title: Evaluation of a comprehensive cardiovascular magnetic resonance protocol in young adults late after the arterial switch operation for d-transposition of the great arteries.
abstract: BACKGROUND
  In adults with prior arterial switch operation (ASO) for d-transposition of the great arteries, the need for routine coronary artery assessment and evaluation for silent myocardial ischemia is not well defined. In this observational study we aimed to determine the value of a comprehensive cardiovascular magnetic resonance (CMR) protocol for the detection of coronary problems in adults with prior ASO for d-transposition of the great arteries.
  
  
  METHODS
  Adult ASO patients (≥18 years of age) were recruited consecutively. Patients underwent a comprehensive stress perfusion CMR protocol that included measurement of biventricular systolic function, myocardial scar burden, coronary ostial assessment and myocardial perfusion during vasodilator stress by perfusion CMR. Single photon emission computed tomography (SPECT) was performed on the same day as a confirmatory second imaging modality. Stress studies were visually assessed for perfusion defects (qualitative analysis). Additionally, myocardial blood flow was quantitatively analysed from mid-ventricular perfusion CMR images. In unclear cases, CT coronary angiography or conventional angiography was done.
  
  
  RESULTS
  Twenty-seven adult ASO patients (mean age 23 years, 85% male, 67% with a usual coronary pattern; none with a prior coronary artery complication) were included in the study. CMR stress perfusion was normal in all 27 patients with no evidence of inducible perfusion defects. In 24 cases the coronary ostia could conclusively be demonstrated to be normal. There was disagreement between CMR and SPECT for visually-assessed perfusion defects in 54% of patients with most disagreement due to false positive SPECT.
  
  
  CONCLUSIONS
  Adult ASO survivors in this study had no CMR evidence of myocardial ischemia, scar or coronary ostial abnormality. Compared to SPECT, CMR provides additional valuable information about the coronary artery anatomy. The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia. In this situation it is likely that routine evaluation with stress CMR is unnecessary.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tobler
authors.forename: Manish
authors.initials: M
authors.lastname: Motwani
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Wald
authors.forename: Susan L
authors.initials: SL
authors.lastname: Roche
authors.forename: Flavia
authors.initials: F
authors.lastname: Verocai
authors.forename: Robert M
authors.initials: RM
authors.lastname: Iwanochko
authors.forename: John P
authors.initials: JP
authors.lastname: Greenwood
authors.forename: Erwin N
authors.initials: EN
authors.lastname: Oechslin
authors.affiliation: Toronto Congenital Centre for Adults, Peter Munk Cardiac Centre, University Health Network, Toronto General Hospital, 585 University Avenue, 5 N-525, Toronto M5G 2N2, ON, Canada. andrew.crean@uhn.ca.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Crean
mesh_terms: D000328:Adult; D000367:Age Factors; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D003326:Coronary Circulation; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000473:pathology; D009864:Ontario; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D014188:Transposition of Great Vessels / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D014665:Vasodilator Agents; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult
chemical_list: D014665:Vasodilator Agents