A heart-monitoring procedure used more than a million times a year during major operations appears to serve no benefit and may actually raise the risk of heart attacks, a study found.
Right heart catheterization _ in which a thin, flexible tube is inserted into a neck vein and guided into the right side of the heart _ is used during major, non-cardiac operations such as hip replacements and gall bladder removal on patients who have a history of heart trouble.
It has been used for 30 years to monitor the heart for everything from fluid pressure to oxygen content.
However, researchers at Brigham and Women's Hospital in Boston found no benefit to the procedure and said the risk of heart attacks and other cardiac problems was three times greater among patients who had it than among those who did not.
The procedure should be re-evaluated, the researchers said. Their study, which appeared in today's Journal of the American Medical Association, supports earlier findings.
It is unclear whether the procedure itself causes problems or whether information provided by the monitoring leads to overly aggressive corrective treatments, said Dr. Thomas Lee, an associate professor at Harvard Medical School who led the study.
It is also possible that patients who underwent catheterization simply were sicker than the study's data indicated, he said.
The National Heart, Lung and Blood Institute is now conducting two studies on the use of right heart catheterization.
"I don't think it's dangerous, but the study shows we have some real work to do to say which patients can really benefit," Lee said.
Lee said there are no other safer procedures that monitor heart function to the same extent. Without a catheter, doctors simply keep track of blood pressure, heart rate and oxygen saturation.