NOTION: TAVR in Low-Risk Patients Maintains Its Momentum Through 6 Years

PARIS, France—Findings continue to roll in from the all-comers NOTION trial, which studied transcatheter versus surgical aortic valve replacement in low-risk patients. The most recent update, presented here yesterday at EuroPCR 2018, shows that TAVR with the self-expanding CoreValve (Medtronic) continues to hold the edge through 6 years of follow-up in terms of hemodynamic performance and lack of structural valve deterioration.

No valve thrombosis occurred in either group, and both had similar rates of endocarditis and bioprosthetic failure, reported Lars Søndergaard, MD, DMSc (Rigshospitalet, Copenhagen, Denmark), in a hotline session.

Five-year outcomes from NOTION were presented at the American College of Cardiology 2018 Scientific Session, with 5-year durability data presented at least year’s EuroPCR meeting.

Commenting on the new findings for TCTMD, Luca Testa, MD, PhD (IRCSS Policlinico San Donato, Milan, Italy), said he agrees “about the need for long-term data.” While valuable, he added, “the NOTION trial is just a confirmation. . . . Data around 6-year follow-up is not enough. We need longer.”

Bernard Prendergast, MD (St Thomas’ Hospital, London, England), told TCTMD the NOTION data offer no surprises but are nonetheless good news.

“There’s been an important question mark hanging over the issue of TAVR durability for the last 2 or 3 years. The randomized trials are very reassuring. We have reassuring information from the pioneering centers [of Rouen, France, and Vancouver, Canada] and their registries. And there are also emerging larger registries from Italy and Germany in much larger numbers of patients providing reassurance out to 7 and 8 years,” said Prendergast, who was not part of the current study. “What NOTION does is use structured, new definitions to demonstrate that in fact there is . . . no concern and if anything TAVI appears to be performing better than surgical bioprostheses.”

Valve Dysfunction Trends Lower With TAVR

NOTION enrolled and randomized 280 patients ages 70 or older who had severe aortic stenosis and a life expectancy of 1 year or greater. Mean STS score was around 3 in the TAVR and SAVR groups, with more than 80% of patients having STS scores less than 4.

At 6 years, all-cause mortality did not significantly differ between TAVR and SAVR at 42.5% and 37.7%, respectively (P = 0.58). Effective orifice area was larger for TAVR than for SAVR (1.53 vs 1.16 cm2), while mean gradient was lower (9.9 vs 14.7 mm Hg; P < 0.001 for both).

Bioprosthetic valve dysfunction—using the definition set forth in a 2017 consensus statement that encompasses structural valve deterioration, nonstructural valve deterioration, bioprosthetic valve thrombosis, or endocarditis—trended lower at 6 years with TAVR compared with SAVR (56.1% vs 66.7%; P = 0.07). Structural valve deterioration, which involves having a mean gradient of at least 20 mm Hg, a change in mean gradient of at least 10 mm Hg from baseline, or moderate/severe intraprosthetic aortic regurgitation that’s new or worsening from baseline, was significantly less common with TAVR (4.8% vs 24.0%; P < 0.001). Nonstructural valve deterioration, on the other hand, was 54.0% with TAVR and 57.8% with SAVR, and the two groups had endocarditis rates of approximately 6% (P = NS for both). There were no instances of valve thrombosis over 6-year follow-up.

Bioprosthetic valve failure, also using the 2017 definition, involves valve-related death, aortic valve reintervention, or severe hemodynamic structural valve deterioration (mean gradient of at least 40 mm Hg, a change in mean gradient of at least 20 mm Hg from baseline, or severe aortic regurgitation that’s new or worsening from baseline). The rate of this endpoint at 6 years was 7.5% for TAVR and 6.7% with SAVR (P = NS).

Søndergaard pointed out that rates of paravalvular leak, a component of nonstructural valve deterioration, were higher in the trial, which ran from 2009 to 2013, than they would be today. At that time, aortic annulus sizing was done using echocardiography instead of CT imaging, he explained. “I’m sure quite a few of these patients would have a larger valve prosthesis if they were treated today. Also, no core lab was used for reading the echocardiography.”

Following the presentation, Ran Koronowski, MD (Rabin Medical Center, Petah Tikva, Israel), asked whether there’s a continuum from bioprosthetic valve dysfunction to failure: “How many patients that initially had deterioration went on into failure? Or [were there] those a priori with failure versus deterioration?”

“Actually we haven’t looked into that,” Søndergaard replied. “That’s a very good point to try to dive back [into] because this consensus report was only published last year and then we applied it.

“You’ve also seen there’s been some worrying reports about valve failure after TAVI,” he continued. “But I think what’s very important is if you want to talk about failure, you need [agreement on] how to define failure or dysfunction, both for the surgical group and for the transcatheter group, and maybe even more important, you need to have something to compare against. A failure rate by itself doesn’t say anything. You have to say, what was the alternative for the patient? In this case it would be surgery.”