Determinación cualitativa de marcadores de necrosis miocárdica desde la fase prehospitalaria del síndrome coronario agudo

Summary Objective: We measured the diagnostic value of troponin I (TnI), mioglobin (Miog) and creatine kinase MB (CPK-MB) in patients with thoracic pain during the period of preadmission to the hospital. Methods: We included patients who requested prehospital attention with intensive therapy ambulance or who were in the first hours of hospitalization for thoracic pain. A 12-lead electrocardiogram was carried out in the ambulance or in the emergency room. The levels of total creatine phosphokinase were determined (as reference pattern). Five study groups were included: group I, 13 patients with acute myocardial infarction without elevation of the ST segment; group II, 11 patients with unstable angina; group III, 14 patients with atypical thoracic pain for angina; group IV, five healthy patients; and group V, five patients with acute myocardial infarction with elevation of the ST segment. A qualitative evaluation was made with an automatic device for quick interpretation of TnI, Miog and CPK-MB. Results: Forty eight patients were studied with an average age of 55 ± 18 years, 25 men (52%) and 23 women (48%), average time of symptom evolution was 3.5 h (quartiles 2 and 6 h). Total level of CPK was taken as a reference pattern. Sensitivity of TnI, Miog, and CPK-MB was 100%, specificity was 94, 91 and 94%, respectively. Positive predictive value was 89, 84 and 89%, respectively. Negative predictive value was 100%. Likelihood of probability was 8.7, 5.5 and 8.7, respectively. Conclusions: TnI, Miog and CPK-MB have high diagnostic value in acute coronary syndrome (ACS) from the time of prehospital admission. Determination is advisable as part of the diagnostic protocol, which is of great importance in order to plan the hospitalization and treatment in this group of patients.