Valve-in-valve implantation may offer solution for failed bioprosthetic heart valves

Transcatheter valve-in-valve implantation successfully restored valve function in most patients who experienced bioprosthetic valve failure, suggesting that the noninvasive procedure may be a viable alternative to repeat operations, according to a published study.

Researchers from Canada and the United Kingdom performed valve-in-valve implantations among 24 high-risk patients who experienced bioprosthetic valve failure in aortic (n=10), pulmonary (n=6), mitral (n=7) and tricuspid (n=1) tissue.

The procedure was successful in all but one patient in whom a percutaneous transseptal approach was used to implant the transcatheter valve into mitral tissue. The patient underwent conventional surgery after embolization occurred due to “noncoaxial and too ventricular positioning within the prosthesis,” according to the researchers, and the patient died of multisystem failure the next day.

At a median of 135 days of follow-up, 91.7% of patients were alive with satisfactory valve function. NYHA functional class status improved with 88% of patients in class III or IV prior to the procedure and 88% in class I or II after the procedure.

“Transcatheter valve-in-valve implantation is a reproducible option for the management of bioprosthetic valve failure. Aortic, pulmonary, mitral and tricuspid tissue valves were amenable to this approach,” the researchers wrote. “This finding may have important implications with regard to valve replacement in high-risk patients.”

Repeat operations are the standard of care among patients with prosthetic valves who develop severe stenosis or regurgitation, but these operations pose significant risks, according to the researchers. Using a risk calculator from the Society of Thoracic Surgeons, they approximated the mortality risk for an 80-year-old man with no comorbidities at 5% for aortic reoperation and 10% for mitral reoperation. Major morbidity risk for these two operations is 20% and 23%, respectively, and increases significantly when comorbidities are present.

The researchers emphasized the importance of documenting and sharing clinical information regarding transcatheter valve-in-valve procedures as rigorous testing “of all potential combinations of available surgical and transcatheter valve types, frames configurations and sizes” is unlikely. – by Nicole Blazek

Webb JG. Circulation. 2010;doi:10.1161/CIRCULATIONHA.109.924613.

Transcatheter valve implantation technology offers potential therapy for a wider range of patients that are currently allowed into the ongoing randomized U.S. trials. One of these is valve-in-valve implantation for patients with failing bioprostheses — either in the aortic or mitral position (though as the one patient failure in this study points out, the aortic seems to be more appealing). Nevertheless, because such patients have all by definition had previous thoracotomy, they are higher risk for repeat surgery, and many have other comorbidities that add to their risk of repeat operation.

Transcatheter valve implantation is not for everyone with a failed bioprosthesis, but it offers some patients, carefully selected, to have another option for therapy that potentially can help them significantly. Issues remain-longevity of the new bioprosthesis, concern about embolization, the safest approach, etc., but the upside has great potential.

– Peter C. Block, MD
Cardiology Today Editorial Board
Vascular Medicine/Intervention Co-Section Editor

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