Published May 13, 2019, in JAMA Neurology, a large new retrospective analysis of more than 130,000 patients found that people with no history of heart disease or stroke who take low-dose aspirin face a heightened risk of bleeding in the skull. The results support the latest American Heart Association guidelines recommending that most individuals who have never had a heart attack or stroke avoid aspirin therapy because of bleeding risks. “The absolute risk difference of head bleed is small between aspirin and no aspirin use,” says one of the study’s author, Meng Lee, MD, a member of the department of neurology at Chang Gung University College of Medicine in Taiwan. “However, given that many individuals in the general population have a very low risk of atherosclerotic cardiovascular events, if low-dose aspirin is given universally, adverse outcomes from intracranial hemorrhage may outweigh the beneficial effects of low-dose aspirin.” RELATED: Risks of Daily Aspirin Use May Outweigh Benefits in Healthy Older People Using a statistical model, Dr. Lee and his collaborators pooled results from 134,446 individuals who participated in 13 randomized trials targeting the use of low-dose aspirin to prevent heart-related events. Researchers calculated that those who took aspirin had a 0.63 percent risk of having a hemorrhage in the head compared with a 0.46 percent risk among those who received a placebo (a pill with no active ingredients). Among every 1,000 people treated with low-dose aspirin instead of placebo, two more had intracranial hemorrhage events.
Disastrous Effects of Brain Bleeds
Generally, brain bleeding is associated with higher chances of death and disability compared with harm caused when arteries to your brain become narrowed or blocked, according to Lee. “A bleed into the brain can be devastating, and can result in a stroke leading to permanent disability,” says Sarah Samaan, MD, a cardiologist with Baylor Scott & White Legacy Heart Center in Plano, Texas. The Cleveland Clinic warns that intracranial hemorrhage is an emergency that requires immediate medical attention. Symptoms include sudden tingling, weakness, numbness, paralysis, severe headache, difficulty with swallowing or vision, loss of balance or coordination, difficulty understanding, speaking, reading, or writing, and a change in the level of consciousness or alertness.
Aspirin May Still Help People With Heart Issues
Dr. Samaan stresses that the results from this study apply only to someone without heart or vascular problems who is taking the drug. “If you are on aspirin because of a heart attack, heart disease, arrhythmia, stroke, coronary stent, vascular stent, or vascular disease, do not stop it,” she says. “Before stopping or starting any medication, including aspirin, check with your physician. Be sure you understand why you should, or should not, take this drug.” The American Heart Association indicates that doctors may recommend aspirin for people with a strong family history of heart disease or if coronary calcium scans reveal substantial plaque buildup in the arteries. Aspirin thins the blood, which helps prevent clots from forming. Lee adds that patients with atrial fibrillation (a common type of irregular heartbeat) may need to take medications that inhibit blood clots but may increase brain bleeds. “The benefits of oral anticoagulants such as warfarin or novel oral anticoagulants [such as rivaroxaban, dabigatran, and apixaban] in preventing stroke are much higher than bleeding risk in atrial fibrillation patients.” For those without cardiovascular disease, healthy habits can help keep heart problems away. “Don’t smoke, maintain a healthy body weight, exercise two and a half hours weekly, follow a Mediterranean diet with very little, if any, meat, and keep track of your blood pressure, cholesterol, and blood sugar,” advises Samaan.
Higher Risk for Asians and People With Low BMI
The investigation also notes that Asians taking low-dose aspirin tended to experience more frequent head bleeds than non-Asian populations, which is consistent with previous research. This may be due to a higher frequency of uncontrolled blood pressure, smoking, and a buildup of proteins (called amyloids) on the walls of brain arteries, according to the study’s authors. Low body mass index (BMI) was another factor that raised the likelihood of intracranial hemorrhage among aspirin takers — a result that also aligned with prior investigations. The underlying reason behind this remains unclear. RELATED: What Is BMI? Investigators recognize that combining results from a number of different independent studies has its limitations because research approaches vary and more clinical research needs to be done. Still, overall data support their conclusions. “Because the benefits of low-dose aspirin for primary prevention of cardiovascular events are not well established, and the outcomes of intracranial hemorrhage are often catastrophic, these findings suggest caution regarding using low-dose aspirin in individuals without symptomatic cardiovascular disease,” wrote Lee and his coauthors.
