Hospital teams commonly perform revascularization procedures more than 24 hours after patients have experienced acute myocardial infarction even though studies have found no benefit because too much muscle damage has already occurred.
The report and accompanying commentary are published in Tuesday's Archives of Internal Medicine.
"I think there has been a very long standing belief – a strong belief – that having an open artery long term is better than having a closed artery. And that belief is coupled by the fact that you can get paid to do the procedure, coupled with the fact that patients...don't want to have a closed artery. They know you can open it up," corresponding author Judith Hochman, MD, said in an interview.
"I don't think it's only for the money" that the practice persists, she said.
She added that another factor is that since the findings in those studies did not show that the patients were significantly harmed from the procedure, there has probably been a delay in implementing practice changes. "To have a negative study may take longer to impact a practice than a positive study," she said.
"And there's another aspect, which is that the whole malpractice issue is a big consideration. You leave an artery closed and the patient has a bad outcome, you're much more likely to be liable than if you say 'I did everything I could.' "
"The reasons are multi-factorial. It takes a long time, sometimes, for a recommendation to filter down to practice."
In what was thought by some as a surprise, a large, federally funded randomized trial, Occluded Artery Trial (OAT) of 2006, found no benefit when patients had revascularization procedures more than 24 hours after their myocardial infarction, and when their conditions were considered stable.
Other reports estimated the cost of those procedures at about $7,000, Hochman said.
In 2007, the American College of Cardiology and the American Heart Association subsequently revised guidelines to reflect the new findings, saying that when patients with persistently occluded arteries are stable, and when their heart attacks occurred a day or more previously, revascularization "should not be performed."
The patients were stable, Hochman explained, because "Whatever heart muscle was still alive in the area of the blocked coronary was being supplied by other blood vessels through what we call collateral blood flow."
Hochman, Harold Snyder Family Professor of Cardiology at New York University Langone Medical Center, along with Marc. W. Deyell, MD, of the University of British Columbia in Vancouver, and others wanted to find out whether hospital teams have since changed their practice.
They examined data from the CathPCI Registry, which includes data from hospitals where cardiac catheterizations take place. In their study, they included 896 hospitals and 28,780 patient visits, between 2005 and 2008 and divided them into three groups, before the OAT results were published, between the OAT trial study publication and the issuance of guidelines, and after the guidelines.
They found no significant change in the rates of PCI.
The authors speculate that some of the "clinical inertia" may be due to "lack of agreement regarding interpretation of data, especially when it contradicts long-held beliefs and external influences, such as conflicting patient expectations and financial incentives to perform the unindicated procedure, and fear of litigation."
She added that in courtrooms, a bad outcome may still result in a jury verdict against a physician, even though he followed the guidelines. In New York State for example, she said, judges vary widely on whether they will admit the guidelines in testimony.
"A lot of judges won't allow it because they say the guidelines can't be cross-examined," she said.
In an invited commentary, Mauro Moscucci of the Cardiovascular Division of the University of Miami, FL, said the paper "further focuses our attention on procedures that certainly increase healthcare expenditures without clear benefit."
He said the U.S. "must heed the call to professional responsibility aimed at the elimination of tests and treatments that do not result in any benefit for our patients, and for which the net effects will be added costs, waste, and possible harm."
Hochman said that for now, physicians should become more diligent about doing what's in the best interests of patients. "It's incumbent on them to take it upon themselves to stop doing procedures with no demonstrated benefit so that we can bring down healthcare costs before some expert body, like a health insurance company says we're not going to reimburse for it.