Ann Thorac Surg 2008;86:472-481. doi:10.1016/j.athoracsur.2008.04.046
© 2008 The Society of Thoracic Surgeons
Original Articles: Adult Cardiac
Mitral Valve Replacement in Rheumatic Patients: Effects of Chordal Preservation
Rafael García-Fuster, MD, PhD*,
Vanessa Estevez, MD,
Oscar Gil, MD,
Sergio Cánovas, MD, PhD,
Juan Martínez-Leon, MD, PhD
Department of Cardiac Surgery, University General Hospital of Valencia, Valencia, Spain
Accepted for publication April 2, 2008.
* Address correspondence to Dr García-Fuster, C/ Artes Gráficas n° 4, esc. izda, pta 3, Valencia, 46010, Spain (Email: rgfuster{at}terra.com).
Presented at the Forty-fourth Annual Meeting of The Society of Thoracic Surgeons, Fort Lauderdale, FL, Jan 28–30, 2008.
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Abstract
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Background: Subvalvular preservation is beneficial in patients undergoing mitral valve replacement, especially in degenerative mitral regurgitation. Its feasibility and benefit is less evident in rheumatic disease. Our aim was to study the impact of preservation techniques in rheumatic patients and determine risk factors for mortality.
Methods: Five hundred sixty-six rheumatic patients undergoing mitral valve replacement between 1996 and 2006 have been included. One hundred fifty-six patients had complete excision of the subvalvular apparatus (group 1), 248 had preservation of the posterior leaflet (group 2), and 162 had total chordal preservation (group 3). Echocardiography was performed preoperatively, at discharge, at 1 year, and at late follow-up.
Results: Reduction of ventricular volume was greater in groups 2 and 3, especially if previous mitral regurgitation or mixed disease were present. In mitral stenosis, valve resection caused postoperative increase of volume. Ventricular ejection and pulmonary hypertension had better outcome with valve preservation. Valve resection was associated with late mortality (hazard ratio, 2.64; p < 0.05), and complete chordal preservation was protective (hazard ratio, 0.31; p = 0.13). Actuarial survival (130 months) was better in group 3: 77.18% ± 0.04%, 85.38% ± 0.03%, and 93.22% ± 0.02%, respectively (p < 0.01 group 1 versus group 3). Group 1 exhibited more low cardiac output syndrome (p < 0.01) and more patients in New York Heart Association functional class III and IV at last follow-up: 17.8% versus 3.9% and 2.0% (p < 0.001).
Conclusions: Complete chordal preservation is possible in a large percentage of rheumatic patients. Greater decrease of ventricular volume is obtained for mitral regurgitation. In mitral stenosis, subvalvular preservation may avoid postoperative ventricular dilatation. Consequently, ventricular ejection, pulmonary hypertension, and clinical outcomes may improve with time.
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Introduction
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Mitral valve (MV) replacement with preservation of subvalvular apparatus aids in maintaining left ventricular (LV) function, but this can be particularly difficult in rheumatic mitral stenosis (MS) [1]. The main evidence of this benefit is based on mitral regurgitation (MR) [2–4], and it is unclear in rheumatic patients with fibrosis and calcification [5–7]. A variety of techniques has been advocated [8–11], but complete preservation is often hindered by several factors such as pathologic processes in the native valve, greater technical complexity, longer operating time, and concerns about interference with the prosthesis or LV outflow tract obstruction. Thus, many surgeons continue to retain only the posterior leaflet.
The objective of our study was to analyze the feasibility and impact of preservation techniques in rheumatic patients undergoing MV replacement, determining risk factors for early and late mortality.
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Patients and Methods
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We reviewed all the patients undergoing MV surgery at our institution from 1996 to 2006 (n = 1,035). Mitral valve repair, other approaches than median sternotomy, and nonrheumatic disease were not considered (n = 390). Multiple valve replacement (n = 61) and previous MV replacement (n = 18) were also excluded. Concomitant procedures (coronary artery bypass grafting, tricuspid valve repair, or Maze operation) and other previous MV operations (repairs or commissurotomies) were not discarded. The final cohort comprised 566 patients. The study was approved by the institutional review board. All patients gave informed consent for the operation and had previously granted permission for use of their medical records for research purposes.
Surgical Technique
A surgical computer-based databank and surgery notes were retrospectively revised to determine the surgical technique, the type and size of the prostheses, and the cardioplegic protocol. Eleven surgeons performed the operations. A longitudinal right-sided left atriotomy was the conventional approach. Moderately hypothermic (28°–32°C) cardiopulmonary bypass and cold blood cardioplegia were used. Mitral valve replacement was indicated according to American College of Cardiology/American Heart Association Guidelines [1].
The technique for subvalvular preservation was at the discretion of the surgeon. Intraoperative transesophageal echocardiography was routinely used. The surgeons attempted to retain the subvalvular tissue whenever possible: redundant tissue was imbricated, excessive cuspal tissue was sliced, and the calcific nodules were excised. The patients were allocated to one of three groups. In patients with severe leaflet calcification with annular extension and subvalvular fusion, the MV was completely excised (group 1). When partial excision of the posterior leaflet was required, the patient was also included in this group. In group 2 (partial preservation group), the anterior leaflet was completely excised and the whole posterior leaflet was preserved. These patients had extensive scarring, shortening, and calcification of the whole anterior chordopapillary apparatus. Finally, in the complete preservation group (group 3), the entire chordopapillary apparatus was preserved by means of several techniques. In some patients, the anterior leaflet was divided into two or more segments and reattached to the annulus according to Khonsari I [9] technique (small segments; n = 28) or to the procedure described by Miki and associates [11] (large segments; n = 86). The latter one was preferred since 1999 because larger patches with chords could be implanted with lower risk of LV outflow tract obstruction. In other patients (n = 48), a technique of posterior (or oblique) transposition of the anterior leaflet, previously described by us [12], was performed. This technique has been used more frequently during the later years when calcification involved commissures and the free edge of the anterior leaflet without impairment of its basal area. The whole leaflet was detached and reimplanted as a patch (Fig 1).
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Fig 1. Operative technique of oblique transposition of anterior mitral leaflet. (A–G) Sequential surgical views. (H) Schematic drawing.
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Four hundred twenty-four patients received a mechanical valve: 393 bileaflet (107, 164, and 122, in groups 1 through 3, respectively) and 31 monoleaflet (18, 10, and 3, respectively). Bioprostheses were implanted in 142 patients (31, 74, and 37, respectively). They were implanted with several pledgeted mattress sutures with pledgets on the atrial side. The prosthesis size was 25 mm in 328 patients (86, 156, and 86, respectively), 27 mm in 231 (68, 89, and 74, respectively), 29 mm in 6 (2, 3, and 1, respectively), and 31 mm in 1 patient from group 3.
Postoperative Studies
Follow-up data were analyzed by using cardiology and cardiac surgery outpatient follow-up notes, computer-based databank, and telephone interviews. Survivors were followed echocardiographically (Hewlett Packard Sonos 5500 [Andover, MA] with 2.7- or 3.5-MHz transducer) at discharge (or first month), at mid-term (6 months to 1 year; mean, 9 ± 2 months), and at 29 ± 3 months (range, 26 to 32 months). Preoperative and first-month postoperative data were available in every patient. Four hundred fourteen patients (134, 139, and 141 in respective groups) and 298 patients (96, 104, and 98, respectively) had registered data at 6 months to 1 year and at late follow-up. Data were measured according to the criteria of the American Society of Echocardiography [13], focusing on LV end-systolic and end-diastolic diameters, LV ejection fraction (LVEF) and fractional shortening, indexed LV end-diastolic volume, left atrial diameter, and pulmonary artery systolic pressure (PASP). Measurements of LV dimensions were made from two-dimensional images in the parasternal long-axis view and M-mode echocardiography. Left ventricular volumes and LVEF were calculated by a modified Simpson's method [14]. Pulmonary artery systolic pressure was estimated from the maximal tricuspid regurgitation velocity in 533 patients before the operation and in 521, 396, and 279 patients, respectively, at follow-up.
Statistical Analysis
Data were analyzed with SPSS 12.0 Statistical Package (SPSS Inc, Chicago, IL). Descriptive statistics were calculated for continuous and categorical variables. Student's t test was used to identify differences between two groups of continuous variables. Differences among the three study groups for continuous variables were identified by one-way analysis of variance with the Bonferroni post-hoc test. The 
2 test was used to identify association among the groups for categorical variables. Repeated measures two-way analysis of variance was used to assess the influence of time for type of operative procedure on all echocardiographic data. Logistic regression and Cox proportional hazards models determined independent factors associated with in-hospital and late mortality, respectively. Both models were adjusted for clinically significant covariables and propensity score. This score has been used to reduce the selection bias and control for the imbalance in covariables that usually occurs in nonrandom treatment assignment. Treatment category was dichotomized in resection versus preservation procedures. This propensity score is defined as the estimated probability of assignment to one treatment category over another, given the observed baseline covariables. It was estimated using logistic regression, in which the outcome was treatment-group assignment and the independent variables were the observed covariables (32 preoperative and surgical variables). The propensity score was then used as a covariable in mortality models to estimate the treatment effect.
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Results
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Patient and Surgical Data
Patient clinical profiles are depicted in Table 1. Most patients had mixed MV disease or predominant MS. The EuroSCORE reflected a similar operative risk, and the three groups were comparable with respect to hypertension, diabetes, chronic obstructive pulmonary disease, previous stroke, peripheral vascular disease, or preoperative atrial fibrillation. Some differences were observed: chronic renal failure (creatinine 
2 mg/dL) was more prevalent in group 2, preoperative New York Heart Association functional class III or IV was more frequent in groups 2 and 3, and LV diameters and volume were higher in both groups with lower LVEF than group 1 (Tables 2, 3).
Left atrial diameters were similar, and the prevalence of giant left atrium (diameter > 65 mm) was 10.6% (14, 27, and 19 patients, respectively). In these patients a surgical reduction of the left atrium was performed, extending the atriotomy along the inferior wall between the pulmonary veins and the posterior mitral annulus. A strip 3 to 4 cm in width was excised, and the cut margins were reapproximated. Reoperation was more frequent in group 1 because more patients had a previous commissurotomy.
Early Outcomes
There were 38 early deaths (6.7%): 13 (8.3%), 20 (8.1%), and 5 (3.1%) in groups 1 to 3, respectively (p = 0.09). All were in-hospital deaths and the main causes were low cardiac output syndrome (8, 3, and 0 patients, respectively), stroke (1, 3, and 1, respectively), sepsis or pneumonia (2, 6, and 2, respectively), and acute renal failure (1, 3, and 2, respectively). Moreover, 2 patients from group 2 died as a result of respiratory distress syndrome, and 1 other died as a result of ventricular arrhythmia. One patient from group 1 died because of early prosthetic valve endocarditis. When only cardiac death (low cardiac output, arrhythmia, or endocarditis) was considered (13 patients, 2.3%), the difference in mortality was significant: 9 (5.8%), 4 (1.6%), and 0, respectively (p = 0.002). The resection group exhibited a higher incidence of low cardiac output syndrome: 14 (9.0%) versus 8 (3.2%) and 3 (1.9%), respectively (p < 0.01). There were no differences with respect to other complications (Table 4).
Late Outcomes
There were 53 late deaths (10.0%): 25 (17.5%), 22 (9.6%), and 6 (3.8%), respectively (p < 0.001). Death owing to congestive heart failure (35 patients, 6.6%) was more frequent in group 1: 20 (14.0%), 13 (5.7%), and 2 patients (1.32%), respectively (p < 0.001). Other causes of late death were prosthetic endocarditis (1 patient in each group), pneumonia (1, 2, and 1, respectively), major cerebrovascular accident (2, 3, and 1, respectively), tumor (1 patient in both groups 1 and 2), or unknown (3 patients). Eighteen patients had thromboembolic complications (6, 8, and 4, respectively). Prosthetic valve endocarditis developed in 6 patients (2, 3, and 1, respectively). Eight patients were reoperated on at follow-up because of severe paravalvular leakage (1 patient from group 1), structural bioprosthetic deterioration (2 and 1 patients in groups 1 and 2), and prosthetic valve endocarditis (1, 2, and 1, respectively). No complications related to the preservation technique were observed. The sizes of the valves and the postoperative transmitral gradients were similar for the three groups (2.8 ± 1.7, 2.9 ± 1.2, and 2.8 ± 1.1 mm Hg at first month, respectively) and for the three techniques considered in group 3 (2.7 ± 1.8, 2.8 ± 1.1, and 2.8 ± 1.3 mm Hg, respectively).
Follow-up was 98% complete (mean, 57 ± 38 months; range, 3 to 135 months) with 2,532 patient-years. At 130 months the actuarial survival was 77.18% ± 0.04%, 85.38% ± 0.03%, and 93.22% ± 0.02% in the respective groups (Fig 2A). By log-rank test, the difference was statistically significant between groups 1 and 3 (p < 0.01) and marginally significant between groups 2 and 3 (p = 0.06). The actuarial free survival from cardiac death was 80.70% ± 0.04%, 93.27% ± 0.01%, and 97.33% ± 0.01%, respectively (Fig 2B). This difference was significant between groups 1 and 3 (p < 0.01) and groups 2 and 3 (p < 0.05) and marginally significant between groups 1 and 2 (p = 0.059). At last follow-up 17.8% of survivors in group 1 (21 patients) were in New York Heart Association functional classes III or IV, compared with 3.9% (8 patients) and 2.0% (3 patients) in groups 2 and 3 (p < 0.001). The Maze operation was performed more frequently in groups 2 and 3 (Table 1), and at last follow-up 40.7% of survivors in group 1 (48 patients) remained in atrial fibrillation compared with 36.4% (75 patients) and 29.8% (45 patients) in groups 2 and 3 (p = 0.16).
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Fig 2. Kaplan–Meier survival curves for the three mitral valve replacement groups. (A) Free survival from all causes of death. (B) Free survival from cardiac death.
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Mortality Models
Univariable and multivariable analyses of in-hospital mortality and survival at follow-up are shown in Tables 5 and 6.
Reoperation, chronic renal failure, and preoperative low LVEF were independent predictors of in-hospital mortality. Complete chordal preservation was a significant protective factor (p = 0.03). In the model adjusted with propensity score, reoperation was not significant, and complete chordal preservation maintained a marginal significance as a protective factor (p = 0.059). Resection of the native valve was a significant factor of late mortality (Table 6). Complete chordal preservation was a protective factor against late mortality in univariable analysis and maintained this protective effect in the multivariable models (nearly significant). Other predictors of late mortality were higher preoperative PASP, higher age, and associated coronary disease.
Echocardiographic Follow-Up
Preoperative and postoperative echocardiographic data are shown in Table 2 and summarized as follows:- 1 Left ventricular diameters (LVEDD and LV end-systolic diameter) and indexed LV end-diastolic volume demonstrated a different behavior in group 1. They decreased slightly from the preoperative level in the immediate postoperative period, but a gradual increase was observed at 6 months to 1 year and at late follow-up. Preoperatively, the other groups had higher LV diameters and volume, but they demonstrated significant reduction in the immediate as well as late postoperative periods.
- 2 Preoperatively LVEF and fractional shortening were higher in group 1, but postoperatively both variables continued to decline with time in this group. In chordal-preservation groups, LVEF increased immediately and was maintained above the preoperative level at later follow-up. A significant negative correlation was observed between indexed LV end-diastolic volume and LVEF (indexed LV end-diastolic volume as a function of LVEF at 6 months to 1 year: r2, 0.19; β, –0.19; Pearson correlation, –0.43; p < 0.001). In preservation groups a higher postoperative decrease of volume was related with a concomitant increase of LVEF. In the resection group, the unfavorable LV remodeling might be responsible for the postoperative decline of LVEF.
- 3 Pulmonary artery systolic pressure decreased in all three groups, but this decrease was higher in preservation groups in the immediate and 1-year postoperative period. Left atrial diameter also decreased in all three groups, but this decrease was higher in groups 2 and 3 at 1-year follow-up. In the resection group, the unfavorable LV remodeling might be also responsible for this lower decline in PASP at 1-year follow-up.
- 4 The type of MV disease had a particular impact on these echocardiographic outcomes (Table 3). Although patients with MS had a nondilated LV at the time of surgery, loss of the annuloventricular continuity in group 1 caused progressive LV dilatation and concomitant reduction of LVEF at 6 months to 1 year and at later follow-up. Patients with subvalvular preservation did not experience these changes, and postoperative LV function was maintained. On the contrary, in patients with MR the LV was dilated before the operation, and postoperatively, reduction in preload caused by elimination of the regurgitant volume might explain the immediate decrease of LV volume that was still maintained at 6 months to 1 year in the three groups. However, loss of the annuloventricular continuity (group 1) caused progressive LV dilatation at later follow-up (>1 year).
In summary, a significant reduction of LVEDD (>10% at 1 year) was more frequent in groups 2 and 3: 92 (40.4%) and 59 patients (37.6%) versus 30 (21.0%; p < 0.001). The main factor associated with this significant reduction was preoperative LVEDD (odds ratio, 1.28; 95% confidence interval, 1.19 to 1.38; p < 0.0001), especially increased in those patients with MR. Mitral valve resection was predictive of less reduction (odds ratio, 0.42; 95% confidence interval, 0.18 to 0.99; p < 0.05). Mortality at follow-up was doubled in the absence of significant reduction of LVEDD (13% versus 7.1%; p < 0.05). Mitral valve resection (versus preservation) was also associated with higher late mortality: 25 (17.5%) versus 28 (7.3%); p < 0.01. The main consequence of the lower postoperative decrease of PASP in group 1 was a higher persistence of pulmonary hypertension (PASP > 40 mm Hg at 1 year in 279 patients studied): 36 of 79 (45.6%) versus 36 of 107 (33.6%) and 22 of 93 (23.7%), respectively (p < 0.05).
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Comment
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Partial Versus Complete Preservation
Many studies have demonstrated that LV dimensions and function are improved with subvalvular preservation [2, 3, 15], but the issue of complete versus partial preservation has been less frequently addressed [15–17]. According to some reports, no significant differences were noted between posterior or bileaflet chordal preservation [15, 16]. Others have shown a significant advantage with complete preservation [4, 17]. Unfortunately, there is a lack of prospective randomized trials [4]. We have compared three groups: complete resection and posterior leaflet and bileaflet preservation. Superior results were obtained with the latter one.
Several techniques for complete preservation have been reported [3, 8–12], with differences in the preserved tissue (strut chordae, several chords, or the whole anterior leaflet) and reimplantation site on the annulus. The selection of the best technique is controversial. Some authors argue in favor of an anterior reimplantation as a more natural orientation [9–11]. But this is a quasi-anatomic position, because the native chords are inserted in the leaflet far from the annulus. Moon and colleagues [18] compared resection with anterior and posterior chordal-sparing techniques. Resection was associated with depression in systolic contractility, and systolic function was better after anterior than after posterior MV replacement, but the relative changes did not attain statistical significance. More recently, these authors reported the effects of MV replacement on regional LV systolic strain [19]. Anterior chordal-sparing MV replacement did not alter regional strain; however, complete resection or posterior chordal-sparing resulted in alterations. We have used a variety of techniques, especially anterior (Khonsari or Miki's techniques), but also a posterior or oblique transposition of the whole anterior leaflet preserving all the MV structures. In the oblique transposition the A1 segment was reattached at 9 to 10 o'clock and A3 at 5 to 6 o'clock on the annulus according to the simplified chordal reconstruction reported by Soga and coworkers [20], based on previous experimental studies about the optimal direction of chords.
Preservation in Rheumatic Disease: Feasibility, Safety, and Benefit
Mitral valve repair is the best treatment in rheumatic MR, although it is less stable than in degenerative disease because of calcification or scarring. In fact, 149 patients with isolated MR underwent MV replacement in this study, and some of these procedures were reoperations for previous unsuccessful repairs. Chordal preservation was routinely performed in this subgroup except for 37 patients undergoing surgery at the beginning of the study. However, this preservation may be especially difficult in rheumatic patients with MS [5]. In selecting which type of chordal-sparing technique to use, the choice must guarantee a proper orientation of papillary muscles in addition to safety, simplicity, and reproducibility. We did not observe complications related to the technique. The use of artificial Gore-Tex chordae has been popularized by some authors [5, 20], but in our experience, it has not been frequent and we have not considered it in the present study. This procedure does not seem to be as beneficial as native chordal preservation in terms of LV systolic performance [5], which may be related to the direction of chordal reattachment and other complex factors: chordal tension and length or number of neochordae. In the natural condition, the chordal bundle has the shape of a fan that originates from the papillary muscle heads and spreads in many directions to reach the mitral leaflets. These multiple chordal directions make a rigorous study of the natural direction of chordal tension a difficult one [8].
Most of the studies about subvalvular preservation were performed in degenerative MR [2–4], and the reported series of rheumatic patients [5–7] are small, with a limited follow-up; the impact on postoperative pulmonary hypertension has seldom been addressed. We have studied a large cohort of rheumatic patients undergoing MV replacement during the last 11 years.
In our patients, LV volume was negatively correlated with LVEF. Preservation techniques were able to obtain a higher decrease of volume in patients with MR (or mixed MV disease) and at least maintain the preoperative volume in MS. Consequently, increase of postoperative LVEF was also obtained. On the contrary, patients with MV resection might experience a postoperative LV remodeling with increase of volume. In pure MS, without previous LV dilatation, this postoperative increase of volume was apparent at 6 months to 1 year and was maintained at later follow-up. In MR, the effect of this postoperative LV remodeling was delayed at more than 1 year. In fact, patients with MR (or mixed disease) had an enlarged remodeled LV at the time of surgery, and postoperatively, the correction of the regurgitation led to an immediate decrease of volume (reverse remodeling) that was maintained below the preoperative level during the first year. However redilatation of the LV was observed at later follow-up in those patients with MV resection.
The impact of this effect on survival was evident: incomplete reduction of LVEDD (<10% at 1 year), more frequently observed in the resection group, was associated with higher late mortality. Persistence of significant PASP (>40 mm Hg at 1 year) was also higher in this resection group. Preoperative higher PASP was a predictor of late death, and low LVEF was associated with higher in-hospital mortality. Complete preservation showed a protective effect on early and late mortality, and MV resection was an independent predictor of late mortality. The differences were enhanced when cardiac death was considered. Preservation techniques also reduced the incidence of postoperative low cardiac output syndrome and chronic heart failure at follow-up but did not affect the outcome of postoperative atrial fibrillation. More patients from group 1 remained in atrial fibrillation at last follow-up, but they had a lower frequency of Maze operation.
We conclude that complete chordal preservation is possible in a large percentage of rheumatic patients. Higher reductions in LV volumes may especially be obtained in patients with MR. In patients with pure MS, preservation may avoid postoperative increase of LV volume. Consequently, LV ejection and pulmonary hypertension may improve with time because of more favorable LV remodeling. Clinical outcomes may also improve with subvalvular preservation, especially with complete preservation. Avoidance of complete MV resection should be mandatory in modern cardiac surgery.
Limitations
Although this is one of the largest series of rheumatic patients reported from a western country undergoing chordal-sparing MV replacement, several limitations must be taken into account. A retrospective, nonrandomized single-center analysis is subjected to the effects of selection bias. However, a propensity score adjustment has been used in addition to multivariable analyses. This selection bias might have been against the chordal-sparing groups given their larger preoperative LV diameters and volume and the lower LVEF in comparison to the resection group. The fact that these cohorts performed better provides further support to the importance of retaining the MV apparatus. Right cardiac catheterization was not routinely performed, and PASP was estimated by echocardiography.
The paper lacks assessment of ventricular wall motion. Echocardiographic evaluation of LV systolic function is reliable and reproducible provided there is no regional wall motion abnormality. Radionuclide-derived LVEF is easily reproducible and more accurate than echocardiographic estimation without geometric assumption to calculate LVEF and eliminates the interobserver and intraobserver variabilities. Assessment of ventricular remodeling does involve study of LV dimensions, LVEF, fractional shortening, and regional and global wall motion abnormalities, and, probably, the gold standard technique at this moment is cardiac magnetic resonance imaging.
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Discussion
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DR MARC MOON (St. Louis, MO): I would anticipate that your initial goal with each patient is to preserve the chords all the time, and that has been the case throughout this entire series. Can you tell ahead of time which patients you are going to be able to preserve all the chords and which you aren't based on echocardiographic evidence or any other preoperative evaluation?
DR GARCÍA-FUSTER: Echocardiographic evidence in order to assess preoperatively the potential preservation?
DR MOON: Correct.
DR GARCÍA-FUSTER: We try to preserve in every patient. Of course, this is a long-term follow-up study, and in the latest years we have tried to preserve in every patient. We must remember that this group of patients is rheumatic patients with extensive calcification, and with this last technique that we have presented in this meeting, we try to preserve the whole integrity of the mitral valve. Perhaps you must try to decalcify the valve, make pliable the tissues, and this posterolateral transposition avoids interference with the left ventricular outflow tract and with the mechanism of the valve. So we try indeed to preserve in every patient.
Of course, echocardiography can give you some insight preoperatively about this feasibility. Perhaps, in our country, rheumatic fever is not so aggressive as in other countries. And, nowadays in our country, this low-intensity rheumatic disease especially affects elderly patients with extensive calcification. So I think a large proportion of patients can benefit from this complete preservation.
DR VINAY NAITHANI (Rajasthan, India): Thanks, for a nice and informative presentation. I was thrilled to hear so many papers from western countries where valve repair is the main treatment for valvular pathology as they get less rheumatic cases (or get them in early stages) and more degenerative pathology.
In India the incidence of rheumatic fever is high, and we get heart valves calcified with severe subvalvular pathology. Most of the times valve repair is not possible, and valve replacement remains the only hope.
Anterior and posterior mitral valve apparatus preservation is the right choice along with mitral valve replacement. We also have good experience with it. This technique definitely improves outcome, and we also have studies on it.
Well, I just want to add few things in continuation as you told that inserting a large valve is difficult. Previously, we were doing MVR (mitral valve repair) with chordal preservation with the same technique and we face the same problem. Now we modified our technique; we now divide the anterior mitral leaflet in the middle from leaflet margin to annulus, then resect out the leaflet as much as possible leaving a rim of leaflet along with the chordae. Then we fix and plicate the divided AML (anterior mitral leaflet) rim to the annulus near the commissures. Further dividing the posterior mitral leaflet at P1, P2, and P3 and plicating them to the annulus gives additional space. Many times sacrificing the obstructing chordae and refixing them to other place helps further. I feel my way of doing it may help you further.
Thanks for paying attention.
DR GARCÍA-FUSTER: Thank you very much. I think one of the concerns about implementing this preservation technique is the need to undersize the valve. In our series, as you can see here, we have observed no differences with respect to prosthesis size among the three groups. Our patient population is a low body surface area population, and the most frequent prosthesis size was 27, and in second place, 25 mm. But no difference was observed with respect to prosthesis size among the three groups: resection, partial preservation, or complete preservation.
DR ADIB H. SABBAGH (Tucson, AZ): This is really an excellent paper, especially when you try to preserve the geometry of the ventricle. In a prosthetic valve have you ever had any of the chordae interfere with the motion of the disks of the valve?
DR GARCÍA-FUSTER: No, we have not observed any problem with the technique with respect to interference with the prosthesis or with respect to interference with the left ventricular outflow tract. So I think the safety of the technique is evident. Several cases with interference with the prosthesis have been reported in the literature, but in our experience I think the technique has been quite safe, particularly in this difficult rheumatic patient population. In degenerative mitral valve patients it is quite easy to perform this kind of technique, but not in rheumatic, calcified valves.
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References
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- Bonow RO, Carabello BA, Kanu C, et al. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Circulation 2006;114:e84-e231.[Free Full Text]
- Lee EM, Shapiro LM, Wells FC. Importance of subvalvular preservation and early operation in mitral valve surgery Circulation 1996;94:2117-2123.[Abstract/Free Full Text]
- Smerup M, Funder J, Nyboe C, et al. Strut chordal-sparing mitral valve replacement preserves long-term left ventricular shape and function in pigs J Thorac Cardiovasc Surg 2005;130:1675-1682.[Abstract/Free Full Text]
- Yun KL, Sintek CF, Miller DC, et al. Randomized trial comparing partial versus complete chordal-sparing mitral valve replacement: effects on left ventricular volume and function J Thorac Cardiovasc Surg 2002;123:707-714.[Abstract/Free Full Text]
- Okita Y, Miki S, Ueda Y, Tahata T, Sakai T, Matsuyama K. Mitral valve replacement with maintenance of mitral annulopapillary muscle continuity in patients with mitral stenosis J Thorac Cardiovasc Surg 1994;108:42-51.[Abstract/Free Full Text]
- Tarelli G, Musazzi A, Semeraro F, Ceriani L, Respighi E. Effect of the preservation of annulo-papillary continuity on left ventricular ejection fraction after mitral valve replacement. A clinical randomized study on patients affected by rheumatic valve disease. Eur J Cardiothorac Surg 1994;8:478-481.[Abstract]
- Chowdhury UK, Kumar AS, Airan B, et al. Mitral valve replacement with and without chordal preservation in a rheumatic population: serial echocardiographic assessment of left ventricular size and function Ann Thorac Surg 2005;79:1926-1933.[Abstract/Free Full Text]
- Komeda M, DeAnda Jr A, Glasson JR, et al. Exploring better methods to preserve the chordae tendineae during mitral valve replacement Ann Thorac Surg 1995;60:1652-1657.[Abstract/Free Full Text]
- Sintek CF, Pfeffer TA, Kochamba GS, Khonsari S. Mitral valve replacement: technique to preserve the subvalvular apparatus Ann Thorac Surg 1995;59:1027-1029.[Abstract/Free Full Text]
- Vander Salm TJ, Pape LA, Mauser JF. Mitral valve replacement with complete retention of native leaflets Ann Thorac Surg 1995;59:52-55.[Abstract/Free Full Text]
- Miki S, Kusuhara K, Ueda Y, et al. Mitral valve replacement with preservation of chordae tendineae and papillary muscles Ann Thorac Surg 1988;45:28-34.[Abstract]
- Fuster RG, Rodriguez I, Estevez V, Vazquez A. Posterior transposition of anterior leaflet for complete chordal preservation Eur J Cardiothorac Surg 2007;31:550-551.[Abstract/Free Full Text]
- Douglas PS, Khandheria B, Stainback RF, Weissman NJ. ACCF/ASE/ACEP/ASNC/SCAI/SCCT/SCMR 2007 appropriateness criteria for transthoracic and transesophageal echocardiography J Am Coll Cardiol 2007;50:187-204.[Free Full Text]
- Weyman AE. Principles and practice of echocardiographyPhiladelphia: Lea & Febiger; 1994. pp. 575-624.
- Rozich JD, Carabello BA, Usher BW, Kratz JM, Bell AE, Zile MR. Mitral valve replacement with and without chordal preservation in patients with chronic regurgitation: mechanisms for differences in postoperative ejection performance Circulation 1992;86:1718-1726.[Abstract/Free Full Text]
- Hannein HA, Swain JA, McIntosh CL, Bonow RO, Stone CD, Clark RE. Comparative assessment of chordal preservation versus chordal resection during mitral valve replacement J Thorac Cardiovasc Surg 1990;99:828-837.[Abstract]
- Natsuaki M, Itoh T, Tomita S, et al. Importance of preserving the mitral subvalvular apparatus in mitral valve replacement Ann Thorac Surg 1996;61:585-590.[Abstract/Free Full Text]
- Moon MR, DeAnda A, Daughters GT, Ingels NB, Miller DC. Experimental evaluation of different chordal preservation methods during mitral valve replacement Ann Thorac Surg 1994;58:931-943.[Abstract]
- Moon MR, DeAnda A, Daughters GT, Ingels NB, Miller DC. Effects of mitral valve replacement on regional left ventricular systolic strain Ann Thorac Surg 1999;68:894-902.[Abstract/Free Full Text]
- Soga Y, Nishimura K, Yamakazi K, Komeda M. Simplified chordal reconstruction: oblique placement of artificial chordae tendineae in mitral valve replacement Eur J Cardiothorac Surg 2003;24:653-655.[Abstract/Free Full Text]
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Abstract
Introduction
