Marginal donors: can older donor hearts tolerate prolonged cold ischemic storage?

Background and aims Both advanced donor age and prolonged ischemic time are significant risk factors for the 1-year mortality. However, its functional consequences have not been fully evaluated in the early-phase after transplantation; even early graft dysfunction is the main determinant of long-term outcome following transplantation. We evaluated in vivo left-ventricular (LV) cardiac and coronary vascular function of old-donor grafts after short and prolonged cold ischemic times in rats 1 h after heart transplantation. Methods The hearts were excised from young donor (3-month-old) or old donor (18-month-old) rats, stored in cold preservation solution for either 1 or 8 h, and heterotopically transplanted. Results After 1 h of ischemic period, in the old-donor group, LV pressure, maximum pressure development (dP/dt(max)), time constant of LV pressure decay (tau), LV end-diastolic pressure and coronary blood flow did not differ compared with young donors. However, endothelium-dependent vasodilatation to acetylcholine resulted in a significantly lower response of coronary blood flow in the old-donor group (33 +/- 4 vs. 51 +/- 15 %, p < 0.05). After 8 h preservation, two of the old-donor hearts showed no mechanical activity upon reperfusion. LV pressure (55 +/- 6 vs. 72 +/- 5 mmHg, p < 0.05), dP/dt(max) (899 +/- 221 vs. 1530 +/- 217 mmHg/s, p < 0.05), coronary blood flow and response to acetylcholine were significantly reduced and tau was increased in the old-donor group in comparison to young controls. Conclusions During the early-phase after transplantation, the ischemic tolerance of older-donor hearts is reduced after prolonged preservation time and the endothelium is more vulnerable to ischemia/reperfusion.