Crowded emergency departments pose greater risks for patients with heart attacks.

Patients with heart attacks and other forms of chest pain are three to five times more likely to experience serious complications after hospital admission when they are treated in a crowded emergency department (ED), according to a new study published in the journal Academic Emergency Medicine. The authors say that this dramatic difference in rates of serious complications underscores the need for action on the part of hospital administrators, policymakers and emergency physicians to find solutions to what has been termed "a national public health problem." More than six million patients per year come to U.S. emergency departments with chest pain (see also Wiley-Blackwell).

"What shocked us is that these complications were not explained by what goes on in the ED, like getting aspirin or a rapid electrocardiogram," says lead author Jesse M. Pines, M.D., MBA, an assistant professor of emergency medicine and epidemiology at the Hospital of the University of Pennsylvania and a senior fellow at the Leonard Davis Institute of Health Economics. "The adverse events occurred after the patient had been admitted to the hospital. Emergency department crowding is really more of a marker of a dysfunctional hospital."

The study followed 4,574 patients who were admitted to the Hospital of the University of Pennsylvania for symptoms of chest pain over an eight-year period. Ultimately, 802 were diagnosed with an acute coronary syndrome (chest pain of cardiac origin); of those, 273 had a true heart attack. There were 251 complications that occurred in the hospital after initial emergency department treatment. Complications included serious events, such as heart failure, delayed heart attacks, dangerously low blood pressure, heart arrhythmias and cardiac arrest.

When the emergency department was at its highest occupancy and waiting room census, patients with acute coronary syndrome were three times more likely to experience complications in the hospital. When the "patient-hours" was highest, they were more than five times more likely to have a complication. Patient-hours is a sum of the total hours that all patients in the emergency department have been waiting. "It is a measure of real ED workload," says Pines.

Patients without acute coronary syndrome, but still were sick enough to be admitted to the hospital, also had three to four times more complications at highest waiting room census and patient-hours. The authors were unable to pinpoint the exact ...