Ann Thorac Surg 2008;85:932-939. doi:10.1016/j.athoracsur.2007.11.021
© 2008 The Society of Thoracic Surgeons
Original Articles: Cardiovascular
Recurrence of Mitral Regurgitation Parallels the Absence of Left Ventricular Reverse Remodeling After Mitral Repair in Advanced Dilated Cardiomyopathy
Michele De Bonis, MD*,
Elisabetta Lapenna, MD,
Alessandro Verzini, MD,
Giovanni La Canna, MD,
Antonio Grimaldi, MD,
Lucia Torracca, MD,
Francesco Maisano, MD,
Ottavio Alfieri, MD
Department of Cardiac Surgery, San Raffaele University Hospital, Milan, Italy
Accepted for publication November 5, 2007.
* Address correspondence to Dr De Bonis, Cardiac Surgery Department, San Raffaele University Hospital, Via Olgettina 60, Milan, 20132, Italy (Email: michele.debonis{at}hsr.it).
 |
Abstract
|
|---|
Background: The aim of this study was to assess the occurrence of reverse left ventricular (LV) remodeling after effective mitral valve repair in advanced dilated cardiomyopathy and its impact on clinical outcome and repair durability.
Methods: Of 111 patients undergoing mitral valve repair in ischemic or idiopathic dilated cardiomyopathy, 79 patients with no or trivial residual mitral regurgitation (MR) at discharge and with a follow-up length of at least 6 months were included in this study. Preoperatively they had 3 to 4+ functional MR, an ejection fraction of 0.28 ± 0.055, an indexed LV end-diastolic volume of 113 ± 33.0 mL/m2, an indexed LV end-systolic volume of 80.8 ± 26.3 mL/m2, a tenting area of 2.7 ± 0.9 cm2, and a coaptation depth of 1.1 ± 0.3 cm. Sixty-three patients (79.8%) were in New York Heart Association class III or IV. A complete, rigid or semirigid undersized ring annuloplasty (with or without "edge-to-edge") was used. Concomitant procedures were coronary artery bypass grafting (49 of 79 patients, 62%), tricuspid valve repair (11 of 79 patients, 13.9%), and ablation of permanent atrial fibrillation (13 of 79 patients, 16.4%).
Results: At a mean follow-up of 2 ± 1.3 years (median, 1.8 years), LV reverse remodeling was documented in 41 patients (51.8%), whereas in 38 patients (48.1%) LV dimensions remained unchanged or increased compared with preoperative values. The persistence or progression of LV remodeling paralleled the recurrence of MR and worsening of symptoms. Recurrence of MR of 3+ or greater was 0% in the "reverse remodeling" group and 18.4% in the "no reverse remodeling" one (p = 0.008). At 3 years, freedom from recurrence of MR of 2+ or greater was 74% ± 11.7% and 62% ± 9.2% (p = 0.004) and New York Heart Association class was 1.5 ± 0.61 and 2 ± 0.72 (p < 0.0001), respectively. Predictors of reverse remodeling were ischemic etiology (p = 0.04), concomitant coronary artery bypass grafting (p = 0.02), successful ablation of atrial fibrillation (p = 0.05), and shorter history of congestive heart failure (p = 0.06). The use of the edge-to-edge showed a trend toward favoring reverse remodeling compared with isolated annuloplasty (p = 0.08).
Conclusions: In patients with functional MR undergoing effective repair, the occurrence of reverse LV remodeling is associated with longer repair durability and a better clinical outcome compared with those with persistence or progression of the remodeling process.
|
Introduction
|
|---|
Functional mitral regurgitation (MR) is frequently observed in patients with ischemic or idiopathic dilated cardiomyopathy (DCM) and results from remodeling of the left ventricle, leading to displacement of the papillary muscles, annular dilatation, and tethering of the mitral leaflets. This condition is associated with a high morbidity and mortality when treated conservatively [1, 2]. Surgical restoration of adequate competence of the mitral valve (MV) abolishes left ventricular (LV) volume overload and may prevent the progression of LV remodeling. The precise relation between mitral repair and remodeling of the left ventricle, however, is still unknown. After undersized mitral annuloplasty, some patients do show echocardiographic evidence of reverse LV remodeling early or late after surgery [3, 4], whereas in others a persisting or progressing remodeling pattern is clearly documented witih time despite an initially successful mitral repair [5]. In the presence of ongoing remodeling of the left ventricle, the initial annular compensation for ventricular dilatation, provided by the undersized annuloplasty, may not be durable, and recurrence of MR may occur as a result of retethering of the leaflets [5]. In the present study we specifically addressed this issue by reviewing our own experience in this field. In particular we assessed the occurrence of reverse LV remodeling after effective mitral repair for functional MR and its impact on clinical outcome and repair durability.
|
Patients and Methods
|
|---|
Study Population
The institutional ethics committee approved this study and waived individual consent for this retrospective analysis. In our institution, from 1998 to March 2005, 111 patients with end-stage DCM (ejection fraction of 0.35 or less) and severe (4+/4+) or moderately severe (3+/4+) functional MR, refractory to medical therapy, underwent mitral repair with or without concomitant coronary artery bypass grafting (CABG), ablation of atrial fibrillation, and tricuspid repair. This series of 111 patients did not include patients with intrinsic MV disease, unstable angina or recent myocardial infarction (<6 months), papillary muscle rupture, severe right ventricular dysfunction, multiple organ failure, ejection fraction greater than 0.35, or concomitant LV reconstruction. The preoperative, postoperative, and follow-up data of these 111 patients were reviewed, and, of them, 79 patients with no or trivial (<1+/4+) residual MR at hospital discharge and follow-up length of at least 6 months were considered suitable for the purpose of this study and analyzed. All 79 patients belonging to the final study population had 3 to 4+ MR secondary to ischemic (51 patients) or idiopathic (28 patients) DCM and had been hospitalized one to five times for congestive heart failure (CHF) in the previous 6 months despite maximal medical therapy. All presented with severe LV dilatation and dysfunction. One or more previous myocardial infarctions had occurred in 38 of the 51 ischemic DCM patients (74.5%: anterior, 48%; inferior, 42%; lateral, 10%). The baseline characteristics of these 79 patients are presented in Table 1. The remaining 32 patients of the initial 111 cases were excluded from the final study population for the following reasons: residual MR of 1+ or greater at discharge (14 patients), death within 6 months after surgery (7 patients), or follow-up length less than 6 months (11 patients).
Echocardiography
Preoperatively a transthoracic echocardiography followed by a transesophageal echocardiography was performed in all patients. The severity of MR was graded as follows: mild, 1+ (jet area to left atrial area <10%); moderate, 2+ (jet area to left atrial area 10% to 20%); moderately severe, 3+ (jet area to left atrial area 20% to 45%); and severe, 4+ (jet area to left atrial area >45%) [6]. The vena contracta width at the narrowest portion of the regurgitant jet and the site of origin of the jet were also measured and analyzed [7]. An average was taken of three cardiac cycles for each MR measurement. Immediately after surgery, transesophageal echocardiography was repeated to assess residual MR, transmitral diastolic gradient (from continuous-wave Doppler), and MV area (by direct planimetry). Serial transthoracic echocardiographies were then performed at hospital discharge and every 6 months thereafter. Left ventricular volumes, LV sphericity index, MV tenting area, and coaptation depth were measured before and after surgery. Left ventricular volumes were measured with the biplane Simpson’s rule. The end-diastolic and end-systolic volumes were indexed (LVEDVI and LVESVI, respectively) by the body surface area. "Reverse LV remodeling" was defined as a decrease of 15% or more in the LVESVI or in both LVESVI and LVEDVI at the last echocardiographic follow-up compared with the preoperative values. Analysis of LV remodeling changes was performed preoperatively and at early (<3 months after surgery), mid (9 ± 5.7 months), and late (24 ± 15.6 months; median, 21.6 months) postoperative stages. Dobutamine stress echocardiography was performed preoperatively in ischemic DCM patients as previously described [8] to distinguish akinetic viable segments that could benefit from concomitant CABG from nonviable myocardial regions.
"Echocardiographically Guided" Approach and Surgical Technique
The "echocardiographically guided" surgical approach to MV repair adopted in our institution has been previously described [9]. Briefly, accordingly to the echocardiographic findings, in the presence of annular dilatation and moderate leaflet tethering (coaptation depth <1 cm), an undersized annuloplasty alone, with a complete rigid or semirigid ring, was used. On the other hand, when the degree of tethering was more pronounced (coaptation depth 
1 cm), an association of the edge-to-edge technique with the undersized annuloplasty was preferred to counteract the higher tethering forces by suturing the leaflets together. The edge-to-edge repair was always performed in correspondence of the site of origin of the regurgitant jet: centrally (in case of central jet) or posteromedially (when the regurgitant jet was in correspondence of the posterior commissure). All patients, with or without edge-to-edge, received an undersized annuloplasty with a complete rigid ring (Carpentier–Edwards, Classic, Edwards Lifesciences, Irvine, CA) or semirigid ring (Seguin, St. Jude Medical, St. Paul, MN).
Follow-Up
After surgery, patients were managed with standard heart failure medications, including β-blockers, angiotensin-converting enzyme inhibitors, and diuretics. Every 6 months, they were assessed in a dedicated heart failure clinic with physical examination, electrocardiography, and transthoracic echocardiography. Functional status was assessed according to the New York Heart Association criteria (for symptoms of heart failure) and the Canadian Cardiovascular Society classification (for angina pectoris). Events included cardiac death, reoperation, being listed for heart transplantation, endocarditis, thromboembolisms, myocardial infarction, and hospitalization for CHF. Follow-up was 100% complete (mean time, 2 ± 1.3 years; range, 0.5 to 5.7 years; median, 1.8 years).
Statistical Analysis
All data were prospectively entered in a dedicated database and analyzed. Calculations were performed using SPSS version 11.5 (SPSS Inc, Chicago, IL) for Windows (Microsoft Corp, Redmond, WA) software package. Continuous data were expressed as mean ± standard deviation and compared with the Student’s t test for paired and unpaired samples, as indicated. Comparison of categorical variables was performed using 
2 and Fisher’s exact test. Repeated measurements were analyzed by analysis of variance to evaluate differences across time and between different groups. The Bonferroni test was used to adjust the observed significance level for the fact that multiple comparisons were made. Cardiac event rate was evaluated by Kaplan–Meier analysis. Comparison among groups was performed according to the log-rank method. Univariate analysis with logistic regression was performed to characterize predictors of reverse LV remodeling. A multivariable analysis was then carried out by entering in the model all variables with a probability value of less than 0.1. All data are presented as mean ± standard deviation (for repeated measurements analyzed by analysis of variance and for actuarial estimates, standard error of the mean is reported instead).
|
Results
|
|---|
Study Population
Isolated undersized annuloplasty was performed in 40 patients (50.6%) whereas the edge-to-edge technique was performed in the remaining 39 patients (49.3%). The edge-to-edge suture was applied centrally in 32 cases (84.2%) and posteromedially in 6 cases (15.7%). Concomitant procedures were CABG (49 of 79 patients, 62%), ablation of permanent atrial fibrillation (13 of 79 patients, 16.4%), and tricuspid valve repair (11 of 79 patients, 13.9%). In two other ischemic DCM patients, myocardial revascularization was not performed owing to unsuitable coronary anatomy. Moreover, surgical ablation of atrial fibrillation was not carried out in 3 more patients, despite permanent atrial fibrillation, because they were operated on at the beginning of our experience, when this concomitant procedure was not performed on a routine basis. During follow-up 8 patients (10.1%) died, 7 of them of cardiac causes. Overall survival was 73% ± 10.9%, and freedom from cardiac death was 74% ± 11.0% at 3.7 years. Nine patients required hospitalization for heart failure (11.3%) and 2 for acute coronary syndrome (2.5%). Endocarditis and cerebrovascular or thromboembolic events were not observed. According to the inclusion criteria adopted in this study, at hospital discharge all patients had no or trivial (<1+/4+) MR. Mean MV area was 2.6 ± 0.65 cm2 (range, 1.9 to 3.5 cm2) and mean transmitral diastolic gradient 4 ± 1.2 mm Hg. With time, the mean grade of mitral insufficiency gradually increased, reaching the value of 1.1 ± 0.9 at last follow-up (p = 0.0001 compared with early follow-up). In particular, 2 years after surgery, 74.6% of the patients (59 of 79 patients) had no or mild MR, 16.4% (13 of 79 patients) showed moderate (2+), and 8.8% (7 of 79 patients) moderate to severe (3+) or severe (4+) mitral insufficiency. At 3.7 years, freedom from MR of 3+ or greater was 78.4% ± 10.7%, whereas freedom from MR of 2+ or greater was 55% ± 9.2%.
Patterns of Left Ventricular Remodeling
Preoperatively all patients presented with severe LV dilatation and dysfunction. Mean LVEDVI and LVESVI were on average 113 ± 33.0 mL/m2 and 80.8 ± 26.3 mL/m2, respectively. Mean ejection fraction was 0.28 ± 0.055. Looking at LV dimensions and function by serial echocardiographic assessments, two different patterns of LV remodeling were noted. In 41 patients (51.8%), early after surgery, LVEDVI, LVESVI, and sphericity index significantly decreased and mean ejection fraction significantly increased. Tenting area and coaptation depth showed a significant reduction as well. Those positive changes further improved at mid and at late follow-up, consistent with reverse LV remodeling (reverse remodeling group or group 1; Fig 1,
Table 2). Mitral insufficiency was abolished after repair and, at late follow-up, the mean regurgitation grade was 0.7 ± 0.6 with only 4 patients (9.7%) showing moderate (2+) MR.
View larger version (9K):
[in this window]
[in a new window]
|
Fig 1. Echocardiographic changes in the "reverse remodeling" group at preoperative, early, mid, and late postoperative stages. Reported as mean ± standard error of the mean. (LVEDVI = left ventricular end-diastolic volume indexed; LVESVI = left ventricular end-systolic volume indexed; preop = preoperative.)
|
|
View this table:
[in this window]
[in a new window]
|
Table 2 Preoperative and Follow-Up Echocardiographic Data in the "Reverse Remodeling" and "No Reverse Remodeling" Groups
|
|
In the remaining 38 patients (48.1%), LV volumes did not significantly change early after surgery and, at the following echocardiographic examinations, LVEDVI remained stable whereas LVESVI gradually increased, reaching a mean value significantly higher compared with the preoperative one (p = 0.02; "no reverse remodeling" group or group 2). Ejection fraction did not improve. Sphericity index and coaptation depth, although decreasing soon after surgery, started again to increase at the following controls, and at 24 months they were similar (coaptation depth) or higher (sphericity index) compared with the preoperative state. The tenting area decreased after surgery as well, then it started to increase again. However, at the last control, its mean value was still lower compared with the preoperative one (Fig 2,
Table 2).
View larger version (9K):
[in this window]
[in a new window]
|
Fig 2. Echocardiographic changes in the "no reverse remodeling" group at preoperative, early, mid, and late postoperative stages. Reported as mean ± standard error of the mean. (LVEDVI = left ventricular end-diastolic volume indexed; LVESVI = left ventricular end-systolic volume indexed; preop = preoperative.)
|
|
Left Ventricular Remodeling Pattern and Recurrence of Mitral Regurgitation
Changes in LV dimensions and sphericity index paralleled those of MR. Persistence or progression of LV remodeling (group 2) resulted in increased tethering of the mitral leaflets and recurrence of MR, which was never caused by ring detachment or rupture of the edge-to-edge suture. At the last echocardiographic follow-up, the mean grade of MR was significantly higher in the patients who did not show signs of reverse LV remodeling (1.5 ± 1.0 versus 0.8 ± 0.6; p = 0.0001). Recurrence of MR of 3+ or greater was 0% in the "reverse remodeling" group and 18.4% (7 of 38 patients) in the "no reverse remodeling" one (p = 0.008). Figure 3
reports the freedom from recurrence of MR of 3+ or greater at 2.7 years. If we consider the recurrence of MR of 2+ or greater, freedom from this event at 2.7 years was 74% ± 11.7% in group 1 and 62% ± 9.2% in group 2 (p = 0.004). Logistic regression analysis identified the absence of reverse remodeling as the only important predictor of recurrence of MR of grade 2+ to 4+ (odds ratio, 6.7; p = 0.002). In the "no reverse remodeling" group recurrence of MR of 2+ or greater occurred in 16 patients (42.1%). The temporal trend of recurrence of mitral insufficiency in those patients is shown in Figure 4. Early after surgery (<3 months) all of them had no or trivial MR, which did not significantly increase at mid follow-up (mean time, 9 months). However, in this same time frame, despite the absence of recurrent MR, a progression of LV dilatation was documented as demonstrated by LV volumes and sphericity index, which all significantly increased compared with early follow-up. The mean coaptation depth increased as well from 0.9 ± 0.2 to 1.1 ± 0.2 cm (p = 0.005). Finally, at the last echocardiographic control, a further increase in LV volumes, sphericity index, tenting area, and coaptation depth was paralleled by the recurrence of significant MR. Such a temporal relation between progression of LV remodeling and recurrence of MR suggests that the ongoing remodeling of the left ventricle precedes the recurrence of MR, which occurs again once the retethering of the mitral leaflets reaches such a grade to overcome the initial mitral competence provided by the surgical repair. In summary, in those patients, progression of remodeling takes place despite a competent MV and leads to leaflet retethering and gradual recurrence of mitral insufficiency, which occurs when the degree of LV remodeling is such that the undersized annuloplasty and even the edge-to-edge are unable to counteract the high tethering forces exerted on the leaflets.
View larger version (15K):
[in this window]
[in a new window]
|
Fig 3. Freedom from recurrence of mitral regurgitation of grade 3+ to 4+ in the "reverse remodeling" and "no reverse remodeling" groups.
|
|
View larger version (12K):
[in this window]
[in a new window]
|
Fig 4. Echocardiographic changes in the 16 patients with no reverse left ventricular remodeling who developed recurrence of mitral regurgitation (MR). Early after surgery all of them had no or trivial mitral regurgitation, which did not significantly increase at mid follow-up. In this same time frame, despite the absence of recurrent mitral regurgitation, a progression of left ventricular remodeling was documented as demonstrated by the increase in left ventricular volumes and sphericity index. This temporal relation suggests that the ongoing remodeling of the left ventricle precedes the recurrence of mitral regurgitation. Reported as mean ± standard error of the mean. (EDVI = end-diastolic volume indexed; ESVI = end-systolic volume indexed; JA/LAA = jet area to left atrial area; preop = preoperative.)
|
|
Predictors of Reverse Left Ventricular Remodeling After Mitral Repair
Table 3
summarizes the preoperative characteristics of the two groups of patients. The duration of the CHF history was significantly shorter in group 1. There were no other significant differences between the two groups although more patients in the reverse remodeling one underwent concomitant CABG, ablation of atrial fibrillation, and edge-to-edge technique. The dimensions of the mitral annulus and the type of ring did not significantly differ between the two groups. Predictors of reverse remodeling were ischemic etiology (p = 0.04), concomitant CABG (p = 0.02), and successful ablation of atrial fibrillation (p = 0.05). The use of the edge-to-edge technique showed a trend toward favoring reverse remodeling compared with isolated annuloplasty (p = 0.08). Finally, the longer the duration of the CHF history, the lower the likelihood of occurrence of postoperative reverse remodeling (p = 0.06). Ring size and type and preoperative LV dimensions were not predictors of reverse remodeling. At multivariable analysis only the duration of CHF history was significantly associated with the occurrence of reverse remodeling (p = 0.05; Table 4).
View this table:
[in this window]
[in a new window]
|
Table 3 Preoperative Clinical and Echocardiographic Data in the "Reverse Remodeling" and "No Reverse Remodeling" Groups
|
|
Clinical Outcome
From a clinical point of view, at baseline in groups 1 and 2, medications included angiotensin-converting enzyme inhibitors in 75% and 73% of the patients, respectively (not significant) and β-blockers in 62% and 64% of the patients, respectively (not significant). Postoperatively, at 9 and 24 months, groups 1 and 2 were comparable for use of angiotensin-converting enzyme inhibitors (82% versus 79% and 78% versus 81%, respectively, both not significant), β-blockers (60% versus 66% and 58% versus 63%, respectively, both not significant), and spironolactone (not significant). In addition almost 90% of the patients in both groups were taking other diuretics both at baseline and at follow-up (not significant). During the follow-up, 5 patients (12.1%) in group 1 and 7 patients (18.4%) in group 2 (not significant) underwent cardiac resynchronization therapy and intracardiac defibrillator implantation. Cardiac resynchronization therapy, however, was not positively related to the occurrence of reverse remodeling, probably owing to the small number of patients. At each study point, patients’ New York Heart Association functional class was defined. In both groups New York Heart Association class significantly decreased: from 3 ± 0.7 to 1.5 ± 0.61 (p < 0.01) in the reverse remodeling group and from 3 ± 0.6 to 2 ± 0.72 (p < 0.01) in the no reverse remodeling one. The improvement in New York Heart Association class was therefore significantly more pronounced in group 1 than in group 2 (p < 0.001 between the two groups). In addition overall cardiac events were significantly less frequent in group 1 than in group 2 (12.1% versus 34.2%; p = 0.03).
|
Comment
|
|---|
The main finding of this study is that in patients with functional MR undergoing effective mitral repair, reverse LV remodeling occurs in about 50% of the cases and is associated with longer repair durability and better clinical outcome compared with those with persistence or progression of the remodeling process. Bolling and associates [10] first reported that stabilization of the mitral annulus and unloading of the left ventricle by undersized annuloplasty leads to reverse LV remodeling in patients with dilated cardiomyopathy and functional MR. Dion and coworkers [4] demonstrated that significant reverse remodeling occurs in more than 70% of the patients with ischemic cardiomyopathy undergoing myocardial revascularization and restrictive annuloplasty whereas no reduction in LV dimensions takes place in the remaining 30% of the cases. In their experience, reverse LV remodeling was not documented in patients with larger LV dimensions at baseline, suggesting that extensive LV dilation may be an irreversible process and surgery should preferably be performed before extensive dilatation has occurred. Horii and coworkers [11] also reported that, in idiopathic DCM, isolated mitral reconstruction may not suffice for extremely enlarged LV (LVESVI >150 mL/m2 or LV end-diastolic diameter >70 mm), and concomitant LV reconstruction or containment surgery should be associated in such advanced stages. This is particularly important also for mitral repair durability, considering that ongoing remodeling of the left ventricle leads to recurrence of MR despite an initially successful repair as described by Hung and coworkers [5].
The results of our study show that after mitral repair for functional MR, LV volumes may change in different directions. There are patients who develop reverse remodeling of the left ventricle and patients who do not. The occurrence of reverse remodeling is inversely related to the duration of the CHF history and is favored by concomitant procedures like myocardial revascularization and ablation of permanent atrial fibrillation whose association to the mitral repair has, therefore, important clinical and prognostic implications. Our data confirm the results of previous studies that have already proved the beneficial effect of concomitant myocardial revascularization on early and midterm prognosis and on the evolution of the LV remodeling process [4]. However, it should be emphasized that, in our series, CABG was also performed in more than 50% of the patients who sustained persisting or ongoing LV dilatation despite the concomitant coronary surgery, which confirms that, in the individual patient, the likelihood of reverse remodeling to occur depends on the presence and interaction of several factors that have not been fully recognized yet. In our series, the use of the edge-to-edge technique showed a trend toward favoring reverse remodeling compared with isolated annuloplasty. This finding could be explained by the fact that the edge-to-edge technique, by anchoring the leaflets together, could exert a kind of "reins" effect on the LV chamber, counteracting the progression of the LV remodeling. Moreover, by ensuring leaflet coaptation exactly where the tethering is more pronounced, it could abolish the occurrence of the "loitering effect" [12] and prevent the recurrence of MR. In our study, baseline LV volumes and diameters failed to predict the fate of LV remodeling. This finding could be explained by the inclusion in our series of only patients with severe LV dilatation and severely depressed ejection fraction (
0.35). From a clinical point of view, patients with signs of reverse LV remodeling, together with an improvement in LV geometry, showed a lower incidence of mitral repair failure, a more pronounced improvement in heart failure symptoms, and a lower rate of cardiac events during follow-up. Conversely, those with persisting or ongoing LV remodeling presented a significantly higher recurrence of MR and a less significant improvement of the CHF picture. In our experience ring annuloplasty (with or without edge-to-edge technique), although successful acutely, did not prevent the recurrence of MR in more than 40% of the patients showing persisting or ongoing ventricular remodeling. The recurrence of MR was preceded by ongoing LV dilatation and progressively increasing leaflet retethering. The forced coaptation imposed by the undersized ring (alone or associated with the edge-to-edge technique), despite being immediately effective, was partially neutralized in the following months by the increased tethering forces exerted on the mitral leaflets by the severe LV dilatation, leading again to inadequate coaptation and recurrence of MR.
Our results demonstrate that reverse LV remodeling is a strong predictor of repair durability and good clinical outcome. Unfortunately, in a significant number of patients with functional MR, reverse LV remodeling is unlikely to occur. In those patients, who are still difficult to identify preoperatively, MV repair as sole therapy represents only a partial solution because it seems to be unable to halt or reverse the LV remodeling process. In those patients mitral repair, although initially successful in restoring the competence of the valve, does not prevent the recurrence of MR.
Therefore, surgical approaches that are able to alleviate ventricular remodeling have to be used for a comprehensive and effective management of the functional MR patients, either independently or in conjunction with ring annuloplasty. Papillary muscle approximation, LV reconstruction, or containment surgery should be part of an atrioventricular approach that should be pursued whenever possible in the most advanced cases to decrease the rate of patients in whom the LV remodeling process is not going to revert.
In conclusion, in patients with functional MR undergoing effective mitral repair, reverse LV remodeling occurs in about 50% of the cases and is favored by concomitant CABG, ablation of atrial fibrillation, and short CHF history. The edge-to-edge technique may favor this process as well. The occurrence of reverse LV remodeling is associated with longer repair durability and better clinical outcome, whereas progression of the remodeling process leads to recurrence of mitral regurgitation and heart failure symptoms.
This study has several limitations. The number of patients is relatively small, together with the number of late events. The assignment of the patients to isolated undersized annuloplasty or to edge-to-edge and annuloplasty was not performed in a randomized fashion but on the basis of the coaptation depth, which represents the ultimate mechanism of functional MR independent of LV function and shape (sphericity index) [13]. The inclusion in the same series of patients with ischemic and idiopathic dilated cardiomyopathy, concomitant myocardial revascularization, and ablation of atrial fibrillation has certainly influenced the results. However, it should be emphasized that this was done on purpose with the aim to identify all the possible predictors of LV reverse remodeling in a population of very sick patients who usually present similar clinical and pathophysiologic pictures despite the etiology of DCM and in whom the concomitant procedures reported in this series are usually required and associated. Although in the current study some predictors of reverse LV remodeling were identified, preoperative identification of patients who will benefit from surgery remains difficult, and larger studies are needed to further evaluate this issue.
|
References
|
|---|
- Trichon BH, Felker GM, Shaw LK, Cabell CH, O’Connor CM. Relation of frequency and severity of mitral regurgitation to survival among patients with left ventricular systolic dysfunction and heart failure Am J Cardiol 2003;91:538-543.[Medline]
- Grigioni F, Enriquez-Sarano M, Zehr KJ, Bailey KR, Tajik AJ. Ischemic mitral regurgitation: long-term outcome and prognostic implications with quantitative Doppler assessment Circulation 2001;103:1759-1764.[Abstract/Free Full Text]
- Bolling SF, Smolens IA, Pagani FD. Surgical alternatives for heart failure J Heart Lung Transplant 2001;20:729-733.[Medline]
- Bax JJ, Braun J, Somer ST. RA. Restrictive annuloplasty and coronary revascularization in ischemic mitral regurgitation results in reverse left ventricular remodeling Circulation 2004;110(Suppl 2):II-103-II-108.[Medline]
- Hung J, Papakostas L, Tahta SA, et al. Mechanism of recurrent ischemic mitral regurgitation after annuloplasty: continued LV remodeling as a moving target Circulation 2004;110(Suppl 2):II-85-II-89.[Medline]
- Thomas JD. How leaky is that mitral valve?. Simplified Doppler methods to measure regurgitant orifice area. Circulation 1997;95:548-550.[Free Full Text]
- Grayburn PA, Fehske W, Omran H, Brickner ME, Luderitz B. Multiplane transesophageal echocardiographic assessment of mitral regurgitation by Doppler color flow mapping of the vena contracta Am J Cardiol 1994;74:912-917.[Medline]
- La Canna G, Alfieri O, Giubbini R, Gargano M, Ferrari R, Visioli O. Echocardiography during infusion of dobutamine for identification of reversibly dysfunction in patients with chronic coronary artery disease J Am Coll Cardiol 1994;23:617-626.[Abstract]
- De Bonis M, Lapenna E, La Canna G, et al. Mitral valve repair for functional mitral regurgitation in end-stage dilated cardiomyopathy: the role of the "edge-to-edge" technique Circulation 2005;112(Suppl 1):I-402-I-408.[Medline]
- Bolling SF, Pagani FD, Deeb GM, Bach DS. Intermediate-term outcome of mitral reconstruction in cardiomyopathy J Thorac Cardiovasc Surg 1998;115:381-386.[Abstract/Free Full Text]
- Horii T, Suma H, Isomura T, et al. Left ventricle volume affects the result of mitral valve surgery for idiopathic dilated cardiomyopathy to treat congestive heart failure Ann Thorac Surg 2006;82:1349-1355.[Abstract/Free Full Text]
- Glasson JR, Komeda M, Daughters GT, et al. Early systolic mitral leaflet "loitering" during acute ischemic mitral regurgitation J Thorac Cardiovasc Surg 1998;116:193-205.[Abstract/Free Full Text]
- Yiu SF, Enriquez-Sarano M, Tribouilloy C, Seward JB, Tajik AJ. Determinants of the degree of functional mitral regurgitation in patients with systolic left ventricular dysfunction: a quantitative clinical study Circulation 2000;102:1400-1406.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
F. Onorati, A. S. Rubino, D. Marturano, E. Pasceri, G. Santarpino, S. Zinzi, G. Mascaro, and A. Renzulli
Midterm clinical and echocardiographic results and predictors of mitral regurgitation recurrence following restrictive annuloplasty for ischemic cardiomyopathy
J. Thorac. Cardiovasc. Surg.,
September 1, 2009;
138(3):
654 - 662.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Onorati, G. Santarpino, D. Marturano, A. S. Rubino, E. Pasceri, S. Zinzi, G. Mascaro, L. Cristodoro, and A. Renzulli
Successful surgical treatment of chronic ischemic mitral regurgitation achieves left ventricular reverse remodeling but does not affect right ventricular function.
J. Thorac. Cardiovasc. Surg.,
August 1, 2009;
138(2):
341 - 351.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Taramasso, M. De Bonis, E. Lapenna, A. Verzini, G. La Canna, A. Grimaldi, and O. Alfieri
Reverse Remodeling Effect of the CorCap Despite the Presence of Severe Mitral Regurgitation.
Ann. Thorac. Surg.,
March 1, 2009;
87(3):
e23 - e24.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
