January 26, 2006

Chest pain drug may fail in many Asians

NEW YORK (Reuters Health) - New research indicates that up
to 50 percent of Asians carry a genetic variant or
"polymorphism" that makes nitroglycerin less effective, or even
ineffective, for the treatment of angina.

Angina is a pain in the chest that occurs when blood flow,
and thus oxygen flow, to the heart is insufficient. It is the
top symptom of coronary artery disease.

Stable angina occurs during exertion and can usually be
treated with rest and nitroglycerin, which is placed under the
tongue. Unstable angina generally occurs when a person is at
rest. It is much more serious than stable angina and often
signals an impending heart attack.

Findings from a recent study showed that for nitroglycerin
to work, a functioning enzyme, known as ALDH2, is required. The
enzyme is responsible for forming nitric oxide, the metabolite
of nitroglycerin.

In The Journal of Clinical Investigation, Dr. Li Jin, from
Fudan University in Shanghai, China and associates present
evidence to suggest that the reason many Asians have a
suboptimal response to nitroglycerin is because they harbor a
gene variant -- Glu504Lys -- that makes ALDH2 virtually

The study involved 111 Chinese patients taking
nitroglycerin for heart disease, of whom 31 did not respond to
the drug.

The investigators think that this genetic factor needs to
be considered when nitroglycerin is given to patients,
especially Asian patients.

SOURCE: Journal of Clinical Investigation, online January
26, 2006.