A comprehensive and longitudinal cardiac magnetic resonance imaging study of the impact of coronary ischemia duration on myocardial damage in a highly translatable animal model

Abstract

Objectives We performed a comprehensive assessment of the effect of myocardial ischemia duration on cardiac structural and functional parameters by serial cardiac magnetic resonance (CMR) and characterized the evolving scar. Background CMR follow‐up on the cardiac impact of time of ischemia in a closed‐chest animal model of myocardial infarction with human resemblance is missing. Methods Pigs underwent MI induction by occlusion of the left anterior descending (LAD) coronary artery for 30, 60, 90 or 120 min and then revascularized. Serial CMR was performed on day 3 and day 42 post‐MI. CMR measurements were also run in a sham‐operated group. Cellular and molecular changes were investigated. Results On day 3, cardiac damage and function were similar in sham and pigs subjected to 30 min of ischemia. Cardiac damage (oedema and necrosis) significantly increased from 60 min onwards. Microvascular obstruction was extensively seen in animals with ≥90 min of ischemia and correlated with cardiac damage. A drop in global systolic function and wall motion of the jeopardized segments was seen in pigs subjected to ≥60 min of ischemia. On day 42, scar size and cardiac dysfunction followed the same pattern in the animals subjected to ≥60 min of ischemia. Adverse left ventricular remodelling (worsening of both LV volumes) was only present in animals subjected to 120 min of ischemia. Cardiac fibrosis, myocyte hypertrophy and vessel rarefaction were similar in the infarcted myocardium of pigs subjected to ≥60 min of ischemia. No changes were observed in the remote myocardium. Conclusion Sixty‐minute LAD coronary occlusion already induces cardiac structural and functional alterations with longer ischemic time (120 min) causing adverse LV remodelling.

Characterizing the immune response to myocardial infarction in pigs

“…The type, extent, and pattern of spatial distribution and the temporal sequence of ischemia–reperfusion in pigs resemble the human clinical situation more closely than many other animal models [ 19 , 33 ]. Moreover, utilizing pigs allows researchers to employ the same techniques, such as cardiac catheterization or magnetic resonance imaging, and derived key parameters as in examinations of the human heart [ 57 , 64 ].…”

A Pig as a Model to Test Cardiovascular Devices

“…A properly selected animal model will make it possible to install the implant being tested with great success, avoid fatal complications and death of experimental animals due to the discrepancy in the size of the structures in their hearts, blood vessels and medical devices. The most advantageous method to accurately measure the size of the heart and its structures is undoubtedly multispiral computed tomography [9,10]. However, in daily experimental practice, preference should be given to the simplest and fastest method to evaluate the anatomy of the target zone.…”

Pigs as Models to Test Cardiovascular Devices

“…Moreover, it will help researchers to avoid fatal complications and deaths of experimental animals caused by the mismatch in the sizes of the anatomical structures and medical devices. Multispiral computed tomography is considered to be the most advantageous method for making accurate measurements of the heart and its structures [ 9 , 10 ]. However, in daily experimental practice, it is preferable to use the simplest and quickest method to evaluate the anatomy of the target area.…”