"The two types of stroke - ischemic, caused by a clot cutting off the brain's blood supply, and hemorrhagic, caused by bleeding in the brain - share many of the same risk factors," says Eric Smith, MD, MPH, of MGH Neurology, the study's senior author. "Physicians often see patients with a history of intracerebral hemorrhage who are also at risk for ischemic stroke or heart attacks and need to decide what kind of preventive treatment to recommend. We have not yet had a good answer to whether daily aspirin therapy would be safe for these patients or would increase the risk of another hemorrhage."
The researchers followed a group of 207 patients who had survived intracerebral hemorrhage during the period from 1994 to 2004. The patients were surveyed by telephone every six months and asked about any recurrence of hemorrhage or other neurologic disorders and whether they took aspirin or other antiplatelet therapies. While 18 percent of the study participants had recurrent hemorrhages during an average of 20 months of follow-up, the risk was no greater among the 46 patients who reported taking antiplatelet therapy than it was among the 161 who did not take aspirin. The only factor associated with increased risk of recurrence was the location of the original hemorrhage, with greater risk associated with hemorrhage in the cerebral cortex than in the deep structure of the brain, which had been observed in previous studies.
"While it would be premature to conclude that all patients with intracerebral hemorrhage can safely take aspirin, our results suggest it may be appropriate for some patients at elevated risk of ischemic stroke or heart disease," says Smith. "The most definitive information would come from a clinical trial in which patients were randomly assigned to receive aspirin or a placebo. But I think such a trial is unlikely, so this may be the best data that will be available." Smith is an instructor in Neurology at Harvard Medical School.
The study's coauthors are first author Anand Viswanathan, MD, PhD; Susan Rakich; Chana Engel; Ryan Snider; Jonathan Rosand, MD, MSc; and Steven Greenberg, MD, PhD - all of the MGH Department of Neurology. The study was supported by funding from the National Institute of Neurological Disorders and Stroke.
Massachusetts General Hospital, established in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of nearly $500 million and major research centers in AIDS, cardiovascular research, cancer, cutaneous biology, medical imaging, neurodegenerative disorders, transplantation biology and photomedicine. In 1994, MGH and Brigham and Women's Hospital joined to form Partners HealthCare System, an integrated health care delivery system comprising the two academic medical centers, specialty and community hospitals, a network of physician groups, and nonacute and home health services.