAL levels before primary PCI suggesting renal tubular damage are common among STEMI patients. Further trials are needed to assess the complex cardio-renal interactions.