COX-2 inhibitor increases the risk of heart attack in heart healthy elderly adults

New research published in the on-line version of the Annals of Internal Medicine today, documents an increased risk of
heart attack with one of the COX-2 inhibitors used in elderly adults with no previous history of heart attack--a group
previously considered low-risk.


The study, sponsored by the Canadian Institutes of Health Research (CIHR) and conducted by researchers at the McGill
University Health Centre (MUHC) in Montreal, examined the relationship between the use of all nonsteroidal anti-inflammatory
drugs (NSAIDs) and the risk of heart attack in 113,927 Quebec senior citizens. Only one of these agents, a COX-2 inhibitor
called Vioxx--a new class of NSAIDs--carried a greater risk of heart attack.


"Many believe that COX-2 inhibitors increase the chance of a heart attack in high risk groups, for example people who have
already suffered a heart attack," explains primary author Linda L?vesque, a pharmacist and McGill University PhD candidate in
the Department of Epidemiology and Biostatistics. L?vesque worked with co-author Dr. James Brophy, a cardiologist and
Director of the Technology Assessment Unit (TAU) at the MUHC and Associate Professor of Medicine at McGill University. "This
study demonstrates the overall risk of heart attack is increased 24% for users of Vioxx who have not previously suffered a
heart attack," L?vesque says.


The study also reveals that aspirin use can help offset the damaging effects of Vioxx. "Aspirin mitigates the risk to
individuals," confirms L?vesque. "But only in those on a low dosage of Vioxx."


The study also demonstrates that the increased risk of heart attack is only present while taking the drug. "Past users of
Vioxx were not at increased risk," explains L?vesque. "While the risk more than doubles for those who are taking high doses
of the drug even when using aspirin."


COX-2 inhibitors are commonly used to relieve the pain and inflammation caused by arthritis in the elderly. These drugs are
believed to increase the 'stickiness' of blood platelets--the tiny bodies that assist in blood clot formation. "It is
possible that stickier platelets increase the chance of a blockage forming in a blood vessel of the heart," explains
L?vesque. "This study contributes to the growing body of evidence concerning the cardiac safety of COX-2 inhibitors."



About the McGill University Health Centre (MUHC)


The McGill University Health Centre (MUHC) is a comprehensive academic health institution with an international reputation
for excellence in clinical programs, research and teaching. The MUHC is a merger of five teaching hospitals affiliated with
the Faculty of Medicine at McGill University--the Montreal Children's, Montreal General, Royal Victoria, and Montreal
Neurological Hospitals, as well as the Montreal Chest Institute. Building on the tradition of medical leadership of the
founding hospitals, the goal of the MUHC is to provide patient care based on the most advanced knowledge in the health care
field, and to contribute to the development of new knowledge.


Ian Popple

ian.popplemuhc.mcgill.ca

514-843-1560

McGill University


View drug information on Vioxx.