Trimetazidina na injúria de isquemia e reperfusão em cirurgia de revascularização do miocárdio

Abstract

ResumoFundamento: A injúria de isquemia e reperfusão constitui um mecanismo fisiopatológico frequente e de difícil controle durante a Cirurgia de Revascularização do Miocárdio (CRVM) com circulação extracorpórea, sendo o momento crítico o término da cirurgia, quando ocorre o desclampeamento da aorta e a liberação dos radicais hiperóxidos causadores da injúria.Objetivo: Avaliar, em estudo prospectivo, duplo-cego randomizado, controlado com placebo, os efeitos da Trimetazidina (Tmz) sobre a injúria de isquemia e reperfusão miocárdica, identificando a variação dos marcadores plasmáticos de agressão miocárdica (troponina T e CPK-Mb), e as alterações ecocardiográficas da função ventricular.Métodos: Foram estudados 60 pacientes, divididos em dois grupos (Placebo e Tmz) com, no máximo, disfunção ventricular leve, estratificados por ecocardiografia e recebendo medicação/placebo na dose -no pré-operatório sem medicação, 12 a 15 dias de medicação/placebo colhida cinco minutos após o desclampeamento aórtico, e nas 12, 24 e 48 horas seguintes. Resultados: Tanto a troponina T como a CPK-Mb atingiram valores altamente significativos (p = 0,0001) no grupo tratado em relação ao grupo controle nos quatro momentos analisados − 5 min, 12 h, 24 h e 48 h. As variáveis ecocardiográficas não evidenciaram mudanças evolutivas em cada grupo isoladamente e quando comparados em conjunto. Conclusão AbstractBackground: The ischemia and reperfusion ischemia is a common physiopathological mechanisms, which has difficult control during Coronary Artery Bypass Grafting (CABG) with cardiopulmonary bypass, the critical moment of which happening by the end of surgery, when there is declamping of aorta and release of hyperoxic radicals causing the injury.

Trimetazidina e resposta inflamatória em cirurgia de revascularização do miocárdio

“…When extending the analysis to compare the Tmz and placebo groups of this study with those of the study by Martins et al 6 , those variables showed no significant difference.…”

“…Martins et al 6 have assessed 137 patients with echocardiographic indication for CABG-ECC, 75 of whom, with normal ventricular function or mild dysfunction, were selected. Of those, 60 patients, distributed in the treated and placebo groups, completed the tests for the serum markers of myocardial injury (troponin-T and CPK-MB).…”

“…Trimetazidine has a protective effect on the cardiac cell against the ischemia and reperfusion injury, leading to a reduction in the markers of myocardial aggression, of oxidative stress, and, thus, of inflammatory response 6,28 . In this clinical trial, which evidenced significant differences in the IL6 levels in the Tmz group as compared with those in the placebo group, a tendency towards lower C3 and C5 levels was observed, with no statistically significant reduction in the groups.…”

“…Table 2 shows the analysis of the surgical variables, which evidences uniformity of the Tmz and placebo groups regarding additional to glycolysis, with the consequent reduction in protons, elevation of the intracellular pH and tissue acidosis, recovery of the cardiac efficiency, and improvement in the production of acetyl-CoA. In addition, it limits calcium build-up, inflammation and the production of superoxide free radicals that occur after reperfusion, without causing hemodynamic changes 6 .…”

“…In particular, of the superoxide radicals, which are formed in the obstructions to coronary flow and can cause injury after aortic unclamping during heart surgery. Those superoxide radicals comprise the superoxide anion (O²-), hydroxyl radical (OH), and hydrogen peroxide (H²O²), which can be removed from the cells by enzyme systems with antioxidant functions, usually present in myocardial physiology 5,6 .…”