Pain Response to Nitroglycerin Does Not Predict Cardiac Etiology

From Medscape / Reuters, excerpted below:

"Pain Response to Nitroglycerin Does Not Predict Cardiac Etiology"

The degree to which chest pain responds to sublingual nitroglycerin is not useful in determining if the pain stems from a cardiac cause, according to a report in the Annals of Emergency Medicine for June.

Previous reports looking at the predictive value of the response to sublingual nitroglycerin have yielded conflicting results. However, unlike the present investigation, many of these studies did not use validated pain measures.

The findings are based on a study of 664 patients who presented to a tertiary care emergency room with chest pain between May 24, 2001 and April 30, 2002. The pain was graded with an 11-point numeric descriptive scale before and after the subjects were treated with sublingual nitroglycerin.

The median patient age was 52 years with a nearly even ratio of men to women, the report indicates. Cardiac-related pain was defined as a discharge diagnosis of acute MI or a diagnosis of coronary artery disease through measures such as noninvasive imaging or cardiac catheterization.

Eighteen percent of patients had cardiac-related chest pain, lead author Dr. Deborah B. Diercks, from the University of California in Sacramento, and colleagues note.

Nineteen percent of patients had no change in their pain with nitroglycerin, 31% had a slight reduction, 22% had a moderate reduction, while 28% had major or complete resolution of their pain. However, none of these responses was useful in identifying pain of cardiac origin.

Although sublingual nitroglycerin is a useful treatment for suspected cardiac chest pain, the response to this agent is not particularly helpful in differentiating cardiac- from noncardiac-related pain, the investigators conclude.