title: Tissue characterization and phenotype classification in patients presenting with acute myocardial infarction: Insights from the iWonder study.
abstract: OBJECTIVE
  We sought to assess a new modality of radiofrequency intravascular ultrasound (IVUS) called iMAP-IVUS (Boston Scientific, Santa Clara, California) during the evaluation of patients presenting with high-risk acute coronary syndromes.
  
  
  BACKGROUND
  There are limited data on plaque tissue characterization and phenotype classification using iMAP-IVUS.
  
  
  METHODS
  In the iWonder study patients presenting with ST-elevation myocardial infarction (STEMI) or non-STEMI underwent three-vessel grayscale IVUS and iMAP-IVUS tissue characterization prior to percutaneous intervention. In total 385 lesions from 100 patients were divided into culprit (n = 100) and nonculprit (n = 285) lesions. Lesion phenotype was classified as (i) thin-cap fibroatheroma (iMAP-derived TCFA); (ii) thick-cap fibroatheroma; (iii) pathological intimal thickening; (iv) fibrotic plaque; and (v) fibrocalcific plaque.
  
  
  RESULTS
  Culprit lesions had smaller minimum lumen cross-sectional area (MLA) with greater plaque burden compared to non-culprit lesions. Volumetric analysis showed that culprit lesions had longer length and larger vessel and plaque volumes compared to non-culprit lesions. iMAP-IVUS revealed that culprit lesions presented more NC and fibrofatty volume, both at lesion level and at the MLA site (all P < 0.001). Any fibroatheroma was more frequently identified in culprit lesions compared with non-culprit lesions (93% vs. 78.9%, P = 0.001), anywhere within the lesion 19.0%, P < 0.001) as well as at the MLA site (18.0% vs. 9.5%, P = 0.07).
  
  
  CONCLUSIONS
  Three-vessel radiofrequency iMAP-IVUS demonstrated a greater plaque burden and higher prevalence of any fibroatheroma as well as iMAP-derived TCFAs in culprit versus non-culprit lesions in patients presenting with STEMI or non-STEMI undergoing percutaneous coronary intervention. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Interventional Cardiology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Cristiano F
authors.identifier: http://orcid.org/0000-0001-9800-8665
authors.initials: CF
authors.lastname: Souza
authors.affiliation: IVUS core laboratory, Cardiovascular Research Foundation, New York, New York.|Department of Interventional Cardiology, Columbia University Medical Center, New York, New York.
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
authors.affiliation: IVUS core laboratory, Cardiovascular Research Foundation, New York, New York.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.affiliation: IVUS core laboratory, Cardiovascular Research Foundation, New York, New York.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Matsumura
authors.affiliation: Department of Interventional Cardiology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Claudia M R
authors.initials: CMR
authors.lastname: Alves
authors.affiliation: Department of Interventional Cardiology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Antonio
authors.initials: A
authors.lastname: Carlos Carvalho
authors.affiliation: Department of Interventional Cardiology, Federal University of São Paulo, São Paulo, Brazil.|Department of Interventional Cardiology, Hospital Israelita Albert Einstein, São Paulo, Brazil.
authors.forename: Adriano
authors.initials: A
authors.lastname: Caixeta
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D000368:Aged; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005355:Fibrosis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D000072658:Non-ST Elevated Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D062645:Percutaneous Coronary Intervention; D010641:Phenotype; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012422:Rupture, Spontaneous; D000072657:ST Elevation Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000379:methods*; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000473:pathology
keywords: acute myocardial infarction; atherosclerosis; intravascular ultrasound