Global Valve-in-Valve Registry: Procedure Technically Challenging, but Highly Feasible

PARIS, France—Treating a failed bioprosthesis via transcatheter aortic valve replacement (TAVR)—the so-called valve-in-valve approach—is feasible and often effective but technically demanding, according to registry findings released Tuesday, May 15, 2012, at EuroPCR.

Danny Dvir, MD, of the Washington Heart Center (Washington, DC), presented details of the Global Valve-in-Valve Registry culled from 54 centers in Europe, North America, Australia, New Zealand, and the Middle East on 416 high-risk patients. All underwent TAVR inside surgically implantedbioprosthetic valves that had degenerated. Percutaneous valves used included:

• 225 Sapien (Edwards Lifesciences, Irvine, CA)
• 190 CoreValve (Medtronic; Minneapolis, MN)
• 1 Melody (Medtronic)

The mechanism of failure was predominately stenosis in 168 patients, regurgitation in 125 patients, and a combination of both factors in 123 patients. Median time to valve-in-valve procedure ranged from 8 to 10 years across the 3 indications.

Complications Common Though Function Improved

The various mechanisms of failure were equally distributed between the CoreValve and Sapien subgroups. 

Procedures were complicated, with “relatively high rates” of initial device malapposition, attempted valve retrieval, implantation of a second device, post-implantation valvuloplasty, need for emergent surgery, and clinically-evident coronary obstruction. Mean duration of hospital stay was 8 days.

But at 30 days, valve-in-valve therapy had improved functional capacity, with 87.5% of patients classified as NYHA class I/II. Mortality was statistically similar for all indications but slightly higher in those treated for stenosis (table 1).

Table 1. Mortality at 30 Days

Independent predictors for elevated post-procedure aortic valve gradient greater than 20 mm Hg included baseline stenosis (HR 6.3 vs. regurgitation), baseline combination of stenosis and regurgitation (HR 3.4 vs. regurgitation), and Sapien valve use, predominately in smaller bioprostheses (HR 2.1 vs. CoreValve). In additional findings provided to TCTMD by Dr. Dvir, the rates of aortic gradients greater than 20 mm Hg and 40 mm Hg were 29.0% and 2.7%, respectively.

On Kaplan-Meier analysis, 1-year survival was highest in patients treated for regurgitation and lowest in those treated for stenosis (log-rank P value = 0.008). The strongest predictor of 1-year mortality by far was an initial indication of stenosis (HR 7.1; 95% 2.27-20.0 vs. combined stenosis/regurgitation and HR 3.7; 95% CI 1.54-8.33 vs. regurgitation).

Encouraging Data Despite Caveats

Bioprosthetic valves are increasingly used in open surgical procedures to treat aortic valve disease but commonly fail within 10 to 15 years, Dr. Dvir said. The repeat procedure is high risk but TAVR may serve as a less invasive alternative. “However,” he said. “valve-in-valve procedures have been reported in only small case series, and the safety and efficacy of this technique is largely unknown.”

Based on the current findings, the “valve-in-valve procedure, although feasible, is technically demanding, [involves] several safety concerns, and should probably be reserved for highly experienced centers,” Dr. Dvir concluded, noting that the “technique is clinically effective in most patients, with results comparable to other TAVI cohorts.” Longer-term follow-up is needed, as are dedicated devices for treating smaller bioprosthetic valves, he added.

Commenting on the presentation, Jose-Luis Pomar, MD, PhD, of Hospital Clinico de Barcelona (Barcelona, Spain), reported being struck by how soon patients required valve-in-valve treatment after surgery compared to what has been documented in the literature.

John G. Webb, MD, of St. Paul’s Hospital (Vancouver, Canada), the trial's other discussant, agreed. “The mean age of a failed bioprostheses was only 9 years,” he said. “Most of us have heard in our careers that surgical valves have a durability perhaps of 10 to 20 years, maybe 15, but many patients find out that it's just not so.” This places TAVR devices within the same realm of durability as some surgical devices, he noted.

The registry results support screening for obstruction, Dr. Webb pointed out. In addition, operators should consider the internal diameter of bioprostheses when sizing TAVR devices. Very little is known about these measurements, he said, and the disparate outcomes between Sapien and CoreValve may relate to size.

Despite the limitations of valve-in-valve therapy, Dr. Pomar characterized the registry results as “positive. . . .They tell us that there is a good future for this technique.”

Importantly, though, “not all devices behave the same,” so better designs might improve outcomes, Dr. Pomar noted. One implication for practice may be that clinicians will be more willing to treat patients with surgically implanted bioprostheses at a younger age, he added, in the hope that failed cases can be rescued later using the valve-in-valve approach.

Study Details

Patients suffering from regurgitation tended to be male, while those with stenosis were most likely to have diabetes, and those with both stenosis and regurgitation had the highest mean Society of Thoracic Surgeons score. Valves exhibiting stenosis were most likely to have previously received bioprostheses that were stented and those sized 21 mm or smaller.

Most Sapien valves measured 23 mm (72.9%) and were inserted transapically (73.8%), while most CoreValve devices were 26 mm (83.7%) and were implanted transfemorally (93.2%). Sapien-treated patients were more likely than CoreValve-treated patients to undergo transesophageal echocardiography (82.2% vs. 38.4%) and to receive general anesthesia (85.3% vs. 48.9%; P < 0.001 for both comparisons).

 

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Source:
Dvir D. TAVI for degenerative bioprosthetic surgical valves: Results of the Global Valve-in-Valve registry. Presented at: EuroPCR. May 15, 2012. Paris, France.

 

 

Related Stories:

• Early Results of ‘Valve-in-Valve’ Implantation for Failed Bioprostheses Encouraging
• ‘Valve-in-Valve’ Technique Effective in Treating CoreValve Leaks
• Studies Show Valve-in-Valve TAVR Successful for Failed Surgical Bioprostheses

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