FOR IMMEDIATE RELEASE
For More Information: Bob Schwadron, 212-468-3616, [email protected]
LAB TEST CAN IDENTIFY POTENTIAL HEART ATTACK VICTIMS,
STUDY IN AMERICAN JOURNAL OF HYPERTENSION REPORTS
Plasma Renin Test Highly Predictive For White Male Hypertensives
NEW YORK, NY -- By measuring levels of the hormone renin,
which is produced in the kidney, physicians can identify hypertensive
patients at risk of heart attacks, leading hypertension experts found in a
study published in the January issue of the American Journal of
Hypertension.
"Plasma renin activity is directly and independently associated
with the occurrence of total cardiovascular disease, especially
myocardial infarction (heart attack), among hypertensive patients," the
authors say. "This relationship was strongest among men, particularly
white men, who were most likely to experience heart attack. This
association did not hold for women or blacks and was muted in younger
subjects."
Lead author of the study is Michael H. Alderman, MD, president of
the American Society of Hypertension, the largest US organization
devoted exclusively to hypertension and related cardiovascular
diseases. John Laragh, MD, a founder of the society, is a co-author.
"Alderman and his colleagues have provided practicing
physicians with a simple approach for figuring the risk in their patients,"
says Michael Weber, MD, an editor of the American Journal of
Hypertension. "They found that high renin predicts an increased
probability of heart attacks, while low renin seems to point to a safer
outcome.
"Their study shows that renin levels, measured by a technique
available at a modest cost from regular commercial laboratories, is a
strong predictor of the likelihood of heart attacks," he continued. "This
discovery has two important practical implications. Physicians can now
more readily identify hypertensive patients at risk of heart attacks and
they can potentially block the actions of the renin system, which, at least
in theory, provide a measure of protection against serious cardiac
events."
Drug classes that could provide this benefit, Dr. Weber says,
include the angiotensin converting enzyme (ACE) inhibitors and the
angiotensin receptor blockers.
"A further interesting discovery was that strokes, which are
another common result of hypertension, occur equally in patients with
low, normal and high renin levels," he continued. "Any drug that
decreases blood pressure, may be helpful in preventing strokes in
hypertensive patients."
Plasma renin activity levels of 2,902 hypertensive patients (38
percent white, 65 percent males, median age, 55 years) were examined
as part of the study. During 9.4 years follow-up (January 1981 through
June 1990), there were 107 cardiovascular disease deaths and 22
deaths not related to cardiovascular disease among the patients. Of the
107 deaths, there were 55 due to heart attacks, 21 due to strokes, and
31 due to other cardiovascular causes.
The authors found death rates were higher in patients with higher
plasma renin activity as compared to patients with lower plasma renin
activity. The authors note that renin activity was not a predictor of
stroke.
"Analyses revealed that even after controlling for specific
baseline attributes," they say, "higher plasma renin activity subjects
were at greater risk for myocardial infarction than those with lower
plasma renin activity, among whites, men and older (median 55 years)
subjects. Of note, however, is the absence of a significant relationship
between plasma renin activity and myocardial infarction at lower (less
than 95 mm Hg) diastolic pressures."
The authors also found that in addition to hypertension, when
patients were classified according to other cardiovascular disease risk
factors such as smoking, high cholesterol levels or the presence or
absence of left ventricular hypertrophy (enlargement of the portion of the
heart that pumps blood to the body) "higher plasma renin activity subjects
with two or more such risk factors were 4.2 times more likely to develop
a myocardial infarction than their counterparts with lower plasma renin
activity."
They said the 44 of the 2,902 subjects (1.5 percent) with both a
high risk profile and high plasma renin levels accounted for 11.4 percent
of all heart attacks while 468 subjects with both a low risk profile and
low plasma renin levels (468 of the 2,902 or 16.1 percent) had less than
one percent of all heart attacks. Low risk women and black males who
also had low renin levels did not experience a single heart attack.
Authors of the study, "Plasma Renin Activity: A Risk Factor for
Myocardial Infarction in Hypertensive Patients," are Dr. Alderman, Hillel
Cohen and Shantha Madhavan, all from the Department of Epidemiology
and Social Medicine, Albert Einstein College of Medicine, Bronx, NY; Wee
Lock Ooi, the Hebrew Rehabilitation Center for the Aged, Research and
Training Institute, Boston, MA; and Jean E. Sealey and Dr. Laragh from
the Cardiovascular Center, Department of Medicine, Cornell University
Medical College, New York, NY.
Nearly 50 million Americans have high blood pressure, called the
silent killer because it prematurely ages the body's arteries and can lead
to strokes, heart attacks and kidney disease, often without warning.
The American Society of Hypertension is committed to alerting
physicians, allied health professionals and the public about new medical
options, facts, research findings and treatment choices designed to
reduce the risk of cardiovascular disease.
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