EVEREST II: Device reduced mitral regurgitation in patients at high risk for surgery

The MitraClip device may have a role in the treatment of symptomatic patients with moderate-to-severe or severe mitral regurgitation who are at high risk for mortality with mitral valve surgery, new data from the EVEREST II High Risk Study suggest.

“MitraClip device placement in this selected high-risk group is feasible, effective in reducing symptoms and improving clinical status, and relatively safe in patients who otherwise have no safe option to reduce mitral regurgitation,” the researchers said.

The High Risk Study included 78 symptomatic patients (mean age, 77 years) with 3+ to 4+ mitral regurgitation who underwent the MitraClip procedure (Abbott Vascular). More than 50% of patients had previous cardiac surgery; 46 had functional mitral regurgitation and 32 degenerative mitral regurgitation. The researchers also analyzed 36 patients in a comparator group who were screened for the High Risk Study but were not enrolled for various reasons.

Improvements over 12 months

According to results, the protocol-predicted surgical mortality rate in MitraClip patients was 18.2% and the Society of Thoracic Surgeons (STS) calculator estimated mortality rate was 14.2%. In the comparator group, surgical mortality rate was 17.4% and STS calculated estimated mortality rate was 14.9%.

Thirty-day procedure-related mortality was higher in the comparator group: 8.3% vs. 7.7%. However, 12-month survival was 76% in MitraClip patients vs. 55% in the comparator group (P=.047).

When the researchers examined surviving patients with matched baseline and 12-month data, 78% had a mitral regurgitation grade of <2+. Left ventricular end-diastolic volume improved in these patients from 172 mL to 140 mL; a similar trend was observed for LV end-systolic volume, from 82 mL to 72 mL (P=.001 for both). At baseline, 89% of patients had NYHA Class III/IV. At 12 months, 74% had NYHA Class I/II (P<.0001). Researchers also noted improvement in quality of life (from 32.1 to 36.1; P=.014) and mental component score (45.5 to 48.7; P=.065). Additionally, the annual hospitalization rate for congestive HF in surviving patients decreased from 0.59 to 0.32 (P<.02).

“Long-term follow-up is ongoing and needed to confirm whether the benefits observed at 12 months are sustained,” the researchers wrote.

Moving forward

In an accompanying editorial, Zoltan G. Turi, MD, of the department of internal medicine, and Michael Rosenbloom, MD, of the department of surgery, both at Cooper Medical School of Rowan University in New Jersey, said, “The preliminary results of the EVEREST High Risk Registry suggest that the percutaneous approach has a reasonable enough risk-to-benefit ratio that it should continue to be available, albeit only if performed under investigational protocols by operators skilled at transseptal puncture and working in institutions with extensive experience in percutaneous structural heart interventions as well as a proven track record with mitral valve repair in at least moderate-risk patients.”

For more information:

• Turi ZG. J Am Coll Cardiol. 2012;59:140-142.
• Whitlow PL. J Am Coll Cardiol. 2012;59:130-139.

Disclosure: The study is sponsored by Abbott Vascular, and some of the EVEREST II High Risk Study researchers report financial involvement with various companies. Dr. Turi has received grant support from Abbott Vascular and St. Jude Medical and is a consultant for St. Jude Medical. Dr. Rosenbloom is a consultant for St. Jude Medical and Edwards Lifesciences.

Renu Virmani

Although the technique [of this study] is difficult, the results look very promising. At 12 months, the vast majority [of patients] seemed to improve from whatever grade of baseline mitral regurgitation they had. Overall, this is a promising technique because the patients don’t have much of an option unless they could go to surgery. However, these are patients who were high risk and told they would not be able to undergo surgery. With that in mind, I think this is an option for patients who have severe mitral regurgitation.

– Renu Virmani, MD
Cardiology Today Editorial Board member

Disclosure: Dr. Virmani reports no relevant financial disclosures.

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