July 10, 2006 -- It's time to change the way doctors predict heart attacks and stroke, says a group of prominent cardiologists. They call for routine use of CT scans to directly measure artery-clogging plaque, or ultrasounds to directly measure narrowing of the arteries.
Nearly every man aged 45-75, and nearly every woman aged 55-75, would get at least one of these tests under a new recommendation from the Association for Eradication of Heart Attack (AEHA). The group's Screening for Heart Attack Prevention and Education (SHAPE) task force came up with the proposal.
Reliance on the new testing technology would be a big change from current medical practices.
Doctors now estimate a person's risk of heart attack by looking at a combination of so-called risk factors. Those factors include high blood pressure, high cholesterol, smoking, age, diabetes, and a family history of stroke or heart disease.
But that's old hat, says AEHA.
AEHA founder and president Morteza Naghavi, MD, chaired the SHAPE task force. "For a long time in cardiology, we dictated to individuals based on risk factors in large populations -- which is inaccurate," Naghavi tells WebMD. "Now we have ways to evaluate a person's risk of heart attack. We have the means to look into the heart and see plaque. We now have individualized risk assessment."
The new guidelines will change health care, predicts another SHAPE task force member, Prediman K. Shah, MD, head of cardiology at
Cedars-Sinai Medical Center and professor of medicine at UCLA.
"It is a sea change in practice," Shah tells WebMD. "Since heart attack risk starts in arteries, we should be looking there. If you can identify plaque in a patient, then this individual -- regardless of risk factors -- is actually at risk. If you want to identify people with heart disease, don't look at risk factors. We say, look directly at where the plaque is."
Do Guidelines Promise Too Much, Too Soon?
The SHAPE guidelines appear in the July 10 issue of the American Journal of Cardiology. The authors include a long list of prominent heart specialists.
But some other prominent specialists aren't signing on, arguing the technology can not yet do what the AEHA group suggests. One is Eric J. Topol, MD, professor of genetics at Cleveland's Case Western Reserve University, and one of the world's 10 most-cited biomedical researchers.
"This organization is taking a very aggressive approach," Topol says. "It says we are ready to screen the arteries directly," he tells WebMD. "They want to noninvasively detect plaques days, weeks, or months before they will cause trouble. But no technique can do this. They are not even close yet.
"Many years from now this may be possible. But we are not there yet," says Topol.
No Change in Official Guidelines
The SHAPE recommendations won't change official U.S. guidelines, says Diane Bild, MD, deputy director of the division of epidemiology and clinical applications at the National Heart, Lung, and Blood Institute of the National Institutes of Health, Bethesda, Md.
"What we really need for [federal] guideline recommendations is just not available yet," Bild tells WebMD. "This is a laudable effort to move preventive cardiology forward. But it occurs with a lack of the complete and clear information that we need to make guidelines.
"The tests are out there. They are being used," Bild says. "It is just not clear what the value of these tests really is -- and whether treatment should be targeted based on those tests."
Naghavi bristles at the argument that the screening tests aren't ready for prime time.
Tests Uncover Major Risks
"To those who say the technology isn't there yet, we say check with recent discoveries," Naghavi says.
"For the very first time in heart medicine, we now have a test that can show someone has up to a 65-fold increased risk of a heart attack," he says. "With the traditional risk factors, the biggest risk is high cholesterol, which has only up to 4.5-fold increased risk. So you can see how much of a jump in prediction we get from this."
But Bild says there are simply too many unanswered questions about the new screening tools.
"We always advise caution before launching a widespread screening program," she says. "We would emphasize the need for a clear look at the tests' cost effectiveness, the accuracy of the tests, the availability of the tests, and most important, what interventions should be done based on the tests. We would also be concerned about telling people they have a disease that puts them at risk without clear evidence that treatment will change their outcomes."
Topol notes that screening has risks -- and that the tests' unproven benefit does not outweigh those risks.
"These tests just show you have a lot of cholesterol in your artery, or an artery that is narrowing," he says. "We don't know how good they are in predicting heart attacks. So you could get a test that shows a narrowing of your artery, and end up with a drug-coated stent in your artery for no reason."
Shah says the real risk is that people will continue to die of heart attacks their doctors never saw coming.
"If we wait for definitive clinical trials, we will keep losing individuals to heart attacks because they have never been screened," he says. "This is a challenge to the medical community. It does not preclude clinical trials. But in the meantime, you have to do medicine based on collective wisdom and collective knowledge.
"The bulk of evidence supports this initiative," says Shah.
How Much Would You Pay?
The new screening tests aren't cheap. Shah estimates that a CT heart scan ranges from $100 to $350, while an ultrasound arterial scan ranges from $300 to $400. Since the tests aren't officially recommended, most insurance and health maintenance plans won't pay for them.
Multiply the costs by nearly every middle-aged American adult and you have a big up-front expense -- even if the SHAPE doctors persuade insurance companies the tests will save them money in the long run.
WebMD asked Shah what he says to patients who balk at the price tag. His response: "You spend $400 or $500 on car maintenance. Isn't your body worth as much?
"As the evidence behind the tests builds and they become more mainstream, the costs are going to come down," Shah adds. "Meanwhile, it is still much more expensive to have a heart attackthan CT scan."