| Aspirin increases hemorrhagic stroke risk regardless of patient characteristics http://www.reutershealth.com/WESTPORT, Dec 09 (Reuters Health) - Aspirin therapy for the prevention of CVD increases the absolute risk of hemorrhagic stroke in all patients, but reductions in the likelihood of death, MI and ischemic stroke outweigh the risk in many patients, according to the results of a meta-analysis. Dr. Jiang He, of Tulane University, New Orleans, Louisiana, and colleagues there and at Johns Hopkins University, Baltimore, Maryland, included in the meta-analysis 16 English-language randomized clinical trials, involving 55,462 patients, which investigated the efficacy of 75 to 1,500 mg/day of aspirin versus placebo or no aspirin therapy. Other inclusion criteria were that aspirin was not combined with any other anticoagulant or antiplatelet agent, aspirin was administered for at least 1 month, and the occurrence of stroke subtypes was recorded during follow-up. Per 10,000 persons, aspirin treatment was associated with an absolute risk of 12 more hemorrhagic stroke events but with 97 fewer deaths from CVD, 137 fewer MI events and 39 fewer ischemic stroke events, Dr. He's team reports in The Journal of the American Medical Association for December 9. The corresponding relative risks were an 84% greater risk of hemorrhagic stroke, a 16% lower risk of death from CVD, a 31% lower risk of MI and an 18% lower risk of ischemic stroke, the investigators calculated. The absolute risk of hemorrhagic stroke did not change significantly according to patient characteristics or study design, the research team observed. "Even in healthy populations older than 50 years in western countries, the [absolute risk] of myocardial infarction and ischemic stroke is much higher than that of hemorrhagic stroke," Dr. He's group points out. "Therefore, the overall benefit of aspirin use of myocardial infarction and ischemic stroke almost certainly overcomes the potential risk of hemorrhagic stroke in such groups." The authors recommend using aspirin "with caution" in patients who are at high risk of hemorrhagic stroke. They also note that the benefits of aspirin "...have not been well documented in healthy persons who are younger than 50 years," so that "...aspirin treatment may not be recommended to such persons for the purpose of primary prevention of cardiovascular disease." In an editorial, Dr. Jean-Pierre Boissel, of Hopital Neuro-Cardiologique, Lyon, France, says that the meta-analysis is important, even though its conclusion is not new, because it quantifies the excess risk due to aspirin. Previous studies provided only "...the vague notion that the risk is increased," he notes. Because patient characteristics such as age, sex, race and indication for therapy did not influence the absolute risk of hemorrhagic stroke, Dr. Boissel infers that "...the absolute benefit [of aspirin] is proportional to the patient's absolute risk of developing an ischemic cardiovascular event." "For primary prevention, in which the risk of cardiovascular events is, on average, much less than in secondary prevention, the excess risk may well exceed the benefit of therapy," the editorialist warns. "In low-risk patients, particularly in primary prevention, clinicians should be cautious in prescribing aspirin." JAMA 1998;280:1930-1935,1949-1950. |
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