title: Early assessment of strain echocardiography can accurately exclude significant coronary artery stenosis in suspected non-ST-segment elevation acute coronary syndrome.
abstract: BACKGROUND
  Many patients with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) do not have significant coronary artery disease. The current diagnostic approach of repeated electrocardiography and cardiac biomarker assessment requires observation for >6 to 12 hours. This strategy places a heavy burden on hospital facilities. The objective of this study was to investigate whether myocardial strain assessment by echocardiography could exclude significant coronary artery stenosis in patients presenting with suspected NSTE-ACS.
  
  
  METHODS
  Sixty-four patients presenting to the emergency department with suspected NSTE-ACS without known coronary artery disease, inconclusive electrocardiographic findings, and normal cardiac biomarkers at arrival were enrolled. Twelve-lead electrocardiography, troponin T assay, and echocardiography were performed at arrival, and all patients underwent coronary angiography. Significant coronary stenosis was defined as >50% luminal narrowing. Global myocardial peak systolic longitudinal strain was measured using speckle-tracking echocardiography. Left ventricular ejection fraction and wall motion score index were calculated.
  
  
  RESULTS
  No significant stenosis in any coronary artery was found in 35 patients (55%). Global peak systolic longitudinal strain was superior to conventional echocardiographic parameters in distinguishing patients with and without significant coronary artery stenosis (area under the curve, 0.87). Sensitivity and specificity were calculated as 0.93 and 0.78, respectively, and positive predictive value and negative predictive value as 0.74 and 0.92, respectively. Feasibility of the strain measurements was excellent, with 97% of segments analyzed.
  
  
  CONCLUSIONS
  Myocardial strain by echocardiography may facilitate the exclusion of significant coronary artery stenosis among patients presenting with suspected NSTE-ACS with inconclusive electrocardiographic findings and normal cardiac biomarkers.
authors.affiliation: Sørlandet Hospital, Arendal, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dahlslett
authors.affiliation: Sørlandet Hospital, Arendal, Norway.
authors.forename: Sigve
authors.initials: S
authors.lastname: Karlsen
authors.affiliation: Sørlandet Hospital, Arendal, Norway; St. Olavs Hospital, Trondheim, Norway.
authors.forename: Bjørnar
authors.initials: B
authors.lastname: Grenne
authors.affiliation: Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Eek
authors.affiliation: Sørlandet Hospital, Arendal, Norway.
authors.forename: Benthe
authors.initials: B
authors.lastname: Sjøli
authors.affiliation: Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Helge
authors.initials: H
authors.lastname: Skulstad
authors.affiliation: Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Otto A
authors.initials: OA
authors.lastname: Smiseth
authors.affiliation: Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Thor
authors.initials: T
authors.lastname: Edvardsen
authors.affiliation: Sørlandet Hospital, Arendal, Norway. Electronic address: harald.brunvand@sshf.no.
authors.forename: Harald
authors.initials: H
authors.lastname: Brunvand
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000000981:diagnostic imaging*; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
keywords: Acute coronary syndrome; Echocardiography; Emergency department; Myocardial strain; Speckle-tracking