Though it’s used routinely to discourage repeat cardiovascular disease (CVD) events, a daily dose of aspirin is unlikely to prevent a first-time heart attack, according to research presented this week in Munich.
Despite three decades’ worth of clinical trials, the role of aspirin in preventing first-time myocardial infarction isn’t well understood, first author J. Michael Gaziano, MD, and colleagues said in the Lancet. CVD patients are often prescribed blood thinners to prevent another stroke or heart attack, but aspirin can also boost a patient’s risk of bleeding, especially in the gastrointestinal tract.
“The use of aspirin remains a decision that should involve a thoughtful discussion between a clinician and a patient, given the need to weigh cardiovascular and possible cancer prevention benefits against bleeding risks, patient preferences, cost and other factors,” Gaziano, a Harvard Medical professor and preventive cardiologist at Brigham and Women’s Hospital in Boston, and co-authors wrote.
Gaziano presented his team’s findings this week at the European Society of Cardiology’s 2018 Congress.
To evaluate the effect of preventive aspirin on modern heart patients—who may already be taking blood pressure- or lipid-lowering medications like statins—Gaziano et al. designed ARRIVE, a multi-country trial that randomized 12,546 participants with a moderate risk of CVD to either 100 milligrams of aspirin a day or a placebo pill. The patients, from Poland, the U.K., Germany, Italy, Spain and the U.S., were monitored for a primary endpoint of cardiovascular death, first heart attack, unstable angina, first stroke or mini stroke.
During the study period, the authors said, rates of major adverse heart events remained similar between the two patient groups. In fact, 4.29 percent of the aspirin group experienced an adverse CVD event like the ones listed above, while 4.48 percent of the placebo group experienced the same thing.
Sixty-one patients in the aspirin group did have gastrointestinal bleeding, Gaziano et al. wrote. That figure was 29 in the placebo group.
“Aspirin did not reduce the occurrence of major cardiovascular events in this study,” Gaziano said in a release from Brigham and Women’s Hospital. “However, there were fewer events than expected, suggesting that this was in fact a low-risk population. This may have been because some participants were taking medications to lower blood pressure and lipids, which protected them from disease.”
A similar, seven-year study of 15,480 adults found a daily 100-milligram dose of aspirin helped prevent first-time cardiovascular events in patients with diabetes and no evidence of heart disease. But, according to the research, published August 26 in the New England Journal of Medicine, those benefits came at the expense of major bleeding risks.
The trial, termed ASCEND (A Study of Cardiovascular Events in Diabetes) and funded in part by the British Heart Foundation, found 8.5 percent of participants in the aspirin group experienced a serious vascular event in the years of study, compared to 9.6 percent in the placebo group. However, 4.1 percent of patients in the aspirin group also saw major bleeding events, compared to 3.2 percent of the placebo group.
“Aspirin use prevented serious vascular events in persons who had diabetes and no evident cardiovascular disease at trial entry, but it also caused major bleeding events,” the authors wrote. “The absolute benefits were largely counterbalanced by the bleeding hazard.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.