Editorial Comment Percutaneous Balloon Versus Surgical Closed Commissurotomy for Mitral Stenosis John W. Kirklin, MD T he elegant paper by Turi and colleagues in this issue of Circulation' describes a well-conducted randomized trial and contains important information about therapy. It does invite some discussion of open and closed surgical commissurotomy, possible flaws in the study described, criteria to use as surrogates for outcome events, and the bases for decision-making in individual patients. Although controversy as to the comparative benefits of open and closed surgical commissurotomy continues, currently the latter is performed uncommonly in more-developed countries. Nonetheless, there is no evidence that the prevalence of unfavorable outcome events is any different when one or the other surgical method is used. Indeed, in a recent study by Hickey and colleagues2 of a heterogeneous group of 331 patients treated by open or closed surgical commissurotomy, with detailed and nearcomplete follow-up of up to 20 years and riskadjusted comparison of the outcomes of the two types of surgical commissurotomy, no difference was found in survival, freedom from thromboembolism, duration of palliation of symptoms, or freedom from reintervention. Patient-specific risk factors for unfavorable outcome events were identified. The patients cared for and studied by Turi and colleagues' had no unfavorable risk factors. See p 1179 In a similar study of outcome events after percutaneous balloon commissurotomy (P. Block, I.F. Palacios, J.W. Kirklin, E.H. Blackstone, and E. Block, unpublished observations), but with follow-up for only 2 years, patient-specific risk factors for unfavorable outcome events were also identified. In patients with pliable leaflets and without subvalvar disease, who were thus similar to those cared for by Turi and colleagues,' the 2-year freedom from death, important symptoms, and mitral valve replacement after balloon commissurotomy, predicted by equaThe opinions expressed in this editorial comment are not necessarily those of the editors or of the American Heart Association. From the Division of Cardiothoracic Surgeiy, Department of Surgery, University of Alabama at Birmingham School of Medicine and Medical Center, Birmingham, Ala. Address for correspondence: John W. Kirklin, MD, Department of Surgery, University of Alabama at Birmingham, UAB Station, Birmingham, AL 35294

tions derived from the observations by Block et al, is 77% (70% confidence limits, 64-86%); in similar patients, that predicted after surgical commissurotomy by equations from the Hickey study2 is 98% (70% confidence limits, 97-99%). Turi and colleagues' de-emphasized the limited information they had concerning outcome events. However, among their 20 patients randomly assigned to the percutaneous balloon method for commissurotomy, one crossed over immediately to surgical commissurotomy, and one underwent mitral valve replacement shortly after balloon commissurotomy. This left, at 1 week, only 18 of 20 patients (90%; 70% confidence limits, 78-97%) free of a surgical procedure after randomly assigned percutaneous balloon commissurotomy, and only 18 of 19 patients (95%; confidence limits, 83-99%) who actually received balloon commissurotomy free of mitral valve replacement. All 20 patients randomized to balloon commissurotomy are considered to have survived to 8 months, but seven (18%) of the total group of 40 patients were untraced at 8 months. It is well known that untraced patients have a higher prevalence of unfavorable outcome events than traced patients,3 although in the study by Turi and colleagues the patients' being in the rural area of India is blamed. The functional status was said to be good at 8 months in all patients of Turi et al, but the limitation imposed by the considerable number of untraced patients is again pertinent. Information about the risk-adjusted time-related functional status, freedom from valve replacement, and survival is required, in my opinion, for judging the comparative benefits of surgical commissurotomy and percutaneous balloon commissurotomy for mitral stenosis. In the case of percutaneous commissurotomy, an additional appropriate criterion of benefit is the duration of freedom from an operation of any type on the mitral valve. Pulmonary arterial wedge pressures, mitral valve gradients, and calculated mitral valve areas, objective criteria as they are, are surrogates for the outcome events, not the outcome events themselves. These hemodynamic variables are correlated with the symptomatic status at the time they are determined, but their prognostic value for the time-related outcome events in patients with mitral stenosis is ill defined. Thus, a complete eval-

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Kirklin Percutaneous Balloon Versus Surgical Commissurotomy

uation of percutaneous balloon commissurotomy as a substitute for surgical commissurotomy and its welldefined outcome benefits probably requires a comparison in the domain of the time-related outcome events themselves. Nonetheless, I am in general agreement with the thrust of the study by Turi and colleagues.' If the institution performing the balloon commissurotomy has a low prevalence of untoward events associated with the procedure itself, percutaneous balloon commissurotomy would appear to be the initial procedure of choice for patients with important mitral stenosis with mobile leaflets and minimal chordal thickening or agglutination. This avoids a surgical procedure and provides a 75% probability of survival for several years with a good functional result and without valve surgery. In patients with somewhat immobile leaflets or considerable chordal thickening and agglutination, the probability of being alive, without valve surgery, and in New York Heart Association class I or II for at least 2 years after balloon commissurotomy is slightly less than 30% (unpublished observations by Block et al), whereas after


surgical commissurotomy 70% are predicted to be alive, without valve replacement, and in NYHA class I or 11.2 In patients with chordal thickening and agglutination an open surgical technique is preferable, not only because of the more favorable outcome of surgical commissurotomy but also because, with an open technique, valve replacement can be performed at that time should the morphology of the mitral stenosis be more unfavorable than expected. References 1. Turi ZG, Reyes VP, Raju BS, Raju AR, Kumar DN, Rajagopal P, Sathyanarayana PV, Rao DP, Srinath K, Peters P, Connors B, Fromm B, Farkas P, Wynne J: Percutaneous balloon versus surgical closed commissurotomy for mitral stenosis: A prospective randomized trial. Circulation 1991;83:1179-1185 2. Hickey MSJ, Blackstone EH, Kirklin JW, Dean LS: Outcome probabilities and life history after surgical mitral commissurotomy: Implications for balloon commissurotomy. J Am Coil

Cardiol 1991;17:29-42 3. Austin MA, Berreyesa S, Elliott JL, Wallace RB, BarrettConnor E, Criqui MH: Methods for determining long-term survival in a population based study. Am J Epidemiol 1979;110: 747-752

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Percutaneous balloon versus surgical closed commissurotomy for mitral stenosis. J W Kirklin Circulation. 1991;83:1450-1451 doi: 10.1161/01.CIR.83.4.1450 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 1991 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539

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Percutaneous balloon versus surgical closed commissurotomy for mitral stenosis.

1450 Editorial Comment Percutaneous Balloon Versus Surgical Closed Commissurotomy for Mitral Stenosis John W. Kirklin, MD T he elegant paper by Turi...
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