Medicare Stirs CT Heart-scan Issue
April 02, 2008
Medicare stirs CT heart-scan issue
Debate over necessity, cancer risk hasn't missed beat after ruling
By Katy Human
The Denver Post
Article Last Updated: 03/24/2008 12:49:52 AM MDT
CT scans can produce stunning images of a person's heart, but they expose a patient to the radiation of 85 to 200 chest X-rays, increasing cancer risk. (Special to The Denver Post )
The debate over whether a popular heart scan is medically valuable or a needless increase in cancer risk will not be settled by a ruling last week that Medicare will continue to cover some of the scans, physicians said.
Many Denver doctors welcomed the decision to cover some of the scans — called CT heart angiograms — under the federal health program for the elderly.
In minutes and for about $1,000, a 64-slice CT machine can generate spectacular images of the heart and coronary arteries, and doctors in Denver say they rely on the pictures for diagnosis and treatment decisions.
The devices, however, also deliver cancer-causing radiation, Medicare officials wrote in their Wednesday ruling.
No studies to date have shown better health outcomes in people who receive the sophisticated scans, the federal officials said.
Consumers Union labeled the CT heart scans one of the country's 10 most overused medical tests and treatments in 2007.
A study last year estimated that U.S. doctors perform about 62 million CT heart angiograms annually.
Simeon Abramson, a radiologist at Porter Adventist Hospital in Denver, said he believes the benefits of CT heart scanning far outweigh any risks.
Even so, only about half of private insurance companies operating in Colorado reimburse for the scans, Abramson said.
"So most people can't afford it," Abramson said. "We would be saving lives here every day if insurance companies would follow through and cover this."
There's just no evidence to support that claim, said Marvin Lipman, an emeritus professor at New York Medical College and chief medical adviser for Consumers Union.
Lipman said he believes most CT angiograms in the U.S. are done for patients or doctors who are simply curious whether there is any hardening of coronary arteries.
For that type of patient, no peer-reviewed studies demonstrate any benefit, Lipman said, and the radiation exposure is equal to 85 to 200 chest X-rays, enough to increase cancer risk by about 1 in 2,000.
"This is an overused test that contributes to astronomical medical costs," Lipman said.
Physicians use CT heart angiograms on three types of people: high-risk patients known to have heart disease, intermediate-risk patients and low-risk patients with no history or risk factors for heart disease.
For high- and intermediate-risk patients, a quick CT heart scan can prevent a more costly and time-consuming treatment called an invasive angiogram, said Anthony Long, director of Exempla St. Joseph Hospital's cardiac program.
Invasive heart scanning requires an incision near the groin and the threading of a catheter to a person's heart, where dye is released to reveal possible blockages.
"Before you start puncturing groins and going more invasive, this is a better way to drill down and make a rule-out, to say this is not a person we have to take down to the cath lab," Long said.
Medicare officials wrote that CT heart scans do show "promise" in emergency settings but that there is "insufficient evidence" that the CT scans reduce the need for the more invasive technique.
Lipman said the standard procedure for a high-risk patient should usually be a catheter study, which delivers more accurate information than a CT scan.
"I don't know a surgeon worth his salt that would do a bypass on someone based on a CT angiogram," Lipman said.
Some intermediate-risk patients coming into emergency rooms with chest pain may benefit from the scans, Lipman said.
Anthem Blue Cross Blue Shield of Colorado won't even cover that type of scan, however, said Alan Rosenberg, vice president of medical policy.
"In our determination, except for a very narrow indication, they remain experimental," he said. "There are issues around sensitivity, too many false negatives and false positives."
"Despite the beauty of the images," Rosenberg said, Anthem won't cover them until peer-reviewed studies show they lead to better outcomes for patients.
David Brenner, the Columbia University researcher who co-wrote a paper last year on the scans' benefits and risks, said doctors should be able to weigh risks and benefits for individual patients.
"If it was me with heart pain, I would be running to the CT scanner," Brenner said. "Now for the worried well, there, the risk/benefit ratio is very different."
Porter's Abramson, however, said he believes the benefits are clear.
"The worried well, they benefit immensely," Abramson said. "We see patients that need to take meds, that need statins, but they don't take them because they feel good."
"We won't wait until the articles come out showing that it makes sense," Abramson said.
Katy Human: 303-954-1910 or firstname.lastname@example.org
Many scans with many uses
A look at different types of advanced medical imaging scans:
PET scan: Positron emission tomography creates images by detecting subatomic particles emitted from a radioactive substance given to the patient. Used to detect abnormal function, usually in the brain and heart.
CT scan: Computed tomography (sometimes called a CAT scan, for computerized axial tomography) takes multiple X-rays from different directions, and a computer instantly assembles a high-clarity image allowing two-dimensional and three-dimensional views. Used to look for structural abnormalities in bone, organs, muscles and tumors, for diagnosis and during surgery and radiation-therapy treatment.
Magnetic resonance imaging: Uses a powerful magnetic field, radio waves and a computer to produce detailed images of organs, soft tissues, bone and virtually all other internal body structures. Enables doctors to evaluate some body areas and certain diseases or injuries better than X-rays, ultrasound or CT scans.
Nuclear cardiology: A segment within nuclear medicine, this procedure uses radioactive material called a radiotracer that's injected, swallowed or inhaled and gives off gamma rays, which are detected by a gamma camera or other probe. A computer measures how much radiotracer is absorbed by the body and produces detailed pictures of the structure and function of the heart. Nuclear medicine can also be used on other organs and internal body parts.
Sources: American College of Radiology; Radiological Society of North America; Merck Manual of Medical Information