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."