Cardiologists urge arterial screening of asymptomatic older people
Florida
Fred Charatan
An international group of prominent cardiologists has called for non-invasive screening for heart disease of all US asymptomatic men aged 45-75 and women aged 55-75.
The Screening For Heart Attack Prevention And Education (SHAPE) task force says that screening should be carried out to measure coronary artery calcium, with computed tomography scan, and carotid intima media thickness and plaque, with carotid ultrasonography.
The group’s recommendations were published as a supplement to the American Journal of Cardiology in July, with Pfizer as the major sponsor.
The proposal hinges on the basic principle that traditional risk factor screening—the Framingham risk score and the SCORE criteria in Europe—does a good job of identifying people at very low and high risk of myocardial infarction or stroke over a decade but fails to single out "at risk" men and women who represent everything in between. The Framingham risk factors include hypertension, hypercholesterolaemia, history of smoking, age, diabetes, and a family history of stroke or heart disease.
Prediman Shah, the head of cardiology at Cedars-Sinai Medical Center, professor of medicine at the University of California in Los Angeles, and a member of the task force, predicted that the new proposed guidelines will change health care.
"It is a sea change in practice. 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."
In February 2004, the US Preventive Services Task Force recommended against routine screening with electron beam computed tomography scanning for coronary calcium, however, for either the presence of severe coronary artery stenosis or the prediction of coronary heart disease, events in adults at low risk for coronary heart disease.
A member of this task force, who did not want to be named, told the BMJ that he thought the recommendation of the SHAPE task force "was a dramatic assault on evidence based medicine," and said that there were no prospective trial data or even good cohort data to support the claims of the Houston based Association for Eradication of Heart Attack, SHAPE’s parent body.
He referred to an editorial in the Archives of Internal Medicine (2006:166;1342-4), which concluded that Framingham risk estimation works well and novel risk factors add little. Finally, the US Preventive Services Task Force recommended against screening for coronary artery disease in low risk adults, including with electron beam computed tomography, as there was fair to good evidence that the harms outweighed the benefits in a low risk population.
Diane Bild, deputy director of the division of epidemiology and clinical applications at the National Heart, Lung, and Blood Institute of the National Institutes of Health, said that SHAPE’s recommendations would not change official US guidelines.
She added, "What we really need for [federal] guideline recommendations is not available yet . . . the precise screening approach
recommended by SHAPE has not been proven to reduce morbidity and mortality through randomised controlled trials, which is
the type of evidence we’d like to see before making public health recommendations."