Optimizing donor heart outcome after prolonged storage with endothelial function analysis and continuous perfusion.
BACKGROUND
By minimizing tissue ischemia, continuous perfusion (CP) during organ transport may increase the safety of "marginal donors." My colleagues and I investigated whether an analysis of donor heart viability predicts recovery of grafts challenged with a 24-hour preservation interval.


METHODS
Dog hearts underwent cold static storage (CS) for 8 hours (n = 8) or 24 hours (n = 2) or CP for 24 hours with cold asanguinous, oxygenated solution (n = 8). Myocardial systolic and diastolic function and oxygen and lactate consumption were assessed at base line, during CP, and after Langendorff blood reperfusion. Base line endothelial function was evaluated by the percentage transcoronary change ([coronary sinus - aorta]/aorta) in myeloperoxidase and by platelet function and coronary flow reserve after 20 seconds of coronary artery occlusion. During CP, the endothelium was assessed by transcoronary protein release and coronary resistance. Edema was assessed by weight gain and histology.


RESULTS
Base line systolic and metabolic functions showed no relation to post-Langendorff function. Compared with CS, CP resulted in a greater recovery in systolic function (87% +/- 35% vs 65% +/- 15% of baseline; p = 0.05) and a shorter interval required for lactate consumption to exceed production (7.0 +/- 6.8 minutes vs 15.0 +/- 8.9 minutes; p = 0.06). Endothelial function was heterogeneous: coronary flow reserve, 2.7 +/- 0.7; percentage change in myeloperoxidase, -8.4% +/- 6.8%; and change in platelet function, 4.3% +/- 3.5%, as determined by thromboelastography angle at base line. Protein release during CP for 24 hours was 8.3 +/- 7.1 g. Two factors predicted more than 75% systolic pressure generation recovery: use of CP and normal endothelial function (p = 0.05; Fisher's exact test). However, CP led to edema according to histology, weight gain (72 +/- 29 g), and impaired diastolic function versus CS (end-diastolic pressure-volume relationship, 1.4 +/- 0.4 mm Hg/mL vs 0.8 +/- 0.3 mm Hg/mL; p = 0.08).


CONCLUSIONS
Better systolic function despite 16 hours' more preservation than cold storage corroborates the idea that CP supports aerobic metabolism at physiologically important levels. Viability analysis focused on endothelial function and identified organs that were able to tolerate this 24-hour preservation interval.
University of Maryland School of Medicine and Veterans Affairs Medical Center at Baltimore, Division of Cardiac Surgery, Baltimore, Maryland, USA. rposton@smail.umaryland.edu
Robert S
RS
Poston
Junyan
J
Gu
Deyanira
D
Prastein
Fred
F
Gage
John W
JW
Hoffman
Michael
M
Kwon
Agnes
A
Azimzadeh
Richard N
RN
Pierson
Bartley P
BP
Griffith
D000332:Aerobiosis; D000818:Animals; D003331:Coronary Vessels / Q000502:physiology; D015925:Cryopreservation / Q000379:methods* / Q000706:statistics & numerical data; D003971:Diastole; D004285:Dogs; D004730:Endothelium, Vascular / Q000502:physiology; D004734:Energy Metabolism; D006321:Heart / Q000502:physiology*; D016027:Heart Transplantation; D007773:Lactates / Q000378:metabolism; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism; D009926:Organ Preservation / Q000379:methods* / Q000706:statistics & numerical data; D019188:Organ Preservation Solutions / Q000494:pharmacology; D009929:Organ Size; D010101:Oxygen Consumption; D009195:Peroxidase / Q000032:analysis; D013599:Systole; D013997:Time Factors; D014019:Tissue Donors; D016277:Ventricular Function, Left
D007773:Lactates; D019188:Organ Preservation Solutions; D009195:Peroxidase