乌鸦传媒

SAN DIEGO -- Transcatheter valve-in-valve replacement had lasting benefits in a high-risk patient population requiring valve reintervention, registry data showed.

Starting with 365 patients who got valve-in-valve transcatheter aortic valve replacement (TAVR), death took its toll in 12.1%, 22.2%, and 32.7% by 12, 24, and 36 months, respectively. Stroke and repeat valve replacement had plateaued to 5.1% and 0.6% over 24 months, rising to 6.2% and 1.9% at the 36-month mark.

Valve performance was sustained the whole time, as effective orifice area had a significant boost from baseline to discharge, staying stable thereafter out to 3 years; mean gradient dropped after the procedure and similarly stayed unchanged over time, according to John Webb, MD, of St. Paul's Hospital in Vancouver, at the Transcatheter Cardiovascular Therapeutics (TCT) conference.

Among survivors, early improvements in functional status were also maintained over the 3-year period, Webb said. Most patients started off in New York Heart Association class 3 and 4 and were reclassified as class 1 and 2 after TAVR. Quality of life also was better, as shown in improved Kansas City Cardiomyopathy Questionnaire overall summary scores: 43.1 at baseline to 70.8 at 30 days (P<0.0001), and staying stable out to 3 years.

The results were not influenced by surgical valve size, failure mode, approach, or residual gradient.

These data are "certainly reassuring out 2-3 years" but the concern lies in anticipation of lower-risk and younger patients who are expected to start getting TAVR in the future, commented Stephan Windecker, MD, of the University of Bern in Switzerland, who was a panelist at the TCT late-breaker trial session.

There are some concerns regarding coronary obstruction, Webb acknowledged. "This is true in surgical valves and it would be every bit as true in transcatheter valves, if not more so."

The study population came from the PARTNER II initial and continued access registries, and had an average Society of Thoracic Surgeons risk of 9.1%.

Patients received the 23- or 26-mm Sapien XT transcatheter heart valves. They were treated for surgical bioprostheses that were more than 10 years old in two-thirds of cases.

After the valve-in-valve procedure, the proportion of patients with moderate-or-worse aortic regurgitation fell from 45.1% at baseline to 2.5% at 3 years (P<0.0001). Paravalvular aortic regurgitation dropped from 7.2% to 1.4% (P=0.006).

Interestingly, mitral regurgitation and tricuspid regurgitation also showed significant and lasting reductions.

"The improvement was more than we expected by quite a lot," Webb said, adding that the result didn't appear to be explained by survival bias alone.

"There's no sign of leaflet thrombosis playing a role in reintervention ... It wasn't clear that leaflet thrombosis was a factor. That said, we weren't looking for it," Webb said at a TCT press conference. He acknowledged that leaflet thickening and thrombosis weren't on the radar at the time the data were collected.

Instead, valve-in-valve TAVR was usually performed for leaks and valves that were too small.

As for the generalizability of this valve-in-valve experience, Webb said that "some of these are the easiest TAVR procedures that we do. You don't get annual rupture, you don't need pacemakers very often ... It's not a difficult procedure when you know how to do it."

None of the patients in the study group had surgical valve fracturing or cracking, however, which Webb said would have helped the valve-in-valve procedure. As the practice becomes more routine in some centers, data may show that it improves the function and durability of the new bioprosthesis, he suggested.

Comment