Predictors of Adverse Outcomes of Patients with Chest Pain and Primary Diagnosis of Non-Cardiac Pain at the Time of Discharge from Emergency Department: A 30-Days Prospective Study

BACKGROUND Chest pain is a common symptom for referring patients to emergency departments (ED). Among those referred, some are admitted to hospitals with a definite or tentative diagnosis of acute coronary syndrome and some are discharged with primary diagnosis of non-cardiac chest pain. This study aimed at investigating 30 days' adverse outcomes of patients discharged from ED of a major heart center in Iran. METHODS Out of 1638 chest pain admissions to the centre during 2010-2011, 962 patients (mean age= 50.9±15.9 years) who were admitted to Afshar Heart Center's ED with chest pain as their chief complaint, and discharged with primary diagnosis of non-cardiac chest pain, were followed for any adverse cardiac events 30 days post discharge. The adverse events were: unstable angina, non-ST-elevated myocardial infarction (NSTEMI), ST elevated myocardial infarction (STEMI), coronary revascularization (percutaneous angioplasty, coronary artery bypass grafting) and death. RESULTS Adverse cardiac events, including acute coronary syndrome (ACS), revascularization and death were observed in 30 patients (3.1%) including: acute MI n=5 (0.5%, sudden cardiac death inn=1 (0.1%, coronary revascularization in n=8 (0.8%) and hospitalization due to unstable angina/NSTEMI in n=16 (1-7%). Adverse events were seen more frequently in patients with history of hypertension, dyslipidemia and previous coronary artery disease. In univariate analysis, the chance of postdischarge adverse cardiac events was higher in patients with hypertension (OR=9.36, CI=3.24-27.03), previous coronary artery disease (OR= 3.8, CI=1.78-8.0), dyslipidemia (OR=3.5, CI=1.7-7.38) and discharge against medical advice (OR=2.85, CI= 1.37-5.91). CONCLUSION The extent of adverse cardiac events in patients with a primary diagnosis of non-cardiac chest pain within 30 days of discharge was significant, mandating nation-wide registries to provide better care for these patients.