Release of markers of myocardial and endothelial injury following cold cardioplegic arrest in pigs

Cold cardioplegic arrest causes reperfusion injury to both endothelium and myocardium. We investigated release of troponin-T (TnT), tissue plasminogen activator activity (t-PA) and histamine (HA) from the heart before and after 2 h of cold crystalloid cardioplegia in eight Swedish landrace pigs. Coronary sinus blood flow was measured in an external shunt between the coronary sinus and the right atrium. TnT, t-PA and HA were measured concomitantly in arterial and coronary sinus plasma, and the cardiac release was calculated. Cardiac release of TnT increased from 18 (15–25) μg/min (median (central 90% percentile)) before cold cardioplegia to maximum 281 (132–510) μg/min 30 min after aortic declamping (p < 0.02 vs initial value). t-PA rose from -4 (-52–34) to maximum 249 (75–691) IU/min 2 min after declamping (p < 0.01) and thereafter returned to baseline levels. The net cardiac release of HA was 72 (-80–1321) nmol/min before cardioplegia, rising to 234 (-188–524) after 2 min of reperfusion (p < 0.02) and re...