Serial Measurement of Heart-Type Fatty Acid Binding Protein for the Rapid Diagnosis of Acute Coronary Syndromes in the Emergency Department

Introduction We aimed to investigate the diagnostic accuracy of heart-type fatty acid binding protein (H-FABP) at admission and the third and sixth hour after admission in patients presenting to the emergency department (ED) with chest pain or equivalent symptoms. Methods This prospective study was performed over two months in the ED. Patients presenting with ischaemic-type chest pain or other symptoms suggestive of myocardial ischaemia were included in the study. A bedside, point-of-care, quantitative H-FABP level was measured. If the initial electrocardiography (ECG) was non-diagnostic, the patients were observed for six hours. During the observation period, serial H-FABP measurements were obtained at admission, the third hour and the sixth hour; serial measurements of total creatine kinase (CK), CK-MB, troponin I and myoglobin were recorded at admission and the sixth hour. Results A total of 183 patients were included in the study. Initial H-FABP was measured in a joint group of ST segment elevation myocardial infarction (STEMI) and non ST segment elevation myocardial infarction (NSTEMI) patients, with a sensitivity of 80.9%, specificity of 19.2%, positive predictive value (PPV) of 23% and negative predictive value (NPV) of 77.1%. The third-hour H-FABP was measured in the NSTEMI group, with a sensitivity of 46.7%, specificity of 80.2%, PPV of 42.4% and NPV of 82.6%. The sixth-hour H-FABP had a sensitivity of 33.3%, specificity of 73.9%, PPV of 24.2% and NPV of 81.5%. Conclusion H-FABP is superior to myoglobin for diagnosing myocardial infarction in a joint group of STEMI and NSTEMI patients. The third-hour NPV value for H-FABP indicates that, for safety considerations, the cardiac observation time should not be shortened. (Hong Kong j.emerg.med. 2014;21:213-221)