Can low-risk chest pain patients with two or more cardiac risk factors be safely admitted to an emergency department observation unit?

Study objectives: The purpose of this study is to compare the proportion of low-risk chest pain patients with less than or 2 or greater cardiac risk factors who are admitted to the hospital from the emergency department observation unit (EDOU) or receive cardiac catheterization after admission. Methods: We prospectively enrolled a convenience sample of low-risk chest pain patients to our EDOU. "Low-risk" criteria for admission to the EDOU were defined as having no significant ECG changes and an initial troponin level less than 0.1. Patient interviews were performed, and emergency department and EDOU medical records were reviewed. Risk factors for coronary artery disease were defined as smoking, hyperlipidemia, known hypertension, diabetes mellitus, family history of heart disease, and history of coronary artery disease. History of coronary artery disease was defined as a previous myocardial infarction or previous coronary artery interventions (coronary artery bypass grafting [CABG] or angioplasty). Patients were categorized into the following 2 groups: having less than 2 or 2 or more risk factors. The following outcomes between groups were compared: final discharge status from the EDOU (admit to the hospital or discharge home) and proportion of patients receiving cardiac catheterization. χ 2 Statistics were calculated to determine the association between risk factor group and admission or receiving a cardiac catheterization during visit. Descriptive statistics were used to report specific location of admission per risk group. Results: Two hundred seventy-four patients with low-risk chest pain were enrolled. Demographic characteristics for the entire sample are as follows: men (139), women (135), white (139), black (96), Hispanic (24), Asian (8), black/Hispanic (1), Middle Eastern (2), and other (3). One hundred twenty-four patients had 2 or more risk factors for coronary artery disease. Patients with 2 or more risk factors were equally likely to be admitted (n=12) compared with patients with less than 2 risk factors (n=16, χ 2 =.07, P =.78). Patients with 2 or more risk factors were equally likely to receive cardiac catheterization during admission (n=8) compared with patients with less than 2 risk factors (n=6, χ 2 =.84, P =.35). The Table describes location of admission per risk factor group. Only 2 of the 14 patients who underwent cardiac catheterization were found to have significant coronary artery disease requiring angioplasty. On further evaluation of the 124 patients with 2 or more risk factors for coronary artery disease, 13 patients had a previous diagnosis of coronary artery disease. Four of these patients were admitted to the hospital from the EDOU, and 9 were discharged home. Of the 4 admitted patients, 3 were admitted to telemetry, and 1 patient was admitted to the general medicine floor. Two patients subsequently underwent cardiac catheterization; neither required angioplasty. Of the entire sample of patients, none required CABG, and none died. Conclusion: The rate of positive testing, admission to the hospital, and catheterization is not notably different between groups. Continued admission of these patients and monitoring of 30-day outcomes will provide a better understanding of the safety of this practice.Table, abstract 10Location of admission per risk factor group.Risk FactorsGeneral MedicineTelemetryCatheterization LaboratoryICUTotals