Abstract 17771: High-Response to Antiplatelet Therapy and the Increasing Risk of Bleeding
Background: There are few reports demonstrating that high-response to antiplatelet therapy is associated with the increasing risk of bleeding in Caucasian patients receiving dual antiplatelet therapy. As it has been reported that Asian patients have higher bleeding risk, bleeding complication may frequently occur in Asian patients with high-response to antiplatelet therapy.
Methods and results: Elective drug-eluting stent implantation was performed in 184 Japanese patients treated with aspirin and thienopyridine. The adenosine diphosphate-induced platelet aggregation was assessed with screen filtration pressure method before stenting. The upper quartile group of platelet inhibition was defined as high-responders. We evaluated the incidence of major bleeding according to REPLACE2 and TIMI definitions during an average of 15 months follow-up between high-responders and the remainder. There were no significant differences in baseline characteristics including duration of antiplatelet therapy among 2 groups. A total of 12 (6.5%) patients experienced REPLACE2 major bleeding. Major bleeding occurred more frequently in high-responders than in the remainders (15 vs 4%, p<0.01). In multivariate regression analysis, high-response to antiplatelet therapy was significantly associated with the occurrence of major bleeding (odds ratio 4.59 (1.19, 17.7), p=0.02). According to receiver operating characteristic curve, high-response predicted the occurrence of major bleeding (area under the curve 0.678). On the other hand, TIMI major bleeding occurred in 4 (2.1%) patients. The incidence of major bleeding was higher in high-responders than in the remainders (7 vs 1%, p=0.01), and the occurrence of major bleeding was also predicted by high-response (area under the curve 0.755).
Conclusion: High-response to antiplatelet therapy is associated with the increasing risk of major bleeding in Japanese patients, whichever definition is adopted. The measurement of pre-PCI platelet reactivity can identify Asian patients at risk for major bleeding.
- © 2010 by American Heart Association, Inc.