A modified rabbit model of reperfused myocardial infarction for cardiac MR imaging research.

Abstract

We sought to obtain a rabbit myocardial infarction (MI) model for research with cardiac magnetic resonance imaging (cMRI) by overcoming a few technical difficulties. A novel endotracheal method was developed for intubation and ventilation. Fourteen rabbits were divided into group-1 (n = 8) with open-chest occlusion of left circumflex coronary artery and closed-chest reperfusion, and group-2 (n = 6) of non-ischemic control; and received ECG-triggered cMRI with delayed contrast enhancement (DE-cMRI) at a 1.5 T clinical scanner. The MI areas in group-1 were morphometrically compared between DE-cMRI and histochemically stained specimens. Left ventricular (LV) functions were compared between two groups.The success rate of intubation and reperfused MI was 8/8 and 6/8, respectively. Global and regional LV functions significantly decreased in group-1 as evidenced by significant hypokinesis of lateral LV-wall and wall thickening (P \ 0.001). Mean MI-area was 19.41 +/- 21.92% on DE-cMRI and 19.10 +/- 22.61% with histochemical staining (r = 0.985). Global MI-volume was 17.92 +/- 7.42% on DE-cMRI and 16.62 +/- 7.16% with histochemistry (r = 0.994). The usefulness of this model was successfully tested for assessing a new contrast agent. The present rabbit MI model may offer a practical platform for more translational research using clinical MRI-facilities.