An ovine model of chronic stable heart failure

Chronic stable large animal models of heart failure are difficult to establish. We report an ovine model of chronic stable heart failure achieved by a technique of repetitive myocardial infarctions (one of the most common causes of cardiac failure) with catheter-based techniques.

Ejection fraction (EF) was assessed by echocardiography. A perfusion catheter was positioned in either the left anterior descending or circumflex artery by using standard angioplasty techniques. Myocardial infarction was induced by a Gelfoam embolism via this catheter and was confirmed by electrocardiographic (ECG) changes and new segmental abnormalities. The procedure was repeated at 2 weekly intervals until the EF was less than 40%. Target EF was achieved in 15 animals, with a mean of 3.4 embolizations (range 2 to 8). Baseline EF was 68%, with a mean final EF of 33%. This resulted in a 54% reduction in EF (range 44% to 68%) from baseline values. Two animals developed late symptomatic heart failure and died, whereas EF was stable at 3-month follow-up echocardiography in the remaining animals with no significant spontaneous improvement.

Chronic stable heart failure can be established in sheep with catheter-based skills and a microembolization technique that causes repetitive myocardial infarctions.