Altman, Lawrence K. "Safety of Catheter Into the Heart Is Questions, Startling Doctors," New
York Times, 18 September 1996, pp. 1, B6.
A standard procedure used more than a million times a year on seriously ill patients in this
country offers no benefit and may kill some people, according to a new study that is causing
consternation among many doctors.
For 25 years, doctors working In the high-technology world of intensive care units have relied on
the procedure to diagnose, monitor and treat very sick patients, like those experiencing heart,
lung or multiorgan failure. The procedure involves inserting a thin tube into the heart through a
neck vein to collect data to guide minute-to-minute therapeutic decisions. The information
concerns actions of the heart and lungs, the amount of fluids in the body and other bodily
But the authors of the study, led by Dr. Alfred F. Connors Jr. of Case Western Reserve
University in Cleveland, said that doctors had never tested the procedure in a large randomized
controlled trial, the most scientifically rigorous type of study.
This study was not that type of trial, and some experts immediately challenged the study's
findings. Nevertheless, the authors said it offered compelling evidence but not proof of the
procedure's dangers. They also said they could not determine precisely why the procedure might
be dangerous. They said the procedure led to several billion dollars' worth of medical bills each
The controversy is a window on a common problem in medicine: many doctors prescribe a drug
or use a device before its benefits and hazards are fully evaluated in scientifically rigorous trials.
"This is an instance where the technology exists and provides the information it was designed
for, but the benefit to the patient is not clear," said Dr. William A. Knaus, an expert in critical
care medicine at the University of Virginia and a co- author of the study.
The procedure is known as pulmonary artery catheterization, or right heart catheterization, and
the controversy over it results from a study and an editorial in today's issue of The Journal of the
American Medical Association. The study's findings have been known to some experts for
The study found that patients who underwent the "procedure, in the first 24 hours of their stay in
an intensive are unit had a higher death rate, longer hospital stays and larger medical bills than
those who did not receive it. The study involved more an 5,700 patients at five teaching hospitals
and is believed to be the largest, most detailed study ever on the procedure. But some experts in
critical care medicine criticized the method used in the study as being less precise than that sed in
a randomized controlled trial.
In the editorial, Dr. James E. Dalen of the University of Arizona and Roger C. Bone, the
journal's consulting editor, demanded that either National Heart, Lung and Blood Institute should
immediately subject procedure to a randomized controlled trial or the Food and Drug
ministration should declare a moratorium on its use.
The procedure relies on a device named after Dr. H. J. C. Swan and Dr. William Ganz, who
reported developing it in 1970. Other doctors quickly adopted the technique in the belief that its
benefits were obvious.
Dr. Peter F. Pasternack, a cardiologist at New York University, said at many experts believed that
the devices were used too often and left place too long, risking infection and the formation of
dangerous clots. Additional complications result from the need for a patient to remain immobile
while the Swan- Ganz catheter is in place, which can last days.
Previous calls for a moratorium have gone unheeded, and attempts to randomized controlled
trials ave failed because many doctors, believing the procedure to be helpful, have said it would
be unethical to put patients in a control group that would not get the treatment. For example,
1991, a trial in Ontario, Canada, stopped largely because most doctors were convinced that the
procedure was beneficial and considered it unethical for them or their patients to participate in a
trial in which a computer dictated the choice treatment.
Other studies could not be started because ethics committees refused to approve them, experts
Dr. John W. Hoyt, president of the of Critical Care Medicine, a group of 9,000 doctors, nurses
and allied health professionals, said the of the new study were "inconclusive" and called the
demand for a moratorium "inappropriate" and "misleading to patients, their families and health
He said in an interview that the Swan-Ganz catheter was such a standard device and that doctors
were so dependent on information from its use that "if you suddenly take it away from me, I am
not sure patients are going to do very well in my hands."
Without the technique, doctors would have to do a different and perhaps more dangerous
procedure as a left-heart catheterization in which a tube is inserted in an artery to reach the heart,
or base their decisions on less precise information from physical examinations. A moratorium
could endanger the lives of thousands of seriously ill patients, Dr. Hoyt said.
"We do not want news coverage of the issues raised by the authors to alarm patients and their
families or to compel physicians to change their Method of practice," Dr. Hoyt said in a news
release issued by his society. He said the release had been financed by a grant from Baxter
International, a manufacturer of the device.
Nevertheless, Dr. Hoyt said in the interview that he "did not want to put down the study" because
"it is very important" and raised questions that needed to be answered by additional research. He
said his group would convene an expert panel to develop new recommendations and a
randomized controlled study.
In the procedure, the thin, balloon-tipped catheter is inserted into a vein in the neck or shoulder
and then inflated so the tube is carried along by the flow of blood to the right side of the heart
until it lodges in a lung artery.
Thirty days after the procedure, there were about 50 more deaths per 1,000 patients among those
who had undergone the procedure than among those who had not. The mean cost of the hospital
stay was $49,300 for those having the procedure, compared with $35,700 for those who had not.
The mean length of stay was nearly two days longer for the group receiving the procedure, 14.8
days, compared with 13 days. No significant differences were found among the five hospitals in
the study, which was carried out from 1989 through 1994.
Dr. Claude E. Lenfant, who directs the National Heart, Lung and Blood Institute, said the new
study "is very significant" and that his Federal institute would be happy to provide technical
assistance, but not necessarily financing, for a randomized controlled study. "All it would take to
do the study is for doctors in hospitals to randomize the patients who are treated there every day,"
Dr. Lenfant said.
In the absence of randomized controlled trials, other, second-best, types of studies of pulmonary
artery catheterization have found the risk of death to be higher in the elderly and in patients who
had suffered heart attacks.
The new study was based on a methodology known as case matching. In it, the authors developed
a scoring method to. assess the outcome of critically ill patients with certain conditions. These
included three types of lung disease, congestive heart failure, liver damage from cirrhosis and
cancer, coma not resulting from injury and multi-organ failure due to infection or cancer.
Nurses in each hospital were trained to collect certain data from the records of each participant
and to interview the patient or the individual designated to make decisions for the patient.
Independent checks were made on a number of the cases to insure the validity of the data.
Of the 5,735 participants, 2,184, or 38 percent, had a pulmonary artery catheterization, and 3,551
did not. The researchers selected patients at random from those who had undergone the
procedure and then searched the records of the others for patients of the same age, sex, type of
disease and severity of illness.
The researchers then made their findings by matching 1,008 pairs of patients who did and did not
undergo the procedure. They offered several possible explanations for the outcome.
One is that the procedure might have some direct harmful effect. A second is that its use may
lead to changes in therapy that produce higher death rates. A third is that the use of the technique
encourages a type of aggressive care that leads to higher death rates and costs. "A point may be
reached in the care of some critically ill patients where adding another procedure provides little
marginal benefit to the patient while exposing them to all the risks of the procedure," the authors
wrote. "In this setting, a less invasive approach may be associated with better outcomes."
The five teaching hospitals that participated in the new study included Beth Israel Hospital in
Boston; Duke University in Durham, N.C.; Metro-Health Medical Center in Cleveland; St.
Joseph's Hospital in Marshfield, Wis., and the University of California at Los Angeles. George
Washington University coordinated the study, which was paid for by the Robert Wood Johnson
Foundation of Princeton, N.J.