Percutaneous treatment of ischaemic mitral regurgitation in sheep.

AIMS: A percutaneous mitral annuloplasty device for implantation in the coronary sinus was evaluated in surviving sheep with ischaemia-induced mitral regurgitation.

METHODS AND

RESULTS

Microspheres were injected in the left coronary artery of thirty-seven sheep. The treatment was repeated in one month intervals until the resulting myocardial infarctions caused significant mitral regurgitation. Fourteen animals developed a mitral regurgitation degree 2 or higher after 130+/-16 days and 3.4+/-0.4 treatments. The annuloplasty device was implanted percutaneously within the coronary sinus and the animals were followed 97+/-6 days (n=14) with monthly intracardiac echocardiograms. The MR grade (0-4) decreased from 3.1+/-0.2 at the time for implantation to 0.8+/-0.2 (p=0.0005) at the 3 month follow up. The vena contracta decreased from 6.5+/-0.4 mm to 2.0+/-0.7 mm after 3 months (p=0.0007). The mitral septo-lateral diameter was reduced after insertion of the device, from 38+/-1 mm before implantation to 35+/-1 mm after 3 months (P=0.0322). Angiography showed no signs of impairment of the coronary arteries. No thrombosis was observed.

CONCLUSION

These results indicate that experimentally induced ischaemic mitral regurgitation can be significantly reduced by means of a percutaneous catheter technique from the coronary sinus in surviving sheep.