The serum heart-type fatty acid-binding protein (HFABP) levels can be used to detect the presence of acute kidney injury on admission in patients admitted to the non-surgical intensive care unit

Abstract

Background: No cardiac biomarkers for detecting acute kidney injury (AKI) on admission in non-surgical intensive care patients have been reported. The aim of the present study is to elucidate the role of cardiac biomarkers for quickly identifying the presence of AKI on admission.

Methods: Data for 1183 patients who underwent the measurement of cardiac biomarkers, including the serum heart-type fatty acid-binding protein (s-HFABP) level, in the emergency department were screened, and 494 non-surgical intensive care patients were enrolled in this study. Based on the RIFLE classification, which was the ratio of the serum creatinine value recorded on admission to the baseline creatinine value, the patients were assigned to a no-AKI (n = 349) or AKI (Class R [n = 83], Class I [n = 36] and Class F [n = 26]) group on admission. We evaluated the diagnostic value of the s-H-FABP level for detecting AKI and Class I/F. The mid-term prognosis, as all-cause death within 180 days, was also evaluated.

Results: The s-H-FABP levels were significantly higher in the Class F (79.2 [29.9 to 200.3] ng/mL) than in the Class I (41.5 [16.7 to 71.6] ng/mL), the Class R (21.1 [10.2 to 47.9] ng/mL), and no-AKI patients (8.8 [5.4 to 17.7] ng/mL). The most predictive values for detecting AKI were Q2 (odds ratio [OR]: 3.743; 95 % confidence interval [CI]: 1.693-8.274), Q3 (OR: 9.427; 95 % CI: 4.124-21.548), and Q4 (OR: 28.000; 95 % CI: 11.245-69.720), while those for Class I/F were Q3 (OR: 5.155; 95 % CI: 1.030-25.790) and Q4 (OR: 22.978; 95 % CI: 4.814-109.668). The s-HFABP level demonstrating an optimal balance between sensitivity and specificity (70.3 and 72.8 %, respectively; area under the curve: 0.774; 95 % CI: 0.728-0.819) was 15.7 ng/mL for AKI and 20.7 ng/mL for Class I/F (71.0 and 83.1 %, respectively; area under the curve: 0.818; 95 % CI: 0.763-0.873). The prognosis was significantly poorer in the high serum HFABP with AKI group than in the other groups.

Conclusions: The s-H-FABP level is an effective biomarker for detecting AKI in non-surgical intensive care patients.

Keywords: Biomarker; Cardiovascular disease; Emergency care; Mortality; Renal dysfunction.

Fig. 1

The patient selection process. HFABP, heart-type fatty acid-binding protein; Nt-proBNP, N-terminal pro-brain-type natriuretic peptide; hs-TropT, high-sensitivity troponin-T

Fig. 2

The distribution of the HFABP levels. The median value among all 494 intensive care patients was 11.7 ng/ml. The HFABP level was <10 ng/mL in 220 patients (44.5 %) and >100 ng/mL in 37 patients (7.5 %). HFABP, heart-type fatty acid-binding protein

Fig. 3

a The sensitivity and specificity of the HFABP level for detecting AKI were 70.3 and 77.4 % (AUC: 0.774; 95 % CI: 0.728–0.819), respectively, with a cut-off value of 15.7 ng/mL. b The sensitivity and specificity of the HFABP level for detecting a Class I/F status were 71.0 and 83.1 % (AUC: 0.818; 95 % CI: 0.763–0.873), respectively, with a cut-off value of 29.2 ng/mL for the overall patients. HFABP, heart-type fatty acid-binding protein; AKI, acute kidney injury; AUC, area under the receiver-operating characteristic curve

Fig. 4

The Kaplan-Meier survival curves showed that the prognosis, including all-cause death, was significantly poorer in the high serum HFABP (≥15.7 ng/mL) with AKI group than in the low serum HFABP (<15.7 ng/mL) with AKI group, high serum HFABP without AKI group, and low serum HFABP without AKI group. HFABP, heart-type fatty acid-binding protein; AKI, acute kidney injury