title: Diagnostic and prognostic value of dobutamine thallium-201 single-photon emission computed tomography after heart transplantation.
abstract: BACKGROUND
  Cardiac allograft vasculopathy (CAV) is a major cause of mortality in heart transplant recipients. We investigated the diagnostic and prognostic value of dobutamine thallium-201 ((201)Tl) single-photon emission computed tomography (SPECT) in heart transplant recipients.
  
  
  METHODS
  We studied 47 patients (age 51.6 +/- 11.7 years, 37 men), at a mean of 34.0 +/- 21.4 months after heart transplant, who received dobutamine (201)Tl SPECT, echocardiography and coronary angiography within 1 month of each other. SPECT was considered abnormal in the presence of reversible or fixed defects in >/=2 segments. Significant CAV was defined as >/=50% luminal stenosis.
  
  
  RESULTS
  Coronary angiograms were normal in 37 patients. Non-significant CAV was detected in 1 patient and significant CAV in 9 patients. The sensitivity, specificity, positive predictive value and negative predictive value of SPECT for the detection of significant angiographic CAV were 89%, 71%, 42% and 96%, respectively. Large reversible perfusion defects (>/=6 segments) always indicated significant CAV. In patients with normal left ventricular function, a lung/heart ratio (LHR) of >/=0.37 during stress was also an independent predictor of significant CAV (odds ratio 15.5, p = 0.04). A higher stress LHR was associated with greater vessel involvement (r = 0.516, p = 0.0002). Patients with impaired left ventricular function also had higher stress and resting LHR. Over 40.3 +/- 21.9 months after the first SPECT, 1 patient developed significant angiographic CAV and another 4 had cardiac death. Large reversible perfusion defect was a significant predictor of cardiac death (p = 0.002).
  
  
  CONCLUSIONS
  Dobutamine (201)Tl SPECT is a useful method for detecting patients with significant CAV and assessing prognosis. It is reasonable and safe to design individualized surveillance intensity of coronary angiography for post-transplant patients on the basis of non-invasive monitoring of dobutamine (201)Tl testing.
authors.affiliation: Department of Nuclear Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Wu
authors.forename: Ruoh-Fang
authors.initials: RF
authors.lastname: Yen
authors.forename: Chii-Ming
authors.initials: CM
authors.lastname: Lee
authors.forename: Yi-Lwun
authors.initials: YL
authors.lastname: Ho
authors.forename: Nai-Kuan
authors.initials: NK
authors.lastname: Chou
authors.forename: Shoei-Shen
authors.initials: SS
authors.lastname: Wang
authors.forename: Por-Jau
authors.initials: PJ
authors.lastname: Huang
mesh_terms: D000328:Adult; D002316:Cardiotonic Agents; D004280:Dobutamine; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D002316:Cardiotonic Agents; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D004280:Dobutamine