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Mitral Valve Surgery Volume Matters

— Study supports having centers of excellence in mitral valve repair

Last Updated May 4, 2017
MedpageToday

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Mitral valve prolapse is more likely to be repaired successfully if operators perform the procedure at least 25 times a year, researchers found.

Records from a New York State mandatory-reporting cardiac surgery database showed that operators achieved a degenerative mitral valve repair rate of 67% on average. Operators with 10 or fewer cases annually had a mean as low as 48%, whereas surgeons with at least 51 such operations a year boasted a mean of 77% (P<0.001).

Action Points

  • Mitral valve prolapse is more likely to be repaired successfully if surgeons perform the procedure at least 25 times a year, based on data from a New York State mandatory-reporting cardiac surgery database.
  • Note that these data represent the first time that individual surgeon volume was directly linked to survival and freedom from reoperation after 1 year in patients operated on for degenerative mitral valve disease.

Over the median 6.8 years of follow-up, David H. Adams, MD, of Mount Sinai Medical Center in New York, and colleagues reported online in the Journal of the American College of Cardiology and at the American Association for Thoracic Surgery Centennial meeting in Boston that a was tied to:

  • Higher repair rate: adjusted OR 1.13 for every 10 mitral cases (95% CI 1.10-1.17)
  • Drop in reoperation risk: adjusted HR 0.45 for annual volumes of at least 25 cases (95% CI 0.26-0.76)
  • Improved 1-year survival: adjusted HR 0.95 for every 10 mitral cases (95% CI 0.92-0.98)

The low repair rate associated with a low-volume surgeon (fewer than 25 mitral cases annually) could be offset by having high-volume, high-repair rate surgeons working at the same institution (adjusted OR 1.79, 95% CI 1.24-2.60).

"This study adds further clarity to the American Heart Association and American College of Cardiology guidelines which already recognize that patients with degenerative mitral valve disease should be referred to experienced mitral surgeons whenever feasible," Adams said in a statement. "Our study found for the first time that individual surgeon volume was directly linked to freedom from reoperation and survival after 1 year in patients operated on for degenerative mitral valve disease."

He and his colleagues suggested that "a minimum volume target of 50, or even more, cases would be optimal."

"Of note, even among high-volume surgeons, there was a variability of degenerative repair rates observed, ranging from 19% to nearly 100%. This reflects that surgeon volume is not the only factor for better outcomes, and emphasizes the need for more transparency of surgeon factors and outcomes of degenerative mitral valve surgery for patients and referring cardiologists."

Training specialists in mitral valve repair is likely to be a good thing for patients both with complex disease and those who have no symptoms, the authors maintained.

"Practice does not make perfect, but, for most surgeons, practice certainly makes better," agreed the Cleveland Clinic's Marc Gillinov, MD, Stephanie Mick, MD, and Rakesh M. Suri, MD. In an accompanying editorial, the trio called the "jack of all trades" cardiac surgeon an outdated, "unattainable ideal."

Being average across the board "does not represent surgeons' best work," they wrote. "Excellence requires specialization. Today, trainees often choose to focus on particular areas within cardiac surgery: these include thoracic aortic disease, heart failure, congenital heart surgery, and transcatheter aortic valve replacement. Practicing surgeons should do the same. In addition, we must acknowledge that mitral valve repair should be added to this list of specialties."

For the editorialists, this applies to cases as "simple" as the P2 prolapse.

"We recognize that this statement will generate controversy, as it challenges the status quo. Accept or reject this data-driven recommendation by answering this question: 'Who do you want to fix your mitral valve?'"

Adams and colleagues accessed the New York State database that contained records of patients who underwent mitral surgery from 2002 to 2013, of whom 5,475 had degenerative disease. Two-thirds got mitral valve repair, while the rest got valve replacements.

Surgeons performed a median of 10 mitral cases a year (range one to 230) and had an average repair rate of 55%.

Low-volume operators tended to see more patients for urgent admissions and those with major comorbidities. "This leads to a double jeopardy, where sicker patients are adversely affected by the lower repair rates and poorer outcomes seen with lower-volume surgeons, and underscores the need to refer the highest-risk patients to high-volume surgeons," the authors commented.

Meanwhile, they admitted, "although the use of a statewide, rather than a single-center database improved our ability to detect reoperations, we could not identify patients with residual or recurrent mitral regurgitation, patients who underwent replacement for immediate failure of repair during the same operation, or patients who subsequently migrated out of state, potentially causing us to underestimate the rate of repair failure."

  • author['full_name']

    Nicole Lou is a reporter for MedPage Today, where she covers cardiology news and other developments in medicine.

Disclosures

Adams is National co-PI of the CoreValve U.S. Pivotal Trial (supported by Medtronic).

Mount Sinai receives royalties from Edwards Lifesciences and Medtronic for Adams' role in developing three valve repair rings.

Gillinov reported consulting for Edwards Lifesciences, Medtronic, St. Jude Medical, Abbott, and Cryolife; and has received research support from Tendyne and St. Jude Medical.

Mick and Suri had no disclosures.

Primary Source

Journal of the American College of Cardiology

Chikwe J, et al "Relation of mitral valve surgery volume to repair rate, durability, and survival" J Am Coll Cardiol 2017.

Secondary Source

Journal of the American College of Cardiology

Gillinov M, et al "The specialty of mitral valve repair: degenerative MV disease: who and where?" J Am Coll Cardiol 2017.