title: Influence of microvascular obstruction on regional myocardial deformation in the acute phase of myocardial infarction: a speckle-tracking echocardiography study.
abstract: BACKGROUND
  In the acute phase of myocardial infarction (MI), infarct size and microvascular obstruction (MVO) are important prognostic factors for cardiovascular outcome. MI size is a major determinant of myocardial function, but the specific effect of MVO is less documented. The aim of this study was to evaluate the impact of MVO on longitudinal myocardial strain assessed by speckle-tracking echocardiography.
  
  
  METHODS
  Speckle-tracking echocardiography and contrast-enhanced cardiac magnetic resonance studies were performed in 69 patients 72 hours after first acute MI. Segmental and global longitudinal systolic strain (εL) was measured using speckle-tracking echocardiography. Transmural extent of MI, MI size, and the presence or absence of MVO were assessed using contrast-enhanced cardiac magnetic resonance. Left ventricular (LV) ejection fraction was assessed at 6 months using echocardiography.
  
  
  RESULTS
  The mean infarct size was 23 ± 13% of LV mass. MVO was present in 64% of patients. MVO was significantly associated with εL impairment (-7.8 ± 4.9% vs -16.3 ± 6.4%, P < .001), and εL remained significantly worse in MVO-positive segments after adjustment for transmural extent of MI. A εL value > -12.5% predicted the presence of MVO with 83% sensitivity and 75% specificity. On multivariate analysis, global εL and MI size, but not MVO, were identified as independent predictors of LV ejection fraction at follow-up (β = -0.9, P = .023, and β = -0.2, P = .034, respectively).
  
  
  CONCLUSIONS
  In the acute phase of MI, segmental and global εL is significantly altered by the presence of MVO, in addition to MI size. However, MI size but not MVO independently predicts LV ejection fraction at follow-up.
authors.affiliation: Centre d'Investigation Clinique de Lyon (CIC) et Service d'Explorations Fonctionnelles Cardiovasculaires, Groupement Hospitalier Est, Lyon, France; INSERM UMR-1060, CarMeN Laboratory, Université Claude Bernard Lyon 1, Lyon, France. Electronic address: cyrille.bergerot@chu-lyon.fr.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Bergerot
authors.affiliation: Centre d'Investigation Clinique de Lyon (CIC) et Service d'Explorations Fonctionnelles Cardiovasculaires, Groupement Hospitalier Est, Lyon, France; INSERM UMR-1060, CarMeN Laboratory, Université Claude Bernard Lyon 1, Lyon, France.
authors.forename: Nathan
authors.initials: N
authors.lastname: Mewton
authors.affiliation: Centre d'Investigation Clinique de Lyon (CIC) et Service d'Explorations Fonctionnelles Cardiovasculaires, Groupement Hospitalier Est, Lyon, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Lacote-Roiron
authors.affiliation: Centre d'Investigation Clinique de Lyon (CIC) et Service d'Explorations Fonctionnelles Cardiovasculaires, Groupement Hospitalier Est, Lyon, France.
authors.forename: Laura
authors.initials: L
authors.lastname: Ernande
authors.affiliation: Centre d'Investigation Clinique de Lyon (CIC) et Service d'Explorations Fonctionnelles Cardiovasculaires, Groupement Hospitalier Est, Lyon, France; INSERM UMR-1060, CarMeN Laboratory, Université Claude Bernard Lyon 1, Lyon, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Ovize
authors.affiliation: CREATIS-LRMN, CNRS UMR 5220 - INSERM U630 - Université Claude Bernard Lyon 1, Lyon, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Croisille
authors.affiliation: INSERM UMR-1060, CarMeN Laboratory, Université Claude Bernard Lyon 1, Lyon, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Thibault
authors.affiliation: INSERM UMR-1060, CarMeN Laboratory, Université Claude Bernard Lyon 1, Lyon, France.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Derumeaux
mesh_terms: D001783:Blood Flow Velocity; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004452:Echocardiography / Q000379:methods*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: CI; CMR; Cardiac magnetic resonance; Confidence interval; Contrast-enhanced magnetic resonance imaging; LV; LVEF; Left ventricular; Left ventricular ejection fraction; Longitudinal systolic strain; MI; MVO; Microvascular obstruction; Myocardial infarction; ST-segment elevation myocardial infarction; STE; STEMI; Speckle-tracking echocardiography; TME; Transmural extent; ε(L)