EVEREST II at 4 Years: Surgery Maintains Early Advantage, But MitraClip Durable

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At 4 years, patients with mitral valve regurgitation who undergo repair with a novel percutaneous device experience mortality rates and mitral regurgitation (MR) levels comparable to those that accompany surgery, according to updated data from the EVEREST II trial scheduled to be published online May 7, 2013, ahead of print in the Journal of the American College of Cardiology. While surgery continues to hold an early advantage in MR and need for surgical reintervention, few differences between treatment groups were apparent beyond 1 year.

The EVEREST II trial randomized 279 patients with moderately severe or severe (grade 3+ or 4+) MR in a 2:1 ratio to percutaneous treatment with the MitraClip system (Abbott Vascular; Santa Clara, CA; n = 184) or surgical repair or replacement (n = 95).

At 1 year, rates of the primary efficacy endpoint, a composite of freedom from death, surgery for mitral valve dysfunction, and grade 3+ or 4+ MR, favored surgery (73% vs. 55%; P = 0.007), with need for surgical intervention for mitral valve dysfunction tenfold lower than in the percutaneous group (2% vs. 20%; P < 0.01). However, the percutaneous approach was safer (30-day MACE 15% vs. 48%; P < 0.001).  

Both Approaches Show Durability

For the current study, investigators led by Laura Mauri, MD, of Brigham and Women’s Hospital (Boston, MA), analyzed data at 4-year follow-up. The composite efficacy endpoint was numerically higher with surgery, but the difference was no longer significant. Rates of mortality and moderate-to-severe and severe MR were comparable between the groups. However, the need for surgery for mitral valve dysfunction was almost 5 times greater after percutaneous therapy (table 1).

Table 1. Four-Year Cumulative Outcomes

 

Percutaneous
(n = 161)

Surgical
(n = 73)

P Value

Composite Efficacy Endpoint

39.8%

53.4%

0.070

Death

17.4%

17.8%

0.914

Surgery or Re-operation for Mitral Valve Dysfunction

 
24.8%

 
5.5%

 
< 0.001

MR 3+ or 4+

21.7%

24.7%

0.745

 
In the percutaneous group, 5 patients underwent reintervention with a second MitraClip within the first year. Implantation failed in 1 case, and a second, successful reintervention was performed between the first and fourth years. The majority of the surgeries required for residual regurgitation occurred within the first year after implantation, with only 3 patients undergoing surgical repair after that time point. In the surgical group, 2 patients underwent  reoperation over the first 12 months and 2 between years 1 and 4.

The surgical group experienced a greater reduction in MR at discharge and throughout follow-up compared with the percutaneous group (20.6% vs. 9.1% at 4 years). Also at 4 years, the percutaneous and surgical arms showed similar improvements in left ventricular dimensions, except for a larger left ventricular internal diameter, diastolic, in the device group (5.25 ± 0.65 cm vs. 4.84 ± 0.67 cm; P < 0.001). Likewise, both groups experienced substantial declines in the proportion of patients in NYHA class III or IV from baseline to 12 months (45.7% to 2% for the percutaneous group, 44.8% to 13.4% for the surgical group) that were mostly maintained at 4 years (5.7% and 6.3%, respectively).

Surgical Benefit Attenuated for Functional MR

Similar to the 1-year results, analysis at 4 years showed interaction for age (< 70 vs. ≥ 70; P = 0.025) and the etiology of MR (functional vs. degenerative; P = 0.023) with efficacy. In the subgroup with functional MR (n = 66), rates of the composite efficacy endpoint were similar for percutaneous and surgical patients (34.1% vs. 22.7%; P = 0.344). Furthermore, among those with 3+ or 4+ regurgitation, functional MR was more prevalent in the surgical arm than the percutaneous arm.

The authors observe that “[w]hile there was an upfront lower procedural success rate with percutaneous therapy in the overall trial population, if the percutaneous approach was initially successful, the results were durable, without evidence of late device complications.”

Interestingly, patients with functional MR appeared to derive greater benefit from percutaneous treatment relative to surgery, they note. While these subgroup findings are only exploratory, they say the hypothesis is being tested in 2 ongoing randomized trials of MitraClip vs. surgery.

Surgery Is ‘Best Bet’

Granted that the 4-year results for MitraClip are durable, it is important to keep in mind what those results are, said Jeffrey S. Borer, MD, of SUNY Downstate Medical Center (New York, NY), pointing to significantly larger left ventricular volume with percutaneous repair, which is a determinant of long-term survival.

In a telephone interview with TCTMD, Dr. Borer observed, “To me, the data suggest that if you want the best bet at getting the best possible results over the long haul, a relatively low-risk surgical procedure gives you that.” In addition, he noted, patients who undergo surgery for MR “have every expectation of living a lot longer than 4 years, so they want to know what things are going to be like at 10 or 15 years.” Even those who did well with MitraClip had a 1 in 5 chance of needing backup surgery, he added, although it is reassuring that having a device in place did not preclude successful surgery.

One reason the device may not perform as well as surgery, Dr. Borer said, is that while it repairs the leaflets, unlike surgery, it does not address mitral annulus problems, which contribute to residual MR.

MitraClip may prove appropriate for patients with functional MR, Dr. Borer acknowledged, but he stressed that further data are required to support that potential role. Additionally, the question of whether the device should be an option for patients ineligible for surgery is not addressed by EVEREST II, he added.

Dr. Borer concluded that while the percutaneous approach remains promising, “the data don’t yet tell us that we have a device solution that is as good as the surgical solution. As the authors say, surgery remains the standard.” 

Note: A coauthor of the study, William Gray, MD, is a faculty member of the Cardiovascular Research Foundation, which owns and operates TCTMD. 

 


Source:
Mauri L, Foster E, Glover DD, et al. Four-year results of a randomized controlled trial of percutaneous repair versus surgery for mitral regurgitation. J Am Coll Cardiol. 2013;Epub ahead of print.

 

 

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EVEREST II at 4 Years: Surgery Maintains Early Advantage, But MitraClip Durable

At 4 years, patients with mitral valve regurgitation who undergo repair with a novel percutaneous device experience mortality rates and mitral regurgitation (MR) levels comparable to those that accompany surgery, according to updated data from the EVEREST II trial scheduled to
Disclosures
  • The EVEREST II trial was sponsored by Abbott Vascular.
  • Dr. Mauri reports receiving institutional grants from Abbott, Boston Scientific, Bristol-Myers Squibb, Cordis, Daiichi Sankyo, Eli Lilly, Medtronic, and Sanofi-Aventis.
  • Dr. Borer reports no relevant conflicts of interest.

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