CONICET | Buscador de Institutos y Recursos Humanos

Introduction: It is known that remote ischemic preconditioning (rIPC) reduces infarct size in experimental models of myocardial infarction (MI); while its effect is controversial in the clinical setting. Particularly, the effect of rIPC on post-infarction ventricular remodeling is unknown. The aim of this work is to evaluate the effect of rIPC on early ventricular remodeling, considering the myocardial infarction expansion.Methods: Male FVB mice, 2-6 months old, underwent MI by permanent ligation (for 7 days) of the left anterior coronary artery; In a second group, a rIPC protocol (3 cycles of 5 min ischemia/reperfusion in the left lower limb) was performed prior to MI. Finally, a third group was undergoing to left thoracotomy, but without myocardial ischemia (Sham). Infarct size was measured with triphenyltetrazolium, ventricular function by hemodynamic and echocardiography, and MMPs 2 and 9 activity was evaluated by zymography.Results: There were no significant differences in the risk area and infarct size between groups. IM decreased ejection fraction and area shortening fraction to a value of 55,06±2,6% and 26,76±1,21%; respectively (p≤0,05 vs sham). rIPC improved systolic function increasing ejection fraction and the area shortening fraction to a value of 67,64%±1,42 and 37,41±2,37%, respectively (p≤0,05 vs IM). We did not observe significant differences between groups in the end-systolic stress values (afterload index). The relationship between end-systolic stress and ejection fraction was plotted, observing a significant improvement in the rIPC group, compared to the MI group. Finally, rIPC reduced significantly MMP-9 activity in the left ventricle (infarct area), but not MMP-2.Conclusion: We have showed that rIPC has a beneficial effect on early remodeling, reducing myocardial post-infarction expansion and improving ventricular function. This beneficial effect could be related to a lower MMP-9 activity.