title: Relationship between aspirin/clopidogrel resistance and intra-stent thrombi assessed by follow-up optical coherence tomography after drug-eluting stent implantation.
abstract: OBJECTIVE
  No data exist regarding the relationship between aspirin/clopidogrel resistance and intra-stent thrombi on follow-up optical coherence tomography (OCT) after drug-eluting stent (DES) implantation. The purpose of this study was to evaluate the relationship between aspirin/clopidogrel resistance and intra-stent thrombi on the follow-up OCT in DES-treated patients.
  
  
  RESULTS
  A total of 308 DES-treated patients who underwent follow-up OCT and simultaneous measurement of aspirin reaction unit (ARU) and P2Y12 reaction unit (PRU) using the VerifyNow assay system were selected for the study. Aspirin and clopidogrel resistance were defined as ARU ≥550 and PRU ≥275, respectively. Intra-stent thrombi were detected in 29 patients (9.4%). The mean time interval from DES implantation to OCT was 195 ± 133 days (202.9 ± 103.0 days for patients with intra-stent thrombi vs. 194.7 ± 136.0 days for patients without intra-stent thrombi; P = 0.750). There were no significant differences between patients with and without intra-stent thrombi with regard to the incidence of aspirin resistance (13.8 vs. 11.1%, respectively; P = 0.630) or clopidogrel resistance (72.4 vs. 50.5%, respectively; P = 0.056). The percentage of uncovered struts was 17.9 ± 15.8% in patients with intra-stent thrombi and 12.7 ± 17.3% in patients without intra-stent thrombi (P = 0.098). Stent length was significantly longer in patients with intra-stent thrombi (22.9 ± 6.0 vs. 19.4 ± 5.0 mm, P = 0.006). Multivariate logistic regression analysis showed that stent length (odds ratio = 1.152, 95% confidential interval 1.025-1.295; P = 0.017) was the only independent risk factor for the presence of intra-stent thrombi on OCT.
  
  
  CONCLUSIONS
  This OCT study suggested that the presence of intra-stent thrombi may not be associated with aspirin/clopidogrel resistance in DES-treated patients.
authors: Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Junbeom
authors: J
authors: Park
authors: Dong-Ho
authors: DH
authors: Shin
authors: Byeong-Keuk
authors: BK
authors: Kim
authors: Ae-Young
authors: AY
authors: Her
authors: Yong Hoon
authors: YH
authors: Kim
authors: Hyun Hee
authors: HH
authors: Choi
authors: Jung-Sun
authors: JS
authors: Kim
authors: Young-Guk
authors: YG
authors: Ko
authors: Donghoon
authors: D
authors: Choi
authors: Yangsoo
authors: Y
authors: Jang
authors: Myeong-Ki
authors: MK
authors: Hong
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000379:methods; D001241:Aspirin / Q000008:administration & dosage; D000077144:Clopidogrel; D015331:Cohort Studies; D016001:Confidence Intervals; D017023:Coronary Angiography / Q000379:methods; D003328:Coronary Thrombosis / Q000000981:diagnostic imaging / Q000628:therapy*; D004351:Drug Resistance; D054855:Drug-Eluting Stents / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D011475:Prosthesis Failure; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013927:Thrombosis / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin
keywords: Intra-stent thrombi; Optical coherence tomography; Platelet resistance