Prognostic Significance of Serum NGAL and Troponin I against Acute Kidney Injury in Egyptian ICU Patients after Open Heart Surgery: A Pilot Study

Abstract

Background: Acute kidney injury (AKI) is a common complication following cardiac surgery and percutaneous coronary interventions, with an estimated incidence rate around 30%, depicted by long-term intensive care unit stay and culminating renal dysfunction over time, triggering either perpetual renal damage evolving to chronic kidney disease/end-stage renal disease transitions or high vulnerability for sudden death after surgery. The classical diagnosis of AKI is based on a sharp rise in serum creatinine that takes at least 48 h to be visible and is associated with multiple nonrenal factors. Objective: We aimed to evaluate the predictive performance of both neutrophil gelatinase-associated lipocalin (NGAL) and Klotho for AKI in patients who underwent cardiothoracic surgery using cardiopulmonary bypass (CPB). Results: Out of the 182 patients included in the study, 65 had AKI and 117 had non-AKI according to the Kidney Disease: Improving Global Outcomes criteria relying on serum creatinine levels. Baseline serum NGAL was 103.5 ± 41.69 μg/L in the AKI group compared to 79.12 ± 48.02 μg/L in the non-AKI group (p < 0.01) and then manifested a peak-fall-rise pattern until 48 h of CPB, with a more remarkable change in the AKI than in the non-AKI group. ROC curve analysis for all measured biomarkers after 2 h of CPB showed that serum NGAL (0.819, > 75% cutoff, 83.5% accuracy) came after serum creatinine (0.864, > 140% cutoff, 85% accuracy), and troponin I was poorer than both (0.606, > 5.5% cutoff, 60% accuracy). Furthermore, multivariate analysis showed that preoperative serum NGAL, preoperative eGFR ≤60 mL/min/1.73 m², and arterial hypertension were possible risk factors for AKI with adverse outcomes. Conclusions: Our study suggests the role of preoperative serum NGAL as a prognostic tool for renal consequences after cardiac surgery. Besides, postoperative serum NGAL is a sensitive marker for AKI, but is less specific than serum creatinine. Troponin I is considered to be a risk confirmatory tool and may help in the prediction of AKI. However, its diagnostic utility is restricted due to age-dependent cutoff values and poor standardization and harmonization because of interassay variations.

Prognostic utility of neutrophil gelatinase associated lipocalin in cardiac ICU: A prospective study

“…Our data revealed that NGAL values were significantly higher in patients who developed AKI than in those without AKI. Mosa 8 did a similar study in patients of open heart surgery and found that baseline serum NGAL values were higher in the AKI group compared to the non-AKI group ( p < 0.01). Haase-Fielitz et al 9 found similar performance of NGAL in patients of cardiac surgery.…”

Beta-Trace Protein as a Potential Marker of Acute Kidney Injury: A Pilot Study

“…The early increase of BTP and CysC might reflect already some degree of kidney dysfunction prior to surgery, possibly induced by the medical condition necessitating the surgery. The absence of pre-op rise in sCr can be explained by tubular excretion of sCr when GFR decreases [1,5,7,[13][14][15]. The absence of pre-op rise in NGAL levels in both groups is puzzling, as other groups observed an increase in NGAL 12-24 h before a rise in sCr in AKI [5,7,8,[11][12][13][14][17][18][19][20].…”

“…The absence of pre-op rise in sCr can be explained by tubular excretion of sCr when GFR decreases [1, 5, 7, 13-15]. The absence of pre-op rise in NGAL levels in both groups is puzzling, as other groups observed an increase in NGAL 12–24 h before a rise in sCr in AKI [5, 7, 8, 11-14, 17-20]. Different explanations may underly this observation.…”

“…Acute kidney injury (AKI) is common in patients at the intensive care unit (ICU), with incidences varying from 35 up to 48% after surgery, especially after cardiac surgery [1][2][3][4]. Epidemiological data suggest that an epi- sode of AKI increases mortality risk, both at the long and short term [1][2][3][4][5][6][7][8][9][10][11][12], as well as the risk for developing CKD [3,4,13].…”

“…As such, serum NGAL is regarded as an early marker for tubular injury. It can be identified in plasma and urine starting 2-4 h after kidney injury and precedes an increase in sCr by 12-24 h [5,7,8,[11][12][13][14][17][18][19][20]. However, elevated plasma NGAL levels are not specific, and increased plasma levels are also reported in malignancy, CKD, pancreatitis, chronic obstructive pulmonary disease, and urinary tract infection.…”