Mitral Valve Repair Versus Replacement for Ischemic Mitral Regurgitation: Controversy Remains Alive - Letter 2

Mitral Valve Repair Versus Replacement for Ischemic Mitral Regurgitation: Controversy Remains Alive - Letter 2

1490 CORRESPONDENCE References 1. Dayan V, Soca G, Cura L, Mestres CA. Similar survival after mitral valve replacement or repair for ischemic mitral...

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1490

CORRESPONDENCE

References 1. Dayan V, Soca G, Cura L, Mestres CA. Similar survival after mitral valve replacement or repair for ischemic mitral regurgitation: a meta-analysis. Ann Thorac Surg 2014;97: 758–65. 2. Onorati F, Santini F, Dandale R, et al. Functional mitral regurgitation: a 30-year unresolved surgical journey from valve replacement to complex valve repairs. Heart Fail Rev 2014;19:341–58. 3. He S, Lemmon JD Jr, Weston MW, Jensen MO, Levine RA, Yoganathan AP. Mitral valve compensation for annular dilatation: in vitro study into the mechanisms of functional mitral regurgitation with an adjustable annulus model. J Heart Valve Dis 1999;8:294–302.

Ann Thorac Surg 2015;99:1488–92

Rocío Díaz, MD Daniel Hernandez-Vaquero, MD, PhD Heart Department Central University Hospital of Asturias Celestino Villamil Oviedo, Spain e-mail: [email protected] Zain Khalpey, MD, PhD Division of Cardiothoracic Surgery University of Arizona Medical Center Tucson, AZ Cesar Morís, MD, PhD

MISCELLANEOUS

Mitral Valve Repair Versus Replacement for Ischemic Mitral Regurgitation: Controversy Remains Alive - Letter 2 To the Editor: Despite the publication of a rigorous metaanalysis addressing the controversy of repair or replacement for a severely regurgitant mitral valve in ischemic patients, the authors of this article [1] commented that a prospective randomized trial [2] was being developed to clarify this dilemma. This trial, published earlier this year by Acker and colleagues [2] concluded that, although there was no difference in postoperative survival, the rate of moderate mitral regurgitation at 1 year was almost 15 times higher in the repair group [2]. These findings may indicate that a mitral valve replacement should be the first-choice treatment for severe ischemic mitral regurgitation. However, we believe that these results should be interpreted with caution. It is known that complete preservation of the subvalvular apparatus may produce disc interference when mechanical prostheses are used and can often be a lengthy process. Biologic prostheses, however, do not have this problem, and that makes them easier to introduce, although their life expectancy is limited. This recent trial [2] fails to inform us of the type of implanted prosthesis, nor does it specify the surgical approach and technique. Additionally, this study [2] has not accounted for factors that can accurately predict the recurrence of mitral valve regurgitation after a repair. It is well known that leaflet tethering is the key to prediction of this complication. This tethering, produced as a consequence of left ventricular remodeling, can be quantified by echocardiographic measurements such as interpapillary muscle distance, coaptation depth, or left ventricular end-diastolic index [3]. In this trial [2], patients in whom recurrence of mitral regurgitation was expected could undergo a repair and were compared with patients who underwent a replacement. Interestingly, postoperative surveillance [3] has shown that more than 95% of patients with recurrent mitral regurgitation after repair during the follow-up period previously had an interpapillary muscle distance of more than 20 mm. Therefore, Acker and colleagues [2] do not conclude something new: improperly selected patients do better with a valve replacement rather than a repair. However, one still has to ask whether a mitral valve replacement with complete preservation of the subvalvular apparatus fares better or the same as a repair in appropriately selected patients and in experienced hands. Thus, the controversy remains alive.

Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier

Heart Department Central University Hospital of Asturias Celestino Villamil Oviedo, Spain

References 1. Dayan V, Soca G, Cura L, Mestres CA. Similar survival after mitral valve replacement or repair for ischemic mitral regurgitation: a meta-analysis. Ann Thorac Surg 2014;97:758–65. 2. Acker MA, Parides MK, Perrault LP, et al. Mitral-valve repair versus replacement for severe ischemic mitral regurgitation. N Engl J Med 2014;370:23–32. 3. Roshanali F, Mandegar MH, Yousefnia MA, Rayatzadeh H, Alaeddini F. A prospective study of predicting factors in ischemic mitral regurgitation recurrence after ring annuloplasty. Ann Thorac Surg 2007;84:745–9.

Reply To the Editor: “To be simple is no small matter” –Gustave Flaubert Recently, Acker and colleagues [1] published the first randomized trial regarding repair versus replacement in ischemic mitral regurgitation. This trial included 8 centers that were highly experienced in mitral repair. Subvalvular repair techniques were mandatory in case significant tethering was found. Surprisingly (or not), their findings were identical to our results [2]. The main results included no differences in mortality, survival, or changes in ventricular function or dimensions and an excessive increase in mitral recurrence in the repair group. Are these results because surgeons in the trial were inexperienced in mitral valve repair? We certainly do not think so. Mitral valve repair for ischemic mitral regurgitation is an exquisite handcrafted procedure that requires highly trained surgeons and echocardiographers. Reports from these highly trained centers may be misleading for the general surgical community. External validity is a main issue in these studies. Should guidelines base their recommendations on results from high-volume mitral centers? Conversely, mitral valve replacement is a simple and reproducible technique. Meta-analysis and randomized trials are able to increase external validity and therefore are of use for the general surgical community. The most important take-home message from our meta-analysis, which was later confirmed by the trial of Acker and colleagues, is that mitral valve replacement with preservation of the subvalvular apparatus has mortality and survival similar to that of

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