Risk factors for heart transplant survival with greater than 5 h of donor heart ischemic time

Abstract

Objective Implantation of donor hearts with prolonged ischemic times is associated with worse survival. We sought to identify risk factors that modulate the effects of prolonged preservation. Methods Retrospective review of the United Network for Organ Sharing database (2000–2018) to identify transplants with >5 (n = 1526) or ≤5 h (n = 35,733) of donor heart preservation. In transplanted hearts preserved for >5 h, Cox‐proportional hazards identify modifiers for survival. Results Compared to ≤5 h, transplanted patients with >5 h of preservation spent less time in status 1B (76 ± 160 vs. 85 ± 173 days, p = .027), more commonly had ischemic cardiomyopathy (42.3% vs. 38.3%, p = .002), and less commonly received a blood type O heart (45.4% vs. 50.8%, p < .001). Longer heart preservation time was associated with a higher incidence of postoperative stroke (4.5% vs. 2.5%, p < .001), and dialysis (16.4% vs. 10.6%, p < .001). Prolonged preservation was associated with a greater likelihood of death from primary graft dysfunction (2.8% vs. 1.5%, p < .001) but there was no difference in death from acute (2.0% vs. 1.7%, p = .402) or chronic rejection (2.0% vs. 1.9%, p = .618). In transplanted patients with >5 h of heart preservation, multivariable analysis identified greater mortality with ischemic cardiomyopathy etiology (hazard ratio [HR] = 1.36, p < 0.01), pre‐transplant dialysis (HR = 1.84, p < .01), pre‐transplant extracorporeal membrane oxygenation (ECMO, HR = 2.36, p = .09), and O blood type donor hearts (HR = 1.35, p < .01). Conclusion Preservation time >5 h is associated with worse survival. This mortality risk is further amplified by preoperative dialysis and ECMO, ischemic cardiomyopathy etiology, and use of O blood type donor hearts.

Implication of prolonged ischemic time of donor heart for the heart transplant recipients

“…Tang et al 1 demonstrated that a pre-transplant use of extracorporeal membrane oxygenation, pre-transplant dependence on dialysis, and ischemic etiology for heart failure was associated with further risk of mortality in the heart transplant recipients who received donor hearts with prolonged ischemic time. Several concerns have been raised.…”

“…In their study, patients using donor hearts with >5 h of preservation time were sicker than those with the shorter ischemic time of the donor's hearts. 1 It might be better to perform multivariate analysis to validate independence in the prognostic impact of prolonged ischemic time by adjusting for other potential confounders.…”

“…Survival for an ischemic time >5 h was superior in the authors' geographic region compared with other regions, despite several risk factors that were statistically not different between the regions. 1 Detailed description and assessment of their unique management protocol for the recipients receiving donor hearts with prolonged ischemic time would be useful and educative for the many struggling clinicians.…”

Response to letter by Miyauchi et al

“…For the more than five donor heart group, this revealed independent factors associated with mortality to be pretransplant extracorporeal membrane oxygenation (ECMO), pretransplant dialysis, ischemic etiology for heat failure and O blood type donor hearts. 1 While these recipient and donor risk factors are largely nonmodifiable, there are developing molecular therapeutic strategies to increase the resilience of donor hearts to ischemic injury during preservation as well as introduction into a hostile recipient. Research is currently underway to inhibit inflammatory (e.g., inflammasome) and cell death pathways that occur during cold storage and in the setting of deceased cardiac death donation.…”

“…A multivariable analysis was then performed on variables found to be significant on univariable analysis. For the more than five donor heart group, this revealed independent factors associated with mortality to be pretransplant extracorporeal membrane oxygenation (ECMO), pretransplant dialysis, ischemic etiology for heat failure and O blood type donor hearts 1 …”