Speaker provides insight on mitral valve-in-valve implantation in degenerated bioprostheses

SAN FRANCISCO — For nonoperative, high-risk and potential intermediate-risk surgical patients experiencing structural bioprosthetic valve degeneration, mitral valve-in-valve replacement provides a suitable surgical option, according to a speaker at TCT 2013.

Isaac George, MD, of New York-Presbyterian Hospital, discussed the technical requirements and procedural considerations for valve-in-valve mitral valve replacement procedures in these patient populations.

“Structural valve degeneration is an emerging problem. There are over 200,000 valve replacements each year in the United States. The incidence of structural valve degeneration has been reported at somewhere between 20% to 50% at 15 years, in comparison to mechanical valves which have a very low failure rate at this time,” George said. “The actual mechanism of failure includes wear and tear, as well as calcification and pannus, but chronic thrombus can also cause the valve to fail. While these factors are mediated by immunologic, atherosclerotic and hemodynamic mechanisms, valve failure is inevitable with bioprosthetic valves.”

Moreover, patient mortality rates have been found to increase with each additional sternotomy. In a retrospective review of hospital records performed for 671 patients who underwent first repeat heart valve operations between 1969 and 1998, published in the Journal of Thoracic and Cardiovascular Surgery, patient mortality increased from 3% for reoperation for a failed repair or reoperation at a new valve site to 10.6% for prosthetic valve dysfunction or periprosthetic leak and to 29.4% for endocarditis or valve thrombosis.

“With each progressive sternotomy, obviously mortality increases due in part to surgical risks in both tissue and mechanical valves,” George said.

George described advantages of the transapical retrograde access route for mitral valve-in-valve replacement, including the fact that it is not limited by peripheral vascular anatomy, sheath diameter or aortic angle, and crosses the valve easily while avoiding passing the device across the aortic arch.

While advocating this approach, George also expressed caution.

“We primarily will do the TAVR followed by the transcatheter mitral valve replacement as there is a risk of embolization and disruption of the mitral valve during TAVR balloon inflation. However, the larger concern is obviously that the deployment of any balloon can cause interaction in both the aortic and mitral position, which can affect movement in both, so this is important to keep in mind during inflation. Finally, continued follow-up of these patients will help us learn about their long-term durability.”

For more information:

George I. Approaches to the degenerative mitral prosthesis. Presented at: TCT 2013; Oct. 27-Nov. 1, 2013; San Francisco.

Disclosure: George reports no relevant financial disclosures.