The benefits of mitral valve reconstruction for operative

Prophylactic Mitral Reconstruction for Mitral Regurgitation Iva A. Smolens, MD, Francis D. Pagani, MD, PhD, G. Michael Deeb, MD, Richard L. Prager, MD, Seema S. Sonnad, PhD, and Steven F. Bolling, MD Section of Cardiac Surgery, Department of Surgery, University of Michigan Hospitals, Ann Arbor, Michigan Background. Mitral regurgitation (MR) will produce myocardial dysfunction. The goal of this study was to review outcomes of mitral valve reconstruction in asymptomatic patients with severe MR. Methods. From 1992 to 2000, 93 asymptomatic patients with degenerative disease and severe MR underwent mitral valve reconstruction. Mean preoperative left ventricular internal diameter diastole was 56 8 mm and ejection fraction was 60% 6%. Mean age was 47 10 years and mean follow-up 23 27 months. All patients underwent complex reconstruction. Results. There were no deaths and two late reoperations. One was for systolic anterior motion of the anterior leaflet of the mitral valve requiring valve replacement and one for hemolysis requiring re-repair. There was one perioperative transient ischemic attack and no late thromboembolic events. At follow-up all but 1 patient remains in NYHA class I and all had no MR except in 2 patients at 63 and 89 months. Conclusions. Mitral valve reconstruction for asymptomatic MR can be performed with no mortality and low morbidity before development of left ventricular dysfunction. Early prophylactic repair is advocated in the presence of severe MR if valve reparability is assured. (Ann Thorac Surg 2001;72;1210 6) 2001 by The Society of Thoracic Surgeons The benefits of mitral valve reconstruction for operative correction of mitral regurgitation (MR) are well established. These benefits include low perioperative mortality, preservation of left ventricular (LV) function, avoidance of long-term anticoagulation, decreased thromboembolic complications, a low risk of native valve endocarditis, excellent long-term freedom from reoperation, and improved survival as compared with that of patients undergoing valvular replacement [1 6]. The optimal timing of surgical intervention in MR remains controversial. It is difficult to decide when is the most appropriate time to operate on a patient with chronic MR, as these patients may remain asymptomatic or only mildly symptomatic for a long time. Unfortunately, all the while these patients are experiencing a subtle, relentless, silent deterioration in LV function. Historically surgery was delayed until either the patient was symptomatic or there was evidence of LV dysfunction because all that could be offered to the patient was mitral valve replacement. By the time the patients became symptomatic, however, serious and often irreversible LV dysfunction may have developed [7, 8]. The recognition of the advantages of mitral valve repair over replacement for MR has led to progressively earlier surgical intervention. Most authors and the current American College of Cardiology/American Heart Association guidelines now advocate surgical repair of Presented at the Thirty-seventh Annual Meeting of The Society of Thoracic Surgeons, New Orleans, LA, Jan 29 31, 2001. Address reprint requests to Dr Bolling, Section of Cardiac Surgery, The University of Michigan Hospitals, 2120D Taubman Center, Box 0348, Ann Arbor, MI 48109-0348; e-mail: sbolling@umich.edu. the mitral valve for MR in patients if more than mild symptoms develop (New York Heart Association [NYHA] functional class II or greater), if the ejection fraction (EF) falls toward 60%, or if the end-systolic dimension approaches 45 mm, even in the absence of symptoms, if the valve appears amenable to repair [7, 9]. Comparable to atrial septal defect repair, which is undertaken in asymptomatic young patients to prevent long-term sequelae of pulmonary hypertension, mitral valve repair should perhaps be considered before distortion of LV function occurs, to prevent long-term sequelae of congestive heart failure [9]. The clinical impact of surgical correction of MR in patients with no symptoms or mild symptoms is still unclear in terms of short- and long-term outcomes. In this study we reviewed a single center s experience of isolated mitral valve repairs in patients with myxomatous disease of the mitral valve with no or only mild symptoms. It is the goal of this study to assess surgical as well as valve-related morbidity and mortality, and to ascertain long-term functional status of the patients. Material and Methods Between July 1992 and December 2000 a total of 1,503 mitral valve operations (repair and replacement) were performed at the University of Michigan. This study was a retrospective review of a single institution s experience with the surgical correction of MR. The inclusion criteria were as follows: (1) mitral valve repair procedure performed between July 1992 and December 2000. (2) Preoperative NYHA functional class I or 2001 by The Society of Thoracic Surgeons 0003-4975(01)$20.00 Published by Elsevier Science Inc PII S0003-4975(01)02984-8

Ann Thorac Surg SMOLENS ET AL 2001;72:1210 6 PROPHYLACTIC MITRAL RECONSTRUCTION 1211 Table 1. Mechanism of Mitral Regurgitation Mechanism of Regurgitation Number % Posterior leaflet prolapse 42 45 Anterior leaflet prolapse 9 10 Bileaflet prolapse 42 45 Popped chords/flail leaflet 62 67 II. The patient s functional status was determined by review of their medical records. Patients were classified as NYHA class I if they had no symptoms and as NYHA class II if they had only minimal limitation of physical activity. (3) Isolated moderate-to-severe or severe MR (3 or 4 ) with no associated mitral stenosis as defined by preoperative echocardiography. (4) Degenerative/ myxomatous mitral valve disease as the underlying etiology of the MR. Patients who had a remote history of endocarditis superimposed on the degenerative disease were included. (5) Patients undergoing concomitant closure of a patent foramen ovale or atrial septal defect. The exclusion criteria were as follows: (1) MR attributable solely to geometric distortion of the LV, as seen in patients with dilated or ischemic cardiomyopathy. (2) Mitral regurgitation attributable to anatomic distortion of the mitral valve apparatus, other than that due to degenerative disease of the valve, as seen in rheumatic mitral valve disease or acute endocarditis. (3) Associated or previous surgical procedures including concomitant coronary artery bypass grafting or associated valve procedures. During this study period 1,211 mitral valve repair procedures were performed. Of these, 93 patients corresponded to the inclusion/exclusion criteria and they comprise our study population. The mean age was 47.2 10.2 years (range 21 to 69 years). There were 33 women (35%) and 60 men (65%). In all, 53 patients were in NYHA class I (57%) and 40 (43%) were in NYHA class II. All patients in this study had degenerative/myxomatous disease of the mitral valve as the sole underlying etiology of their MR; the mechanisms of MR are summarized in Table 1. Five of the patients had a remote history of endocarditis (5.3%). Nineteen patients (20.4%) underwent incidental closure of a patent foramen ovale and 3 (3.2%) underwent atrial septal defect (1 patch, 2 primary) closure simultaneous with the mitral valve repair procedure. The severity of MR was assessed by either transthoracic or transesophageal echocardiography. Of the 93 study patients, 89 (96%) had complete preoperative echocardiographic measurements. Eleven (12%) of the 93 study patients had a documented preoperative episode of atrial fibrillation or atrial flutter. The decision to operate on these patients was based on the presence of moderate-to-severe or severe MR (3 or 4 ) and if the valve appeared amenable to repair based on its echocardiographic appearance. Valve repair was attempted and successfully performed in all 93 patients. Mitral valve reconstruction included implantation of an annuloplasty ring in all cases; circumferential (69 cases) and hemi-ring (24 cases). The additional complex repair Table 2. Mitral Valve Repair Techniques Utilized Repair Technique Number % Posterior quadrangular resection 80 86 Anterior leaflet resection 10 11 Chordal shortening 4 4 Chordal transposition 67 72 Gore-Tex prosthetic chords 23 25 techniques used are outlined in Table 2. All patients underwent intraoperative transesophageal echocardiographic assessment of the valve to ensure that there was no residual MR or mitral stenosis upon completion of the repair procedure. All patients received anticoagulation with warfarin at the time of discharge and were maintained on anticoagulation for 1 month after the procedure, with an International normalized ratio of 2.0 to 2.5. All postoperative patient care was standardized by preestablished pathway protocol. Follow-up data were collected through review of the medical records maintained at our institution. Telephone contact with patients was initiated if follow-up data were not available in the records. Complete follow-up data were available for 87 (94%) patients. Mean follow-up was 23.5 26.9 months, for a cumulative follow-up of 180 patient-years. Statistical Analysis All data are reported as mean one standard deviation. Student s t test for unpaired data was used to analyze the significance of differences between preoperative and postoperative echocardiographic data. The Kaplan-Meier method was used for calculating the complication and risk of reoperation rates. The statistical analysis was performed according to the protocols incorporated in the STATA statistical software package (Stata Corporation, College Station, TX). Statistical significance was defined at a p value less than or equal to 0.05. Results Mortality There were no deaths, for a 100% 5-year survival rate. Hospital Length of Stay The mean length of stay in the hospital was 4 2 days. Perioperative Morbidity All patients identified with NYHA functional class I or II with 3 to 4 MR and who underwent isolated correction of their MR had repair at the initial operation. No patients were identified as potential mitral valve repair candidates, who then underwent initial mitral valve replacement. One patient required reoperation for bleeding within the first 24 hours after the procedure and there were no adverse sequelae related to this event. Two patients developed significant pericardial effusions in the perioperative period and both were treated with drain-

1212 SMOLENS ET AL Ann Thorac Surg PROPHYLACTIC MITRAL RECONSTRUCTION 2001;72:1210 6 Reoperation-Free Survival and Valve-Related Complications There have been two (2%) late reoperations at 8 and 10 months for valve repair failure. In the first case, the patient underwent anterior leaflet resection, chordal shortenening, and annuloplasty for severe bileaflet prolapse. The cause for reoperation was the late development of significant exercise-induced LV outflow tract obstruction that developed secondary to failure of the chordal shortening procedure. At reoperation, the patient underwent mitral valve repalacement with a mechanical prosthesis. In the second case, the patient underwent postorior leaflet resection and annuloplasty for bileaflet prolapse. The reason for reoperation in this case was the development of severe hemolysis, and at the time of the operation the patient was found to have a ruptured anterior chordal group. This pathology was amenable to rerepair with an anterior leaflet resection and insertion of Gore-Tex (W.L. Gore & Associates, Flagstaff, AZ) prosthetic chords. No deaths occurred with reoperation. At 5 years, the rate of freedom from reoperation was 96.5% 2.5% (CI 0.8643 to 0.9913) as shown in Figure 1. One patient (1%) had a thromboembolic event in the immediate postoperative period. This patient had a transient ischemic attack with complete resolution of symptoms. All patients received anticoagulation for the first month after the procedure and there were no anticoagulation-related complications. One patient is maintained on long-term anticoagulation for his prosthetic valve, and to date there have been no significant hemorrhagic complications. Three patients developed mild and selflimiting hemolysis in the postoperative period 3, 8, and 8 months postoperatively. Two of these 3 patients have been noted to have moderate MR (2 ) on follow-up echocardiography, yet they remain asymptomatic. No patients in this study group have had valvular endocarditis following a repair procedure. Five-year freedom from any event (thromboembolism, anticoagulantrelated hemorrhage, hemolysis, infection, mediastinitis, and endocarditis) was 89.6% 5.6% (CI 0.7121 to 0.9654) as shown in Figure 2. Fig 1. Actuarial curve of 5-year freedom from reoperation. age procedures without any complications. These 3 patients had significant 30-day perioperative events that required a second intervention, for a cumulative rate of 3.2%. Atrial Fibrillation Eleven (11.8%) patients had a history of atrial arrhythmias at the time of their presentation for surgical evaluation. None of the patients had been in chronic atrial fibrillation. Eighteen (19.5%) patients developed atrial fibrillation in the immediate postoperative period (30 days), all of whom responded to either chemical (15 patients) or electrical (3 patients) cardioversion, and there was no correlation between those patients who had experienced atrial fibrillation preoperatively and postoperatively. All but 1 patient currently (1.1%) remains in sinus rhythm at follow-up. No patients experienced heart block or required permanent pacemaker insertion. Functional Status Preoperatively a total of 53 patients were in NYHA class I (57%) and 40 (43%) were in NYHA class II. Of the 87 patients with complete follow-up data, 86 patients remain in NYHA class I and 1 patient is in NYHA functional class II. Echocardiographic Data As determined by preoperative echocardiographic studies, all patients had grade 3 (37%) or 4 (63%) MR on a scale of 1 to 4, with a mean of 3.6 0.5. The mean preoperative LV end-systolic and end-diastolic diameters were 36.7 7.0 mm and 56.0 8.5 mm, respectively, and only 28 patients (31%) had an LV end-diastolic diameter greater than 60 mm. The mean left atrial diameter was 43.0 8.3 mm. Postoperative two-dimensional echocardiography with Doppler examination was available in 30 (32.3%) patients. The mean follow-up time at which these studies were performed was 24.8 25.8 months after the Fig 2. Actuarial curve of patients free from an event (valve-related episode of thromboemboli, hemorrhage, hemolysis, infection, mediastinitis, endocarditis) in the postoperative period as a function of time after the initial operation.

Ann Thorac Surg SMOLENS ET AL 2001;72:1210 6 PROPHYLACTIC MITRAL RECONSTRUCTION 1213 Table 3. Preoperative and Postoperative Echocardiographic Data valve repair procedure. These echocardiographic data show that the LV chamber dimensions decrease significantly after the repair procedure. The data are summarized in Table 3. The mean grade of residual MR as recorded at late follow-up was 0.41 0.8, attributable entirely to 3 patients who had grade 2 or greater residual MR at follow-up. Comment Preoperative Follow-up p Value LVIDd 56.6 8.3 45.7 4.8 0.001 LVIDs 39.2 7.9 32.4 5.9 0.001 LAD 43.9 7.6 41.2 4.9 0.07 EF 58.8 5.9 60.0 4.5 0.225 (NS) MR 3.7 0.5 0.4 0.8 0.001 p 0.05. EF ejection fraction (%); LAD left atrial diameter (mm); LVIDd left ventricular internal diameter diastole (mm); LVIDs left ventricular internal diameter systole (mm); MR mitral regurgitation (grade 1 to 4 ). To consider surgical intervention early in a disease process, it must be demonstrated that the surgical procedure improves the overall survival and quality of life in comparison to the disease process natural course. Degenerative/myxomatous disease of the mitral valve represents the leading cause of isolated MR that requires surgical intervention in the United States [10]. Mitral regurgitation is a progressive disorder that leads to enlargement of the left atrium and ventricle, increased left ventricular filling pressure, and reduced afterload. All of these physiologic alterations contribute to annular dilation and worsening of leaflet coaptation, which then results in more MR [11]. As the MR progresses, dilation and hypertrophy of the LV occur. The clinical markers of LV dysfunction are when the EF falls to less than 60% or the LV diameter at end-systole is greater than 45 mm [7]. Previous studies have demonstrated that the contractile function of the LV is impaired in patients with MR, even in the presence of a normal EF [12]. In patients with severe MR and LV dysfunction, after surgical correction of the regurgitation, there is no demonstrable improvement in contractile function [13]. The presence of LV dysfunction in the postoperative patient carries a poor prognosis, suggesting that operative repair should be considered before the development of the functional impairment. In this study, the decision to operate was based on assessment of the severity of the MR and the feasibility of repair. Myxomatous mitral valve disease in this series was 100% repairable with the initial operative procedure. There were no patients in this series who had an initial preoperative plan of valve repair who ultimately required valve replacement. This success reflects both our routine use of intraoperative transesophageal echocardiography to assess valvular competence postrepair, as well as the surgeons extensive experience with mitral valve reconstruction. In our series, there were no perioperative deaths and only 3 patients had significant 30-day perioperative morbid events for a cumulative operative morbidity risk of 3.2%. Additionally, 18 patients (19.5%) developed perioperative atrial fibrillation, and all of these patients converted back to normal sinus rhythm at 30-day follow-up. Based on our study data as well as that data published in the literature, the short-term perioperative risks of the surgical procedure itself are minimal and deemed to be acceptable. The natural history of medically treated MR is difficult to delineate, with a wide range of survival estimates in the literature [14]. The best data so far are from the study by Ling and colleagues [15], which defined the natural history of MR. In this study the outcomes of 229 patients with isolated MR who were asymptomatic and treated medically were examined. The entire cohort of patients had a significantly reduced survival rate when compared with that of the general population (6.3% mortality/year). Patients who were even transiently in NYHA class III or IV had the highest mortality rate of 34% yearly, and the mortality rate was significant (4.1% yearly) even among those in NYHA functional class I or II with degenerative mitral valve disease. Furthermore, the 10-year survival rate was only 69% for patients in NYHA functional class I with an EF greater than 60%, and 90% of the patients who presented initially in NYHA functional class I or II either underwent surgical correction of the MR (only after they had progressed to NYHA class III or IV) or died. From these data we can conclude that the natural history and survival of patients with MR, even when in NYHA functional class I or II, is worse than the expected mortality rate in the comparable general population [15]. Currently it is accepted practice that patients with symptoms of heart failure (NYHA functional class III or IV) who have a mitral valve amenable to repair should undergo surgical correction for the MR. Although the postoperative outcome for these patients is far better than the medical treatment, a significant number of these patients will incur a notable incidence of LV dysfunction, when allowed to progress to NYHA class III or IV before operative intervention. Operative intervention is now being applied more frequently to patients who are in NYHA functional class I or II with signs of early LV dysfunction (EF 60% or end-systolic diameter 45 mm) [7, 8]. The most controversial group of patients are those with significant MR who are in NYHA functional class I or II with no signs of LV dysfunction. An early operation is a reasonable approach in these patients and represents a new perspective in the treatment of MR. The benefits of early surgical intervention in patients with MR have been reported. Sousa and colleagues [12] reported surgical results on a series of patients who were in NYHA class I or II with grade 3 to 4 isolated MR who underwent mitral valve repair. The overall operative mortality was 1.7%, 5-year freedom from reoperation was 97.0% 0.8%, and 5-year event free survival was 91.0% 2%. Ling and colleagues [15] reported results of operative

1214 SMOLENS ET AL Ann Thorac Surg PROPHYLACTIC MITRAL RECONSTRUCTION 2001;72:1210 6 Fig 3. The number of mitral valve repair procedures performed per year of the study. intervention in a similar patient population in two studies. In a multivariate analysis of patients who underwent surgical correction of MR there was a statistically significantly associated reduction in overall mortality rate. In a later study, these same authors performed a retrospective review comparing two groups of patients. One group of patients were operated on early after the diagnosis of MR was made, whereas the second group of patients being followed medically were operated on when symptoms developed. Despite the early occurrence of symptoms in the first group, the 10-year survival after surgery was superior in the patients operated on earlier than those referred to surgery after development of symptoms. Additionally, the early surgery strategy was followed by a lower incidence of congestive heart failure and chronic atrial fibrillation. This outcome advantage suggested that early surgery is the treatment option to be considered in low-risk candidates with repairable valves and severe MR, regardless of symptoms [16]. We share this philosophy of earlier surgical intervention. In our series we demonstrated, in 93 patients who underwent early mitral valve repair, that this procedure can be performed safely with no mortality and minimal morbidity. In this series, the mean preoperative endsystolic and end-diastolic LV diameters of 39 and 57 mm, respectively, were lower than the guidelines suggested in the literature [7, 9, 13]. This reflects in part our bias toward early surgical intervention in this patient population. The number of repair procedures performed in patients who were asymptomatic or only mildly symptomatic, with degenerative disease, in our institution has also risen dramatically (Fig 3), with only two procedures being performed in 1992 and 41 in 2000. In all of the cases in this series, the MR was due to leaflet prolapse secondary to degenerative disease of the valve. Early in the series, 4 patients underwent chordal shortening procedures for anterior leaflet prolapse. Gillinov and associates [17], from the Cleveland Clinic, reported a series of 86 patients analyzing those who underwent reoperation for failure of a mitral valve repair procedure. Rupture of previously shortened chordae was found to be the most common cause of late failure. In this study we had two failures of repair, and in 1 of these patients the failure of the repair was associated with a chordal shortening procedure for the correction of anterior leaflet prolapse. Chordal shortening procedures are no longer performed in our institution, and chordal transposition or use of Gore-Tex prosthetic chords are the favored techniques for the correction of anterior leaflet prolapse. Postoperative EF has been shown to correlate with long-term outcome and to be predicted by preoperative echocardiographic EF as well as by systolic LV diameter [15]. In this series 91% of the patients had late LV systolic dimensions within the normal range. Mitral valve repair in the absence of symptoms achieved the goal of preserving postoperative LV function and should contribute to an excellent long-term late outcome. In this series we achieved a 5-year freedom from reoperation rate of 96.5%. Our freedom from reoperation is similar to, or better than, what is published in other series [1, 2, 5] and demonstrates that mitral valve repair is a reproducible and durable procedure. There are certain limitations of the study presented that warrant discussion. There are expected and inherent limitations of a retrospective study. In this particular series, we had a limited number of postoperative echocardiograms (31%) available for comparison with preoperative studies. Although this is a limitation of our study inherent to the retrospective design, we do have complete follow-up information regarding functional status and clinical outcome of all of our patients. No information in our particular population can be obtained regarding the number of patients who are asymptomatic or minimally asymptomatic and were not referred for surgical intervention. The NYHA functional classification system has limitations unto itself that may have altered the inclusion and exclusion process. Ideally, patients should be classified with provocative exercise testing, as many patients may self-limit their own activity level and therefore falsely report their actual functional status. Clear demonstration of the superiority of mitral reconstruction in patients with no symptoms or mild symptoms would require a randomized prospective study comparing optimal medical management with early surgical intervention. This study would be impossible to conduct in today s times, and may even be considered by some to be unethical, as virtually no patients would be available for the control group because many are referred earlier and earlier for surgical intervention. To advocate early surgical intervention for MR, two conditions should always be met: the valve must consistently be able to be repaired as opposed to being replaced, and operative mortality must approach zero [14]. In this series 100% of our patients underwent initial valve repair, with only 1 patient requiring replacement after repair failure. Additionally, we demonstrated a 0% operative mortality and a very low rate of procedure-related morbidity. We believe that surgical treatment of severe MR should be advocated in patients with no symptoms or only mild symptoms, as valve repair can be performed with no mortality and very low morbidity. Although our results with mitral valve repair in patients with NYHA functional class I and II are only intermediate to date, our

Ann Thorac Surg SMOLENS ET AL 2001;72:1210 6 PROPHYLACTIC MITRAL RECONSTRUCTION 1215 results as well as those of others support the position that early surgical intervention can be undertaken in this patient population, with low morbidity and mortality. References 1. Cosgrove DM, Chavez AM, Lytle BW, et al. Results of mitral valve reconstruction. Circulation 1986;74:182 7. 2. David TE, Armstrong S, Sun Z, et al. Late results of mitral valve repair for mitral regurgitation due to degenerative disease. Ann Thorac Surg 1993;56:7 12. 3. David TE, Uden DE, Strauss HD. The importance of the mitral apparatus in left ventricular function after correction of mitral regurgitation. Circulation 1983;68:II76 82. 4. Enriquez-Sarano M, Schaff H, Orszulak T, et al. Valve repair improves the outcome of surgery for mitral regurgitation. Circulation 1995;91:1022 8. 5. Galloway AC, Colvin SB, Baumann FG, et al. Long-term results of mitral valve reconstruction with Carpentier techniques in 148 patients with mitral insufficiency. Circulation 1988;78(3 Pt 2):I97 105. 6. Lee EM, Shapiro LM, Wells FC. Superiority of mitral valve repair in surgery for degenerative mitral regurgitation. Eur Heart J 1997;18:655 63. 7. Carabello BA, Crawford FA. Medical progress: valvular heart disease. N Engl J Med 1997;337:32 41. 8. Enriquez-Sarano M, Orszulak TA, Schaff H, et al. Mitral regurgitation: a new clinical perspective. Mayo Clin Proc 1997;72:1034 43. 9. Mudge GH. Asymptomatic mitral regurgitation: when to operate? J Card Surg 1994;92:248 51. 10. Freed LA, Levy D, Levine RA, et al. Prevalence and clinical outcome of mitral valve prolapse. N Engl J Med 1999;341:1 7. 11. Quinones MA. Management of mitral regurgitation: optimal timing for surgery. Cardiol Clin 1998;16:1 20. 12. Sousa UM, Dreyfus G, Rescigno G, et al. Surgical treatment of asymptomatic and mildly symptomatic mitral regurgitation. J Thorac Cardiovasc Surg 1996;112:1240 8. 13. Starling MR. Effects of valve surgery on left ventricular contractile function in patients with long-term mitral regurgitation. Circulation 1995;92:811 8. 14. Starling MR, Kirsh MM, Montgomery DG, et al. Impaired left ventricular contractile function in patients with longterm mitral regurgitation and normal ejection fraction. J Am Coll Cardiol 1993;22:239 50. 15. Ling LH, Enriquez-Sarano M, Seward JB, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417 23. 16. Ling LH, Enriquez-Sarano M, Seward JB, et al. Early surgery in patients with mitral regurgitation due to flail leaflets; a long-term outcome study. Circulation 1997;96:1819 25. 17. Gillinov AM, Cosgrove DM, Lytle BW, et al. Reoperation for failure of mitral valve repair. J Thorac Cardiovasc Surg 1997; 113:467 73. DISCUSSION DR DAVID H. ADAMS (Boston, MA): That was a very nice presentation. I think the ASD paradigm for mitral repair is something I believe we are also ready for. I wonder if members of the audience have questions. DR CARLOS DURAN (Missoula, MT): I congratulate you for this nice piece of work. I entirely agree with your statements that nowadays with good TEE it should be possible to determine before surgery the feasibility of valve repair. I am a little bit concerned, however, that people might use your numbers, go home, and tell the cardiologist, Send me every case you have of severe mitral regurgitation; I am going to repair them all. But unless they are quite familiar with TEE or TTE, and they can really reassure the patient that the chances of repair are well above 90%, it is going to be dangerous. I have one question. In the abstract, you mentioned that some of the patients had rheumatic disease, and now you are only talking about the myxomatous. Does that mean that you have changed your policy and that this applies only to myxomatous, or does it also apply to rheumatics with a good valve? That is, I am asking if you would recommend surgery to an asymptomatic patient with a rheumatic valve expected to be good for repair. DR SMOLENS: In this presentation, we included only those patients with degenerative mitral valve disease. Patients with rheumatic mitral valve disease are less amenable to mitral valve repair. Therefore, if an asymptomatic patient with rheumatic mitral valve disease were to present, it would be our general recommendation to follow this patient until symptoms were to develop. The data presented in this study should only be applied to those patients with degenerative mitral valve disease. DR IRVING L. KRON (Charlottesville, VA): I want to congratulate you on a great presentation. This is a classic Bolling presentation. You have done very well. The question I have is, are these patients truly asymptomatic? As you know, mitral valve disease is an insidious disease and we don t get to find these folks on the street. They tend to come to our office for some reason, and they usually have been seen by 2 or 3 other physicians. So typically a patient says, yes, they feel fine when they are sitting there. However, if you walk them down the hall they are short of breath, and in fact they are probably quite symptomatic. Can you tell me, what are your thoughts about that? If they have an exercise test and get short of breath, are they symptomatic? DR SMOLENS: I agree with you and I too suspect many patients may not be truly asymptomatic. NYHA classification is based on what the patient reports to the physician, and I think many patients limit their own activity to compensate for some of their own inabilities. Provocative exercise testing would be a helpful tool in better assessing the patients level of symptoms. At the University of Michigan, our cardiology colleagues have witnessed our success rate with mitral valve repair in these young, asymptomatic patients and in response have been referring the patients for surgical evaluation earlier and earlier in the disease process. Therefore many of the patients that we are now seeing are reliably in NYHA class I. DR BALJIT KUMAR SHARMA (Yakima, WA): I enjoyed your paper. A couple of questions. I would like to push this concept a little bit further. Suppose a patient comes to you who is asymptomatic but has atrial fibrillation. Would you still do the same thing? And if you would, why would you not try to do anything to atrial fibrillation, because these are the patients who might get more benefit by surgically treating their atrial fibrillation. Do you normally put them on Coumadin if they have atrial fibrillation, and for how long?

1216 SMOLENS ET AL Ann Thorac Surg PROPHYLACTIC MITRAL RECONSTRUCTION 2001;72:1210 6 DR SMOLENS: Although the NYHA classification system for heart failure does not include atrial fibrillation as a symptom of failure, I do believe that these patients in atrial fibrillation are symptomatic. The atrial fibrillation is attributed to a chronic alteration in the atria, and I do think these patients should undergo mitral valve repair. Many patients will present with a history of paroxysmal atrial fibrillation that has responded to medical therapy and will be in normal sinus rhythm at the time of operation. In these patients, we advocate repair of the mitral valve alone. There is a second group of patients who present with atrial fibrillation and markedly enlarged atria. These patients would be considered for mitral valve repair in combination with an atrial reduction and Maze procedures. This subset of patients was not included this presentation. DR ADAMS: Just to follow-up and close with a couple of quick questions. What is the age cutoff? If you are 80 years old and you have asymptomatic regurgitation, should you undergo elective repair? The second question relates back to atrial fibrillation. Since these really are asymptomatic patients, I am hoping none of them are in atrial fibrillation. Were you able to avoid atrial fibrillation in the entire cohort? DR SMOLENS: We have no strict age cutoff. If the patient is elderly, with no other significant comorbidities, and is in a good state of health, mitral valve repair would be recommended. Eleven patients (11.3%) had a history of atrial arrhythmias at the time of their presentation for surgical evaluation. None of the patients had been in chronic atrial fibrillation. Eighteen patients (19.5%) developed atrial fibrillation in the immediate postoperative period (30 days), all of whom responded to either electrical or chemical cardioversion. All but 1 patient currently (1.1%) remain in normal sinus rhythm at follow-up. DR ADAMS: One final question, and that is, these are young patients having prophylactic valve surgery, so the bar is pretty high, and these are complicated repairs. You do a complicated repair and a postoperative TE echo shows one plus regurgitation, when do you go back and take a second look at the valve? DR SMOLENS: The postoperative TEE should be perfect. In our series only 1 patient required reinstitution of cardiopulmonary bypass to reinspect the valve. It was amenable to repair. In this situation, when a patient is presented for a prophylactic repair, they must leave the OR with a perfect repair. Southern Thoracic Surgical Association: Forty-eighth Annual Meeting The Forty-eighth Annual Meeting of the Southern Thoracic Surgical Association will be held November 8 10, 2001, San Antonio, Texas. The Postgraduate Course will be held the morning of Thursday, November 8, 2001, and will provide in-depth coverage of thoracic surgical topics selected primarily as a means to enhance and broaden the knowledge of practicing thoracic and cardiac surgeons. Carolyn E. Reed, MD Secretary/Treasurer Southern Thoracic Surgical Association 401 North Michigan Ave Chicago, IL 60611-4267 (800) 685-STSA or (312) 644-6610 fax: (312) 644-1815 e-mail: stsa@sba.com; http://www.stsa.org. 2001 by The Society of Thoracic Surgeons Ann Thorac Surg 2001;72:1216 0003-4975/01/$20.00 Published by Elsevier Science Inc