EECP Clinical Research
Researchers at Harvard
University conducted experiments with counterpulsation in the 1950s,
demonstrating that this technique markedly reduces the workload, and
thus oxygen consumption, of the left ventricle. This basic effect
has been demonstrated over the past forty years in both animal
experiments and in human patients. The clinical benefits of external
counterpulsation were not consistently achieved in early studies
because the equipment used at the time lacked some of the features
found in the current EECP systems, such as the computerized
electrocardiographic gating, which makes sequential cuff inflation
possible.
As the technology
improved, however, it became apparent that both internal (i.e.,
intra-aortic balloon pumping) and external forms of counterpulsation
were capable of improving survival in patients with cardiogenic
shock following myocardial infarction. Later, in the 1980s, Dr.
Zheng and colleagues in China reported on their extensive experience
in treating angina using the newly developed "enhanced" or
sequential, inflating EECP device that incorporated a third cuff for
the buttocks. Not only did a course of treatment with the EECP
system reduce the frequency and severity of anginal symptoms during
normal daily functions and during exercise, but the improvements
were sustained for years after therapy.
These results prompted
a group of investigators at the State University of New York (SUNY)
at Stony Brook to undertake a number of open label studies with the
EECP system between 1989 and 1996 to reproduce the Chinese results,
using both objective and subjective endpoints. These studies, though
open and nonrandomized, showed statistical improvement in exercise
tolerance by patients as evidenced by thallium-stress testing and partial or
complete resolution of coronary perfusion defects as evidenced by
radionuclide imaging studies. All of these results have been
reported in medical literature and support the assertion that EECP
therapy is an effective and durable treatment for patients suffering
from chronic angina pectoris.
The MUST-EECP Trial
In 1995, Vasomedical began a large,
randomized, controlled and double-blinded clinical trial,
Multicenter
Study of Enhanced External Counterpulsation (MUST- EECP)
at seven
leading university hospitals in the
United States to confirm the patient benefits observed in the open
studies conducted at SUNY-Stony Brook and to provide definitive
scientific evidence of EECP therapy's effectiveness. MUST-EECP was
completed in July 1997 and the
results were presented at the annual Scientific Sessions of the
American Heart Association in November 1997 and the American College
of Cardiology in March 1998. The
Journal of
the American
College of Cardiology
(JACC),
a major peer-reviewed medical journal, published the results of the
MUSTEECP
trial in June 1999.
This 139 patient
study, which included a sham-EECP therapy control group, showed that
EECP therapy was a safe and effective treatment option for patients
suffering from angina pectoris, including those on maximal
medication and for whom invasive revascularization procedures were
no longer an option. The results of the MUST-EECP study confirmed
the clinical benefits described in earlier studies, namely a decline
in anginal frequency and a
decrease in exercise-induced signs of myocardial ischemia.
In 2000, Vasomedical
completed a quality of life sub-study with patients that
participated in MUST-EECP. Two highly regarded and standardized
means of measurement were used to gauge changes in patients' outlook
and ability to participate in normal daily activities during the
treatment phase and for up to 12 months after treatment. Results of
this study, which have been presented at major scientific meetings
and published in the January 2002
Journal of
Investigative Medicine,
show that the group of patients receiving EECP
therapy enjoyed significantly improved aspects of health-related
quality of life compared to those who received sham treatment.
International EECP Patient Registry
The International EECP
Patient Registry (IEPR) at the Epidemiology Data Center of the
University of Pittsburgh Graduate School of Public Health was
established in January 1998 to track the outcomes of angina patients
who have undergone EECP therapy. More than 100 centers participated
in the registry enrolling 5,000 patients. Phase 2 of the IEPR,
enrolled an additional 2,500 angina patients with coexisting heart
failure and other conditions. Enrollment began in January 2002, and
was completed in September 2004.
The IEPR provides the
medical community with a vital source of information about the
effectiveness of EECP therapy in real-world environments. Data
analyzed by the IEPR include improvement in anginal symptoms,
duration of benefit, quality of life, effects seen in important
patient subgroups and adverse events occurring during the treatment
period. Follow-up data is obtained at six-months post treatment and
then annually for up to three years.
Additional information about the IEPR is available at
www.edc.gsph.pitt.edu/iepr.
The PEECH Trial
As part of its program
to expand the therapy's indications for use beyond the treatment of
angina, Vasomedical applied for and received FDA approval in April
1998 to study, under an Investigational Device Exemption (IDE)
protocol, the application of EECP therapy in the treatment of heart
failure. A 32-patient feasibility study was
conducted simultaneously at the University of Pittsburgh, the
University of California at San Francisco and the Grant/Riverside
Methodist Hospitals in Columbus, Ohio. The results of this study
were presented at the 49th Scientific Sessions of the American
College of Cardiology in March 2000 and the Heart Failure Society of
America's Annual Meeting in September 2000. The July/August 2002
issue of
Congestive Heart Failure
published
a report of this study which concluded that EECP therapy increased
functional
capacity of the patients, was beneficial to left ventricular
function and portended to be a useful adjunct to current medical
therapy in heart failure patients.
That same summer, the
FDA approved an IDE supplement to proceed with a pivotal study to
demonstrate the efficacy of EECP therapy in the most prevalent types
of heart failure patients. This study, known as the PEECH™
(Prospective
Evaluation of EECP in Congestive Heart Failure) Trial, began patient
enrollment in
March 2001. PEECH involves an impressive blend of 29 academic and
community–based centers, including the Cleveland Clinic, Mayo
Clinic, Scripps Clinic, Thomas Jefferson University Hospital,
University of North Carolina at Chapel
Hill, Minnesota Heart Failure Consortium, Advocate Christ Hospital,
The Lindner Center of Cincinnati, Hull Royal Infirmary (UK),
University of California at San Diego Medical Center, University of
Pittsburgh Medical Center and Cardiovascular Research Institute,
Inc.
While the 510(k)
clearance for CHF granted in June 2002 obviated the need to continue
this trial for FDA regulatory reasons, Vasomedical decided to
complete the clinical trial in order to establish clinical
validation of EECP therapy as a treatment for CHF and to obtain
Medicare and other third-party reimbursement for this indication.
The PEECH trial
enrollment was completed in February 2004 with 187 patients. The
protocol for the study requires patient examinations at six months
following treatment and will evaluate improvements in exercise
capacity and oxygen utilization as the primary endpoints.
Researchers completed the six-month follow-up examinations in
December 2004. Results of the PEECH trial will be presented at the
American College of Cardiology (ACC) Annual Scientific Session
(March 6-9, 2005) at the Late Breaking Clinical Trials.
|
|
