Prevention of Ischemic Myocardial Contracture Through Hemodynamically Controlled DCD

Abstract

Purpose: Ischemic myocardial contracture (IMC) or “stone heart” is a condition with rapid onset following circulatory death. It inhibits transplantability of hearts donated upon circulatory death (DCD). We investigate the effectiveness of hemodynamic normalization upon withdrawal of life-sustaining therapy (WLST) in a large-animal controlled DCD model, with the hypothesis that reduction in cardiac work delays the onset of IMC. Methods: A large-animal study was conducted comprising of a control group (n= 6) receiving no therapy upon WLST, and a test group (n= 6) subjected to a protocol for fully automated computer-controlled hemodynamic drug administration. Onset of IMC within 1 h following circulatory death defined the primary end-point. Cardiac work estimates based on pressure-volume loop concepts were developed and used to provide insight into the effectiveness of the proposed computer-controlled therapy. Results: No test group individual developed IMC within 1h, whereas all control group individuals did (4/6 within 30min). Conclusion: Automatic dosing of hemodynamic drugs in the controlled DCD context has the potential to prevent onset of IMC up to 1h, enabling ethical and medically safe organ procurement. This has the potential to increase the use of DCD heart transplantation, which has been widely recognized as a means of meeting the growing demand for donor hearts.