News Release:
Angina May Be Relieved Without Surgery or Drugs
ORLANDO, Fla.--(BW HealthWire)--Nov. 11, 1997--Patients who experience the crushing chest pain of angina appear to benefit
from a new, non-surgical treatment that boosts blood flow to the heart.
Even heart patients who previously have undergone more expensive, invasive interventions to clear blood vessels supplying the
heart may benefit from the treatment, called Enhanced External Counterpulsation (EECP), according to researchers. The findings
from a multi-center clinical trial were presented today in Orlando at the 70th Annual Scientific Sessions of the American Heart
Association.
For many patients with angina, EECP may be an attractive therapy to use in combination with angioplasty or open-heart surgery,
or as an alternative to these invasive procedures, according to Tony Chou, MD, a cardiologist at the University of California San
Francisco. UCSF is the only medical center outside the East Coast to have participated in the first nationwide trial to test the
safety and effectiveness of the treatment.
"Among patients who complete EECP therapy, episodes of angina were halved, and patients in the study also tended to use less of
their nitroglycerin to treat their chest pains," Chou says. "In addition, endurance during treadmill exercise tests improved
significantly," he adds. These improvements on the exercise stress test corresponded to a delay in the time it took for the heart to
become oxygen-starved.
Angina is a chest pain that often afflicts coronary-artery-disease patients because the heart muscle has trouble obtaining sufficient
oxygen to fulfill its pumping duties adequately. The pain may recur continually, even in patients who take medications or who have
had major bypass surgery or angioplasty to clear arteries that supply the blood-pumping organ with oxygenated blood.
Blood pressure in the arteries and veins normally causes blood to flow toward the heart during its pumping phase, called systole,
and also between heartbeats, when the heart is in its filling phase, called diastole. The heart, unlike other organs and tissues, gets
most of the oxygen it needs during diastole.
During EECP treatment, a patient lies on a padded table. Clinicians wrap pressurized cuffs, similar to the one's used to measure
blood pressure, around the calves, thighs and lower buttocks. By increasing diastolic blood pressure, inflation of the EECP
pressure cuffs increases blood flow, supplying more oxygen to the coronary arteries that feed the heart.
Conversely, when the heart pumps, the cuffs deflate instantaneously, momentarily reducing blood pressure and lessening the
heart's workload as it delivers oxygenated blood throughout the body.
Many researchers believe that EECP treatment fosters growth of new, small blood vessels, called collatorals, which feed the heart
additional oxygen, although this has not been proved.
The average age of the 139 angina sufferers who participated in the study was 63, and 87 percent were men. Forty-nine percent
had prior heart attacks and 57 percent had undergone bypass surgery or angioplasty. All participants already were taking the
doses of nitroglycerin or other medications to control their angina.
To control for extraneous effects on the study outcome, the researchers used a sham treatment as a "placebo." Patients were
assigned randomly to receive EECP or sham treatment and the results were compared. The sham treatment was identical to
EECP treatment with the exception that the sham pulses did not change blood flow to the heart. Patients and physicians did not
know whether sham or genuine treatment was provided until the data were collected and analyzed.
"Most patients are quite comfortable during treatment," Chou says. "Many read, listen to music or watch television, and some even
fall asleep." Some patients experience discomfort in the lower legs, but rarely to a degree requiring cessation of treatment,
according to Chou. No serious complications were observed in study participants, he adds.
Vasomedical, Inc. of Westbury, N.Y., the manufacturer of the device used to perform the procedure, sponsored the study, which
was conducted by physicians at seven academic medical centers. |
