The findings of a new study on how best to treat chest pain in the emergency department led to immediate changes in protocol at NewYork-Presbyterian Hospital and may lead to similar changes at affiliated hospitals.
The study by physicians and scientists at P&S and NewYork-Presbyterian Hospital/Columbia Presbyterian Medical Center finds that patients with chest pain who undergo a stress test shortly after being seen in the emergency department have a significantly lower death rate than those who do not take a stress test because patients who take the test are treated when the tests reveal heart disease. The results of the study were published in the June 15 issue of the American Journal of Cardiology.
Each year more than 5 million people go to emergency departments with complaints of chest pain. Doctors use electrocardiograms (EKGs) and blood tests to assess who is having a heart attack so they can be treated quickly.
But it is unclear what should be done for an ER patient with chest pain who is not having a heart attack. Some patients chest pain can be traced to anxiety or heavy lifting, but chest pain can also be a sign of heart disease.
The new study found that during the three months following a chest pain episode, patients who did not take a stress test combined with imaging of the blood flow to the heart were six times more likely to die than those who took the test (3 percent vs. 0.5 percent).
The study demonstrates that stress tests can identify patients with underlying coronary artery disease, says Dr. Steven R. Bergmann, Margaret Milliken Hatch Professor of Medicine and professor of radiology at P&S, director of nuclear cardiology at NYPH/Columbia, and the studys co-principal investigator. Patients who appear normal following EKGs and blood tests are usually sent home, missing an opportunity to diagnose and treat underlying cardiac problems.
A stress test is given to show deficiencies in blood flow in the heart. The test requires that a patient either walk on a treadmill or take medications that simulate the effect of exercise on the heart. A small amount of a radioactive substance is given at peak stress to measure maximum blood flow to the heart. By contrast, an EKG is administered when a patient is at rest.
Because some blood flow problems only show up when the hearts workload is increased, stress tests are a better means to measure cardiac abnormalities than EKGs, says Dr. LeRoy E. Rabbani, associate professor of clinical medicine at P&S, director of the cardiac intensive care unit and the chest pain program at NYPH/Columbia, and the studys co-principal investigator.
The study tracked 1,195 patients who had EKG and blood tests in the normal range for three months after they had gone to the emergency department complaining of chest pain. While a stress test was recommended for all patients with normal EKGs and blood tests, each medical team was allowed to decide if stress tests were necessary. Of the patients studied, nearly half received a stress test.
Of the 565 patients who took the imaging stress test, a little more than half had normal results no evidence of heart disease. A small number of them returned to the hospital for chest pain but none returned with a heart attack. The other patients had abnormal stress tests evidence coronary artery disease was present. Of those, almost a quarter returned to the hospital with recurring chest pain, but again, very few had heart attacks because they had undergone a stress test and began treatment for their disease.
The authors hope to continue their research and follow patients for longer periods of time. We would like to figure out just how long its safe to wait after ruling out a heart attack before administering a stress test, says Dr. Bergmann.