Venoarterial extracorporeal membrane oxygenation improves survival in a rat model of acute myocardial infarction

Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been widely used in high-risk acute myocardial infarction (AMI) patients with promising outcomes. However, the underlying molecular mechanisms remain unknown and a VA-ECMO animal model has not yet been established. The purpose of this study was to establish a VA-ECMO model in AMI rats and evaluate long-term cardiac function.Methods: We first established AMI in 20 Sprague-Dawley (SD) rats by ligating the left anterior descending coronary artery, while five rats underwent a thoracotomy to form the sham group. VA-ECMO was established after 30mins of AMI in 10 rats through the right jugular vein for venous drainage and right femoral artery for arterial infusion. Arterial blood pressure was monitored using a catheter in the left femoral artery, blood gas parameters were measured using a blood gas analyzer, while myocardial enzymes were detected using an ELISA Kit. Cardiac function was assessed through echocardiography on day 15. Masson staining and Western Blot were used for evaluating myocardial fibrosis, while histological injury was evaluated using hematoxylin and eosin staining.Results: VA-ECMO support stabilized blood pressure, decreased the levels of myocardial enzymes including cTnI, cTnT, CK-MB, and was associated with a higher survival rate. In the long term, the VA-ECMO group showed improved cardiac function, significantly increased EF and FS but significantly decreased EDV and ESV compared to the AMI group. Furthermore, VA-ECMO significantly alleviated pathological damage and myocardial fibrosis.Conclusion: We established an economical, reliable, and reproducible VA-ECMO animal model in AMI rats, and demonstrated that VA-ECMO support prevents deteriorated cardiac function.