Aspirin Can Reduce Risk of Recurring Blood Clots, Study Says

Dec. 10 -- Aspirin may be a safe solution for preventing recurrences of dangerous blood clots in the veins, potentially providing a low-cost therapy after prescribed blood thinners, a study found.

Patients who took aspirin daily for two years had a 40 percent reduced risk of clots breaking free and moving in the circulatory system compared with those taking a placebo, according to the study released today at the American Society of Hematology meeting in San Diego.

“The reduction in events was striking, and this I believe will prompt additional studies,” said Evan Sadler, a professor of medicine at Washington University Medical School in St. Louis, and president of ASH, in an interview. “Aspirin's really good at preventing second clots in people with heart attacks and strokes, but it hasn't been thought to be effective on the venous side.”

An earlier study involving almost 40,000 women showed that a daily, low dose of aspirin had little effect in preventing venous thromboembolism, or clots deep in the veins, in healthy women, said Sadler, who wasn't involved in the studies.

Aspirin, the 112-year-old pain killer, has been shown to cut the risk of strokes and heart attacks. The medicine also lowered the danger of colorectal cancer in a U.K. study published in October. Side effects including ulcers and stomach bleeding.

In the new study, patients first took an anti-clotting pill for as long as a year before switching to a 100-milligram dose of aspirin, or placebo, for two years. While the anti-clotting medicine can be effective, it's costly and can lead to increased bleeding, Sadler said.

“Aspirin is appealing because it's so cheap, and we know its safety profile,” he said.