Does excessive dosing of Glycoprotein IIb/IIIa inhibitors contribute to sex differences in major bleeding in patients with NSTE ACS?
Frequent excessive dosing of GP IIb/IIIa inhibitors in women with NSTE ACS accounts for up to one fourth of the sex-related excess risk in major bleeding.
BACKGROUND: Glycoprotein (GP) IIb/IIIa inhibitors are beneficial in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS); their safe use in women, however, remains a concern. The contribution of dosing to the observed sex-related differences in bleeding is unknown. METHODS AND RESULTS: We explored the relationship between patient sex, GP IIb/IIIa inhibitor use, dose, and bleeding in 32 601 patients with NSTE ACS across 400 CRUSADE (Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA guidelines) hospitals, of whom 18 436 were treated. GP IIb/IIIa inhibitor dose was defined as excessive if not reduced when creatinine clearance was or = 0.12, need for transfusion, or intracranial bleeding. Major bleeding was adjusted for clinical factors and antithrombotic dose. The risk for bleeding attributable to excess GP IIb/IIIa dose was determined by sex using prevalence and adjusted odds ratios (ORs). Women had higher rates of major bleeding than men among those treated with GP IIb/IIIa inhibitors (15.7% versus 7.3%, P<0.0001) and among those not treated (8.5% versus 5.4%, P<0.0001). Despite similar serum creatinine levels, creatinine clearance averaged 20 points lower among treated women than men. Treated women were also more likely to receive excess GP IIb/IIIa doses than men (46.4% versus 17.2%, P<0.0001; adjusted OR 3.81, 95% confidence interval CI 3.39 to 4.27). Excess dosing was associated with increased risk of bleeding in women (OR 1.72, 95% CI 1.30 to 2.28) and men (OR 1.27, 95% CI 0.97 to 1.66); however, bleeding risk attributable to dosing was much higher in women (25.0% versus 4.4%). CONCLUSIONS: Women experience more bleeding than men whether or not they are treated with GP IIb/IIIa inhibitors; however, because of frequent excessive dosing in women, up to one fourth of this sex-related risk difference in bleeding is avoidable. Appropriate dosing will improve care of all patients with NSTE ACS, with a particular benefit for women.
Alexander et al. (2006) studied this question.