BACKGROUND: Previously, the inhibition of coronary restenosis with Abciximab (ReoPro (R) ) -coated stent in a porcine model was reported. ReoPro (R) inhibits platelet aggregation, the proliferation of vascular smooth muscle cells and the inflammatory reaction. METHODS: A prospective randomized trial was performed to compare two types of stent for revascularization in the native coronary artery. The primary effective end points were major adverse coronary events (MACE) : cardiac death, acute myocardial infarction, target vessel revascularization (TVR) and restenosis at the 6-month clinical and angiographic follow-ups. RESULTS: One hundred and fifty-five patients were enrolled between August 2001 and June 2003. The mean ages (56.0 +/- 10.0 vs. 56.9 +/- 10.8 years), baseline diameter of stenosis and minimal luminal diameter were no different between the two groups. There was one myocardial infarction and revascularization during the hospital stay in control stent group. During the clinical follow-up there were two myocardial infarctions in control group. Follow-up coronary angiograms were performed in 62.3% (48/77) and 65.4% (51/78) of the coated and control groups, respectively. The diameter of stenosis and late loss were significantly less in the ReoPro (R) -coated stent group compared with the controls (16.4 +/- 5.8% vs. 34.3 +/- 6.1%, p=0.009; and 0.33 +/- 0.28 mm vs. 0.88 +/- 0.41 mm; p=0.002). The restenosis and TVR rates of the ReoPro (R) -coated stent were relatively lower compared with the control stent [14.6% (7/48) vs. 29.4% (15/51), p=0.062; and 9.2% (7/76) vs. 14.7% (11/75) ; p=0.327]. CONCLUSION: A ReoPro (R) -coated stent is safe, and may be effective in the prevention of coronary restenosis.
Antibodies, Monoclonal/pharmacokinetics/*therapeutic use ; Coated Materials, Biocompatible/pharmacokinetics/*therapeutic use ; Coronary Arteriosclerosis/*surgery ; Coronary Restenosis/epidemiology/prevention & control ; Female ; Humans ; Immunoglobulins, Fab/*therapeutic use ; Korea/epidemiology ; Male ; Middle Aged ; Platelet Aggregation Inhibitors/pharmacokinetics/*therapeutic use ; Platelet Glycoprotein GPIIb-IIIa Complex/antagonists & inhibitors ; Prospective Studies ; Research Support, Non-U.S. Gov't ; *Stents

PURPOSE: Clopidogrel is a prodrug that requires transformation into an active metabolite by cytochrome P450 (CYP) in the liver in order to irreversibly inhibit the P2Y12 adenosine diphosphate platelet receptor. CYP2C19 polymorphism has been reported to correlate with reduced antiplatelet activity of clopidogrel in coronary artery disease. We assessed the association between CYP2C19 polymorphism and clopidogrel resistance in patients with cerebrovascular disease. MATERIALS AND METHODS: We retrospectively gathered data from patients who experienced cerebrovascular disease, received clopidogrel, and were tested for clopidogrel resistance and CYP2C19 polymorphism. Clopidogrel resistance was tested by the VerifyNow P2Y12 system, and the CYP2C19 polymorphism was tested by the Seeplex CYP2C19 ACE Genotyping system. Clopidogrel resistance was expressed in P2Y12 reaction units (PRU) and percent inhibition. High PRU and low percent inhibition suggests clopidogrel resistance. CYP2C19 polymorphisms were expressed as extensive, intermediate, and poor metabolizers. Clopidogrel resistance was assessed according to the subgroup of CYP2C19 polymorphism. RESULTS: A total of 166 patients were evaluated. The PRU values of extensive CYP2C19 metabolizers (195.0+/-84.9) were significantly lower than those of intermediate and poor metabolizers (237.9+/-88.0, 302.2+/-58.9). The percent inhibition of extensive metabolizers (44.6+/-21.8) was significantly higher than that of intermediate and poor metabolizers (30.5+/-21.5, 14.0+/-13.4). CONCLUSION: Intermediate and poor metabolizing CYP2C19 polymorphism is associated with reduced clopidogrel antiplatelet activity in patients with cerebrovascular disease. The clinical implications of this finding require further investigation.
Aged ; Aryl Hydrocarbon Hydroxylases/*genetics/metabolism ; Cerebrovascular Disorders/*drug therapy/*enzymology/genetics ; Drug Resistance/genetics ; Female ; Humans ; Male ; Middle Aged ; Platelet Aggregation Inhibitors/pharmacokinetics/*therapeutic use ; Polymorphism, Single Nucleotide ; Retrospective Studies ; Ticlopidine/*analogs & derivatives/pharmacokinetics/therapeutic use

BACKGROUND: Clopidogrel has been widely used to prevent recurrent ischemia in patients with acute coronary syndrome (ACS). However, inter-individual variability in response to clopidogrel has been a problem in the clinical setting. The aim of the present study was to investigate the frequency of clopidogrel resistance and to determine the clinical, pharmacokinetic, and pharmacogenetic factors for clopidogrel resistance in Korean patients with ACS. METHODS: Clinical information, such as the underlying diseases and concurrent medications, of 114 patients with ACS who received clopidogrel therapy was studied. The degree of inhibition of platelets was assessed using the VerifyNow assay (Accumetrics, USA). The patients who showed less than 20% inhibition of platelets were defined as non-responders to clopidogrel treatment. Steady state plasma concentrations of clopidogrel were measured using HPLC/tandem mass spectrometry. CYP2C19 genotyping was also performed. RESULTS: A wide inter-individual variability was observed in platelet inhibition (0-76%); 56 patients (49%) showed less than 20% inhibition. There were no differences between the patients' history of diabetes mellitus and concurrent medications as well as the plasma concentrations of clopidogrel of the responders and non-responders. CYP2C19 variants, including CYP2C19*2 and CYP2C19*3, were more commonly observed in the non-responders than in the responders (P value<0.0001). CONCLUSIONS: The response to clopidogrel was highly variable in Korean patients with ACS. The results of the present study confirmed that the genetic polymorphism of CYP2C19 could be important in clopidogrel response. However, further studies are required to investigate other likely factors involved in clopidogrel resistance.
Acute Coronary Syndrome/complications/*drug therapy/genetics ; Adult ; Aged ; Aged, 80 and over ; Aryl Hydrocarbon Hydroxylases/antagonists & inhibitors/genetics/metabolism ; Asian Continental Ancestry Group/*genetics ; Diabetes Complications ; Drug Resistance ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Platelet Aggregation Inhibitors/blood/pharmacokinetics/*therapeutic use ; Polymorphism, Genetic ; Republic of Korea ; Ticlopidine/*analogs & derivatives/blood/pharmacokinetics/therapeutic use