Tim Russert suffered a fatal heart attack at age 58, shocking the country. He recently passed a stress test, so how could this happen? In a post Dr. Fuhrman explains why stress tests fail to determine heart attack risk. Here’s an excerpt:
A stress test is not an accurate test for determining the risk of a heart attack. A stress test only identifies obstructions, it doesn't identify vulnerable plaque—the plaque that is likely to throw a clot. A stress test can only detect a blockage of more than 80% and the propensity of plaque to rupture has nothing to do with the amount of obstruction…Now, Jane E. Brody of The New York Times talks to Dr. Todd D. Miller, a cardiologist and co-director of the Mayo Clinic’s Nuclear Cardiology Laboratory in Rochester, Minn., about the shortcomings of stress tests. Take a look:
…Stress tests are big money-makers for doctors. They identify those people with large blockages who qualify as candidates for costly angioplasty or bypass surgery. However, drugs and medical procedures reduce risk only slightly.
Mr. Russert’s treadmill test may have put him in the low-risk category, Dr. Miller said, “but that doesn’t mean no risk.”Criticism for stress tests is not new. In 2007, Karen Dente, M.D., a medical journalist based in Brooklyn, New York, stated that as stress-testing and coronary angiograms may no longer be the true gold standard for detecting coronary stenosis. Via Medscape:
“Maybe 3 patients in 1,000 with a low-risk test will die from heart disease within a year,” he said. “Among those deemed at high risk, more than 3 patients in 100 would die within a year.”
Furthermore, when the stress test is used for people who are at low risk for heart disease, an abnormal finding is most often a false positive that prompts further testing that is far more costly, Dr. Miller said.
The stress test’s main advantages are its rapidity and low cost — one-fifth to one-quarter the cost of more definitive and often more time-consuming tests like a nuclear stress test, CT coronary angiogram or standard angiogram. Medicare pays about $150 for a standard stress test, though hospitals typically charge three to four times that when the test is done on younger patients.
"Conventional stress-testing and angiogram gives you no information on whether a plaque is going to rupture," David DuBois, MD, an attendee at the symposium and emergency medicine specialist from Pinehurst, North Carolina, told Medscape. "[With these tests] there are a lot of false-positives and false-negatives," he said.Sadly, this information can’t help Tim Russert, but doctors and patients should now take note that traditional testing procedures might be lulling us into a false sense of security by not revealing crucial life-saving data.
One of the hottest current discussions in the evaluation of acute coronary syndromes is centered around the use of computed tomography coronary angiography. "CT technology is advancing at a very fast rate," said Amal Mattu, MD, associate professor and program director of emergency medicine residency at the University of Maryland, explaining the technology's improved detection in plaque composition and remodeling compared with conventional diagnostic tests.
"If you have a radiologist that can give you an accurate reading with the new 64-head multidetector CT scans, you can detect occlusions better," according to Dr. Dubois. But we are still a long way from having the new technology replace standard coronary angiography for the detection of large coronary stenoses, he said. "It is not going to change the [current] practice any time soon."