title: Effect of rapamycin therapy on coronary artery physiology early after cardiac transplantation.
abstract: BACKGROUND
  Rapamycin has been shown to reduce anatomical evidence of cardiac allograft vasculopathy, but its effect on coronary artery physiology is unknown.
  
  
  METHODS
  Twenty-seven patients without angiographic evidence of coronary artery disease underwent measurement of fractional flow reserve (FFR), coronary flow reserve (CFR), and the index of microcirculatory resistance (IMR) within 8 weeks and then 1 year after transplantation using a pressure sensor/thermistor-tipped guidewire. Measurements were compared between consecutive patients who were on rapamycin for at least 3 months during the first year after transplantation (rapamycin group, n = 9) and a comparable group on mycophenolate mofetil (MMF) instead (MMF group, n = 18).
  
  
  RESULTS
  At baseline, there was no significant difference in FFR, CFR, or IMR between the 2 groups. At 1 year, FFR declined significantly in the MMF group (0.87 +/- 0.06 to 0.82 +/- 0.06, P = .009) but did not change in the rapamycin group (0.91 +/- 0.05 to 0.89 +/- 0.04, P = .33). Coronary flow reserve and IMR did not change significantly in the MMF group (3.1 +/- 1.7 to 3.2 +/- 1.0, P = .76; and 27.5 +/- 18.1 to 19.1 +/- 7.6, P = .10, respectively) but improved significantly in the rapamycin group (2.3 +/- 0.8 to 3.8 +/- 1.4, P < .03; and 27.0 +/- 11.5 to 17.6 +/- 7.5, P < .03, respectively). Multivariate regression analysis revealed that rapamycin therapy was an independent predictor of CFR and FFR at 1 year after transplantation.
  
  
  CONCLUSIONS
  Early after cardiac transplantation, rapamycin therapy is associated with improved coronary artery physiology involving both the epicardial vessel and the microvasculature.
authors.affiliation: Department of Internal Medicine, Stanford University Medical Center, Stanford, CA 94305, USA.
authors.forename: Seema S
authors.initials: SS
authors.lastname: Sinha
authors.forename: Michael X
authors.initials: MX
authors.lastname: Pham
authors.forename: Randall H
authors.initials: RH
authors.lastname: Vagelos
authors.forename: Mark G
authors.initials: MG
authors.lastname: Perlroth
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Hunt
authors.forename: David P
authors.initials: DP
authors.lastname: Lee
authors.forename: Hannah A
authors.initials: HA
authors.lastname: Valantine
authors.forename: Alan C
authors.initials: AC
authors.lastname: Yeung
authors.forename: William F
authors.initials: WF
authors.lastname: Fearon
mesh_terms: D003324:Coronary Artery Disease / Q000188:drug therapy*; D003331:Coronary Vessels / Q000187:drug effects*; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D020123:Sirolimus / Q000494:pharmacology*; D014184:Transplantation, Homologous; D016896:Treatment Outcome
chemical_list: D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid; D020123:Sirolimus