Heart Disease News:

Stress Tests May Fail to Detect Artery Hardening

Stress tests may not adequately screen for atherosclerosis or hardening of the arteries due to plaque build-up, according to a study reported in the August 18th issue of the Journal of the American College of Cardiology.

Stress tests have been used for over fifty years to identify patients with coronary artery disease and to help physicians know which treatment options might be best.

During a stress test, heart rate and blood pressure is measured before, during and after a patient exercises on a treadmill or, when exercise is not possible, medication is used to induce the stress condition.

The study found that a relatively high number of patients with normal readings on stress tests also had a calcium score of greater than 100, which implies that aggressive medical treatment is needed.

Calcium scores of zero are the best scores. Scores between one and 100 correlate with a low risk for any cardiac event over the ensuing five years. Patients with calcium scores from 100 to 400 are at increased risk for cardiac events, while scores above 400 identify patients at the highest risk for a heart attack.

Among the 1,119 patients in the study who had normal stress tests and subsequently underwent coronary calcium scanning, the researchers found that 56 percent had scores greater than 100 and 31 percent of patients had scores greater than 400.

The study suggests that many patients who have normal stress tests could benefit from additional screening for coronary calcium with x-ray computed tomography or CT scanning technology, according to researchers

“Our study shows that patients who have normal imaging stress test results frequently have extensive atherosclerosis as revealed by coronary calcium scanning,” said lead researcher Dr. Daniel Berman, M.D., director of cardiac imaging at Cedars-Sinai. “These findings imply a potential role for the coronary calcium scan, after an imaging stress test among patients whose results are normal. These patients could then be identified as needing an aggressive treatment program of diet, exercise and medications--something which they often would not otherwise get based upon standard blood tests and the imaging stress test results alone.”

Source: Medical Week Staff week of August 21, 2004