Risk of bleeding with ASA-Plavix combination

MATCH trial Diener et al. Took 7599 high risk patients with TIA or stroke, on Plavix, and added ASA 75 mg. Followed patients for 18 months. The results wre highly statistically significant with more major and minor bleeding of all types among patients receiving combination therapy. However, in the combined group, the actual risk of symptomatic intracranial hemorrhage was 1 % in each group; major bleeding of all types combined two percent v. one percent; and minor bleeding of all types combined was 3 % v. 1 %. Thus the overall complication rate is relatively low. The trial was based on the previous CURE trial that showed an acceptable safety profile of combined therapy among patients with acute coronary syndrome.

By contrast, the vascular risk reduction from antiplatelet therapy after TIA or stroke (reduction in stroke, MI or vascular death) was, absolute. 0.72 percent (NTT about 100/.72 or 138) with a relative risk reduction of 5.9 %. Thus by comparison the 3 % risk of hemorrhage is large.

OTHER EVIDENCE
CHARISMA trial supported results of MATCH.

CARESS trial in symptomatic carotid stenosis showed less embolic signals, but not less clinical events in patients on dual therapy.
FASTER trial suggested a role for dual therapy after clopidogrel loading for brief trial (90 days) after TIA. Not conclusive.