TUESDAY, Oct. 14, 2008 (HealthDay News) -- More than half of Americans who undergo non-emergency artery-opening procedures for heart disease don't get the recommended cardiac stress tests beforehand, Medicare records show.
These tests pick out those patients who will benefit from procedures like angioplasty or stenting, and those who won't. But just 44 percent of patients in the new study got the test.
"We didn't expect to find 100 percent, but we expected a much higher percentage than 44," said Dr. Rita F. Redberg, professor of medicine at the University of California, San Francisco, one author of a report in the Oct. 15 issue of the Journal of the American Medical Association.
Redberg was a member of a team that studied the medical records of almost 24,000 people who had what is formally called elective percutaneous coronary intervention (PCI) -- elective meaning they had no urgent need for a PCI, which most lay people know as angioplasty.
Guidelines generally say that a stress test -- in which a walk on a treadmill is done to test heart function -- should be performed in such cases. But the report found that just 44.5 percent of people in the study had stress tests before they underwent PCI. That percentage varied widely, not only geographically, but also by patient characteristics and the age of the doctor doing the PCI.
The regional incidence of stress testing varied from 22.1 percent to 70.6 percent, the researchers found, with doctors in the Northeast and Midwest performing best. Stress tests were less likely to be done for women, anyone 85 years of age or older, or someone having other illnesses, such as congestive heart failure, lung disease or rheumatic disease. Stress tests were more likely for someone treated by a doctor under the age of 40 or over the age of 70.
There are "multiple reasons" for the differing rates of stress testing, Redberg said. One reason is that the guidelines are not as clear as they might be.
"We have a number of different scientific documents come out," she said. That situation may be clarified by new guidelines expected to be released shortly by the American College of Cardiology, she said. "The college is about to release appropriateness criteria that say that in such-and-such a situation, a PCI would be appropriate," she said.
There is also no financial incentive to reduce the number of unnecessary angioplasties, the report said. Changing the Medicare payment system to reward doctors and hospitals who stick to guidelines "would improve the safety and delivery of health care to Medicare beneficiaries while decreasing Medicare expenditures," the report noted.
The under-utilization of cardiac stress tests was reported in a study conducted as far back as 1994, according to that effort's lead author, Dr. Eric Topol, director of the Scripps Translational Science Institute in La Jolla, Calif.
His team "used a private insurers' database many years ago, but the main point is the same -- that patients with stable symptoms of angina [which might rule out PCI] don't get appropriate testing before they get an angioplasty procedure," Topol said.
Guidelines for PCI "should be much more clear-cut," Topol believes, and cardiologists should demonstrate more self-control. "It's the old Mark Twain saying that, to a man with a hammer, everything looks like a nail," he said.
Stress tests should be done regularly, not just when angioplasty is being considered, Topol said. "Then you have a way to follow a patient," he said. "You can do a stress test every year to be sure things are normal. That is an important baseline that is being ignored all too frequently."
Another report in the same issue of the journal warned cardiologists about cutting back on doses of amiodarone, a medicine for the common and potentially dangerous abnormal heartbeat called atrial fibrillation. Reducing how often amiodarone is taken does not cut back on side effects, but it does increase the rate of hospitalization, concluded a report from physicians at the University of Groningen in the Netherlands.
There's more on the why and how of stress testing at the American Heart Association.