Acute Chest Pain Treatment and Evaluation (ACTION) Study

Objective 1. To compare the incidence of adverse cardiac events among the patients discharged after evaluation through ACTION protocol with those through conventional protocol. The adverse cardiac events for the follow-up are defined as any of the followings: * Cardiac related death * Ventricular fibrillation * Myocardial infarction * Cardiogenic shock requiring the inta-aortic balloon pump circulatory assistance * Acute pulmonary oedema requiring endo-tracheal intubation 2. To study the sensitivity / predictive values of the various components of ACTION :12 lead ECG ST monitoring , serial serum markers for myocardial necrosis (myoglobin, CKMB, TnT, graded exercise testing, stress tetrofosmin scan/ stress echocardiography) in predicting adverse cardiac events. Design -prospective randomised clinical trial Participants -patients above 25 years of age presenting to the ED with chest pain consistent with myocardial ischaemia but with a 12 lead ECG non-diagnostic of myocardial ischaemia . Intervention Patients were monitored continuously with a 12 lead ECG and ST segment trend monitoring and blood will be drawn at 0,3,6 hours after arrival at ED for serial myoglobin, creatine kinase MB isoenzyme (CKMB) and Troponin T (TnT) . Patients who have ECG and blood test consistent with myocardial necrosis were admitted to the CCU. A senior doctor in the ED reviewed patients who were not admitted after 6 hours of observation. Study Group A stress tetrofosmin nuclear scan was done . Patients were then admitted and discharged depending on the results of the stress tetrofosmin scan. Control group (conventional protocol) Patients were then be admitted or discharged at the discretion of the senior ED doctor. Measurement Patients were followed up at 1 week , 2 weeks , one month and six months for any adverse cardiac events such as cardiac related death , ventricular fibrillation , and myocardial infarction. Statistical analysis Logistic regression analysis w