Comparison of triple anti-platelet therapy (aspirin, clopidogrel, and cilostazol) and double anti-platelet therapy (aspirin and clopidogrel) on platelet aggregation in type 2 diabetic patients undergoing drug-eluting stent implantation.

Objective: Triple anti-platelet therapy may produce more potent inhibition of platelet aggregation in patients undergoing coronary stent implantation. We tested whether this effect could be maintained in diabetic patients, where platelet reactivity is increased and the risk of stent thrombosis is higher.

Methods: Fifty five type 2 diabetic patients who had undergone drug-eluting stent (DES) implantation and chronic anti-platelet therapy (>1 month) were stratified according to the status of anti-platelet therapy. Platelet aggregation after adenosine diphosphate (ADP; 10 micromol/L and 20 micromol/L) stimulation was compared using light transmittance aggregometry between dual (aspirin plus clopidogrel, n=34) and triple therapy (aspirin, clopidogrel plus cilostazol, n=21) groups.

Results: The 2 groups had similar clinical and procedural characteristics. Maximal ADP-induced platelet aggregation was significantly lower in the triple therapy group than the dual therapy group (ADP 10 micromol/L, 37.1+/-15.4 vs. 28.3+/-11.8, p=0.03; ADP 20 micromol/L, 63.1+/-15.0 vs. 49.1+/-15.1, p=0.01), but there were no differences in diabetic treatment (oral hypoglycemic agent vs. insulin) or diabetic control {hemoglobin Alc (HbA1c) 7}.

Conclusions: Triple anti-platelet therapy showed more potent inhibition of maximal ADP induced platelet aggregation in type 2 diabetic patients receiving chronic anti-platelet therapy. This finding suggests that triple antiplatelet therapy may be more effective in preventing thrombotic complications after DES implantation in type 2 diabetic patients.