A lingering
controversy over the use of drugs many doctors consider mainstays of high-blood-pressure
treatment appears to have been laid to rest by results of a massive new
study, researchers say.
"Now there's
an alternative to what's considered the standard of care," said Dr. Carl
Pepine, chief of cardiovascular medicine at the University of Florida College
of Medicine and the study's chief investigator.
The 22,576-patient
study, reported at a meeting of the American College of Cardiology, found
a strategy using the calcium channel blocker, verapamil, to which other
medications were added as needed, was almost exactly as successful in reducing
high blood pressure -- a leading cause of heart attack and stroke -- as
therapy using drugs called beta-blockers.
Pepine noted
nearly all aspects of treatment between the two groups were indistinguishable,
and more than 60 percent of the patients in the trial were able to reach
their blood pressure goals. All the patients had high blood pressure and
documented heart disease. More than half were over age 65, a group notoriously
difficult to treat for hypertension.
Over the past
decade, numerous scientific articles and studies have scrutinized the use
of calcium channel blockers in treating high blood pressure and other related
diseases. Some have questioned the efficacy of the drugs, while others
have suggested their use could raise safety issues.
"Calcium channel
blockers have been oft-maligned," said Dr. James Ferguson III, associate
director of cardiovascular research at the Texas Heart Institute in Houston.
"However, I don't think that calcium channel blockers needed to be 'rehabilitated.'
This study confirms their utility in treating patients with high blood
pressure and should give confidence to doctors who prescribe them and to
patients who are taking these drugs that they are getting therapy that
is up to the standard of care."
The trial, called
INVEST -- for International Verapamil SR and Trandolapril Study -- showed
"there are no differences in either the systolic or diastolic blood pressure
levels between the two strategies at any time point during the four years
of follow-up," Pepine said.
Patients on
the verapamil-based strategy showed an 18.6 point drop in systolic pressure
-- the upper number in blood pressure readings -- and a 9.9 point drop
is diastolic pressure. Meanwhile, patients on the beta blocker achieved
an 18.9 point drop in systolic blood pressure and a 10.2 point drop in
diastolic pressure -- essentially identical figures, Pepine noted.
"Blood pressure
control by either strategy was excellent in INVEST," said Pepine, the new
president of the American College of Cardiology. "About 64 percent of patients
in both strategies achieved blood pressure control." That is in contrast
to surveys indicating only about 30 percent of U.S. patients are controlling
their blood pressure properly. More than 50 million Americans have high
blood pressure.
About 20 percent
of patients in each group experienced a cardiovascular event -- suggesting
both drug strategies were similar in safety. Pepine said there were no
statistically significant differences in deaths, heart attacks, strokes
or other events between the two groups. For example, 848 patients died
among the calcium channel blocker group, compared with 862 in the beta
blocker group.
In the trial,
patients assigned to receive the calcium channel blockers were allowed
to add the medication trandolapril to their regimen. If that did not work
sufficiently, they were allowed to add diuretics -- fluid discharge pills
-- to the formula. The patients using beta blockers also were allowed to
add diuretics and then trandolapril to control their blood pressure.
Dr. Franz Messerli,
another investigator in the trial, said the results provide another option
for treating patients.
"Beta blocker-type
drugs, for example," he said, "are not very well tolerated."
Pepine noted
more trial participants in the beta-blocker group switched their medication
to calcium channel blockers than vice versa.
Messerli, medical
director for research at the Oschner Clinic Foundation in New Orleans,
said elderly, hypertensive patients with heart disease are especially difficult
to treat.
"I believe that
if you aren't treating your patients with calcium channel blockers you
aren't treating real high blood pressure," he said, adding that calcium
channel blockers need to be a part of the treatment of the disease.
--
Copyright 2003 by United
Press International.
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