ACC: TAVR Trials Demonstrate Device Durability

— CoreValve results improve over time, Sapien benefit holds at 5 years.

Last Updated March 16, 2015
MedicalToday

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SAN DIEGO -- Two years after implant, system continues to outperform surgical transaortic valve repair in high-risk patients with symptomatic aortic stenosis.

The valve is so durable that thoracic surgeon of Houston Methodist Debakey Heart and Vascular Center, told that he thinks "TAVR, with this valve, should be the preferred option over surgery in this high-risk population."

Action Points

  • Note that one study (CoreValve) was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
  • Two years after implant, Medtronic's CoreValve system continues to be superior to standard treatment in patients with severe aortic stenosis who are not suitable for surgery.
  • Note that among high-surgical risk patients with aortic stenosis, TAVR was associated with similar differences in all-cause mortality, cardiovascular mortality, stroke, and need for repeat hospital admission after 5 years compared with surgical aortic-valve replacement.

Reardon reported 2-year results from the CoreValve pivotal trial at a late-breaking clinical trials session at the American College of Cardiology annual meeting.

Reardon said that by every measure the self-expanding CoreValve was superior. For example, hemodynamics were superior for transcatheter aortic valve replacement (TAVR) "at all times points without any structural valve failure."

At 12 months, the difference in all-cause mortality was 4.8% favoring TAVR, but at 2 years that difference increased to 6.5% or a mortality rate of 22.2% for TAVR versus 28.6% for surgery (log rank P=0.04). In absolute terms, 219 of 391 TAVR patients survived to the 2-year mark versus 191 of 359 surgery patients.

For all strokes, the difference at 2 years was 5.7% favoring TAVR, which was also greater than the 3.8% benefit at 12 months (log rank P=0.05), Reardon said; however, there was no difference in major stroke.

TAVR patients had less aortic regurgitation between 30 days and 1 year, and the low level of paravalvular leaks was maintained at 2 years.

, assistant dean and chief of the division of medicine at Northwestern University Feinberg School of Medicine in Chicago, told that he was "impressed that a surgeon would be so enthusiastic," but he warned that patient selection will remain a concern. "I think we need to proceed with caution."

, chair of the Cardiovascular Governance Council at Baylor Scott and White Health of Texas and lead author of the PARTNER trial of the Sapien Transcatheter Aortic Valve System, noted that in the PARTNER studies, TAVR was as good as surgery, and “in a tie, the win goes to TAVR.”

Mack reported 5-year results in both the high-risk and surgically inoperable cohorts. The PARTNER studies, which were simultaneously published in the, tested the Sapien valve from Edwards Life Sciences versus either medical therapy -- for patients considered too ill for surgery -- or surgery in high-risk patients.

Also at ACC, investigators with the PARTNER trial reported 5-year results in both the high-risk and surgically inoperable cohorts. The PARTNER studies, which were simultaneously published in the, tested the Sapien valve from Edwards Life Sciences versus either medical therapy -- for patients considered too ill for surgery -- or surgery in high-risk patients. The PARTNER series demonstrated TAVR, while not inferior to surgery, did not provide a survival benefit.

"At 5 years, risk of death was 67.8% in the TAVR group compared with 62.4% in the SAVR group (hazard ratio 1.04, 95% CI 0.86-1.24, P=0.76)," wrote Michael J Mack, MD, describing the 5-year results from the high-risk surgery cohort of PARTNER. "We recorded no structural valve deterioration requiring surgical valve replacement in either group."

Moderate or severe aortic regurgitation occurred in 40 (14%) of 280 patients in the TAVR group and two (1%) of 228 in the SAVR group (P<0.0001), and was associated with increased 5-year risk of mortality in the TAVR group (72.4% for moderate or severe aortic regurgitation versus 56.6% for those with mild aortic regurgitation or less, P=0.003)."

Mack noted that even mild PVL was a “marker for mortality in PARTNER.”

The two PARTNER trials used a first generation device, which is no longer in use. Nonetheless, Mack said he was pleased that the device demonstrated durability, but he warned that 5 years is not a true test for a valve system.

“I've seen a lot of surgical valves that look good at 5 years, but then we see problems at 8 or 10 years.”

Five-year results from the cohort of PARTNER patients who were not eligible for surgical repair again showed the durability of the Sapien system, and the authors concluded that TAVR was preferable to standard (nonsurgical) management with both improved survival and better function.

"The risk of all-cause mortality at 5 years was 71.8% in the TAVR group versus 93.6% in the standard treatment group (HR 0.50, 95% CI 0.39-0.65, P<0.0001). At 5 years, 42 (86%) of 49 survivors in the TAVR group had New York Heart Association class 1 or 2 symptoms compared with three (60%) of five in the standard treatment group. Echocardiography after TAVR showed durable hemodynamic benefit (aortic valve area 1.52 cm² at 5 years, mean gradient 10.6 mm Hg at 5 years), with no evidence of structural valve deterioration," they wrote.

of the Piedmont Heart Institute in Atlanta, said the 2-year CoreValve results and the 5-year PARTNER results are not "game-changing but they reinforce what we are already doing."

"It is humbling that there is still mortality of 68% at 5 years, which highlights the high-risk nature of these patients," he added.

Disclosures

The CoreValve trial was supported by Medtronic.

Reardon disclosed relevant relationships with Medtronic.

The PARTNER trials were funded by Edwards Lifesciences.

Mack disclosed relevant relationships with Edwards Lifesciences andMedtronic.

Yancy disclosed no relevant relationships with industry.

Kandzari disclosed no relevant relationships with industry.

Primary Source

The Lancet

Mack MJ, et al "5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial" Lancet 2015; DOI: 10.1016/S0140-6736(15)60448-2.

Secondary Source

The Lancet

Kapadia SR, et al "5-year outcomes of transcatheter aortic valve replacement compared with standard treatment for patients with inoperable aortic stenosis (PARTNER 1): a randomised controlled trial" Lancet 2015; DOI: 10.1016/S0140-6736(15)60308-7.

Additional Source

American College of Cardiology

Source Reference: Reardon M, et al "A randomized comparison of self-expanding transcatheter and surgical aortic valve replacement in patients with severe aortic stenosis deemed at increased risk for surgery 2-year outcomes" ACC 2015.