title: Magnetic Resonance for Noninvasive Detection of Microcirculatory Disease Associated With Allograft Vasculopathy: Intracoronary Measurement Validation.
abstract: OBJECTIVE
  Cardiac allograft vasculopathy affects both epicardial and microcirculatory coronary compartments. Magnetic resonance perfusion imaging has been proposed as a useful tool to assess microcirculation mostly outside the heart transplantation setting. Instantaneous hyperemic diastolic flow velocity-pressure slope, an intracoronary physiology index, has demonstrated a better correlation with microcirculatory remodelling in cardiac allograft vasculopathy than other indices such as coronary flow velocity reserve. To investigate the potential of magnetic resonance perfusion imaging to detect the presence of microcirculatory remodeling in cardiac allograft vasculopathy, we compared magnetic resonance perfusion data with invasive intracoronary physiological indices to study microcirculation in a population of heart transplantation recipients with macrovascular nonobstructive disease demonstrated with intravascular ultrasound.
  
  
  METHODS
  We studied 8 heart transplantation recipients (mean age, 61 [12] years, 100% male) with epicardial allograft vasculopathy defined by intravascular ultrasound, nonsignificant coronary stenoses and negative visually-assessed wall-motion/perfusion dobutamine stress magnetic resonance. Quantitative stress and rest magnetic resonance perfusion data to build myocardial perfusion reserve index, noninvasively, and 4 invasive intracoronary physiological indices were determined.
  
  
  RESULTS
  Postprocessed data showed a mean (standard deviation) myocardial perfusion reserve index of 1.22 (0.27), while fractional flow reserve, coronary flow velocity reserve, hyperemic microvascular resistance and instantaneous hyperemic diastolic flow velocity-pressure slope were 0.98 (0.02), cm/s/mmHg, 2.34 (0.55) cm/s/mmHg, 2.00 (0.69) cm/s/mmHg and 0.91 (0.65) cm/s/mmHg, respectively. The myocardial perfusion reserve index correlated strongly only with the instantaneous hyperemic diastolic flow velocity-pressure slope (r=0.75; P=.033).
  
  
  CONCLUSIONS
  Myocardial perfusion reserve index derived from a comprehensive dobutamine stress magnetic resonance appears to be a reliable technique for noninvasive detection of microcirculatory coronary disease associated with cardiac allograft vasculopathy.
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain; Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain. Electronic address: jesus.gmirelis@telefonica.net.
authors.forename: Jesús G
authors.initials: JG
authors.lastname: Mirelis
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: García-Pavía
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cavero
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: González-López
authors.affiliation: Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Servicio de Cardiología, Hospital Clínico San Carlos, Madrid, Spain.
authors.forename: Mauro
authors.initials: M
authors.lastname: Echavarria-Pinto
authors.affiliation: Servicio de Radiología, Hospital Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Pastrana
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Segovia
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Oteo
authors.affiliation: Servicio de Cardiología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Alonso-Pulpón
authors.affiliation: Servicio de Cardiología, Hospital Clínico San Carlos, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
mesh_terms: D064591:Allografts / Q000098:blood supply* / Q000000981:diagnostic imaging; D006328:Cardiac Catheterization; D002316:Cardiotonic Agents; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology; D004280:Dobutamine; D016027:Heart Transplantation; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine
keywords: Cardiac allograft vasculopathy; Dobutamine stress magnetic resonance; Microcirculación; Microcirculation; Resonancia magnética de estrés con dobutamina; Vasculopatía de aloinjerto cardiaco