Hearts Preserved in Somah at Sub-normothermia Demonstrate Rapid Functional Restoration and Are Less Likely To Develop Heart Failure Upon Transplantation

PurposeHeart transplant patients can develop early postoperative clinical heart failure (HF), due to hypothermic storage injury. Prevention of hypothermic injury by preserving hearts at higher temperature may help address this issue. We have demonstrated physiological superiority of hearts preserved in new, rationally designed Somah solution than in Celsior; Somah-preserved hearts show superior viability when stored at 21°C than at hypothermia. We hypothesized that hearts stored in Somah at sub-normothermia are more readily functionally revivable because of prevention of hypothermic injury and maintenance of high-energy phosphates (HEP); such hearts are less likely to develop early HF post-transplant.MethodsPorcine hearts were stored in Somah at 4, 13, 21°C (n=5). After 5-hrs, biopsies were taken for EM and tissue HEP; hearts were reanimated and functionally evaluated with trans-esophageal echo (TEE). Creatinine kinase (CK) and troponin-I (cTnI) release was assessed during storage and upon reanimation.ResultsAll hearts were edema-free by EM and weight, post storage. Ratios (intraoperative vs in vitro) of mean thickness of LV anterior and septal walls were 1.01, 0.9, 0.99 and 1.05, 0.95, 1.08 respectively; HEP levels were 55.7±5.1, 68.4±11.0 and 81.5 ± 19.8 nM/mg tissue respectively; mean cardiomyocyte mitochondrial ischemic scores (by EM) were 0.09±0.20, 0.17±0.03, 0.07±0.02 respectively; upon reanimation, the release of CK and cTnI were 250.1±140.6, 45.7±18.9 and 36.6±11.3 U/L and 10.48±0.58, 4.713±0.81, 6.210±2.36 U/L respectively, in 4, 13 and 21°C groups. Stimulatory interventions varied inversely to storage temperature. The % fractional area change (%FAC; by Echo) was higher at 13/21°C (39.2±8.6, 42.9±13.1) compared to 4°C group (%FAC=16.33±2.6). Ejection fraction was higher (p<0.001) in 21oC hearts, and maximum cardiac output was 1.23±0.05, 1.93±0.36 and 2.1±0.3 L/min in 4, 13 and 21°C groups respectively.ConclusionVigorous metabolism, better functionality upon in vitro reanimation, lesser probability of enduring IRI-dependent damage and lesser requirements for stimulatory interventions confirm our hypothesis that, hearts stored in Somah at 21oC were more likely to rapidly regain robust functionality translating into lesser likelihood of early post-transplant HF. PurposeHeart transplant patients can develop early postoperative clinical heart failure (HF), due to hypothermic storage injury. Prevention of hypothermic injury by preserving hearts at higher temperature may help address this issue. We have demonstrated physiological superiority of hearts preserved in new, rationally designed Somah solution than in Celsior; Somah-preserved hearts show superior viability when stored at 21°C than at hypothermia. We hypothesized that hearts stored in Somah at sub-normothermia are more readily functionally revivable because of prevention of hypothermic injury and maintenance of high-energy phosphates (HEP); such hearts are less likely to develop early HF post-transplant. Heart transplant patients can develop early postoperative clinical heart failure (HF), due to hypothermic storage injury. Prevention of hypothermic injury by preserving hearts at higher temperature may help address this issue. We have demonstrated physiological superiority of hearts preserved in new, rationally designed Somah solution than in Celsior; Somah-preserved hearts show superior viability when stored at 21°C than at hypothermia. We hypothesized that hearts stored in Somah at sub-normothermia are more readily functionally revivable because of prevention of hypothermic injury and maintenance of high-energy phosphates (HEP); such hearts are less likely to develop early HF post-transplant. MethodsPorcine hearts were stored in Somah at 4, 13, 21°C (n=5). After 5-hrs, biopsies were taken for EM and tissue HEP; hearts were reanimated and functionally evaluated with trans-esophageal echo (TEE). Creatinine kinase (CK) and troponin-I (cTnI) release was assessed during storage and upon reanimation. Porcine hearts were stored in Somah at 4, 13, 21°C (n=5). After 5-hrs, biopsies were taken for EM and tissue HEP; hearts were reanimated and functionally evaluated with trans-esophageal echo (TEE). Creatinine kinase (CK) and troponin-I (cTnI) release was assessed during storage and upon reanimation. ResultsAll hearts were edema-free by EM and weight, post storage. Ratios (intraoperative vs in vitro) of mean thickness of LV anterior and septal walls were 1.01, 0.9, 0.99 and 1.05, 0.95, 1.08 respectively; HEP levels were 55.7±5.1, 68.4±11.0 and 81.5 ± 19.8 nM/mg tissue respectively; mean cardiomyocyte mitochondrial ischemic scores (by EM) were 0.09±0.20, 0.17±0.03, 0.07±0.02 respectively; upon reanimation, the release of CK and cTnI were 250.1±140.6, 45.7±18.9 and 36.6±11.3 U/L and 10.48±0.58, 4.713±0.81, 6.210±2.36 U/L respectively, in 4, 13 and 21°C groups. Stimulatory interventions varied inversely to storage temperature. The % fractional area change (%FAC; by Echo) was higher at 13/21°C (39.2±8.6, 42.9±13.1) compared to 4°C group (%FAC=16.33±2.6). Ejection fraction was higher (p<0.001) in 21oC hearts, and maximum cardiac output was 1.23±0.05, 1.93±0.36 and 2.1±0.3 L/min in 4, 13 and 21°C groups respectively. All hearts were edema-free by EM and weight, post storage. Ratios (intraoperative vs in vitro) of mean thickness of LV anterior and septal walls were 1.01, 0.9, 0.99 and 1.05, 0.95, 1.08 respectively; HEP levels were 55.7±5.1, 68.4±11.0 and 81.5 ± 19.8 nM/mg tissue respectively; mean cardiomyocyte mitochondrial ischemic scores (by EM) were 0.09±0.20, 0.17±0.03, 0.07±0.02 respectively; upon reanimation, the release of CK and cTnI were 250.1±140.6, 45.7±18.9 and 36.6±11.3 U/L and 10.48±0.58, 4.713±0.81, 6.210±2.36 U/L respectively, in 4, 13 and 21°C groups. Stimulatory interventions varied inversely to storage temperature. The % fractional area change (%FAC; by Echo) was higher at 13/21°C (39.2±8.6, 42.9±13.1) compared to 4°C group (%FAC=16.33±2.6). Ejection fraction was higher (p<0.001) in 21oC hearts, and maximum cardiac output was 1.23±0.05, 1.93±0.36 and 2.1±0.3 L/min in 4, 13 and 21°C groups respectively. ConclusionVigorous metabolism, better functionality upon in vitro reanimation, lesser probability of enduring IRI-dependent damage and lesser requirements for stimulatory interventions confirm our hypothesis that, hearts stored in Somah at 21oC were more likely to rapidly regain robust functionality translating into lesser likelihood of early post-transplant HF. Vigorous metabolism, better functionality upon in vitro reanimation, lesser probability of enduring IRI-dependent damage and lesser requirements for stimulatory interventions confirm our hypothesis that, hearts stored in Somah at 21oC were more likely to rapidly regain robust functionality translating into lesser likelihood of early post-transplant HF.