title: Multislice computed tomography to rule out coronary allograft vasculopathy in heart transplant patients.
abstract: BACKGROUND
  This study assessed if invasive coronary angiogram (CA) could be replaced by multislice (64- or 256-row) computed tomography (MSCT) to systematically rule out coronary allograft vasculopathy in heart transplant patients.
  
  
  METHODS
  Electrocardiogram-gated contrast-enhanced MSCT (64-row for the first 25 patients and 256-row for the others) was compared with CA. MSCT parameters, adapted to the patient's weight, included 120 kV, 800 mAs, 0.625-mm slice thickness, and 0.42/0.27-second rotation time. The primary end point was the negative predictive value (NPV) of MSCT for the detection of significant (>50%) coronary stenosis. Secondary end points were the comparison of X-ray (mSv) and iodine contrast agent (ml) exposures.
  
  
  RESULTS
  The study prospectively included 102 patients (mean age, 53±14 years). Transplantation occurred 6±5 years before inclusion. At CA, 41.8% had stenosis ≤50% and 8% had stenosis>50%. Among the 1,308 angiographic coronary segments ≥1.5 mm, 1,250 (95.6%) were evaluable by MSCT. The NPV of MSCT was 96.6% by patient analysis and 99.7% by segment analysis. The positive predictive value (PPV) was 45.5%. The total volume of contrast agent was 139±43 vs 91±12 vs 56±19 ml (p<0.05) with 64-row MSCT, 256-row MSCT, and CA, respectively. The effective radiation dose was higher using retrospective gating (17.8±5.5 mSv, p<0.05), but similar with prospective gating (6.2±1.9 mSv, p = 0.571) compared with CA (6.0±3.5 mSv).
  
  
  CONCLUSIONS
  Newer generations of MSCT (64- or 256-row) have a good NPV and may represent an alternative to invasive CA to rule out significant (>50%) coronary vasculopathy in heart transplant patients, despite a low PPV.
authors.affiliation: Interventional Cardiology Unit, Pitié-Salpétrière Hospital, Paris, France. olivier.barthelemy@psl.aphp.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Barthélémy
authors.forename: Dan
authors.initials: D
authors.lastname: Toledano
authors.forename: Shaïda
authors.initials: S
authors.lastname: Varnous
authors.forename: Flor
authors.initials: F
authors.lastname: Fernandez
authors.forename: Rehda
authors.initials: R
authors.lastname: Boutekadjirt
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ricci
authors.forename: Gerard
authors.initials: G
authors.lastname: Helft
authors.forename: Claude
authors.initials: C
authors.lastname: Le Feuvre
authors.forename: Iradj
authors.initials: I
authors.lastname: Gandjbakhch
authors.forename: Jean Philippe
authors.initials: JP
authors.lastname: Metzger
authors.forename: Alain
authors.initials: A
authors.lastname: Pavie
authors.forename: Philippe
authors.initials: P
authors.lastname: Cluzel
mesh_terms: D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014184:Transplantation, Homologous