Extra heart scan needed to assess heart risk: study

By Julie Steenhuysen

CHICAGO (Reuters) - A person's long-term risk of heart disease is better assessed by a pair of studies, as performing only one may miss a dangerous buildup of calcium in arteries, U.S. researchers said on Monday.

They said about half of all patients in a 10-year study who had normal results on a nuclear stress test known as SPECT were found to have significant buildup of calcium on the walls of their arteries when they did a heart CT.

"Typically, when a patient presents with chest pain and the (SPECT) test result is normal, we tell them everything looks fine, but this may not be the case," Dr. John Mahmarian of the Methodist DeBakey Heart and Vascular Center in Texas, who led the study, said in a statement.

He said if a large amount of calcified plaque is found on artery walls -- something that can't be seen in SPECT imaging -- the patient has a high long-term risk of having a heart attack or stroke.

"Based on our findings, using both tests to define risk is better than either test alone," Mahmarian said in a statement.

Nuclear stress tests using single-photon emission computed tomography, or SPECT, examine blood flows to the heart. People with a normal result are generally thought to have less than a 1 percent chance of having a heart attack within a year.

Computed tomography or CT scans use special X-ray equipment and sophisticated computers to measure calcified plaque in the heart arteries. These tests can detect varying degrees of blockages in the heart.

Both tests expose patients to radiation.