Perioperative ischaemic reperfusion injury and allograft function in the early post-transplantation period

Ischaemic reperfusion injury (IRI) is an inevitable complication of heart transplantation (HTX) and is observed as a pathological finding in biopsies from transplanted allografts. The aim of this study was to evaluate the severity of IRI and determine the clinical outcomes of HTX in patients with severe IRI.

We enrolled 74 consecutive patients who had undergone HTX since 2007. Endomyocardial biopsy samples were obtained from the right ventricle of the transplanted heart. IRI was graded as 'trivial', 'mild', 'moderate' or 'severe' according to the extent of IRI-specific findings in the samples. The cohort was divided into a moderate-to-severe IRI group with 21 patients [IRI(+)] and a low-grade group with 53 patients [IRI(-)].

The frequency of mechanical circulatory support and duration of catecholamine dependence in the early postoperative period were significantly higher in the IRI(+) group compared to the IRI(-) group. However, overall survival after HTX and mid-term cardiac allograft function were not significantly different between the groups. Among perioperative factors, cardiac ischaemic time was significantly different between the groups [IRI(-) vs IRI(+), 199 ± 38 min vs 239 ± 39 min; P < 0.001]. Incremental increases in cardiac ischaemic time were correlated with increases in IRI severity. Serum troponin T levels 3 h after donor heart reperfusion was significantly correlated with cardiac ischaemic time (r = 0.418, P = 0.0007).

IRI is associated with a complicated clinical course in the early post-HTX period due to temporary deterioration of allograft function. This may be attributable to myocardial stunning caused by long donor heart ischaemic time during HTX.