title: Comprehensive dobutamine stress CMR versus echocardiography in LBBB and suspected coronary artery disease.
abstract: OBJECTIVE
  This study aimed to compare dobutamine stress cardiac magnetic resonance (DSCMR) with dobutamine stress echocardiography (DSE) in patients with left bundle branch block (LBBB) and suspected coronary artery disease (CAD).
  
  
  BACKGROUND
  Noninvasive diagnosis of CAD in patients with pre-existent LBBB is difficult because single-photon emission computed tomography and stress echocardiography both have limitations. We hypothesized that a comprehensive DSCMR examination including cine, perfusion, and late gadolinium enhancement imaging would be more accurate than DSE, thus potentially reducing the number of unnecessary invasive coronary angiograms.
  
  
  METHODS
  We prospectively evaluated 82 consecutive patients with LBBB referred to our cardiology clinic for investigation of suspected CAD. All 82 patients underwent DSE, DSCMR, and invasive quantitative coronary angiography within 14 days. We compared the diagnostic accuracy of DSE, CMR cine imaging, the additive value of first-pass perfusion, and late gadolinium enhancement. In the comprehensive examination, a positive result was adjudged as the presence of either subendocardial or transmural late gadolinium enhancement with or without inducible peri-infarct ischemia or an inducible perfusion defect corresponding to an inducible regional wall motion abnormality.
  
  
  RESULTS
  CMR cine imaging (regional wall motion abnormalities) had higher specificity, negative predictive value, and overall diagnostic accuracy than did DSE (87.5% vs. 72.9%; 80.8% vs. 67.3%; and 80.4% vs. 72.0%, respectively), although sensitivity was the same (72.0%). The addition of first-pass stress perfusion and late gadolinium enhancement (scar) further improved diagnostic confidence (sensitivity 82.4%, specificity 95.8%, positive predictive value 93.3%, negative predictive value 88.5%, and diagnostic accuracy 90.2%).
  
  
  CONCLUSIONS
  DSCMR is a safe procedure and has greater diagnostic accuracy than does DSE in assessing patients with suspected CAD and LBBB. A comprehensive examination with the addition of perfusion and late gadolinium enhancement to CMR cine imaging significantly boosted specificity and sensitivity, making DSCMR a reliable alternative to invasive quantitative coronary angiography in this group of patients.
authors.affiliation: British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Ify
authors.initials: I
authors.lastname: Mordi
authors.affiliation: Cardiovascular Imaging Research Centre, School of Medicine, University of Queensland, Brisbane, Australia.
authors.forename: Tony
authors.initials: T
authors.lastname: Stanton
authors.affiliation: British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Carrick
authors.affiliation: British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: McClure
authors.affiliation: West of Scotland Regional Heart and Lung Centre, Golden Jubilee National Hospital, Clydebank, United Kingdom.
authors.forename: Keith
authors.initials: K
authors.lastname: Oldroyd
authors.affiliation: British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; West of Scotland Regional Heart and Lung Centre, Golden Jubilee National Hospital, Clydebank, United Kingdom.
authors.forename: Colin
authors.initials: C
authors.lastname: Berry
authors.affiliation: British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; West of Scotland Regional Heart and Lung Centre, Golden Jubilee National Hospital, Clydebank, United Kingdom. Electronic address: niko.tzemos@glasgow.ac.uk.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Tzemos
mesh_terms: D002316:Cardiotonic Agents / Q000008:administration & dosage; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology; D004280:Dobutamine / Q000008:administration & dosage; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine
keywords: bundle branch block; cardiac magnetic resonance; coronary disease; stress echocardiography