For years, hospital emergency physicians have used nitrogylcerin as a gold standard for identifying heart disease as a cause of chest pain. If a patient presents with chest pain, and a nitroglycerin pill or spray under the tongue relieves the pain within a few minutes, the likely diagnosis is coronary artery disease (CAD).
Now a Johns Hopkins study is challenging that belief. Of 459 patients who came to the emergency department at Hopkins' Bayview Medical Center between February and June of this year complaining of chest pain, nitroglycerin relieved chest pain in about 39 percent of patients, whether or not they turned out to have heart disease. Overall, nitroglycerin was only 28 percent accurate in predicting CAD as the source of pain. These findings will be presented Nov. 12 at the American Heart Association's annual Scientific Sessions in Anaheim, Calif.
"This study has the potential to change how emergency departments triage patients with chest pain," says Nisha Chandra-Stobos, M.D., senior author of the study and director of the coronary intensive care unit at Bayview. "Our data suggest that despite the commonly held belief, pain relief with nitroglycerin does not predict coronary artery disease and should not be used to guide diagnosis."
Nitroglycerin works by relaxing the veins (reducing the amount of blood that returns to the heart and easing the heart's workload) and arteries (increasing the heart's blood supply). It's the drug most often used for the one in five patients who comes to the ED complaining of chest pain.
The patients studied had an average age of 58. Forty-six percent were male; 44 percent were smokers; 25 percent were diabetic and 38 percent had a known history of CAD. After initial treatment with nitroglycerin, 261 (57 percent) underwent further cardiac test
Contact: Karen Blum
Johns Hopkins Medical Institutions