Infusion of routinely stored blood may limit reperfusion injury to acutely ischemic myocardial cells.

Emergency thrombolysis and restoration of blood supply to acutely ischemic myocardium kills many reversibly injured muscle cells by free radicals generation and calcium influx. Such reversibly injured cells form the major bulk during the initial 10-20 min of ischaemia and in an era where emergency recanalization of arteries is possible, reperfusion injury becomes significant. Therefore, researchers have been trying to find out ways to limit the reperfusion injury by using antioxidants, complement inhibitors or by reperfusion of leucodepleted autologous blood. Red cell concentrates routinely available in blood banks are already depleted of plasma and hence calcium (chelated to the anticoagulant), leukocytes and most viable plasma proteins including complement. They have reduced oxygen content by virtue of storage; hence there might be less free radical generation. So infusion of such a blood through an intracoronary catheter might limit reperfusion injury. Addition of antioxidants or controlling the oxygen content while infusing this blood might give additional benefits. This hypothesis might be tested in animals by inducing controlled ischaemia with reperfusion of homologous cross-matched and group tested blood followed by cardiac radioactive scans. If the experimental results permit, clinical trials might be carried out eventually.