PARTNER: TAVR Remains as Effective as Surgery at 2 Years

CHICAGO, IL—Transcathether aortic valve replacement (TAVR) and surgical valve repair have similar mortality rates at 2 years in high-risk patients with aortic stenosis who are considered eligible for either procedure, according to results presented March 26, 2012, at the annual American College of Cardiology(ACC)/i2 Scientific Session. The results, simultaneously published in the New England Journal of Medicine, suggest fewer late strokes with TAVR in the long term and may quell some of the worries surrounding the issue.

Susheel K. Kodali, MD, of Columbia University Medical Center (New York, NY), presented the 2-year data from cohort A of the PARTNER (Placement of AoRTic traNscatheterER valves) trial, following up on the 1-year findings presented in April 2011at the annual ACC meeting, which showed similar mortality rates between TAVR and surgery but prompted concern over stroke rates with TAVR.

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). 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.

Similar Clinical Outcomes

At 2 years, all-cause death (primary endpoint) was equivalent between the 2 treatments. As with the 1-year results, major strokes trended higher for TAVR patients but the difference only reached significance when considering the composite of stroke/transient ischemic attack (TIA). Though major vascular complications were increased with TAVI, this difference was balanced by decreases in major bleeding and MI (table 1).

Table 1. Clinical Outcomes at 2 Years

 

TAVR

(n = 348)

Surgery

(n = 351)

P Value

All-Cause Death

33.9%

35.0%

0.78

Major Stroke

7.7%

4.9%

0.517

All Stroke/TIA

11.2%

6.5%

0.05

Major Vascular Complications

11.6%

3.8%

< 0.001

Major Bleeding

19.0%

29.5%

0.002

Endocarditis

1.5%

1.0%

0.61

MI

0

1.5

0.05

However, though “there is clearly a periprocedural hazard of TAVR compared to surgery of stroke, as presented last year, after this initial acute hazard, there is no difference in stroke event rates beyond 30 days,” Dr. Kodali noted. In fact, after 30 days there was a higher incidence of stroke in the surgery cohort (n = 12) vs. TAVR patients (n = 8). This was also true when TIAs were added (n = 18 for surgery, n = 15 for TAVR).

“Between 12 and 24 months, there is a 1.7% event rate in both groups. In the course of the entire follow-up, there was no hazard with TAVR compared with surgery for stroke,” he said.

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

Moderate or severe paravalvular regurgitation was more frequent after TAVR than after surgery at both 1 and 2 years (7.0% vs. 1.9% at 1 year, 6.9% vs. 0.9% at 2 years, P < 0.001 for both). The presence of paravalvular or total aortic regurgitation was associated with increased late mortality (HR 2.11; 95% CI 1.43 to 3.10; P < 0.001), and though the effect was proportional to the severity of the regurgitation, even mild aortic regurgitation was associated with an increased rate of late deaths.

Varied Experience Levels, Comparable Results

“TAVR should be considered an alternative to surgery with similar mortality and clinical benefits,” Dr. Kodali said. “Periprocedural stroke concerns after TAVR have diminished with longer follow-up. TAVR valve hemodynamics have remained stable although periprocedural [aortic regurgitation] has emerged as a predictor of late mortality.”

Going forward, Dr. Kodali said, “future efforts should be directed toward reducing TAVR procedure-related complications including strokes, vascular events, and paravalvular [aortic regurgitation].”

Panelist Alain G. Cribier, MD, of the University Hospital Charles Nicolle (Rouen, France), said that he was “impressed” to see the 2-year endpoints.

“I want to stress that this is really amazing because youd have on one hand a technique, open heart surgery, that was performed by extremely experienced centers, and most of the patients admitted to TAVR received the very first generation device and [the operators had] low experience of this technique when they started this trial,” Dr. Cribier said. “At the end, the results are comparable.”

With regard to aortic regurgitation, Dr. Cribier said it used to be a neglected parameter. Now that the complication’s effect on mortality is known, he said, “the good part is that we can do something, we can do a lot. We’ve learned a lot since the beginning of PARTNER [about patient selection and valvular sizing and positioning].”

Dr. Kodali agreed, and said although there is a learning curve with valvular positioning, “we’ve gotten better at some of these aspects and for those reasons paravalvular [aortic regurgitation] has been decreasing.” He also attributed the positive results to the use of post-dilatation.

Looking forward to third-generation devices, Dr. Kodali said “this procedure is going to continue to evolve…By reducing vascular complications, bleeding events, and stroke rates, we have opportunities to improve this procedure so that down the line the results will continue to improve.”

‘Justified’ Enthusiasm

Robert A. Guyton, MD, of the Emory University School of Medicine (Atlanta, GA), agreed “that [the interventionalists’] enthusiasm is justified” but said the “concern is whether some of the complications of [TAVR] are procedure- and device-related and that as we move to lower-risk patients, wondering if the procedure- and device-related issues can be improved.”

Ultimately, he concluded that “the appropriate steps are being taken to gradually move this to lower-risk patients, which is commendable, and I think we’re on the right pathway at least in the United States.”

Concurrent with the publication of the 2-year findings from PARTNER cohort A, 2-year findings from the trial’s cohort B looking at inoperable patients, were also published in the same issue of NEJM. The results show a lower mortality rate and improved functional status with TAVR vs. standard therapy (P < 0.001 for both), but a higher rate of stroke with TAVR (P = 0.01). Rehospitalization was higher in the standard therapy group (P < 0.001), and echocardiographic analysis showed an improvement in valve hemodynamics.

Sources:

  1. Kodali SK, Williams MR, Smith CR, et al. Two-year outcomes after transcatheter or surgical aortic-valve replacement. N Engl J Med. 2012;Epub ahead of print.
  2. Makkar RR, Fontana GP, Jilaihawi H, et al. Transcatheter aortic valve replacement for inoperable severe aortic stenosis. N Engl J Med. 2012;Epub ahead of print.

 

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Disclosures
  • Dr. Kodali reports serving as a principal site investigator for the PARTNER II Trial for Edwards Lifesciences; consulting for Medtronic and St. Jude Medical; and holding equity in Thubrikar Aortic Valve, Inc.

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