Comparison of Cardioplegic Solutions in Coronary Bypass Surgery Over Autophagy and Apoptosis Mechanisms

Abstract

Background: Coronary artery disease (CAD) due to myocardial ischemia causes permanent loss of heart tissue.

Objectives: We aimed to demonstrate the possible damage to the myocardium at the molecular level through the mechanisms of autophagy and apoptosis in coronary bypass surgery patients.

Methods: One group was administered a Custodiol cardioplegia solution, and the other group was administered a Blood cardioplegia solution. Two myocardial samples were collected from each patient during the operation, just before cardiac arrest and after the aortic cross-clamp was released. The expressions of autophagy and apoptosis markers were evaluated. The level of statistical significance adopted was 5%.

Results: The expression of the BECLIN gene was significant in the myocardial tissues in the BC group (p=0.0078). CASPASE 3, 8, and 9 gene expression levels were significantly lower in the CC group. Postoperative TnT levels were significantly different between the groups (p=0.0072). CASPASE 8 and CASPASE 9 gene expressions were similar before and after aortic cross-clamping (p=0.8552, p=0.8891). In the CC group, CASPASE 3, CASPASE 8, and CASPASE 9 gene expression levels were not found to be significantly different in tissue samples taken after aortic cross-clamping (p=0.7354, p=0.0758, p=0.4128, respectively).

Conclusions: With our findings, we believe that CC and BC solutions do not have a significant difference in terms of myocardial protection during bypass operations.

Figura Central. : Comparação de Soluções Cardioplégicas em Cirurgia de Revascularização Miocárdica sobre Mecanismos de Autofagia e Apoptose

Figura 1. – Diagrama de fluxo da seleção do paciente no estudo. PCR: reação em cadeia da polimerase; RNA: ácido ribonucléico.

Figura 2. – A, B) Comparação dos achados laboratoriais pós-operatórios dos pacientes dos grupos Cardioplegia Custodiol e Cardioplegia Sanguínea. A) Os níveis de TnT foram significativamente diferenciados entre os grupos (p=0,0072). B) Os níveis de CK-MB não foram diferentes entre os grupos (p=0,0731). Figuras 2C-E) Gráficos de expressão. C) Imagens de Western Blot de membrana de marcadores de autofagia no grupo Cardioplegia Sanguínea e Cardioplegia Custodiol. D) Gráficos dos níveis de expressão dos genes Beclin e LC3 nas amostras de tecido miocárdico dos grupos (n=15, BO: Antes do pinçamento aórtico, AO: após a liberação do pinçamento aórtico). (*p<0,05). E) Expressões proteicas de Beclin e LC3 em ambos os grupos.

Figura 3. – Resultados de Western Blot. A. Imagens de Western Blot de membrana de marcadores apoptóticos no grupo Cardioplegia Sanguínea e Cardioplegia Custodiol. B. Gráficos do nível de expressão dos genes das Caspases 3, 8 e 9 nas amostras de tecido miocárdico dos grupos (n=15, BO: Antes do pinçamento aórtico, AO: após liberação do pinçamento aórtico). (*p<0,05).

Central Illustration. : Comparison of Cardioplegic Solutions in Coronary Bypass Surgery Over Autophagy and Apoptosis Mechanisms

Figure 1. – Flow diagram of the patient selection in the study. PCR: polymerase chain reaction; RNA: ribonucleic acid.

Figure 2. – A, B) Comparison of the postoperative laboratory findings of the patients in Custodiol Cardioplegia and Blood Cardioplegia groups. A) TnT levels were significantly differentiated between the groups (p=0.0072). B) CK-MB levels were not different between the groups (p=0.0731). Figures 2C-E) Expression graphs. C) Western blot membrane images of autophagy markers in Blood Cardioplegia and Custodiol Cardioplegia group. D) Beclin and LC3 gene expression level graphs in myocardial tissue samples in the groups (n=15, BO: Before aortic cross-clamping, AO: after releasing aortic cross-clamping). (*p<0.05). E) Protein expressions of Beclin and LC3 in both groups.

Figure 3. – Western Blot Results. A) Western blot membrane images of apoptotic markers in Blood Cardioplegia and Custodiol Cardioplegia group. B) Caspase 3, 8, and 9 gene expression level graphs in myocardial tissue samples in the groups (n=15, BO: Before aortic cross-clamping, AO: after releasing aortic cross-clamping). (*p<0.05).