While most people know that chest pain can signify the presence of heart disease, it is less well known that shortness of breath can also be a serious cardiac symptom.
Now, researchers at Cedars-Sinai Medical Center have found that patients with shortness of breath can have a higher risk of dying from cardiac disease than patients without symptoms, and even than patients with typical cardiac pain.
Authors of a study published in the November 3 issue of the New England Journal of Medicine reported that shortness of breath was a significant predictor of death from cardiac causes, as well as death from any cause.
The study was based on a retrospective evaluation of medical records of nearly 18,000 patients referred for cardiac stress testing who were then followed-up later. Researchers found that when compared to patients without shortness of breath, those with shortness of breath were significantly more likely to experience death from cardiac cause than patients without shortness of breath. More than 1,000 of the patients denied having chest pain but answered "yes" to the question, "Do you experience shortness of breath?"
"Patients often do not interpret shortness of breath as a serious symptom, but particularly in patients who have cardiac risk factors and in patients without lung disease, it may be the only sign of the presence of serious coronary artery disease that may need treatment," said Daniel Berman, M.D., senior author of the study and the Director of Cardiac Imaging at Cedars-Sinai Medical Center. "If we can identify patients with coronary disease before an event occurs, then the vast majority of the cardiac events could be prevented by modern therapies. The problem is identifying the patient at risk," he added.
In the retrospective study, patients without known coronary artery disease who had shortness of breath were four times more likely to suffer death from a cardiac cause than asymptomatic patients and twice as likely as patients who had chest pain that is considered to be typical cardiac pain.
"These findings may in part be due to the fact that doctors are more likely to send patients with chest pain to bypass surgery or angioplasty than patients with shortness of breath," explained Berman.
Coronary artery disease, usually associated with the presence of plaque build-up in the arteries surrounding the heart, is one the main causes of death in both men and women. While it often is associated with chest pain, about half of the patients with this serious disease either die suddenly without prior symptoms or have a heart attack as the first manifestation of the disease.
The New England Journal paper authored by Aiden Abidov, M.D. and associates described the retrospective study of the medical records of 17,991 patients referred for stress testing by their physicians who knew or suspected they had coronary artery disease based on their symptoms or their cardiac risk factors. The stress testing was done with myocardial perfusion imaging, the most widely used noninvasive approach to detect blocked coronary arteries. During the test, patients exercise on a treadmill or, if they can't, are given medication that causes the heart's arteries to dilate. Once the patient reaches "peak" stress, a small amount of radioactive imaging agent is given that concentrates in the heart according to blood flow, emitting signals that are captured by a special type of camera. The cardiac images show the parts of the heart which do not get enough blood flow during stress and is very effective in predicting short-term risk of a cardiac event and determining whether it is necessary to consider angioplasty or surgery at that time. Approximately 8 million stress myocardial perfusion scans were performed in the United States in 2004.