A little electrical
boost may help many heart failure patients
November 11, 2003
ORLANDO, FL (AHA)
electrical device that can strengthen the heart’s pumping power
shows promise as a new treatment for heart failure – a disease
that affects some 4.9 million Americans, researchers reported at
the American Heart Association’s Scientific Sessions 2003.
Heart failure generally results from a weakening of the heart
muscle so that the heart can no longer pump enough blood to
supply the body’s needs. The disease may be caused by a heart
attack, high blood pressure or it can be inherited. Often, the
cause is unknown.
The OPTIMIZER II is an implantable device, similar in size
and shape to an artificial heart pacemaker, but that’s where the
similarity ends. An artificial pacemaker makes sure the
heartbeat doesn’t go too slow by initiating contractions when
there’s a missed beat. In contrast, the OPTIMIZER II senses
when a beat has already started, then sends an electrical signal
to strengthen the heart’s contraction.
Last year, the U.S. Food and Drug Administration approved
devices that deliver a different form of heart failure treatment
called “cardiac resychronization therapy,” or CRT, for treating
a subgroup of patients with heart failure, said Daniel Burkhoff,
M.D., Ph.D., a co-author of the report and a consultant to the
maker of OPTIMIZER II.
“CRT appears to be useful in about 20 percent to 30 percent
of people with heart failure who also have an abnormality in the
timing heart chamber contractractions,” said Burkhoff, an
associate professor of medicine at Columbia University’s College
of Physicians and Surgeons in New York City.
“Our goal is to develop a treatment for the greater number of
heart failure patients who don’t necessarily have a problem with
synchrony,” he said.
The researchers enrolled 25 patients with moderately severe
heart failure from medical centers in Austria, Germany and
Italy. Their average age was 62, and 23 were men. To be
eligible for the study, patients had to have a heart ejection
fraction of less than 35 percent. Ejection fraction is the
percentage of blood the heart expels during contractions. A
normal ejection fraction is 60 percent, Burkhoff said.
Also, the patients had poor exercise tolerance; they
could only walk short distances before becoming fatigued.
During the implantation procedure, which is similar to
implanting a pacemaker, physicians tested the device to ensure
that the patient’s heart responded to the special signals the
device delivered. Two patients did not respond, so the device
was not implanted.
In the other 23 patients, the device was activated three
hours a day for eight weeks. The patients returned
periodically for tests.
At the end of the follow-up period, the patients’
ejection fraction increased from an average of 22 percent to 28
percent, a statistically significant improvement.
“This improvement is comparable to those seen in prior
studies of CRT. This encouraged us that the ultimate impact on
patients’ quality of life would also be similar to that achieved
with CRT, with the hope that this treatment will be applicable
to a larger percentage of the heart-failure population,”
The average distance patients could walk in six minutes
increased from 411 meters to 465 meters (1,348 to 1,526 feet),
also a statistically significant improvement. And participants
reported that they had a better quality of life.
All the patients received appropriate medical treatment prior
to enrolling in the trial, including beta-blockers, and
continued to get treatment during the study, he said.
“The adverse events observed thus far seem to be similar to
those encountered in patients with advanced heart failure and
from normal pacemaker procedures,” Burkhoff said.
“This is a very small study designed primarily to obtain some
basic safety data, and in this regard the results are very
encouraging. We are also encouraged by the efficacy findings,
but we emphasize that this is merely a pilot study, and that
patients knew they had gotten the device. Therefore, the
efficacy findings could be influenced by a placebo effect.”
The team is preparing a much larger trial of the device.
Burkhoff and his colleagues have proposed that a large-scale
patient trial be conducted primarily in the United States.
Some 550,000 new cases of heart failure are diagnosed each
year and 51,500 people die from it annually, according to the
American Heart Association.
“It is a very complex and long path to develop treatments for
heart failure,” Burkhoff said.
Co-authors are Guenter Stix, M.D.; Michael Wolzt, M.D.;
Gabriele Vicedomini, M.D.; Salvatore Rosanio, M.D.; Martin
Borggrefe, M.D.; Christian Wolpert, M.D.; Gerhard Hindricks,
M.D.; Hans Kottkamp, M.D.; Dieter Horstkottre, M.D.; Barbara
Lamp, M.D.; Dirk Böcker, M.D.; Thomas Wichter, M.D.; Yuval Mika,
M.D.; Shlomo Ben-Haim, M.D. and Herwig Schmidinger, M.D.