PARTNER: TAVR Still Safe, Effective at 3 Years, Stroke Risk Diminished

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Key Points:
  • At 3 years, TAVR shows equivalent mortality to surgery for high-risk patients with severe aortic stenosis
  • Stroke rates equalize, no longer a concern with TAVR
  • Focus to shift to procedural complications, patient selection, researchers say

By Yael L. Maxwell
Monday, March 11, 2013

SAN FRANCISCO, CA—Three-year results from the high-risk patient group of the PARTNER trial show similar outcomes in patients with severe aortic stenosis who underwent either transcatheter aortic valve replacement (TAVR) or surgical valve repair. The results were presented March 11, 2013, at the American College of Cardiology (ACC) Scientific Session/i2 Summit and showed that periprocedural stroke is less of a long-term issue than originally thought.

Vinod H. Thourani, MD, of Emory University (Atlanta, GA), presented 3-year data from cohort A of the PARTNER (Placement of AoRTic traNscatheterER valves) trial, following up on the 1- and 2-year findings presented in 2011 and 2012, respectively, at the annual ACC meeting, which showed similar mortality rates between TAVR and surgery but prompted concern over stroke rates with the transcatheter procedure.

Cohort A enrolled 699 high-risk, operable patients at 26 centers with a median age of 84.1 years. The patients, all of whom had symptomatic, severe aortic stenosis, were randomized to undergo either surgery (n = 351) or TAVR (n = 348) with the Edwards Sapien aortic valve system (Edwards Lifesciences, Irvine, CA).

Stroke No Longer a Major Issue

At 3-years, all-cause mortality (primary endpoint) was similar in the 2 study arms, as was stroke. Although major vascular complications were increased with TAVR, this difference was balanced by decreases in major bleeding and MI (table 1). There were also no instances of structural valve deterioration reported.

Table 1. Clinical Outcomes at 3 Years

 

TAVR
(n = 348)

Surgery
(n = 351)

P Value

All-cause Death

44.2%

44.8%

0.483

Stroke

8.2%

9.3%

0.763

All-cause Death or Stroke

47.1%

45.9%

0.839

Major Vascular Complications

12.5%

3.8%

< 0.001

Major Bleeding

20.8%

31.5%

0.003

Endocarditis

1.5%

2.6%

0.37

MI

1.1%

2.7%

0.23


Multivariate analysis found separate baseline predictors for TAVR (BMI, A-fib, mean gradient, liver disease, and renal disease) than for surgery (CABG, pacemaker, moderate or severe MR, liver disease, and STS risk score). When mortality predictors were pooled between the study groups, they included BMI, A-fib, mean gradient, liver disease, and STS risk score.

Both surgery and TAVR improved New York Heart Association functional class, with TAVR holding the advantage at 30 days but not 1, 2, or 3 years.

Moderate or severe paravalvular regurgitation was more frequent after TAVR than after surgery at 1, 2, and 3 years (P < 0.001 for all). The presence of paravalvular or total aortic regurgitation was associated with increased late mortality and though the effect was proportional to the severity of the regurgitation, even mild aortic regurgitation was associated with an increased rate of late death.

Focus Shifts to Procedural Complications, Patient Selection

“TAVR should be considered an alternative to surgery with similar mortality and similar other major clinical outcomes,” Dr. Thourani said. “Periprocedural stroke concerns after TAVR have diminished with longer term follow-up, and TAVR valve hemodynamics have remained stable, although periprocedural regurgitation, even mild, has emerged as a predictor of late mortality.”

Research in the field should now focus on “reducing TAVR procedure-related complications, including strokes, vascular events, and paravalvular regurgitation,” he concluded.

Panelist Bernard J. Gersh, MD, of the Mayo Clinic (Rochester, MN), said, “What we have to learn is to better select patients. The real challenge is going to be how to identify people who have a reasonable 5-year survival for this expensive and complex procedure.”

“Unfortunately,” Dr. Thourani replied, “we’ve been using the STS as our 1 baseline predictor for what patients get what therapy.” What would beneficial, he added, and is in the early stages of development, is a transcatheter valve-specific risk score. “That will really enlighten us on which patients to operate on. We’ve been using a great tool in the STS score, but it’s not perfect for transcatheter valves.”

Combining the PARTNER data with a non-randomized cohort, Dr. Thourani said he anticipates being able to have a “very good outline of which patients to offer this therapy to or not to” within the next year.

Study Details

Among the TAVR group, 244 subjects received treatment using transfemoral access and 104 via the transapical route. Baseline characteristics were largely similar across the 2 treatment groups, although TAVR patients treated transapically had a higher risk profile.

 


Source:
Thourani VH. Three-year outcomes after transcatheter or surgical aortic valve replacement in high-risk patients with severe aortic stenosis. Presented at: American College of Cardiology Scientific Session/i2 Summit; March 11, 2013; San Francisco, CA.

 

Disclosures:

·         Dr. Thourani reports receiving research support from Edwards Lifesciences and Sorin Medical; consulting fees from Sorin Medical and St. Jude Medical; and owning equity/stocks and holding intellectual property rights in Apica Cardiovascular.

 

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