Trimetazidina como aditivo em solução cardioplégica sem pré-tratamento não traz proteção adicional ao miocárdio isquêmico: estudo em modelo suíno de coração isolado

Abstract

The aim of this study is to verify in an isolated working heart swine model if the acute administration of trimetazidine to cardioplegia, without pre-treatment improves heart performance. Eighteen pairs of swine were used in this working heart model, divided into three groups (n = 6) that underwent regional and global ischemia. Each group was selected to a different treatment: St. Thomas cardioplegia (ST), St. Thomas enriched with trimetazidine (TMZ) and control group (Co). Data was collected during reperfusion period at 30, 60 and 90 minutes. Hemodynamic parameters such as elastance contractility index (Emax), preload recruitable stroke work relationship (PRSW) and heart "stiffness" (EDPVR) were measured. Other data included coronary flow, lactate, oxygen and glucose consumption. Results were statistically analyzed. All contractility data were not significantly different among three groups. Lactate became constantly higher according to time uniformly in all three groups. Coronary flow, glucose consumption and oxygen consumption presented large variations during time periods but according to treatments showed no statistical differences in all three groups. Left ventricle final weight was significantly lower in trimetazidine group compared to both other groups. Administration of trimetazidine enhanced cardioplegia, without pre-treatment, showed no hemodynamic or metabolic improvement in swine isolated working heart model.