By Peggy Peck
WESTPORT, CT (Reuters Health) – Among individuals being evaluated for known or suspected coronary artery disease, daily aspirin use is associated with a reduction of more than a third in long-term all-cause mortality, especially among the elderly, those with impaired exercise tolerance, and those with known coronary artery disease, according to results from an observational study by Cleveland Clinic Foundation researchers.
Senior investigator Dr. Michael S. Lauer and colleagues conducted a propensity analysis that compared all-cause mortality in a group of 1351 aspirin users to that in 1351 non-aspirin users. In an interview with Reuters Health, Dr. Lauer said that aspirin use was associated with "between a 30% and 50% reduction in all-cause mortality." The results are reported in The Journal of the American Medical Association for September 12.
All patients included in the analysis were recruited from a cohort of 6174 consecutive patients who were referred to the Cleveland Clinic for stress echocardiography. The propensity analysis design allowed for patients to be prospectively enrolled in the study. "These patients are in all respects the same with the sole difference being aspirin use," said Dr. Lauer. The median length of follow-up was 3.1 years.
The authors write that "during follow-up, 153 (6%) patients died. Aspirin use was associated with a lower risk of death (4% vs 8%, p = 0.002)." The three patient characteristics most strongly correlated with a large absolute mortality benefit were older age, impaired exercise capacity, and a history of known coronary disease."
Dr. Lauer said the finding that aspirin is especially beneficial in patients who are out of shape is "a real take-home message for physicians." There is a well-established correlation between physical conditioning and mortality, he pointed out.
"Now, we actually have a treatment for the out-of-condition patient. We can tell the patient to take an aspirin," said Dr. Lauer. "That won't get them in shape, but it may save their lives."
American Heart Association president Dr. David Faxon said the finding that aspirin reduces all-cause mortality "is a really solid endpoint, easier to establish than reduction in cardiovascular mortality." But Dr. Faxon said an "even more powerful message" is the finding about physical condition and aspirin use.
In an editorial that accompanies the study , Drs. Martha J. Radford and JoAnne M. Foody of Yale New Haven Health System, in Connecticut, write that observational studies based on sophisticated techniques such as propensity analysis make a convincing case for expanding aspirin use to unstudied groups.