Evaluation of serum glypican-6 levels in patients with heart failure registering to the emergency department

Introduction and Objectives: Heart failure is one of the most common diseases assigned to emergency department and has high morbidity and mortality rates. The superiority of many biochemical markers over current laboratory tests and imaging methods is still being investigated in the diagnostic approach and determination of the clinical severity of the disease. One of the most important biomarkers used in the diagnosis of heart failure is N-terminal pro-B-type natriuretic peptide (NT-proBNP). However, studies on the search for new biomarkers in diagnostic approaches continue. One of these biomarkers is Glypican-6 (GPC-6), which is produced by both cardiac fibroblasts and cardiomyocytes. In this study, our purpose is to investigate the usability of serum GPC-6 levels in patients followed up with heart failure in the emergency department, by comparing them with NT-proBNP levels and echocardiographic findings used in the diagnosis of heart failure. Material and methods: This prospective, cohort study included patients over the age of 18 with a diagnosis of heart failure and healthy volunteers with similar demographic characteristics to the patient group, who applied to the Emergency Service of Samsun University Samsun Training and Research Hospital between December 2021 and April 2022. Those who had a concomitant acute ischemia (Cerebrovascular Disease, Pulmonary Embolism, Myocardial Infarction), malignancy, intoxication and sepsis that could affect the GPC-6 level at the time of admission were excluded from the study. Demographic data, vital signs, laboratory results, imaging findings and echocardiographic severity levels of the disease were recorded. Serum GPC-6 levels in blood samples taken from patient and control groups were measured by Enzyme Linked Immuno Sorbent Assay (ELISA) method. Results: A total of 85 cases, 65 in the patient group and 20 in the control group, were included in the study. The mean age of the patient group was 72.4±11.8 years, and the mean age of the control group was 68.2±12.3 years (p=0.173). The median GPC-6 level of the patient group (457 (140-2774) pg/mL) was higher than the median GPC-6 level of the control group (251.50 (145-1084) pg/mL) (p=0.038). The median NT-proBNP level of the patient group (445 (100-2384) pg/mL) was higher than the median NT-proBNP level of the control group (111 (101-580) pg/mL) (p<0.001). For the diagnosis of heart failure, GPC-6 levels above 390 pg/mL had 58.46% sensitivity and 75% specificity (AUC=0.654, CI=0.543-0.754, p=0.017). For the diagnosis of heart failure, NT-proBNP levels above 122 pg/mL had 89.23% sensitivity and 70% specificity (AUC= 0.797, CI=0.696-0.877, p<0.001). While a significant correlation was found between the severity of the disease measured by echocardiography and the serum NT-proBNP level, no significant correlation was found between the serum GPC-6 level (p<0.001 and p=0.425 ; respectively). Conclusion: GPC-6 can be used in the diagnosis of heart failure, but it is not sufficient to determine the severity of the disease. GPC-6, has higher specificity than NT-proBNP in the diagnosis of heart failure. Keywords: Emergency department, Heart Failure, Glypican-6 (GPC-6), N-terminal pro-B-type natriuretic peptide (NT-proBNP)