POT RAISES HEART ATTACK RISK IN SOME, STUDY SAYS

Air pollution and smoking marijuana both temporarily increase heart
attack risk in persons with cardiovascular disease, researchers reported
Monday, June 11.

Baby boomers' heart attack risk increases almost five times within one
hour after smoking marijuana, especially if they have other
cardiovascular risk factors, said Dr. Murray Mittleman, director of
cardiovascular surgery at Beth Israel Deaconess Medical Center and
Harvard University in Boston. "People who have heart attacks triggered
by smoking marijuana almost certainly have a heart condition, which they
may not be aware of, that predisposes them to having a heart attack," he
told United Press International.

"As baby boomers enter the age at which coronary disease is the most
important cause of death and the leading cause of morbidity, we may see
an increase in marijuana-associated heart attacks," Mittleman added. "In
the debate about medicinal use, marijuana may be contraindicated for
people with existing coronary disease."

For an hour after smoking marijuana, the likelihood of having a heart
attack is four and a half times greater than if the person hadn't
smoked, he found. However, by the second hour the risk is 1.7 times
greater. After two hours, the risk is normal. As part of the eight-year
multicenter Determinants of Myocardial Infarction Onset Study, Mittleman
and other researchers interviewed 3,882 heart attack patients between
the ages of 20 and 92 years about a number of factors including drug
use. Twenty-three percent of marijuana smokers were between the ages of
50 and 69 years. Many of these had smoked pot at least once over the
previous 12 months, but among nine patients who had smoked within an
hour before their heart attack, relative risk was nearly five times
higher than for those who had never used the drug.

The findings are published in the June 12 issue the American Heart
Association's journal Circulation. "Smoking marijuana increases the
heart rate by about 40 beats per minute," Mittleman said. "It also
causes the blood pressure to increase when the person is lying down, and
then abruptly falls when the person stands up, often causing dizziness.
These effects may pose significant risk, especially in people with
unrecognized coronary disease."

He noted that marijuana was less dangerous than cocaine for people with
heart disease - about as risky as taking a walk for an active person
with heart disease, or sex for a sedentary patient.

"All medicines have harmful side effects," said Robert Kampia, executive
director of the Marijuana Policy Project, the nation's leading medical
marijuana policy organization. "Because marijuana increases the heart
rate, it might be risky for people with very bad hearts. If your heart
is so bad that you shouldn't even walk up the stairs, you probably also
should not use marijuana," he told UPI.

The study found that exactly nine of the heart attack victims had their
heart attacks within an hour after using marijuana. That is 0.2 percent
of the heart-attack population examined. "Hardly a large enough sample
to draw a newsworthy conclusion," Kampia said.

In a second study, Mittleman reported that exposure to tiny particulates
in air pollution also temporarily increases heart attack risk for at
least two hours. Risk was even greater in patients with other heart risk
factors, the researchers found in interviewing 722 people admitted to
Boston hospitals after a heart attack.

At the same time they measured pollution levels, including fine
particulates less than five millionths of an inch in diameter, at five
sites. Heart attacks increased by 50 percent within two hours after
exposure to high levels of fine particulates, and resulted in a delayed
response within 24 hours. It's estimated the number of heart-disease
deaths due to air pollution ranges from 1,000 to as many as 10,000 each
year nationally. This is the first study to confirm short-term heart
risk from particulate exposure, Middleman said.

Scientists believe fine particulates penetrate the lungs' air sacs and
trigger an inflammatory response in the lungs, followed by systemic
inflammation. Systemic inflammatory response releases proteins into the
bloodstream that are associated with increased risk of heart attack.
Exposure to air pollution also increases the risk of blood clotting and
impeded blood flow to the heart.

"This is another reason for people with heart disease to stay indoors
when air quality is poor, especially during hot, hazy, and humid summer
afternoons," he said.

P. Barry Ryan, a professor of environmental exposures and chemistry at
Emory University in Atlanta, told UPI the study is the first large-scale
examination of particulate exposure and heart attack risk, but that
other studies are under way in Atlanta and Los Angeles "This work is
yielding pertinent information for the study of health effects of air
pollution on persons with different disease conditions, including heart
disease and chronic obstructive pulmonary disease," Ryan said. "We're
finding similar data from people in cities all over the country."