title: CAD detection in patients with intermediate-high pre-test probability: low-dose CT delayed enhancement detects ischemic myocardial scar with moderate accuracy but does not improve performance of a stress-rest CT perfusion protocol.
abstract: OBJECTIVE
  This study sought to compare computed tomography delayed enhancement (CTDE) against cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) for detection of ischemic scar and to test the additive value of CTDE as part of a comprehensive multidetector computed tomography (MDCT) stress-rest protocol including computed tomography perfusion (CTP) and computed tomography angiography (CTA) for the diagnosis of significant coronary artery disease (CAD).
  
  
  BACKGROUND
  CTDE has been recently described as a promising tool for noninvasive detection of myocardial scar, similarly to CMR-LGE techniques. Despite its theoretical potential as an adjunctive tool to improve MDCT accuracy for detection of CAD, its clinical performance has not been validated.
  
  
  METHODS
  One hundred five symptomatic patients with suspected CAD (age 62.0 ± 8.0 years, 67% men) underwent MDCT, CMR, and x-ray invasive coronary angiography. The MDCT protocol consisted of calcium scoring, stress CTP under adenosine 140 μg/kg/min, rest CTP + CTA, and a low-dose radiation prospective scan for detection of CTDE. CMR-LGE was used as the reference standard for assessment of scar. Functionally significant CAD was defined as the presence of ≥90% stenosis/occlusion or fractional flow reserve measurements ≤0.80 in vessels >2 mm.
  
  
  RESULTS
  CTDE had good accuracy (90%) for ischemic scar detection with low sensitivity (53%) but excellent specificity (98%). Positive and negative predictive values were 82% and 91%, respectively. On a patient-based model, MDCT protocol without integration of CTDE results had a sensitivity, specificity, and positive and negative predictive values of 90%, 81%, 80%, and 90%, respectively, for the detection of functionally significant CAD. Addition of CTDE results did not improve MDCT performance (90%, 77%, 77%, and 90%, respectively).
  
  
  CONCLUSIONS
  CTDE has moderate accuracy for detection of ischemic scar in patients with suspected CAD. Integration of CTDE into a comprehensive MDCT protocol including stress-rest CTP and CTA does not improve MDCT accuracy for detection of significant CAD in intermediate-to-high pre-test probability populations.
authors.affiliation: Cardiology Department, Centro Hospitalar de Gaia/Espinho, Vila Nova de Gaia, Portugal; Division of Imaging Sciences and Medical Engineering, King's College London, London, United Kingdom; Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Porto, Portugal. Electronic address: bettencourt.n@gmail.com.
authors.forename: Nuno
authors.initials: N
authors.lastname: Bettencourt
authors.affiliation: Cardiology Department, Centro Hospitalar de Gaia/Espinho, Vila Nova de Gaia, Portugal.
authors.forename: Nuno Dias
authors.initials: ND
authors.lastname: Ferreira
authors.affiliation: Cardiology Department, Centro Hospitalar de Gaia/Espinho, Vila Nova de Gaia, Portugal.
authors.forename: Daniel
authors.initials: D
authors.lastname: Leite
authors.affiliation: Cardiology Department, Centro Hospitalar de Gaia/Espinho, Vila Nova de Gaia, Portugal.
authors.forename: Mónica
authors.initials: M
authors.lastname: Carvalho
authors.affiliation: Cardiology Department, Centro Hospitalar de Gaia/Espinho, Vila Nova de Gaia, Portugal.
authors.forename: Wilson da Silva
authors.initials: WDS
authors.lastname: Ferreira
authors.affiliation: Georg-August-University and German Center for Cardiovascular Research (DZHK, Partner Site), Göttingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schuster
authors.affiliation: Division of Imaging Sciences and Medical Engineering, King's College London, London, United Kingdom.
authors.forename: Amedeo
authors.initials: A
authors.lastname: Chiribiri
authors.affiliation: Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Adelino
authors.initials: A
authors.lastname: Leite-Moreira
authors.affiliation: Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: José
authors.initials: J
authors.lastname: Silva-Cardoso
authors.affiliation: Division of Imaging Sciences and Medical Engineering, King's College London, London, United Kingdom.
authors.forename: Eike
authors.initials: E
authors.lastname: Nagel
authors.affiliation: Cardiology Department, Centro Hospitalar de Gaia/Espinho, Vila Nova de Gaia, Portugal.
authors.forename: Vasco
authors.initials: V
authors.lastname: Gama
mesh_terms: D000241:Adenosine; D000328:Adult; D000368:Aged; D002921:Cicatrix / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000473:pathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011829:Radiation Dosage; D012720:Severity of Illness Index; D014665:Vasodilator Agents
chemical_list: D003287:Contrast Media; D014665:Vasodilator Agents; D000241:Adenosine
keywords: CAD; CI; CMR; CTA; CTDE; CTP; FFR; LGE; MDCT; QCA; ROC; XA; cardiac magnetic resonance; computed tomography angiography; computed tomography delayed enhancement; computed tomography perfusion; confidence interval; coronary artery disease; delayed enhancement; fractional flow reserve; late gadolinium enhancement; multidetector computed tomography; quantitative coronary angiography; receiver-operating characteristic; tomography; x-ray invasive coronary angiography