Patients with baseline stenosis or small surgical valves who undergo transcatheter aortic valve-in-valve implantation for failed bioprosthetic devices have lower survival rates than the overall patient population, according to a study published in the July 9 issue of JAMA.
Cardiac surgeons tend to favor bioprosthetic valves over mechanical valves for surgical aortic valve replacement, but when bioprosthetic valves degenerate they must be replaced. Transcatheter aortic valve-in-valve implantation offers an option to reoperation when patients are at high surgical risk.
To determine that approach’s long-term survival, Danny Dvir, MD, of St. Paul’s Hospital in Vancouver, and colleagues from the Valve-in-Valve International Data (VIVID) Registry analyzed data from cases performed between 2007 and 2013 in the registry’s 55 participating centers. The valve-in-valve cases generally used either a self-expandable or a balloon-expandable procedure. The valves were characterized as either small (21 mm or less), intermediate (between 21 and 25 mm) or large (25 mm or greater).
The study group included 459 patients whose valves failed for one of three reasons: stenosis (39.4 percent); regurgitation (30.3 percent); or a combination of the two (30.3 percent). The stenosis group had a higher percentage of small valves compared with the regurgitation and combined groups (37 percent vs. 20.9 percent and 26.6 percent, respectively.)
At 30-days, 7.6 percent of the patients had died with the stenosis group showing the highest mortality rate, at 10.5 percent. Type of procedure did not affect the 30-day mortality or stroke rates.
The overall, one-year survival rate was 83.2 percent. But the survival rate was lower in the stenosis group, at 76.6 percent vs. 91.2 percent for the regurgitation group and 83.9 percent for the combined group.
Patients with small valves had a survival rate of 74.8 percent vs. 81.8 percent for intermediate valves and 93.3 percent for large valves. There was no difference in survival by type of procedure.
Dvir et al determined that small surgical bioprosthesis and baseline stenosis were associated with worse clinical outcomes at one year. “The mode of failure in the VIVID registry was relatively balanced among stenosis, regurgitation, and a combination of both,” they wrote. “Although there was no difference in patient age or calculated risk scores among the groups, clinical outcomes differed significantly.”
They recommended that cardiac surgeons thoroughly assess patients and evaluate the mechanism of the bioprosthesis failure before undergoing valve-in-valve procedures. If physicians find markers for stenosis, they should assess previous echocardiograms. If regurgitation is the issue, they should evaluate the location of the leak.
Dvir and colleagues also stressed that surgical technique during bioprosthetic implantation could affect the success of a valve-in-valve procedure years later.
“According to the VIVID Registry analysis, valve-in-valve outcomes are worse in patients with small surgical valves (label size ≤21 mm) and those with stenosis as the mechanism of failure; an attempt to address these limitations may possibly be made during the index procedure by providing the largest effective orifice area achievable.”