Discontinuing long-term, low-dose aspirin therapy was associated with a 37 percent increased risk of cardiovascular events in a study of more than 600,000 people.
In patients with a previous history of stroke or heart attack, discontinuation was associated with a 46 percent increased risk—translating to one additional cardiovascular event per year per 36 patients who stopped taking aspirin.
These findings were published in Circulation, an American Heart Association journal.
“Low-dose aspirin therapy is a simple and inexpensive treatment,” Johan Sundstrom, MD, PhD, lead author and professor of epidemiology at Uppsala University in Sweden, said in a press release. “As long as there’s no bleeding or any major surgery scheduled, our research shows the significant public health benefits that can be gained when patients stay on aspirin therapy.”
Of course, patient persistence and adherence is another matter altogether. Sundstrom and colleagues pointed out 10 to 20 percent of heart attack survivors have been shown to stop taking aspirin within three years of MI. In broader patient settings, poor compliance has been noted in up to 50 percent.
“We confirm a high initial discontinuation rate, as seen in prior studies: one of five aspirin-naïve patients did not collect the second aspirin dispense, and the main persistence drop was during the first year after aspirin initiation,” the authors wrote. “In contrast, those who picked up their second prescription had a modest discontinuation rate over time.”
The researchers examined the records of 601,527 participants who were older than 40, cancer-free and showed an adherence rate of greater than 80 percent in the first year of treatment. With a follow-up of three years, researchers monitored patients’ first incidence of cardiovascular disease, defined as hospitalization for MI, stroke or cardiovascular death.
The mean age of the study sample was 73, and half the population was female. Low-dose aspirin was defined as 75 to 160 milligrams.
Sundstrom et al. found the risk associated with stopping aspirin therapy increased shortly after discontinuation and remained constant over time.
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.