title: Impact of Reperfusion Calcium and pH on the Resuscitation of Hearts Donated After Circulatory Death.
abstract: Hearts donated after circulatory death may represent an additional donor source. The influx of sodium and calcium ions across the sarcolemma play a central role in the pathogenesis of ischemia-reperfusion injury; however, this process may be inhibited if the initial reperfusion solution is rendered hypocalcemic and acidic. We sought to determine the calcium concentration and pH of the initial reperfusion solution that yielded optimal functional recovery of hearts donated after circulatory death during ex vivo heart perfusion.
  
  
  
  Pigs were anesthetized, mechanical ventilation was discontinued, and a 15-minute standoff period was observed after circulatory arrest. Hearts were reperfused with a normothermic cardioplegia of varying calcium concentrations (part 1 [50 μmol/L, n = 4; 220 μmol/L, n = 9; 500 μmol/L, n = 4; and 1,250 μmol/L, n = 5]) and pH (part 2 [7.9, n = 5; 7.4, n = 9; 6.9, n = 8; and 6.4, n = 6]). Myocardial function was then assessed in a physiologic working model 1 hour after initiation of normothermic ex vivo heart perfusion.
  
  
  
  The calcium concentration and pH of the cardioplegic solution affected the development of myocardial edema (part 1: 50 μmol/L = 5.8% ± 0.9%; 220 μmol/L = 4.3% ± 0.4%; 500 μmol/L = 7.0% ± 0.6%; and 1,250 μmol/L = 6.6% ± 0.8% weight gain, p = 0.015; part 2: 7.9 = 3.6% ± 0.4%, 7.4 = 4.3% ± 0.4%, 6.9 = 3.7% ± 0.6%, and 6.4 = 6.4% ± 1.3% weight gain, p = 0.056) and the recovery of myocardial function (cardiac index part 1: 50 μmol/L = 2.6 ± 0.6; 220 μmol/L = 6.0 ± 0.8; 500 μmol/L = 2.3 ± 0.5; and 1,250 μmol/L = 1.9 ± 0.6 mL · m-1· g-1, p < 0.001; part 2: 7.9 = 1.5 ± 0.7; 7.4 = 6.0 ± 0.8; 6.9 = 8.4 ± 1.8; and 6.4 = 3.1 ± 0.8 mL · m-1· g-1, p = 0.003) during ex vivo heart perfusion.
  
  
  
  Initial reperfusion of hearts donated after circulatory death with a hypocalcemic and moderately acidic cardioplegia minimizes edema and optimizes functional recovery during subsequent ex vivo heart perfusion.
authors.affiliation: Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada; Department of Surgery, University of Alberta, Edmonton, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: White
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada.
authors.forename: Emma
authors.initials: E
authors.lastname: Avery
authors.affiliation: Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: Alison
authors.initials: A
authors.lastname: Müller
authors.affiliation: Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: Sanaz
authors.initials: S
authors.lastname: Hatami
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada.
authors.forename: Hoa
authors.initials: H
authors.lastname: Le
authors.affiliation: Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Thliveris
authors.affiliation: Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Arora
authors.affiliation: Anesthesia and Perioperative Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Trevor
authors.initials: T
authors.lastname: Lee
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada.
authors.forename: Ian
authors.initials: I
authors.lastname: Dixon
authors.affiliation: National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada.
authors.forename: Ganghong
authors.initials: G
authors.lastname: Tian
authors.affiliation: Department of Surgery, University of Alberta, Edmonton, Canada; Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: Jayan
authors.initials: J
authors.lastname: Nagendran
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada.
authors.forename: Larry
authors.initials: L
authors.lastname: Hryshko
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface Research Center, Winnipeg, Manitoba, Canada; Department of Surgery, University of Alberta, Edmonton, Canada; Department of Physiology, University of Alberta, Edmonton, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada. Electronic address: dhfreed@ualberta.ca.
authors.forename: Darren
authors.initials: D
authors.lastname: Freed
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002314:Cardioplegic Solutions / Q000494:pharmacology*; D004195:Disease Models, Animal; D006324:Heart Arrest, Induced / Q000379:methods*; D016027:Heart Transplantation; D006863:Hydrogen-Ion Concentration; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism*; D013552:Swine; D009927:Tissue and Organ Procurement
chemical_list: D002314:Cardioplegic Solutions; D002118:Calcium