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Low-Volume Cardiac Surgery Programs:  Mitral Valve Surgery Trends and Implications

John Meyer, LFACHE

In our continuing series on low-volume cardiac surgery programs (LVCS), we previously discussed structural heart programs and the importance of valve surgery volumes in the overall assessment of potential cases.

(Refer to Low-Volume Cardiac Surgery Programs:  Valve Surgery Trends and Implications, posted 6/28/18).

While the distribution of cardiac surgical cases presented in the The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2018 Update on Outcomes and Quality (based on 2016 data) favors isolated CABG (54% of total), total valve cases – inclusive of combined CABG/valve procedures, aortic valve replacement (AVR), mitral valve repair/replacement and combined aortic/mitral represent a significant total of 24% of the total cardiac surgery cases.[1] 

Increasingly, open-surgical procedures for AVR are being supplanted by transcatheter procedures, applicable to lower risk patient cohorts, which have a direct impact on overall hospital surgical volumes given the current regulatory limitations placed on hospitals to perform such procedures[2]

Cardiovascular research literature clearly affirms the use of TAVR will continue to grow.  With a prevalence of 4.5%, an estimated 16.1 million people aged ≥60 years across 37 advanced economies have aortic stenosis.  Of these, there are ≈1.9 million patients eligible for surgical aortic valve replacement and 1.0 million patients eligible for transcatheter aortic valve replacement.[3]

Like transcatheter aortic valve replacement (TAVR), mitral valve surgery, while a minority of total procedures, is being increasingly impacted by transcatheter procedures that, like TAVR, will have an impact on overall hospital volume of cardiac surgery cases either directly (by adding or deleting volume) or indirectly (by leakage or referral to TAVR/TMVR centers). A recent large scale worldwide market assessment conducted by the global research firm Business Communications Company (BCC) showed transcatheter mitral valve repair (TMVR) accounted for just 12 percent of transcatheter aortic or mitral procedures in 2017, according to the report, but are expected to grow faster over the next few years than the more established field of transcatheter aortic valve replacement (TAVR).

Transcatheter mitral valve repair (TMVR) accounted for just 12 percent of transcatheter aortic or mitral procedures in 2017, but is expected to grow faster than TAVR over the next few years

In 2023, BBC research predicts TMVR will account for 22 percent of the segment while TAVR will claim the other 78 percent—down from 88 percent in 2017. New interventional technologies, including Abbott’s MitraClip® and potentially Tendyne™ devices, will have the same, potentially profound impact on MVR, as TAVR devices did on AVR.  Therefore, it is important to consider both AVR and MVR strategies in the overall development of cardiac surgical programs, valve programs in particular, and LVCS programs especially.

Mitral Valve Surgery Volume and Distribution

Admittedly, mitral valve procedures currently represent a small total cardiac surgery volumes.  Referring to the STS data for CY 2016 referenced earlier, mitral valve replacement totaled 7,592, repair totaled 8,619 (total 16,211).  In addition, combination CABG plus MV repair/replacements totaled 6,349, for a grand total of 22,560.  These procedures represent approximately 13% of total adult cardiac surgeries during the reporting period.

The Clinical Challenge

Mitral valve disease creates anatomical changes that prevents the flow of blood between the left atrium and left ventricle through leakage or inadequate closure of the valve.  Managing these patients is clinically challenging, especially in frail or elderly patients, where the disease is most prevalent.  MV disease generally falls into three categories:

  • Stenosis, or narrowing of the valve opening
  • Prolapse (MVP), when the leaflets of the valve bulge or do not close tightly
  • Regurgitation (MVR), where significant backwards leakage of blood occurs

Depending upon the diagnosis, anatomical specificity, extent of damage, etc., the definitive treatment has historically relied on surgical repair or replacement with a bioprosthetic (tissue) or mechanical valve through a surgical approach for both MVP and MVR.  Stenosis can be treated with balloon valvuloplasty in many cases and is relatively rare.  Some large surgical centers are using robotics to repair valves.  Clinically, “MV repair is preferred over MV replacement whenever possible.[4] “ Of particular note is the belief that mitral valve replacement, and particularly repair, is a complex, clinical challenging, highly technical procedure heavily dependent upon both individual operator skill and organizational development and capacity to produce quality results.  LVCS programs that commit to valve programs are taking on a considerable challenge.

New and Developing Technologies

Transcatheter devices for valve repair and replacement have been approved for MVR since 2013 for the highest risk patients and are steadily supplanting open surgical approaches.  New and evolving technologies are also now in clinical trials.  Two are summarized below.

The MitraClip® for MV Repair

Abbott’s MitraClip technology, approved in 2013, now in its third generation, is a transcatheter-delivered device used to repair leaky mitral valves and has been used in over 65,000 patients worldwide over the last ten years.  Mitral valve regurgitation, or leakage, is the most common mitral valve problem.  MitraClip is appropriate for the patient that would be the highest risk surgical candidate. 

The Investigational Tendyne™ Device for MV Replacement[5]

A new transcatheter device, Tendyne, has been initially studied in Europe, and is has entered clinical evaluation with the SUMMITT trial in the U.S. as of July 2018.  This device is the first and only MR valve replacement that is repositionable and fully retrievable to allow for more precise implantation, with the hope of improving patient outcomes.  The study will enroll up to 1,010 patients in 80 sites in the U.S., Canada, and Europe.  The initial results of the European trial, released in May 2018, were promising.

Strategic Implications

Why should a LVCS program worry about a low-volume procedure such as mitral valve surgery, particularly when these patients tend to be referred (or self-refer) to high-volume, specialized valve surgery programs capable of utilizing the latest transcatheter technology and marketing themselves based on expertise and excellent clinical outcomes?  The answer is straightforward.  LVCS programs must aggressively (but realistically) understand the total market for cardiac surgery, its component clinical procedures, the overall market for these procedures, and their current and potential role in this market.  If there are patients that are being referred or leaking to competing programs, why are they going?  If it is a question of programming, clinical expertise, outcomes and/or technology, can these issues be successfully addressed to the concerned hospital’s advantage?  If so, what specifically would need to change? For most hospitals with a clear market opportunity the key strategic driver will be access to a skilled TMVR Cardiac surgeon with the right training and expertise. If not, are there ways to compensate for a “disadvantaged situation?”  For example, some hospitals without TAVR capability or minimum volume have negotiated arrangements with TAVR providers to do all pre- and post-TAVR diagnosis and follow-up short of the actual TAVR procedure itself.  Thus, they retain at least a portion of the TAVR patient business.  Could mitral valve cases be “retained” in a similar fashion?  It is well worth thinking about.


CFA has successfully worked with both low- and moderate-volume cardiac surgery programs to assist them in evaluating structural heart program development.  This work has focused on capturing as much available heart valve surgical volume as possible in the hospitals’ situation.  This assistance has included market analyses, strategy development, “readiness” assessment and program implementation tactics aimed at either starting a new program, or building upon an existing program.   It is important to understand the current market, the exact clinical nature of the potential cases that are being lost to competitors, and the existing and required programmatic and clinical capabilities that will be required to re-capture this important market.

If you are interested in learning more about low-volume cardiac surgery programs strategies, please download our updated and expanded white paper (see Low-Volume Cardiac Surgery Programs:  Grow, Consolidate or Divest:  Self-Preservation Strategies and Excellence Expectations, our expanded and updated White Paper).  If you are interested in cardiac services strategic development, service expansion and/or other programmatic needs for cardiovascular or other services, please contact CFA at (949) 443-4005 or by e-mail at  

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[1] D’Agostino, et al.  The Society of Thoracic Surgeons Adult Cardiac Surgery Database:  2018 Update on Outcomes and Quality.  Annals of Thoracic Surgery 2018; 105; 13-23.  Note that the distribution of procedures by type included in this update is for CY 2016 data.

[2] Whether or not current minimum volume requirements tied to Medicare reimbursement will be changed by CMS in FFY 2019 is open to speculation as it is currently under active consideration.



[4] Nishimura R.A., et al, 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guidelines for the Management of Patients with Valvular Heart Disease:  A Report of the ACC/AHA Task Force on Clinical Practice Guidelines, J. Am College of Cardiology 2017; 70:  252-289.

[5] Abbott Begins Tendyne Transcatheter Mitral Valve U.S. Pivotal Trial, Abbott Laboratories press release; July 26, 2018.



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