Aspartate aminotransferase to platelet ratio index as a predictor of mortality in traumatic brain injury

Background: The Aspartate Aminotransferase-to-Platelet Ratio Index (APRI) is traditionally used to assess liver disease but may have prognostic value in other clinical contexts. This study evaluates APRI’s ability to predict mortality in traumatic brain injury (TBI) patients. Methods: This retrospective cohort study included 6252 adult TBI patients (Head/Neck Abbreviated Injury Scale (AIS) ≥3) from the Trauma Registry System at Kaohsiung Chang Gung Memorial Hospital, covering admissions from 1998 to 2023. APRI was calculated at admission using aspartate aminotransferase (AST) levels and platelet counts. The area under the receiver operating characteristic curve (AUC) was used to evaluate APRI’s predictive accuracy for mortality, and an optimal APRI cutoff was determined using Youden’s index. Patients were divided into high and low APRI groups based on this threshold, with mortality and other clinical outcomes compared. Results: Among the cohort, 5658 patients survived, and 594 patients died. APRI demonstrated moderate predictive accuracy for mortality, with an AUC of 0.648. The optimal cutoff for APRI was 0.59, yielding a sensitivity of 63.6% and specificity of 60.3%. Patients with APRI ≥0.59 had significantly higher mortality (14.5% vs. 5.9%, p < 0.001) and longer hospital stays (15.9 vs. 12.0 days, p < 0.001). After adjusting for confounders, elevated APRI remained independently associated with increased mortality (Adjusted odds ratio (AOR) = 1.67, 95% Confidence interval (CI): 1.37–2.02, p < 0.001). This association was strongest in patients with severe injury, indicated as Injury Severity Score (ISS) ≥25), where APRI ≥0.59 yielded an AOR of 1.74 (95% CI: 1.36–2.22, p < 0.001). Conclusions: These results indicate that an elevated APRI is a significant predictor of in-hospital mortality in moderate and severe TBI cases even after adjustment for confounders, whereas its prognostic value is minimal in patients with minor injuries. However, its predictive power remains limited, and APRI should be used alongside existing trauma scoring systems for comprehensive risk assessment, with prospective validation recommended. Prospective studies are recommended to validate APRI’s role in TBI and explore combined biomarker approaches to enhance predictive accuracy.

Trauma; Traumatic brain injury (TBI); Aspartate aminotransferase-to-platelet ratio index (APRI); Prognosis; Mortality

[1] Tsai CH, Rau CS, Chou SE, Su WT, Hsu SY, Hsieh CH. Delta De Ritis ratio is associated with worse mortality outcomes in adult trauma patients with moderate-to-severe traumatic brain injuries. Diagnostics. 2022; 12: 3004.

[2] Lin MH, Lu CC, Chang CH, Tsai TC. Complications affecting the functional outcome after 1 year in older adults with severe head injury. Formosan Journal of Surgery. 2023; 56: 16–21.

[3] Yuguero O, Vena A, Bernal M, Martínez-Alonso M, Farre J, Purroy F. Platelet levels and age are determinants of survival after mild-moderate TBI: a prospective study in Spain. Frontiers in Public Health. 2023; 11: 1109426.

[4] Wang Q, Zhao H, Tong Y, Qin J, Zhou M, Xu L. Aspartate aminotransferase/platelet ratio index upon admission predicts 24-week mortality in patients with HIV-associated Talaromyces marneffei. Open Forum Infectious Diseases. 2023; 10: ofad593.

[5] Lin ZH, Xin YN, Dong QJ, Wang Q, Jiang XJ, Zhan SH, et al. Performance of the aspartate aminotransferase-to-platelet ratio index for the staging of hepatitis C-related fibrosis: an updated meta-analysis. Hepatology. 2011; 53: 726–736.

[6] Ali K, Slah-Ud-Din S, Afzal M, Tariq MR, Waheed T, Yousuf H. Non-invasive fibrosis markers for predicting esophageal varices: a potential alternative to endoscopic screening. Cureus. 2024; 16: e56433.

[7] Çopur B, Sürme S, Tunçer G, Bayramlar OF. The role of APRI, FIB-4, and SAD-60 scores as predictors of mortality in COVID-19 patients. Infectious Diseases and Clinical Microbiology. 2023; 5: 144–152.

[8] Jamil Z, Khalid S, Khan H, Waheed I, Ehsan A, Alissa M, et al. Aspartate aminotransferase-to-platelet ratio index (APRI) as a novel score in early detection of complicated dengue fever. Journal of Multidisciplinary Healthcare. 2024; 17: 2321–2330.

[9] Mattos ÂZd, Mattos AAd, Daros LF, Musskopf MI. Aspartate aminotransferase-to-platelet ratio index (APRI) for the non-invasive prediction of esophageal varices. Annals of Hepatology. 2013; 12: 810–814.

[10] McLellan MA, Donnelly MR, Callan KT, Lung BE, Liu S, DiGiovanni R, et al. The role of preoperative aspartate aminotransferase-to-platelet ratio index in predicting complications following total hip arthroplasty. BMC Musculoskeletal Disorders. 2023; 24: 934.

[11] Donahue DL, Beck J, Fritz B, Davis P, Sandoval-Cooper MJ, Thomas SG, et al. Early platelet dysfunction in a rodent model of blunt traumatic brain injury reflects the acute traumatic coagulopathy found in humans. Journal of Neurotrauma. 2014; 31: 404–410.

[12] Ploplis VA, Donahue DL, Sandoval-Cooper MJ, MorenoCaffaro M, Sheets P, Thomas SG, et al. Systemic platelet dysfunction is the result of local dysregulated coagulation and platelet activation in the brain in a rat model of isolated traumatic brain injury. Journal of Neurotrauma. 2014; 31: 1672–1675.

[13] Villapol S. Consequences of hepatic damage after traumatic brain injury: current outlook and potential therapeutic targets. Neural Regeneration Research. 2016; 11: 226–227.

[14] Xiao G, Yang J, Yan L. Comparison of diagnostic accuracy of aspartate aminotransferase to platelet ratio index and fibrosis-4 index for detecting liver fibrosis in adult patients with chronic hepatitis B virus infection: a systemic review and meta-analysis. Hepatology. 2015; 61: 292–302.

[15] Jin W, Lin Z, Xin Y, Jiang X, Dong Q, Xuan S. Diagnostic accuracy of the aspartate aminotransferase-to-platelet ratio index for the prediction of hepatitis B-related fibrosis: a leading meta-analysis. BMC Gastroenterology. 2012; 12: 14.

[16] Zhang Y, Zhang X. Prognostic value of aspartate aminotransferase to platelet ratio index as a noninvasive biomarker in patients with hepatocellular carcinoma: a meta-analysis. Cancer Management and Research. 2018; 10: 3023–3032.

[17] Liu SH, Patel V, Loyst RA, Lung B, Cohen D, Kashanchi K, et al. Preoperative risk stratification in arthroscopic rotator cuff repair: aspartate aminotransferase-to-platelet ratio index as an estimate of liver dysfunction. Cureus. 2023; 15: e41980.

[18] Wang R, Cai L, Liu Y, Zhang J, He M, Xu J. Liver fibrosis score is associated with the mortality of traumatic brain injury patients. Neurosurgical Review. 2023; 46: 201.

[19] Sanfilippo F, Veenith T, Santonocito C, Vrettou CS, Matta BF. Liver function test abnormalities after traumatic brain injury: is hepato-biliary ultrasound a sensitive diagnostic tool? British Journal of Anaesthesia. 2014; 112: 298–303.

[20] Prus R, Appelhans O, Logash M, Pokotylo P, Nowicki G, Ślusarska B. A histological and morphometric assessment of the adult and juvenile rat livers after mild traumatic brain injury. Cells. 2021; 10: 1121.

[21] Jumaev B, Klichev U, Pirboev F. Comparative characteristics of the morphological parameters of the liver at different periods of traumatic brain injury. The American Journal of Medical Sciences and Pharmaceutical Research. 2021; 3: 51–55.