MEDICAL DEVICE INNOVATION - Medical Device Daily

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Shape-HF offers easier testing
method for CRT therapy patients
By OMAR FORD
Medical Device Daily Staff Writer
Shape Medical Systems (St. Paul, Minnesota) is offering
a much simpler and less intensive way of testing for
measuring ventilation parameters for patients who have
suffered from cardio-illness.
The Shape HF Cardiopulmonary Testing System was
given FDA approval at the end of March and objectively
measures CRT response in real time while the patient is
exercising, according to Shape Medical. Objectivity is the
key selling point of the device.
“Typically patients are given questionnaires or surveys
– more subjective means to test for CRT responses,”
Clarence Johnson, president/COO of Shape Medical told
Medical Device Daily.
Here’s how the device works. As the patient exercises
at a steady state heart rate, the physician adjusts therapy
settings every two minutes, enough time for the adjustments
to be reflected in breathing physiology. At the end of
the test, during which four to five therapy settings are tested,
the Shape-HF System uses a proprietary computer algorithm
to rank the physiological response to exercise at
each setting. The physician then reviews the results and
chooses the therapy setting he or she believes is most
appropriate for the patient. The exercise includes walking
on a treadmill at a very low intensity of one mile per hour
with the treadmill set at a 2% grade.
“Other methods have proven to be very difficult for
patients,” Johnson said. “The Gas inhalation test for example
is very difficult and has often found to bring patients to
the point of exhaustion.”
CRT is a widely used method for treating patients with
severe heart failure when alternative treatment options
have been exhausted. According to Dr. Abraham Kocheril,
professor of medicine and director of Clinical
Electrophysiology at the University of Illinois at Chicago
where the Shape-HF System has already been installed,
“The CRT response rate in heart failure patients is about
70%. The Shape-HF System is likely to help us get the
remaining 30%—those we call non-responders—feeling
better.”
Johnson added that because patient breathing efficiency
is so sensitive to changes in CRT settings, using gas
exchange parameters to assess these changes provides a
completely objective method for defining response to CRT
therapy. Plans call for the company to try and get approval
in Europe.
“We don’t have CE mark yet. This is a device that will
have a wide appeal in Europe,” Johnson said “But we
thought we would go after the domestic market first.” The
company stressed that the Shape-HF System is the only
MEDICAL DEVICE INNOVATION 2010
device that objectively measures CRT response in real time
while the patient is exercising. The system is cost effective,
easy to use, and the test is easy on the patient. “It’s very
easy to use and training for the system can be done in 30
minutes to an hour,” Johnson told MDD. “All of the muss and
the fuss are taken out of the process.”
To date this is the only product the five-year-old company
has released.
CRT is used in severe cases of heart failure to restore
synchrony between the heart chambers—the atria and two
ventricles—during the heartbeat. In patients with advanced
heart failure the heart may not beat strongly enough to
supply adequate oxygen to peripheral tissues, and poor
blood flow to the lungs disrupts the process of exchanging
needed oxygen for carbon dioxide, a waste product of normal
metabolism.
Combined, these effects lower the amount of oxygen in
the blood, which decreases the patient’s ability to exercise
and causes inefficient, labored breathing. Typically shortness
of breath on even mild exertion is a key symptom in
heart failure during CRT therapy. The company said that a
positive response to CRT therapy improves breathing efficiency
during exercise, and that it makes sense that parameters
that can measure patient breathing efficiency, can be
used to determine the proper CRT settings.
(This story originally appeared in the June 2, 2009 edition
of Medical Device Daily.)
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