title: Quantitative optical frequency domain imaging assessment of in-stent structures in patients with ST-segment elevation myocardial infarction: impact of imaging sampling rate.
abstract: BACKGROUND
  The impact of the sampling rate (SR) of optical frequency domain imaging (OFDI) on quantitative assessment of in-stent structures (ISS) such as plaque prolapse and thrombus remains unexplored.
  
  
  RESULTS
  OFDI after stenting was performed in ST-segment elevation myocardial infarction (STEMI) patients using a TERUMO OFDI system (Terumo Europe, Leuven, Belgium) with 160 frames/s and pullback speed of 20 mm/s. A total of 126 stented segments were analyzed. ISS were classified as either attached or non-attached to stent area boundaries. The volume, mean area and largest area of ISS were assessed according to 4 frequencies of SR, corresponding to distances between the analyzed frames of 0.125, 0.25, 0.50 and 1.0 mm. ISS volume was calculated by integrating cross-sectional ISS areas multiplied by each sampling distance using the disk summation method. The volume and mean area of ISS became significantly larger, while the largest area became significantly smaller as sampling distance became larger (1.11 mm(2) for 0.125 mm vs. 1.00 mm(2) for 1.0 mm, P for trend=0.036). In addition, variance of difference was positively associated with increasing width of sampling distance.
  
  
  CONCLUSIONS
  Quantification of ISS is significantly influenced by the applied frequency of SR. This should be taken into account when designing future OFDI studies in which quantitative assessment of ISS is critical for the evaluation of STEMI patients.
authors.affiliation: Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Hector M
authors.initials: HM
authors.lastname: García-García
authors.forename: Il Soo
authors.initials: IS
authors.lastname: Lee
authors.forename: Nico
authors.initials: N
authors.lastname: Bruining
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D000704:Analysis of Variance; D023903:Coronary Restenosis / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D003328:Coronary Thrombosis / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D005060:Europe; D006801:Humans; D009203:Myocardial Infarction / Q000628:therapy*; D015588:Observer Variation; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D015203:Reproducibility of Results; D016037:Single-Blind Method; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome