Cryo-infarction: a method of choice for the establishment of a rat model of myocardial infarction

Ligation of the left anterior descending (LAD) coronary artery is a widely used method for inducing myocardial infarction (MI) in experimental models; however, it is associated with substantial limitations, including high mortality rates, excessive bleeding and variability in infarct size. Cryo-infarction has emerged as a promising alternative that may overcome these challenges by providing improved survival and reproducibility. In the present study, we aimed to refine the cryo-infarction method as a reliable and practical rat model for MI. Adult male Wistar rats underwent open-chest surgery under mechanical ventilation, followed by either LAD ligation or cryo-induced infarction. Model validation was performed using TTC (2,3,5-triphenyltetrazolium chloride) staining and immunofluorescence analysis, serum troponin I measurement, and electrocardiography (ECG) assessment. Infarct severity was further evaluated by echocardiography, hematoxylin, and eosin staining, and Masson's trichrome staining. Our findings demonstrate that cryo-infarction provides several advantages over conventional ligation, including simplicity, reproducibility, and reduced mortality. These results highlight the potential of cryo-infarction as a standard approach for developing robust animal models, benefiting both basic and translational cardiovascular research.