31P MRS of heart grafts provides metabolic markers of early dysfunction.
OBJECTIVE
Early graft failure (EGF) is a life-threatening event still accounting for a significant percentage of early deaths after heart transplantation. We tested whether selected metabolic markers, including high-energy phosphate concentrations measured ex vivo in pre-transplant heart grafts by (31)P magnetic resonance spectroscopy (MRS) are related with early post-transplant outcome.


METHODS
During a 3-year period, 26 heart grafts harvested in the vicinity of the transplantation centre were studied. Evaluation of transplantability was done conventionally. (31)P MRS was performed ex vivo approximately 60min after aortic cross-clamp to quantify ATP, P(i) and PCr concentration ratios. A MRS-score was defined as a combination of intracellular pH (pHi) and the PCr/P(i) ratio. EGF was defined as the need to abnormally extend circulatory support or to use more than two inotropes before weaning the patient from CPB after transplantation. The grafts were attributed to three groups as follows: A1, transplanted with uneventful outcome (n=14); A2, transplanted with subsequent EGF (n=3) and B, not suitable for transplantation (n=9).


RESULTS
Significant differences between groups existed for the following metabolic markers: PCr/ATP (P=0.013), PCr/P(i) (P=0.0004), pHi (P=0.0016) and MRS-score (P=0.0001). The sensitivity, specificity and positive likelihood ratio for EGF with a MRS-score<or=1.95 were, respectively, 100%, 86% and 7.


CONCLUSIONS
In the setting of this study, post-transplant outcome was related to the pre-transplant MRS-score of grafts evaluated ex vivo. This result might help to more securely use grafts from marginal donors.
Caus
Thierry
T
Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS 6612, Fac. Med., 27 Bd Jean Moulin, 13005 Marseille, France. tcaus@ap-hm.fr
Kober
Frank
F
Mouly-Bandini
Annick
A
Riberi
Alberto
A
Métras
Dominique R
DR
Cozzone
Patrick J
PJ
Bernard
Monique
M
D000255:Adenosine Triphosphate / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D051799:Delayed Graft Function / Q000175:diagnosis* / Q000503:physiopathology; D006321:Heart / Q000503:physiopathology; D016027:Heart Transplantation; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008875:Middle Aged; D010725:Phosphocreatine / Q000032:analysis; D010759:Phosphorus Isotopes; D010865:Pilot Projects; D011237:Predictive Value of Tests
D015415:Biomarkers; D010759:Phosphorus Isotopes; D010725:Phosphocreatine; D000255:Adenosine Triphosphate