MATERIALS AND METHODS: Twelve female pigs underwent a transcatheter injection in the left anterior descending artery (LAD), using alcohol, to produce an apicoanteriorseptal AMI. Low pressure ballooning using a 2.5 mm over-the-wire balloon, just above the second and first diagonal branches, followed by a 1 mL injection of 99.9% ethyl alcohol was administered to 8 and 4 pigs, respectively. Follow-up coronary and left ventricular (LV) angiograms and echocardiography were performed 4 weeks after the alcohol injection. Myocardial SPECT using 201Tl (and 99mTc-MIBI) and triphenyl tetrazolium chloride (TTC) stain were performed after sacrifice. The quantity of TTC stain and amount of 201Thallium uptake were compared using the Vision Workstation. The histopathological findings of the infarcted myocardium and coronary artery were demonstrated after 28 days.

RESULTS: Procedure-related mortality was observed in two-pigs of the proximal LAD injection group. Four pigs suffered from ventricular tachycardia, which was converted into sinus rhythm by dc cardioversion. The four-week follow-up coronary angiography revealed persistently occluded LAD in all pigs. The LV angiogram showed akinetic movement in the apicoanteriorseptal wall with an ejection fraction of 46.5±3.3%. Myocardial SPECT revealed a perfusion defect in the apicoanterior wall of all pigs. The percentage area of perfusion defect was 22.2±3.06%. The TTC did not stain the myocardium in the apicoanterior wall. The percentage of non-stained myocardium was 23.5±2.70%. A histological examination revealed severe fibrosis in the infarcted myocardium and massive thrombus, with organization and calcification.

CONCLUSION: The porcine model of acute myocardial infarction using an intracoronary ethanol injection into the distal LAD is safe, reliable and reproducible, and can be used for future research into myocardial regeneration and ischemic LV failure.