The CT scans accurately predicted 84 percent of the treatment procedures that were required, compared to 82 percent accuracy for angiography.
"Until now, there has been doubt about 16-row or 64-row CT scanners being able to diagnose coronary disease," Miller said. The new study dispels that doubt, she said.
But there is no evidence that using a 64-CT scan changes the outcome, Redberg countered. "We need to have a study that uses CT and the traditional strategy and look at the outcome in the two arms to see which is better," she said.
This is more than an argument between academics. Aside from the health of people who might have CT scans, a great deal of money is involved. Redberg's editorial tells a tangled story of how the national Medicare program first declined coverage of the CT scans, asserting at the time that the "evidence is inadequate" to prove their value. However, a series of local decisions means Medicare now covers the scans in every state.
In fact, "the use of cardiac imaging has been increasing by 26 percent per year, despite a lack of evidence of outcome benefit," the editorial said. "Without such evidence, a high-resolution CT angiographic CT image of the heart is just another pretty picture," the expert said.
CT scans also expose patients to a relatively high dose of radiation, the editorial noted, citing a study which estimates that 1.5 percent to 2 percent of all U.S. cancer cases may be attributed to CT radiation.
However, Miller believes that CT scans do have a role in diagnosis.
"The cost to patients is generally reasonable when compared to other noninvasive imaging tests and cheaper than catheterization in general," she said. CT scans of the heart can be considered "for someone complaining of angina [chest pain] who needs further noninvasive evaluat
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