Postischemic infusion of sivelestat sodium hydrate, a selective neutrophil elastase inhibitor, protects against myocardial stunning in swine

It seems controversial whether or not neutrophil elastase inhibitors are effective in attenuating myocardial ischemia/reperfusion injury. We thus investigated possible protective effects of sivelestat, a neutrophil elastase inhibitor, against myocardial stunning i.e., prolonged myocardial dysfunction following a brief episode of ischemia. Swine were divided into control group (group C), low-dose sivelestat group (group L), and high-dose sivelestat group (group H) (n = 7 for each group). All the swine were subjected to myocardial ischemia through ligation of the left anterior descending (LAD) coronary artery for 12-min, followed by 90-min reperfusion. Sivelestat was infused intracoronally at concentrations of 6 and 60 mg/ml throughout the reperfusion period in groups L and H, respectively, while saline was infused in the group C. Heart rate (HR), left ventricular developed pressure (LVdP), maximum rate of LVdP (LVdP/dt (max)), LV end-diastolic pressure (LVEDP), percentage of segment shortening (%SS, an index of regional myocardial contractility), and coronary venous interleukin-6 concentration in the LAD perfusion area were measured before ischemic induction and during reperfusion. The ischemia/reperfusion insult did not cause any significant changes in HR, LVdP, LVdP/dt (max), and LVEDP in all groups. However, it significantly reduced %SS in the LAD perfusion area and increased the interleukin-6 concentration in group C. Those changes in %SS and the interleukin-6 concentration were both greatly attenuated, but not prevented, in groups L and H. Sivelestat presumably attenuates myocardial contractile dysfunction due to myocardial stunning by inhibiting neutrophil-derived elastase, thereby suppressing the production of interleukin-6 in activated neutrophils.