Impact of platelet function test on platelet responsiveness and clinical outcome after coronary stent implantation: platelet responsiveness and clinical outcome.
OBJECTIVE
The aim of this study was to confirm the predictive cut-off values for P2Y12 reaction units (PRU) and aspirin reaction units (ARU) and to evaluate the clinical impact of VerifyNow® assays.


METHODS
From November 2007 to October 2009, 186 eligible patients were prospectively recruited. Post-treatment platelet reactivity was measured by VerifyNow® assays within 12 to 24 hours after intervention, followed by standard dual maintenance dose therapy for 1 year. All patients had scheduled clinical follow-ups at 1, 3, 6, and 12 months.


RESULTS
The rate of low responders to clopidogrel, aspirin, and both drugs were 41.4%, 10.2%, and 3.8%, respectively. The predictive factors for low responsiveness to clopidogrel (PRU ≥240) were female sex, age, and non-use of cilostazol medication in our univariate analysis and age ≥65 years and non-use cilostazol in the multivariate analysis. The predictors of low responsiveness to aspirin (ARU ≥550) were male sex and age in both univariate and multivariate analyses. There was no significant difference in the clinical event rate with a cut-off value of PRU ≥240 or ARU ≥550 for 30 days and 1-year (p>0.05).


CONCLUSIONS
Hyporesponsiveness to antiplatelet agents (namely aspirin and clopidogrel) was identified in about half of the patients. The cut-off point of PRU ≥240 or ARU ≥550 did not confer predictive value for 30-day or 1-year clinical event rates in patients who had undergone coronary intervention with drug-eluting stents.
Department of Cardiology, College of Medicine, Dong-A University, Busan, Korea.
Long Hao
LH
Yu
Moo Hyun
MH
Kim
Hong Zhe
HZ
Zhang
Jong Seong
JS
Park
Tae Ho
TH
Park
Young Dae
YD
Kim
Kwang Soo
KS
Cha
Jin Yeong
JY
Han