Abstract

Objective: Primary graft failure is responsible for 15--20% of early deaths following heart transplantation. Myocardial injury may occur as a consequence of catecholamine 'storm' at brainstem death, inadequate myocardial protection, or delayed reperfusion.

Methods: In order to assess myocardial injury prior to implantation, we investigated myocardial biopsies obtained at organ retrieval in 33 donor hearts by conventional haemotoxylin-eosin histology and immunohistochemical identification of the C5b-9 complement membrane attack complex, a validated early marker of ischaemia*. Donor and recipient records were reviewed to establish inotrope requirement and outcome. Donor hearts were assessed by inspection and haemodynamic evaluation. Acceptance criteria included normal gross morphology, filling pressures <12 mmHg, and cardiac index >2.4 L/min/m² on minimal inotropic support.

Results: All donors had normal ECG patterns. All conventional histology was normal, however 6 biopsies (18%) stained C9 positive. Of these, one heart was not implanted due to donor haemodynamic instability, and 2 patients died of primary graft failure (40% of implants). Two further patients in the C9 positive group required prolonged post-operative inotropic support. In the C9 negative group, 2 of 27 (7.4%) died of primary graft failure, compared to an overall unit 30 day survival of 90%.

Conclusions: This pilot study identifies pre-retrieval myocardial ischaemic injury as an important contributor to recipient outcome, and suggests that improved techniques to evaluate donor hearts may reduce the incidence of primary graft dysfunction.