A novel experimental thrombotic myocardial infarction and primary angioplasty model in swine.

AIMS: We sought to develop a reproducible animal model for acute myocardial infarction (AMI) in adult atherosclerosis-prone pigs.

METHODS AND RESULTS: A coil was placed in the right coronary artery or the left anterior descending artery in 26 downsized spontaneously hypercholesterolemic pigs and left untreated until thrombotic occlusion. Then, we crossed the thrombotic occlusion with a guidewire, followed by pre-dilatation, thrombus visualization with Optical Coherence Tomography (OCT) imaging and, finally, deployment of a stent and repeated OCT. After revascularization, we calculated the index of microcirculatory resistance (IMR). After a feasibility phase (6 animals), acute thrombotic occlusion was achieved in all 20 pigs. Eighteen animals were successfully revascularized and survived until sacrifice. Thrombus formation was confirmed by OCT, thrombin-antithrombin complexes measurements and pathology examination. Myocardial necrosis was confirmed by troponin T elevation, myocardial staining and pathology examination. Distal thrombotic embolization and microvascular obstruction were supported by increased IMR and pathology examination.

CONCLUSIONS: A porcine model of thrombotic occlusion AMI in miniaturized adult spontaneously atherosclerosis-prone pigs is feasible by percutaneous intracoronary placement of a coil. The reperfusion by angioplasty completed this model which mirrors human pathological conditions with myocardial infarction, necrosis and distal embolization.