TAVR Durability: Some Reassurances From CoreValve Trials Out to 9 Years

PARIS, France—Debate continues over TAVR’s durability and exactly why the devices sometimes deteriorate over time. Three studies on the CoreValve self-expanding bioprosthesis (Medtronic), presented yesterday at EuroPCR 2017, are helping to fill the knowledge gap by looking at what happens by 5 years and up to 9 years post-TAVR.

Session co-chair Raj Makkar, MD (Cedars-Sinai Medical Center, Los Angeles, CA), told TCTMD the “great news” now is that 30-day mortality and stroke rates are around 2% across a wide range of TAVR devices, with 1-year survival of around 90%. “I think it tells us the devices have matured and our technique has matured,” he commented.

What happens as the years go by, however, is less clear. Longer-term data on the earliest-generation valves presented last year at EuroPCR 2016 by Danny Divr, MD (UW Medicine, Seattle, WA), first piqued concerns over how transcatheter valves stand the test of time. “What we can say is that the current data sets are limited in terms of making any definitive conclusions about durability because of the competing mortality risk in this patient population,” Makkar said. Though flawed, the reintervention rate can be an informative surrogate, he added.

As such, the new findings shared here offer reassurance, Makkar said, and more will be forthcoming. With time, he observed, “a lot more patients will survive, and that will give us a lot more data on durability.”

Nine Years

Luca Testa, MD, PhD (IRCCS Policlinico San Donato, Milan, Italy), who presented 9-year numbers, said these sorts of studies can help us envision how TAVR might fare in younger and less-sick patients. “Our data suggest a very low rate of ‘clinically relevant’ bioprosthesis failure and provide evidence about reassuring long-term performance,” he commented.

Sharing his registry findings from the Clinical Service Project, Testa said that 2,343 patients have received either CoreValve or Evolut R (Medtronic) at 13 Italian centers between June 2007 and December 2016. The lengthiest follow-up has reached 9 years, with a mean duration of 22 months.

The number of patients was so few at 9 years that investigators truncated their analysis at 7 years, when the mortality rate was 68.1%. Twenty prosthesis-related clinical events, including six deaths and 14 events that led to new rehospitalization for heart failure, occurred over 7 years. The annual rate ranged from 0.2% to 1.5%. No such events happened beyond 7 years. Additionally, the rates of mild and moderate paravalvular leak held steady between discharge and last available follow-up.

Five Years

Representing the NOTION trial investigators, Lars Søndergaard, MD, DMSc (Rigshospitalet, Copenhagen, Denmark), shared data from an all-comers population of 280 lower-risk patients at least 70 years old who were randomized to surgical (SAVR) or transcatheter valve replacement, using the CoreValve.

By 5 years, about three in 10 patients had died, with no difference between the two treatments. Effective orifice area was larger and mean gradient was lower with TAVR compared surgery (P < 0.001 for both). Moreover, patients undergoing SAVR were much more likely to show evidence of structural valve deterioration (mean gradient ≥ 20 mm Hg, ≥ 10-mm Hg change in mean gradient from baseline, or new or worsening moderate/severe intraprosthetic aortic regurgitation) than were patients undergoing TAVR (26.1% vs 3.9%; P < 0.0001); the difference was driven mainly by moderate deterioration.

Signs of bioprosthetic valve dysfunction—including issues that were structural and nonstructural and endocarditis, but no cases of thrombosis—occurred at comparable rates after TAVR and SAVR at 55.4% and 65.2%, respectively, through 5 years (P = 0.10). Bioprosthetic valve failure—including valve-related death, aortic valve reintervention, and severe hemodynamic structural valve dysfunction—was seen in 8.5% and 9.5% of the patients in the TAVR and SAVR groups (P = 0.89).

It’s a moving target, because the valves change. Danny Dvir

“It’s so challenging to look at long-term morbidity of valves, and probably it will take something like 3, 4, [or] 5 years until low-risk and some of the intermediate-risk patients survive enough and we’ll have a large pool of patients that will give us the magnitude to really do statistical analyses,” said Dvir, who was summoned from the audience following Søndergaard’s presentation. “But it’s a moving target,” he added, “because the valves change.”

Panelist Jean-François Obadia, MD (CHU Lyon, France), strongly disagreed, however, stressing that current devices are “the fruit of 30 years of fine-tuning surgery” and thus should have predictable durability.

More data, this time from the multicenter ADVANCE study, also addressed the 5-year performance of CoreValve. Ulrich Gerckens, MD (Gemeinschaftskrankenhaus, Bonn, Germany), presented results on 996 patients enrolled from March 2010 to July 2011.

By 5 years, half of patients had died and 10.2% had experienced stroke. The rate of emergent cardiac surgery/percutaneous intervention was 2.8%. Effective orifice area and mean gradient did not change over follow-up.

Multivariate predictors of 5-year mortality included various comorbidities, with the strongest association seen with acute kidney injury (HR 14.31; 95% CI 5.72-35.79). Patients with moderate or severe aortic regurgitation were less likely to survive than were those with mild or no aortic regurgitation. Survival did not differ by pacemaker use, whether new or existing at baseline.