REPORT LINKS HEART ATTACKS TO MARIJUANA

In what is believed to be the first documented link between smoking
marijuana and heart attacks, a study has found that a middle-age person's
risk of heart attack rises nearly fivefold in the first hour after smoking
marijuana.

The study was presented yesterday by Dr. Murray A. Middleman at the
American Heart Association's annual conference on cardiovascular disease in
San Diego.

Dr. Middleman, an internist, heads a team of specialists that has been
reporting on risk factors in heart attacks for the past six years. Members
of the team are from Beth Israel Deaconess Medical Center, the
Massachusetts General Hospital and Harvard School of Public Health, all in
Boston.

The marijuana report is one of a series of studies on marijuana under way
at medical schools and universities throughout the country. One, at the
Columbia University, reported that a psychological dependency on marijuana
might develop among users. Another, at the University of Washington, found
that skillful child rearing significantly increased the age at which young
people began using marijuana and alcohol.

Describing the heart study, Dr. Middleman said that smoking marijuana
increased the heart rate by about 40 beats per minute.

"It also causes blood pressure to increase when the person is lying down,"
he said, "and then abruptly fall when the person stands up, often causing
dizziness.

These effects may pose significant risk, especially in people with
unrecognized coronary disease."

Dr. Lynn A. Smaha, president of the American Heart Association, said the
study produced important information in the search for factors that bring
on attacks. Dr. Smaha and other specialists said they knew of no previous
study that had pinpointed marijuana as one of them.

Dr. Middleman said the study might be of concern to baby boomers who
continued to use marijuana as they aged.

"Many of these people were users of marijuana when they were in their teens
and 20's," he said, "and sizable portion of them may still use the drug,
either frequently or occasionally.

They should at least be aware that their risk of heart attack suddenly
soars each time they take the drug."

Dr. Middleman also said that in the debate over the medicinal use of
marijuana, it might be judged inadvisable for people with existing coronary
disease.

The Boston group studied 3,882 patients who had survived heart attacks and
found that 124 reported using marijuana regularly.

Of those, 37 said they had used it within 24 hours of their heart attacks
and 9 within the hour of their attacks. The relative risk of heart attack
increased 4.8 times within the first hour but dropped to 1.7 times higher
in the second hour, suggesting a rapid decline in the acute cardiac
effects, the researchers said.

The group previously reported on other triggers of heart attacks, including
cocaine, exercise, sex and psychological conditions.

The latest report said smoking marijuana was "about twice as dangerous as
exercise for a fit person, sex for a sedentary person, a tantrum of anger
or a bout of anxiety." But it also said it was less risky than a "spurt of
exercise for a couch potato or a snort of cocaine."

Further studies will have to determine why marijuana, or the key chemical
in it, tetrahydrocannabinol (THC), may bring on heart attacks. But the
researchers speculate that it is because of the extra physical stress from
the increased heartbeat and blood pressure and the breaks they may cause in
the lining of the blood vessels, especially among people with elevated
cholesterol levels. The breaks may set off the formation of blood clots.

In the study at the College of Physicians and Surgeons at Columbia, Dr.
Mirian W. Fishman said surveys showed that the use of marijuana among young
people had risen sharply since 1990 but little had been determined about
whether people become dependent upon it.

Dr. Margaret Haney, the lead author of the report, and colleagues conducted
a study that Dr. Fishman said suggested that daily use of marijuana might
develop a psychological dependence. Marijuana is not considered physically
addictive.