MONDAY, Feb. 19, 2007 (HealthDay News) -- An advanced CT scan was 75 percent accurate in catching which patients who came to an emergency room with chest pain actually had serious heart problems, cardiologists report.
The findings could translate into savings of both time and money, along with fewer unnecessary hospitalizations, they added.
"Ours is what I believe to be the first randomized study showing that multi-slice CT scanning improves the efficacy of diagnosis of people with chest pain," said study author Dr. James A. Goldstein, director of research and education in the cardiology division of William Beaumont Hospital in Michigan. His report is published in the Feb. 27 issue of the Journal of the American College of Cardiology.
Improved, quick diagnosis is important for the estimated 1 million Americans who come to emergency rooms each year with chest pains that could be a sign of serious heart trouble or simply a false alarm.
Those people now can spend up to 24 hours in the hospital as doctors do blood tests and perform electrocardiograms (ECGs). About 65 percent of those people eventually are found not to have had a heart attack, but many are hospitalized anyway, because doctors would rather err on the side of caution. The diagnostic cost of all that testing tops $10 billion a year, according to the study.
The Michigan researchers used a different approach with 197 people who came to emergency rooms with chest pains but no history of heart disease. Half were given the standard treatment. The other half were assigned to have CT scans of the heart, in which X-rays are first used to measure the amount of calcium in the arteries, and dye is then injected to get a detailed picture of the heart and its arteries, something than can be done in about 15 minutes.
CT scans alone were able to determine whether heart disease was the cause of the chest pains in 75 percent of the cases, the researchers found. The remaining 25 percent needed more tests. Even so, the average cost for diagnosing a patient with a CT scan was $1,586, compared to $1,872 for those given the standard approach, and the average time for diagnosis was 3.4 hours with CT scans, compared to 15 hours with the standard approach.
"We are using it widely," Goldstein said of the new method. "We are using it routinely for appropriate patients, those with chest pains who don't have a previous history of coronary artery disease and whose ECG appears normal."
Improved equipment is on the way, Goldstein added. The study used CT machines that produce images of 64 slices of the heart. A 128-slice machine is being installed, and 256-slice CT devices are on the horizon.
However, CT imaging of the heart is still a technology under development, other cardiologists said.
"My assessment is that while this is a very promising tool for assessment of blockages in arteries, it appears to me that the emergency room might not be the best place for this technology at this time," said Dr. Armin Zadeh, associate director of cardiac CT at the Johns Hopkins University School of Medicine.
The fact that a quarter of the people in the Michigan study needed further tests was bothersome, Zadeh said. "Until we get further information, there is at least a question mark about this use," he noted.
The use of CT scanning to assess coronary arteries appears to be highly promising, Zadeh said. He is taking part in a multi-center trial in which CT scanning is being compared to a more invasive method, insertion of a catheter, for patients hospitalized with chest pain. "We should report the results very soon," he said.
As far as emergency room use is concerned, the Michigan study "does bump it up to a higher level of science," said Dr. Deepak Bhatt, associate director of the cardiovascular coordinating center at the Cleveland Clinic. But the technique does have limitations, he noted, such as inability to determine the best treatment for moderately blocked arteries.
And there are not many carefully controlled studies such as the one done in Michigan, Bhatt added. "There is a fair amount of CT angiography going on out there, not in any structured way, but because the technology exists," he said. "I am a believer in the technology, but we have to do things in a more measured, controlled fashion, and make sure that people are good at it."
A large part of CT scanning usefulness "has to do with the skill of the physicians interpreting them, and it is difficult to be sure the quality is there in some cases," Bhatt noted.
More information
The why and how of computed tomography are described by the National Library of Medicine.
