TUESDAY, Oct. 4, 2005 (HealthDay News) -- Two studies find that the pulmonary artery catheters used to monitor the condition of critically ill heart patients do no harm but don't improve outcomes.
Yet the senior authors of both reports in the Oct. 5 issue of the Journal of the American Medical Association said they see good reason for using the catheters in many cases.
Pulmonary artery catheterization is one of the most controversial issues in critical care medicine, with some studies suggesting it might even increase the risk of death for some patients. Yet, the catheters are used to help guide treatment for a million people a year in the United States.
The reason to justify their use, given by Dr. Lynne W. Stevenson, co-director of the cardiomyopathy/heart failure program at Brigham and Women's Hospital in Boston, and leader of a study on use of the catheters for heart failure, is that they make patients feel better.
Pulmonary artery catheters are used to diagnose various diseases of the heart, monitor the progress of patients, and guide the choice and adjustment of medical therapy, according to the researchers.
The study of 433 heart failure patients, half of whom received the catheters while the others got detailed physical examinations, showed that "catheterization does not seem to have adverse effects, which is very reassuring," Stevenson said. "On the other hand, no benefit could be demonstrated overall in the hard outcomes of death and re-hospitalization."
But then there was the psychological effect. "This study does suggest, in ways that are more difficult to measure, that using information from these catheters helps us adjust therapy more precisely, and thus helps us make patients feel better," she said.
There was "a very consistent trend" for patients who got the catheters to feel better, which poses an intriguing question, Stevenson said.
"How do we balance a therapy that does not seem to change re-hospitalization and death but improves how people feel?" she asked. "We haven't paid attention to whether patients value their lives more and would rather live longer if they feel well. This definitely needs to be something we consider more than we have done in the past."
Overall, Stevenson said, "I don't think this will make a huge amount of difference in the number of catheters used for heart failure."
The second study, led by Dr. Monica R. Shah, who was at Duke University when it was done and later became assistant professor of medicine at Columbia University, analyzed the results of 13 previous studies in which pulmonary catheters were used for patients with a variety of severe heart conditions.
"What the meta-analysis said is that pulmonary artery catheters had a neutral effect," Shah said. "There was no improvement in morbidity and mortality and, importantly, no deterioration in morbidity and mortality."
The fact that the catheters did not improve results might be beside the point, Shah said. "The crux of the matter is that the pulmonary artery catheter at the end of the day is a diagnostic device, and to expect it to be of benefit by itself without being part of an overall plan is unrealistic."
The catheters can be very valuable for specific patients -- for example, those with severe pulmonary hypertension or those who might be candidates for a heart transplant, she said. "Whether or not they should be used should be left to the clinicians," Shah said.
Stevenson agreed with that assessment. In the study she led, the differences in outcomes for patients who were catheterized and those who got expert clinical assessment were small, she said, and they were "relevant only to those patients for whom symptoms remained a major problem. For the majority of patients with heart failure, catheters need not be used. But when clinical assessments are not adequate, the information we get from the catheter may give us an advantage."
For more on heart failure, visit the American Heart Association.