The finding "follows common sense, but no one has actually shown this before in a large group of patients," Bhatt said.
The results appear to support the view that longer therapy with clopidogrel is better but does not completely answer that question, he said. "The very necessary next step is to figure out whether longer duration is better in a randomized, controlled trial."
Such a controlled trial would meet the gold standard for medical research. The newly reported study was observational, Ho noted, meaning that it examined what was happening in medical practice without attempting to single out factors affecting the results.
A decision on whether or when to stop clopidogrel treatment must be made on a case-by-case basis, Ho said. "The final decision should be left to provider and patient," he said. "They have to weigh the risk of discontinuing clopidogrel against the risk of abnormal bleeding if it is continued. The clinician needs to weigh the risk and benefits for each individual patient."
Those making the decision should remember that the risk found in the study was "relatively small," Ho said. Among the more than 3,000 cases studied, there were 163 adverse events in the 90 days after drug treatment stopped, 57 in the following 90 days, and 26 in the third 90-day period.
Learn about the benefits and possible hazards of using clopidogrel from the U.S. Library of Medicine.
SOURCES: P. Michael Ho, M.D., Ph.D, cardiologist, Denver VA Medical Center; Deepak Bhatt, M.D., associate director, Cleveland Clinic Cardiovascular Coordinating Center; Feb. 6, 2008, Journal of the American Medical Association
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