Nuclear stress test accuracy can be improved, study says

Many people undergo a nuclear stress test to look for signs of heart disease. The test involves giving patients a radioactive material and stressing the hearts, either by exercise or with drugs. Measurements looking at blood flow to the heart are then taken twice, after five minutes and at the 60-minute mark. If no changes are seen between the pictures taken from the resting phase and the exercise phase, then doctors conclude heart disease isn’t present. But a change between the two images may mean a heart blockage.

This approach to testing involves giving people two doses of a radioactive material called sestamibi. But, it may be better to give people only one dose, according to research published this month in the Federal Practitioner.

Dr. Richard M. Fleming, a cardiologist at the Cardiovascular Institute of Southern Missouri, says his research shows that sestamibi moves around in the heart over time. Thus, the two-dose method may fail to detect cases of ischemic heart disease while a single-dose approach may detect cases of heart disease that would otherwise be missed. Moreover, Fleming said, two doses of sestamibi result in higher costs and more radiation for the patient. If further studies confirm the finding, a common and important test for heart disease may be simplified and improved for accuracy.

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