ASPIRIN CLAIM OF 44% REDUCTION IN RISK OF FIRST HEART ATTACK UNLIKELY

ASPIRIN CLAIM OF 44% REDUCTION IN RISK OF FIRST HEART ATTACK UNLIKELY to be included in FDA professional labeling, based on the discussion of the Cardio-Renal Advisory Committee at their Oct. 6 meeting. Although the committee agreed to recommend the prophylactic use of aspirin to reduce the risk of primary myocardial infarction ("The Pink Sheet" Oct. 9, p. 2), members questioned whether the benefit would be as high for the general public as for the study population. The estimate that aspirin could reduce the risk of primary myocardial infarction (MI) by as much as 44% was a product of the Physicians' Health Study. The highly publicized trial of the effectiveness of low-dose aspirin in preventing first heart attacks whose results was first published in the July 20 New England Journal of Medicine ("The Pink Sheet," July 24, T&G 3). Julie Burin, co-principal investigator for the study, presented what she called "highly statistically significant" results of the study's 325 mg aspirin regimen on a patient population of 22,000 male U.S. physicians, aged 40-80. "There were 139 total MIs in the aspirin group, and 239 in the placebo group, yielding a 44% reduction in risk of myocardial infarction." The advisory panel was particularly concerned with the potential side effects of long-term asprin use, including increased risk of gastrointestinal disorders and cerebral hemorrhage. PHS data showed a rise in hemorrhagic strokes among the aspirin takers that Burin characterized as "borderline statistically significant," with 23 in the aspirin group and 12 in placebo. The committee also noted that the trial eliminated patients with gastric ulcers, rheumatism, gout; furthermore, it included a screening period during which patients exhibiting sensitivity to aspirin were dropped. "Patient selection for the trial basically would be expected to minimize the adverse effects of aspirin. . . How can you expect to generalize any adverse effect of aspirin from this study?" PHS researchers were asked. Although final wording for the professional labeling will not be determined until later this fall, the committee were unanimously in favor of limiting the indication to patients with the highest liklihood of heart attack: males over forty who have multiple risk factors for coronary heart disease but have not yet suffered an attack. In debating the remaining benefit to this patient population, the committee discussed the apparently above-average health of the doctors studied. For example, only 10% of the physicians in the trial smoked, compared to the 30% nationwide rate for U.S. males in their age group, according to PHS figures. Enrollees also had lower cholesterol and blood-pressure averages than the general public. "This is one of the lowest risk groups ever studied," stated committee Chairman Craig Pratt, MD, Baylor College of Medicine.