No Increase in Deaths or Hospitalizations for Heart Failure Patients Who Have a Pulmonary Artery Catheter
New Orleans, Louisiana The pulmonary artery catheter
(PAC), a device that measures pressures and flows in the heart,
is frequently used to diagnose, monitor, and guide treatment of
congestive heart failure and other conditions. However, use of the
PAC has been controversial with varying opinions as to its risk
and benefits. New findings from a multi-center study supported by
the National Heart, Lung, and Blood Institute (NHLBI) of the National
Institutes of Health show that the PAC did not significantly increase
or decrease deaths or the number of days hospitalized in patients
with severe heart failure.
The results of the Evaluation Study of Congestive Heart Failure
and Pulmonary Artery Catheterization Effectiveness (ESCAPE) Trial
are being presented today in the late-breaking clinical trials section
of the American Heart Association's Scientific Sessions 2004.
"Heart failure affects about 5 million Americans and the numbers
are growing. So it is important to find out the best way to diagnose
and treat this serious condition. The ESCAPE study lays to rest
concerns that use of a pulmonary artery catheter in patients with
advanced heart failure is associated with increased death and hospitalization.
At the same time, the study suggests that PAC should not be used
routinely to guide therapy. This is an invasive procedure with potentially
serious complications and, without a definite survival benefit,
its use should be carefully evaluated," said NHLBI Acting Director
Barbara Alving, M.D.
About 4 percent of the patients undergoing pulmonary artery catheterization
experienced complications, including cardiac arrest and infection
but there were no PAC-related deaths. Patients in both groups studied
those who received a PAC and those whose therapy was guided by
clinical assessment spent about 8 days in the hospital.
ESCAPE was a randomized clinical trial of 433 patients at 26 sites
in the U.S. and Canada. The primary goal of the study was to evaluate
whether the increased precision that a PAC offers regarding heart
and lung pressures translates to improved patient survival and reduced
time spent in the hospital over 6 months compared with therapy primarily
guided by clinical assessment of physical signs and symptoms. Other
study objectives included comparisons of quality of life, ability
to exercise, and changes in the heart's structure and function as
measured by echocardiograms. The study also sought to evaluate costs
and resources associated with the PAC. These results are not yet
Study patients had "Class 4" advanced heart failure (severe
physical limits, symptoms at rest, and low 2-year survival rate).
The average patient age was 56 years. Seventy-four percent of the
participants were male and 40 percent were minority. About half
(215) of the patients were randomly assigned to receive PACs and
218 patients were assigned to the clinical assessment group. Patients
could receive any of the other standard therapies and medications
for heart failure.
The PAC is a thin catheter that is inserted via a neck vein and
passed through the right side of the heart into the pulmonary artery.
Once the catheter is in place, pressures and flows can be measured
from the right side of the heart and the lungs. A tiny balloon is
inflated to allow measurement of pressures from the left side of
the heart. Excess pressure can build up in the heart when it is
not pumping effectively. This can further weaken the heart and lead
to the hallmark symptoms of heart failure, which are shortness of
breath and fluid buildup in the lungs, ankles, and legs.
The PAC, which is used in 3 to 5 percent of heart failure hospitalizations,
is used not only to diagnose the specific part of the heart that
is not functioning or pumping properly but also to gauge the effect
of medications on heart function and symptoms. Physicians can use
the PAC to individualize medications for each patient.
The ESCAPE trial was led by Dr. Lynne Stevenson of the Brigham
and Women's Hospital in Boston and coordinated by the Duke Clinical
Research Institute (DCRI). Dr. Robert Califf, director of the DCRI,
noted that this study demonstrates a critical principle of technology
assessment at a time when many new technologies are being introduced
in the hopes of improving health. "A diagnostic technology,
even if it provides accurate information, can be beneficial, neutral,
or detrimental, and the PAC is neutral," said Califf.
Pulmonary artery catheterization, also called Swan Ganz catheterization,
was introduced for use in 1970 to provide bedside assessment and
management of circulation and blood flow at a higher level of precision
than has been available from other tests. The device was quickly
embraced by the medical community and its use expanded beyond acutely
ill cardiac patients, before its benefits were actually proven.
There was no consensus regarding the risks and benefits of a PAC-based
strategy. In fact, by 1996 the controversy over excessive risks
was so high that several professional societies held a consensus
conference to review the literature and available data on clinical
benefit and safety. The consensus report, endorsed by several organizations
including the Society of Critical Care Medicine, called for a clinical
trial on the use of the PAC. In response to continued concerns,
the NHLBI and FDA convened a workshop on the PAC in 1997 and the
resulting report recommended a randomized clinical trial to test
its safety and effectiveness.
ESCAPE provided important information about the effect of the PAC
on patients' quality of life, although it was not the primary outcome
"It was encouraging that patients in both groups had major
improvement in their symptoms and their ability to exercise. Patients
whose therapy was guided by the PAC reported a greater improvement
in the value they placed on their own daily lives than the other
group of patients," said ESCAPE principal investigator Stevenson,
who is co-director of the cardiomyopathy/heart failure program at
Brigham and Women's Hospital. "While we don't know exactly
how to interpret this information yet, the ESCAPE trial emphasizes
that we need to learn more about what matters most to our patients
as they face disabling symptoms," she said.
"We know that patients who received a PAC felt better, but
then why didn't they have fewer deaths or hospitalizations?"
asked Stevenson, who presented the ESCAPE results at the American
Heart Association meeting.
According to Stevenson, the answer may lie in the fact that there
was a big variation in how PAC information was used to treat patients.
The study did not specify which medications or other types of therapy
would be used, she noted.
George Sopko, M.D., project officer for the ESCAPE trial and Medical
Officer with NHLBI's Division of Heart and Vascular Diseases, said
that "ideally, another study would compare specific choices
"We also need to find out how therapies could be adjusted
using non-invasive tests, such as echocardiograms, to provide similar
information to PAC but without risks. In-depth analysis now underway
of the ESCAPE echocardiogram data should provide clues about these
next steps," said Sopko.
To interview Dr. Sopko, call the NHLBI Communications Office at
301-496-4236; to interview Dr. Stevenson, call Amy Dayton Smith
NHLBI is part of the National Institutes of Health (NIH), the
Federal Government's primary agency for biomedical and behavioral
research. NIH is a component of the U.S. Department of Health and
Human Services. NHLBI press releases and fact sheets, including
a fact sheet on heart failure, can be found online at www.nhlbi.nih.gov.