Management of patients with low-risk chest pain at the time of admission: a prospective study on a non-selected population from the Emergency Department.

Background: The management of patients with acute chest pain is a common and difficult challenge from the epidemiological, clinical, organizational and malpractice points of view. Our purpose was to test and implement a simple clinical protocol for the management of patients with acute chest pain and at low-risk for an acute coronary syndrome (ACS) at the time of admission to the Emergency Department (ED).

Methods: During a 5-month study period, 570 consecutive patients were admitted to the ED with acute chest pain: 224 patients were excluded owing to the presence of a clear diagnosis of an ACS or of high-risk factors. The remaining 346 were considered, at the time of admission, as being at low risk for an ACS and constituted the study group (208 males, 138 females, mean age 65 years). These 346 patients were evaluated in the ED area by means of multiple ECGs and multiple blood sampling for the creatine kinase-MB mass and troponin I serum levels at the time of admission and 6 and 12 hours later. In selected cases a treadmill stress test was requested in order to further clarify the diagnosis.

Results: The ECG at the time of admission was normal or nearly normal in 79% of the patients. Stress testing was performed in 79 patients (25%). Sixty-six/346 low-risk patients (19%) were admitted to the coronary care unit during ED observation: 38 patients because of positive markers, 10 because of a positive ECG, 13 because of positive markers and ECG, and 5 because of a positive stress test. Two hundred and eighty low-risk patients without evidence of acute ischemia were definitively discharged and classified as having non-ischemic chest pain. At 1 month of follow-up, 1 patient underwent coronary artery bypass grafting, 1 patient was again admitted to the ED for acute pulmonary edema, and 2 patients had acute extracardiac events. Within 1 year of follow-up 4 deaths occurred: 2 were cancer-related and 2 were sudden deaths.

Conclusions: The tested strategy, based on integrated clinical, ECG and multimarker data, and on a short "test of time" period of low-risk patient observation, can allow the identification of patients having an ACS on the one hand and of those for whom a safe, rapid and early discharge is possible on the other, in a low-cost environment.