Background: The cause of major cardiovascular events (MACE) after drug eluting stent implantation are mutifactorial. Residual platelet reactivity is one of the factor, which is important in acute phase as well as chronic phase in the development of these events. Objective: We sought to investigate the influence of acute phase residual platelet activity to predict short and mid-term MACE. Methods: We had analyzed 435 consecutive patients who underwent drug eluting stents implantation. Platelet function tests (light transmission aggregometry and VeryfyNow assay) were carried out after PCI, mostly within 24 hrs. MACE was defined as cardiac death, MI, stroke and stent thrombosis. Logistic regression analysis was done using clinical parameters as well as cutoff values of high post-clopidogrel treatment residual platelet activity. All statistical analyses were carried out using SAS version 9.1.3 and MedCalc version 11.6.1 statistical softwares. Results: 6 month MACE occurred in 23 patients (5.3%). Statin use and LTA cutoff values were the predictors of univariate analysis. By mutivariate logistic regression analysis, there was no predictor of 30-day MACE. However, maximal 10µM ADP-induced aggregation>60% by LTA was the only predictor of 6 month MACE (table). Conclusion: High post-clopidogrel residual platelet activity defined by LTA can predict 6 month MACE.

	Univariate			Multivariate
Variable	OR	95% CI	P value	OR	95% CI	P value
Sex (male vs. female)	1.13	(0.45-2.80)	0.80	5.02	(0.53-47.0)	0.16
Age, yrs (���65 vs. <65)	1.09	(0.47-2.53)	0.84
Statin use (yes vs. no)	0.11	(0.015-0.84)	0.033	0.13	(0.012-1.35)	0.087
CCBDHP (yes vs. no)	0.27	(0.036-2.03)	0.20
Cilostazol (yes vs. no)	1.02	(0.34-3.08)	0.98
DM (yes vs. no)	1.58	(0.68-3.68)	0.28
Smoking (yes vs. no)	1.27	(0.52-3.07)	0.60
LTA (���60 vs. <60)	2.84	(0.90-9.02)	0.076	25.03	(2.15-291.4)	0.010
PRU (���240 vs. <240)	0.60	(0.24-1.49)	0.27	0.23	(0.026-2.06)	0.19