Filenews 18 May 2021
An unusual study involving thousands of heart disease patients taking low- or regular-dose aspirin concludes that both dosages seem equally safe and effective in preventing additional heart problems and strokes.
But there is one big caveat: First the health of the participants was monitored online alone. Second, participants showed such a strong preference for low-dose aspirin that it is unclear whether the results can prove that the treatments are truly equivalent. Half of those instructed by the researchers to take the highest dosage either took the lowest anyway, or stopped taking aspirin regularly.
"Patients basically decided for themselves what they wanted to take because they were buying aspirin on their own," Dr. Saunders said. Salim Virani, a cardiologist at Baylor College of Medicine, who had no role in the study.
Also, the results show that there is no good reason to take the highest dosage (aspirin 325 mg), which many doctors assumed would work better than aspirin of 81 mg, he said.
The results were published in the New England Journal of Medicine and discussed at a conference of the American College of Cardiology.
Heart: The role of aspirin
Aspirin helps prevent blood clots, but is not recommended in healthy people who have not yet developed heart disease because it poses a risk of bleeding. Its benefits are clear, however, for people who have already suffered a heart attack, bypass surgery or clogged arteries that require stents.
But the optimal dosage is not known and the study was intended to compare the low and moderate dosage in real environment.
Aspirin for the heart: How the research was done
About 15,000 people received invitations to participate via mail, email or phone call and registered on a website where they returned every three to six months for follow-up. A network of participating health centers provided medical information for participants.
Participants were randomly assigned to take low- or regular-dose aspirin, which they bought themselves. Almost everyone was taking aspirin before the study even started and 85% were already on a low dosage, so "it was a difficult case from the outset" to get participants to follow the dose they were told, dr. Virani.
After about two years, about 7% of each group had died or been hospitalized for a heart attack or stroke. The safety results were also similar: less than 1% had severe bleeding requiring hospitalization and blood transfusion.
Nearly 41% of those instructed to take the highest dose changed at some point to the lowest and this high rate "may hide an even greater difference" in safety or efficacy, dr. Colin Baigent from Oxford University.
The main conclusions of the survey
A study leader, Dr . Schuyler Jones of Duke University said the study still provides valuable guidance. If patients are now taking low-dose aspirin, "staying at this dose is the right choice," he said. But also those who are doing well with 325 mg now perhaps should continue but also talk to their doctors in case they have any concerns.
For new patients, "we generally recommend starting with the low dose," dr. Jones.
Dr.. Virani said that patients should remember that aspirin is a medicine and that although it is sold without a prescription, they should not make decisions about its use on their own:
"Do not change the dose or stop without talking to your doctor. This is important, especially for a treatment like aspirin"
