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Circulation. 1995;92:2496-2503

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(Circulation. 1995;92:2496-2503.)
© 1995 American Heart Association, Inc.

Articles

Congestive Heart Failure After Surgical Correction of Mitral Regurgitation

A Long-term Study

Maurice Enriquez-Sarano, MD; Hartzell V. Schaff, MD; Thomas A. Orszulak, MD; Kent R. Bailey, PhD; A. Jamil Tajik, MD; Robert L. Frye, MD

From the Division of Cardiovascular Diseases and Internal Medicine (M.E.-S., A.J.T., R.L.F.), Section of Cardiovascular Surgery (H.V.S., T.A.O.), and Section of Biostatistics (K.R.B.), Mayo Clinic and Mayo Foundation, Rochester, Minn.


*    Abstract
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 *Abstract
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Background In patients with mitral regurgitation, surgical intervention produces immediate improvement in symptoms, but the long-term incidence and significance of postoperative congestive heart failure are unknown.

Methods and Results The long-term outcome of 576 operative survivors of surgical correction of pure mitral regurgitation performed between 1980 and 1989 was analyzed. Survival was 77±2% and 56±3% at 5 and 10 years, respectively. Cumulative incidence of congestive heart failure was 23±2%, 33±3%, and 37±3% at 5, 10, and 14 years, respectively. Survival after the first episode of congestive heart failure was dismal, 44±4% at 5 years. Cause of congestive heart failure was left ventricular dysfunction in two thirds of the patients and valvular dysfunction in the other third. With multivariate analysis, the independent predictors of postoperative heart failure were preoperative ejection fraction (P=.0001), coronary artery disease (P=.0017), and New York Heart Association functional class (P=.012), with borderline value for atrial fibrillation (P=.10). The performance of valve repair was independently predictive of a lower incidence of the combined end point of death and heart failure (P=.001), compared with valve replacement.

Conclusions Congestive heart failure frequently occurs late after surgical correction of mitral regurgitation and portends dismal prognosis. This complication is due most often to left ventricular dysfunction; its main determinant is decreased left ventricular function preoperatively. These data should lead to earlier indication of surgical correction of mitral regurgitation, before left ventricular dysfunction occurs.


Key Words: follow-up studies • heart failure • mitral valve • prognosis • surgery


*    Introduction
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 up arrowAbstract
 *Introduction
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down arrowDiscussion
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In patients with mitral regurgitation, surgical intervention is intended to treat and to prevent the occurrence of congestive heart failure.1 Indeed, intermediate-term studies have demonstrated marked improvement in symptoms after surgical correction.2 3 4 5 6 However, the long-term outcome after surgical correction of mitral regurgitation is less well known7 8 ; in particular, the incidence and impact of congestive heart failure on late survival after valve repair or replacement remain poorly defined. In addition to the uncertainty about the frequency of this complication, the mechanisms of heart failure have not been fully analyzed. Although the occurrences of primary failure of valve repair9 or replacement10 11 and of left ventricular dysfunction12 have been recognized, their respective roles in postoperative congestive heart failure are unclear. Thus, the potential predictors of this complication are undefined. Because the prognosis of heart failure is usually poor,13 14 it is of utmost importance to determine the long-term incidence, mechanisms, and predictors of congestive heart failure after surgical correction of mitral regurgitation to assess the potential implications for clinical decision making and management.

Therefore, we examined our experience with the outcome of patients operated on between January 1, 1980, and December 31, 1989, for pure mitral regurgitation and hypothesized that congestive heart failure after surgical correction (1) is frequent and of poor prognosis, (2) is due more often to left ventricular dysfunction than to valvular failure, and (3) can be predicted by the preoperative status of the patient and should have major implications on the clinical decision-making process.


*    Methods
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 *Methods
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The study was based on a retrospective review of our experience with surgical correction of mitral regurgitation.

The inclusion criteria were (1) surgical correction (repair or replacement) of mitral regurgitation performed between January 1, 1980, and December 31, 1989; (2) acquired pure mitral regurgitation as defined by echocardiographic and surgical assessment; and (3) immediate postoperative survival allowing for observation of long-term outcome.

Patients with associated coronary artery bypass graft surgery were included.

The exclusion criteria were (1) previous operation for mitral regurgitation; (2) previous or associated aortic or tricuspid valve replacement (tricuspid valve repair was not excluded); (3) operative death, defined as occurring during the first postoperative month or within the same hospitalization; and (4) mitral regurgitation due to dilated cardiomyopathy.

During the study period, 2183 patients had mitral valve operations. Of these, 654 had surgical correction for pure mitral regurgitation; 577 were operative survivors, of whom 576 (99.8%) had complete follow-up to death or 1994, and these 576 patients represent our study population. Some data on part of this patient population have been published previously.15 16 17

Of the 576 patients, the mean age was 64±12 years, 352 (61%) were men, and 242 (42%) were in atrial fibrillation. The cause of mitral regurgitation was defined as (1) ischemic, if it was documented to be due to coronary artery disease (120 patients) and (2) organic, if intrinsic disease of the mitral valve was documented (456 patients: rheumatic, 47; endocarditic, 40; degenerative with prolapse, 353; and miscellaneous, 16). Preoperatively, within 1 month of surgical correction, New York Heart Association (NYHA) dyspnea class III was noted in 276 patients (48%) and class IV in 94 (16%).

The surgical procedure performed was valve repair in 288 patients and valve replacement in 288 (bioprosthesis in 137 patients and mechanical prosthesis in 151). Coronary artery bypass graft surgery was performed in 211 patients. Perioperative myocardial infarction (new Q waves) occurred in 6 patients.

Left Ventricular Function Analysis and Coronary Angiography
Coronary angiography was performed in 477 patients and showed significant (>=70%) stenosis in 253 (in 120, or 100%, of the patients with ischemic mitral regurgitation and in 133, or 29%, of those with organic mitral regurgitation). Preoperative left ventricular function was analyzed with echocardiography as previously reported15 16 18 19 (453 patients) or left ventricular angiography (354 patients) performed within 6 months of surgical correction. When both techniques were performed, the ejection fraction was calculated as the average of the two reported measurements. Therefore, preoperative ejection fraction (mean, 57±13%) was available for 545 patients.

After surgery, the ejection fraction was measured with echocardiography performed at our institution in 410 patients with a mean delay to surgery of 1.2±2.2 years.

Congestive Heart Failure
Congestive heart failure occurring before or after surgical correction was noted as diagnosed by the attending physician. In all cases, class III or IV dyspnea and evidence of pulmonary edema (clinical and/or radiological) and/or global heart failure were present. The cause of heart failure was considered to be valvular failure when, in addition to the signs of heart failure, there was evidence of severe regurgitation or stenosis (or both) of the mitral valve prosthesis or repair. Conversely, heart failure was considered to be due to myocardial failure in patients who were without signs of valvular failure and in whom left ventricular dysfunction was diagnosed. The cause of heart failure was confirmed in 93% of cases with echocardiography, radionuclide angiography, catheterization, or autopsy.

Statistical Analysis
Group statistics were expressed as mean±SD. Group comparisons were based on standard t test or {chi}2 test, as appropriate. The comparison of postoperative variables between groups defined by the presence and cause of congestive heart failure was performed by ANOVA and t test if appropriate. Group survival was estimated with the Kaplan-Meier method and reported as estimated survival±1 standard error. The observed survival of patients was compared with the expected survival of age- and sex-matched actuarial data from the 1980 US white population and tested by the one-sample log-rank test.

The cumulative probability of congestive heart failure was estimated by the Kaplan-Meier method, with death (without heart failure) as a censoring event. The estimates of cumulative incidence of myocardial or valvular cause of heart failure were based on a Kaplan-Meier estimate, with the other cause as a noncensoring event. Unadjusted group comparison of the time to death or congestive heart failure was based on the two-sample log-rank test. The association of preoperative and intraoperative variables with the incidence of congestive heart failure both overall and by valvular or myocardial causes was estimated with the Cox proportional-hazards model. Multivariate analysis was performed in a sequential manner, starting with preoperative clinical variables (age, sex, cause of regurgitation, NYHA functional class, creatinine level, history of hypertension, history of congestive heart failure, and presence of coronary artery disease) and then adding left ventricular function (ejection fraction) and operative variables (valve repair or replacement and occurrence of myocardial infarction perioperatively). For the prediction of congestive heart failure of valvular origin, the presence of posterior leaflet prolapse was added to the model. To assess the possibility that the etiologic groups would have different predictive associations between these variables and the incidence of congestive heart failure, the set of interactions between the cause and each of the final model variables was added to the final model and tested for significance based on the F test. Survival after onset of congestive heart failure was calculated with the Kaplan-Meier method, with onset of heart failure as the starting time of the survival analysis of this subset of patients. The relative risk of death in patients with postoperative heart failure compared with those without heart failure was calculated by use of a time-dependent proportional-hazards model, with heart failure onset as the time-dependent variable. A value of P<.05 was considered significant.


*    Results
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*Results
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The preoperative characteristics of the overall population, the ischemic mitral regurgitation group, and the organic mitral regurgitation group are summarized in Table 1Down. Despite a similar incidence of NYHA class III and IV symptoms, patients with ischemic regurgitation had a markedly decreased ejection fraction compared with that of patients with organic mitral regurgitation.


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  		Table 1. Preoperative Characteristics of the Study Population

Postoperative Survival
At the latest follow-up, 216 patients had died and 360 were alive. Overall survival rate was 77±2% at 5 years (93% of expected survival), 56±3% at 10 years (84% of expected survival), and 44±4% at 14 years (82% of expected survival) and was significantly decreased in comparison with expected survival (P=.0001, Fig 1Down). Patients with organic mitral regurgitation had a better survival rate (62±3% at 10 years, 91% of expected rate) than those with ischemic mitral regurgitation (36±6% at 10 years, 57% of expected rate) (P=.0001) (Fig 2Down). The determinants of postoperative survival, and in particular the essential role of preoperative ejection fraction, have been analyzed elsewhere.16



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  		Figure 1. Graph showing late survival in the overall population. Numbers at bottom indicate the patients at risk for the interval and the percentage of expected survival achieved.



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  		Figure 2. Graph showing comparison of late survival between patients with ischemic mitral regurgitation and those with organic mitral regurgitation. Numbers at bottom indicate the patients at risk for the interval and the percentage of expected survival achieved.

Overall Congestive Heart Failure
Congestive heart failure was diagnosed before surgery in 370 patients and after surgery in 152. The cumulative incidence of postoperative congestive heart failure was 23±2% at 5 years, 33±3% at 10 years, and 37±3% at 14 years (Fig 3Down). The survival rate after the occurrence of heart failure was dismal, 44±4% and 18±5% at 5 and 10 years, respectively, after the first episode of congestive heart failure (Fig 4Down). The relative risk of death after the occurrence of congestive heart failure compared with those without heart failure was 5.2 (95% CI, 3.9 to 6.8). With multivariate analysis, the independent clinical predictors of congestive heart failure were presence of coronary artery disease, cause of regurgitation, preoperative symptoms, and atrial fibrillation. Age, sex, preoperative creatinine level, history of congestive heart failure, and hypertension were not independently predictive of the occurrence of postoperative congestive heart failure. When combined with preoperative ejection fraction and the surgical variables, the only significant independent predictors of congestive heart failure were ejection fraction (P=.0001), coronary artery disease (P=.0017), and NYHA class (P=.012), with a borderline value for atrial fibrillation (P=.10) (Table 2Down). The incidences of congestive heart failure at 10 years according to the level of preoperative ejection fraction were 19±3%, 29±5%, and 70±6% in patients with preoperative ejection fraction >=60%, 50% to 59%, or <50%, respectively (P=.0001) (Fig 5Down). The risk ratio compared with a preoperative ejection fraction >=60% was 1.8 (95% CI, 1.1 to 2.9) for ejection fraction of 50% to 59% and 5.4 (3.6 to 8.2) for an ejection fraction <50% regarding late occurrence of congestive heart failure. The cumulative incidence of congestive heart failure according to the preoperative symptoms and to the presence of coronary artery disease is shown in Figs 6Down and 7Down, respectively. The risk ratio for postoperative congestive heart failure was 1.8 (95% CI, 1.2 to 2.6) for preoperative NYHA functional class III or IV compared with class I or II. Compared with patients with organic mitral regurgitation without coronary artery disease, the risk ratio was 2.1 (95% CI, 1.4 to 3.2) in patients with organic mitral regurgitation with coronary artery disease and 4.5 (95% CI, 3.1 to 6.6) in patients with ischemic mitral regurgitation. Although preoperative congestive heart failure was not independently predictive of postoperative heart failure in multivariate analysis, it was univariately associated with a risk ratio of 1.7 (95% CI, 1.2 to 2.4).



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  		Figure 3. Graph showing incidence of congestive heart failure (CHF) overall and of myocardial and valvular origin in the entire population. Numbers at bottom indicate the patients at risk for the interval in the overall series.



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  		Figure 4. Graph showing survival rate after the first episode of congestive heart failure in the entire population. Numbers at bottom indicate the patients at risk for the interval.


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  		Table 2. Multivariate Analysis of the Determinants of Cumulative Incidence of Postoperative Congestive Heart Failure



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  		Figure 5. Graph showing incidence of congestive heart failure (CHF) according to the level of preoperative ejection fraction (EF). Numbers at bottom indicate the patients at risk for the interval.



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  		Figure 6. Graph showing incidence of congestive heart failure (CHF) of valvular cause in patients with New York Heart Association functional class I or II symptoms before surgery compared with those with class III or IV symptoms before surgery. Numbers at bottom indicate the patients at risk for the interval.



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  		Figure 7. Graph showing incidence of congestive heart failure (CHF) of myocardial cause in patients with ischemic mitral regurgitation (MR) compared with those with organic MR (with [+] or without [w/o] coronary artery disease [CAD]). Numbers at bottom indicate the patients at risk for the interval.

Cause of Congestive Heart Failure
The cause of heart failure was diagnosed clinically and confirmed with echocardiography, radionuclide angiography, catheterization, or autopsy performed either at our institution or outside in 142 of 152 patients (93%). The postoperative echocardiographic variables obtained at our institution in patients classified as without congestive heart failure or with valvular or myocardial congestive heart failure are presented in Table 3Down. In patients with the diagnosis of myocardial congestive heart failure, there was considerable depression of left ventricular function with left ventricular enlargement. In patients with valvular congestive heart failure, left ventricular function was not depressed, but there was residual enlargement of the left atrium.


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  		Table 3. Postoperative Left Ventricular Function1

The cause of heart failure was valvular failure in 45 patients, representing an incidence of 7±1% at 5 years and 11±2% at 10 years. Valvular failure was observed in 24 repairs, 8 mechanical prostheses, and 13 bioprostheses, a distribution not different from the patients without postoperative heart failure (224 repairs, 110 mechanical prostheses, and 90 bioprostheses; P=.34). Reoperation was performed in 28 patients. The cause of congestive heart failure was myocardial failure in 107 patients, representing an incidence of 16±2% at 5 years and 23±2% at 10 years (Fig 3Up).

With multivariate analysis, there was no significant predictor of congestive heart failure due to valvular failure. Conversely, ejection fraction (P=.0001), coronary artery disease (P=.0008), atrial fibrillation (P=.006), and, of more borderline value, NYHA class (P=.06) were independent predictors of heart failure due to myocardial failure.

Cause of Regurgitation
In patients with ischemic mitral regurgitation compared with those with organic mitral regurgitation, the incidence of congestive heart failure was higher (at 5 years, 45±5% versus 17±2% and at 10 years, 65±7% versus 25±3%; P=.0001). However, when classified according to the cause of heart failure, there was no significant difference in congestive heart failure due to valvular dysfunction between patients with ischemic mitral regurgitation and those with organic mitral regurgitation (at 10 years, 11±4% versus 11±2%; P=NS), but patients with ischemic mitral regurgitation had a higher incidence of congestive heart failure of myocardial origin (at 8 years, 48±5% versus 14±2%; P=.0001). However, in multivariate analysis, the degree of left ventricular dysfunction, but not the cause of regurgitation, was independently predictive of postoperative congestive heart failure (Table 3Up). In addition, no interaction between the predictors of congestive heart failure and the cause of regurgitation was noted. The survival rate after the first episode of congestive heart failure was significantly but moderately worse in patients with ischemic rather than organic mitral regurgitation (at 7 years, 24±7% versus 36±6%; P=.007). Overall, coronary artery disease was a powerful predictor of postoperative congestive heart failure, and specifically in patients with organic mitral regurgitation, the incidence of congestive heart failure was significantly higher in patients with associated coronary artery disease than in those without overt coronary artery disease (35±5% versus 21±3% at 10 years; P=.0003).

Repair Versus Replacement
With univariate analysis, there was a lower incidence of postoperative congestive heart failure after valve repair than after valve replacement (P=.04). However, such a difference was not detectable in patients with ischemic mitral regurgitation and was significant only in those with organic mitral regurgitation (at 10 years, 17±3% versus 33±4%; P=.04) and only for the myocardial failure cause (at 10 years, 9±2% versus 22±4%; P=.006). However, with multivariate analysis, valve repair was not independently predictive of a decreased incidence of congestive heart failure when stratified for the other predictors.

Nevertheless, when a combined end point of death and congestive heart failure was analyzed in patients with organic mitral regurgitation, repair was an independent predictor of improved outcome (P=.001) (Fig 8Down). The other independent predictors were ejection fraction (P=.0001), age (P=.0001), coronary artery disease (P=.0047), atrial fibrillation (P=.08), NYHA class (P=.025), and perioperative myocardial infarction (P=.0001). The survival rate after the first episode of congestive heart failure was not significantly different in patients with valve repair or valve replacement (at 8 years after the episode of congestive heart failure, 17±7% in the valve repair group versus 26±6% in the valve replacement group [P=NS] were survivors).



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  		Figure 8. Graph showing incidence of death and congestive heart failure (CHF) compared in valve repair and replacement performed in patients with organic mitral regurgitation. Numbers at bottom indicate the patients at risk for the interval.


*    Discussion
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 up arrowAbstract
 up arrowIntroduction
 up arrowMethods
up arrowResults
*Discussion
down arrowReferences
 
The results of the present study show that congestive heart failure after surgical correction of mitral regurgitation (1) is frequent but of progressively increasing incidence late after surgical correction, (2) is associated with a poor prognosis, (3) is most often due to left ventricular dysfunction and thus is best predicted by an already decreased preoperative ejection fraction, and (4) is more frequent in patients with coronary artery disease.

Congestive Heart Failure After Correction of Mitral Regurgitation
The occurrence of congestive heart failure after surgical correction of mitral regurgitation is particularly disturbing because the intent of the surgical intervention is to eliminate preoperative congestive heart failure or to prevent it.1 Indeed, marked improvement in symptoms after surgical relief of mitral regurgitation is quite common,2 3 4 5 6 with a very small percentage of patients remaining in NYHA functional classes III and IV.20 Such an early improvement may be misleading in terms of the true long-term outcome as reflected in the present study. The incidence of congestive heart failure and cardiac death7 8 21 tends to increase progressively with time, thus emphasizing the importance of long-term follow-up for judging results. The prognosis of postoperative congestive heart failure is dismal: More than one half of the patients who had this complication died within 5 years after the first episode, an incidence similar to nonvalvular causes of heart failure.13 14 Such an impact on prognosis underscores the importance of determining the cause of postoperative heart failure and its predictors and considering how to prevent its occurrence.

Whereas late occurrence of congestive heart failure may be due to primary failure of valve repair,9 mechanical prostheses,11 or bioprostheses,10 the most common cause of heart failure in the present study was left ventricular dysfunction. This complication is frequently present early after surgical correction of mitral regurgitation15 22 and has even been noted with intraoperative imaging techniques.23 The absence of symptoms early after suppression of the valvular regurgitation may be observed even in the presence of left ventricular dysfunction as a result of previously documented normalization of left atrial pressure24 25 and is similar to what is observed in nonvalvular ventricular dysfunction.26 However, with time, overt congestive heart failure occurs in a significant proportion of patients. After the signs of heart failure are present, the prognosis is poor, similar to that of patients with nonvalvular left ventricular dysfunction.13 14

Predictors of Postoperative Congestive Heart Failure
Postoperative congestive heart failure in most cases is due to left ventricular dysfunction and rarely to failure of the surgical procedure,27 which cannot be predicted from preoperative variables. Intraoperative complications, such as myocardial infarction, may lead to left ventricular dysfunction, but these are rare.28 That preoperative left ventricular ejection fraction is the most powerful predictor of postoperative heart failure strongly suggests that left ventricular dysfunction is present preoperatively.29 30 This observation agrees with the fact that preoperative variables of left ventricular function have frequently been noted to be predictors of postoperative survival16 31 and postoperative left ventricular function.15 22 29 30 Judging normalcy of ejection fraction is complicated in patients with mitral regurgitation due to altered loading conditions.32 33 34 However, it should be noted that the incidence of congestive heart failure is very high in patients with severely depressed ventricular function (ejection fraction <50%), but it is also increased in patients with borderline ejection fraction (50% to 59%), which indicates that these patients already have a significant degree of left ventricular dysfunction, which may go unnoticed until the appearance of severe symptoms at a late stage.1

Other preoperative predictors are also important. Severe symptoms (NYHA classes III and IV) and atrial fibrillation tend to be associated with an increased incidence of late congestive heart failure.35 The role of atrial fibrillation suggests the need for appropriate controlled studies to establish the need to intervene aggressively to maintain normal sinus rhythm. Associated coronary artery disease is a powerful predictor of an excess incidence of congestive heart failure and late death,16 36 independent of ejection fraction. Such an effect emphasizes the importance of detecting coronary artery stenosis before surgery, although the impaired prognosis occurred despite bypass operation being combined with valvular correction. The survival rate after correction of ischemic mitral regurgitation was mediocre, as noted previously,37 and the excess mortality was due primarily to the severe left ventricular dysfunction commonly present in that disease.38 The suggested advantage of mitral valve repair over valve replacement in this subset of patients39 was not observed in the present study.

Prevention of Congestive Heart Failure
Congestive heart failure due to dysfunction of the surgical correction of the mitral valve in most cases may be prevented by use of intraoperative transesophageal echocardiography.40 Prevention of valve endocarditis and thrombosis is important in avoiding late valvular complications that could result in congestive heart failure.7 10 11 Prevention of postoperative congestive heart failure due to left ventricular dysfunction is more difficult but of considerable clinical significance.

Early Surgical Correction
Patients with a significant degree of left ventricular dysfunction (ejection fraction <60%) should have surgical correction without waiting for further deterioration of their condition.16 For patients in this category, surgical correction of the regurgitation should not be denied (despite a high incidence of postoperative congestive heart failure) for two reasons: (1) in patients with an ejection fraction <50%, surgical correction, in comparison with medical treatment, improves the prognosis41 42 and (2) the occurrence of congestive heart failure is often delayed, and surgical correction may provide up to several years of marked symptomatic improvement.

Patients with apparently preserved left ventricular function who have an ejection fraction >=60% have a relatively low incidence of postoperative congestive heart failure. These patients have been shown to have an excellent late survival,16 with a low incidence of postoperative left ventricular dysfunction.15 22 Thus, that stage of preserved left ventricular function represents the ideal indication for surgical correction of mitral regurgitation. Even at that stage, severe symptoms (NYHA class III or IV) are associated with increased incidence of heart failure and increased mortality,16 suggesting that correction of mitral regurgitation in patients in NYHA class I or II with an ejection fraction >=60% may be a reasonable approach under certain conditions. Such an aggressive approach is defensible only in patients at low operative risk and in those medical centers with documented high rates of success in repairing the mitral valve with low operative mortality.

Valve Repair as the Preferred Surgical Procedure
Although valve repair does not reduce the incidence of valve failure, it is univariately associated with a lower incidence of postoperative congestive heart failure due to myocardial failure. It is an independent predictor of a lower incidence of the combined end point of congestive heart failure and death in patients with organic mitral regurgitation. Valve repair also has been reported to result in decreased operative mortality and better long-term survival17 43 as well as better left ventricular function.17 23 44 Valve repair should be discussed in all surgical cases of mitral regurgitation.45 The low operative risk is another incentive to perform early surgical correction of mitral regurgitation. However, valve repair does not eliminate the risk of congestive heart failure or the need for surgical correction of mitral regurgitation before the occurrence of left ventricular dysfunction.

Pharmacological Prevention of Congestive Heart Failure
In the present series, medical treatment of heart failure was adapted to the clinical circumstances, and its effect on outcome cannot be analyzed. Angiotensin-converting enzyme inhibitors have been used successfully to prolong survival in patients with congestive heart failure13 14 and to improve the outcome of those with asymptomatic left ventricular dysfunction.26 Although no randomized trial has studied the use of these medications for the prevention of congestive heart failure after surgical correction of mitral regurgitation, their use in patients in whom left ventricular dysfunction has been diagnosed early after surgical correction appears worthy of consideration and future analysis.

Limitations of the Study
Although heavy reliance on echocardiographic estimates of left ventricular ejection fraction may be a cause of concern, the use of echocardiography in this setting is standard practice, and previous studies from our institution have documented the acceptable correlations to angiography and, most importantly, the high prognostic value of these estimates.15 16 However, the importance of careful attention to quality control issues in laboratories that perform such studies needs to be emphasized.

Although all the patients in the present series were considered to have severe mitral regurgitation, an important limitation is the lack of quantitation of the severity. This is another important measurement that needs to be integrated in the assessment of left ventricular function and perhaps may be of value in selecting patients for early intervention. Within the time frame of the present study, such quantitation was not routinely available. However, methods that can be used in routine clinical practice are now available for quantifying not only the regurgitant volume46 but also the effective regurgitant orifice.47 48 Further studies are necessary to delineate the natural history of mitral regurgitation classified according to these variables so as to better define the indications for early surgical intervention.

Conclusions
Congestive heart failure is a frequent postoperative complication of surgical correction of mitral regurgitation. It is rarely due to valvular failure but rather is caused most often by left ventricular dysfunction present before surgery. The poor prognosis of this complication justifies an aggressive detection of left ventricular dysfunction and prevention of heart failure, particularly through the use of early valvular repair.


*    Acknowledgments
 
We appreciate the expert data abstracting assistance of Kim Jones, data analysis of Sara Fett, and secretarial assistance of Jannett Halling.


*    Footnotes
 
Reprint requests to M. Enriquez-Sarano, MD, Mayo Clinic, 200 First St SW, Rochester, MN 55905.

Received February 27, 1995; revision received May 15, 1995; accepted May 30, 1995.


*    References
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up arrowResults
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*References
 

  1. Braunwald E. Heart Disease: A Textbook of Cardiovascular Medicine. 4th ed. Philadelphia, Pa: WB Saunders Co; 1992:1018-1029.
  2. Sand ME, Naftel DC, Blackstone EH, Kirklin JW, Karp RB. A comparison of repair and replacement for mitral valve incompetence. J Thorac Cardiovasc Surg. 1987;94:208-219. [Abstract]
  3. Galloway AC, Colvin SB, Baumann FG, Esposito R, Vohra R, Harty S, Freeberg R, Kronzon I, Spencer FC. Long-term results of mitral valve reconstruction with Carpentier techniques in 148 patients with mitral insufficiency. Circulation. 1988;78(suppl I): I-97-I-105.
  4. Chaffin JS, Daggett WM. Mitral valve replacement: a nine-year follow-up of risks and survivals. Ann Thorac Surg. 1979;27:312-319. [Abstract]
  5. Teoh KH, Ivanov J, Weisel RD. Determinants of survival and valve failure after mitral valve replacement. Ann Thorac Surg. 1990;49:643-648. [Abstract]
  6. Thompson R, Baird J, Squire B, Hilless A, Leslie P, Easthope R. Late results of valve replacement and factors influencing survival in patients with severe chronic mitral regurgitation. N Z Med J. 1985;98:944-947. [Medline] [Order article via Infotrieve]
  7. McGoon MD, Fuster V, McGoon DC, Pumphrey CW, Pluth JR, Elveback LR. Aortic and mitral valve incompetence: long-term follow-up (10 to 19 years) of patients treated with the Starr-Edwards prosthesis. J Am Coll Cardiol. 1984;3:930-938. [Abstract]
  8. Deloche A, Jebara VA, Relland JY, Chauvaud S, Fabiani JN, Perier P, Dreyfus G, Mihaileanu S, Carpentier A. Valve repair with Carpentier techniques: the second decade. J Thorac Cardiovasc Surg. 1990;99:990-1001. [Abstract]
  9. Lessana A, Carbone C, Romano M, Palsky E, Quan YH, Escorsin M, Jegier B, Ruffenach A, Lutfalla G, Aime F, Guerin F. Mitral valve repair: results and the decision-making process in reconstruction: report of 275 cases. J Thorac Cardiovasc Surg. 1990;99:622-630. [Abstract]
  10. Cohn LH, Allred EN, Cohn LA, Austin JC, Sabik J, DiSesa VJ, Shemin RJ, Collins JJ Jr. Early and late risk of mitral valve replacement: a 12 year concomitant comparison of the porcine bioprosthetic and prosthetic disc mitral valves. J Thorac Cardiovasc Surg. 1985;90:872-881. [Abstract]
  11. Miller DC, Oyer PE, Stinson EB, Reitz BA, Jamieson SW, Baumgartner WA, Mitchell RS, Shumway NE. Ten to fifteen year reassessment of the performance characteristics of the Starr-Edwards model 6120 mitral valve prosthesis. J Thorac Cardiovasc Surg. 1983;85:1-20. [Medline] [Order article via Infotrieve]
  12. Hildner FJ, Javier RP, Cohen LS, Samet P, Nathan MJ, Yahr WZ, Greenberg JJ. Myocardial dysfunction associated with valvular heart disease. Am J Cardiol. 1972;30:319-326. [Medline] [Order article via Infotrieve]
  13. Cohn JN, Johnson G, Ziesche S, Cobb F, Francis G, Tristani F, Smith R, Dunkman WB, Loeb H, Wong M, Bhat G, Goldman S, Fletcher RD, Doherty J, Hughes V, Carson P, Cintron G, Shabetai R, Haakenson C. A comparison of enalapril with hydralazine-isosorbide dinitrate in the treatment of chronic congestive heart failure. N Engl J Med. 1991;325:303-310. [Abstract]
  14. The SOLVD Investigators. Effect of enalapril on survival in patients with reduced left ventricular ejection fractions and congestive heart failure. N Engl J Med. 1991;325:293-302. [Abstract]
  15. Enriquez-Sarano E, Tajik AJ, Schaff HV, Orszulak TA, McGoon MD, Bailey KR, Frye RL. Echocardiographic prediction of left ventricular function after correction of mitral regurgitation: results and clinical implications. J Am Coll Cardiol. 1994;24:1536-1543. [Abstract]
  16. Enriquez-Sarano M, Tajik AJ, Schaff HV, Orszulak TA, Bailey KR, Frye RL. Echocardiographic prediction of survival after surgical correction of organic mitral regurgitation. Circulation. 1994;90:830-837. [Abstract/Free Full Text]
  17. Enriquez-Sarano M, Schaff HV, Orszulak TA, Tajik AJ, Bailey KR, Frye RL. Valve repair improves the outcome of surgery for mitral regurgitation: a multivariate analysis. Circulation. 1995;91:1022-1028. [Abstract/Free Full Text]
  18. Quinones MA, Pickering E, Alexander JK. Percentage of shortening of the echocardiographic left ventricular dimension: its use in determining ejection fraction and stroke volume. Chest. 1978;74:59-65. [Abstract/Free Full Text]
  19. Rich S, Sheikh A, Gallastegui J, Kondos GT, Mason T, Lam W. Determination of left ventricular ejection fraction by visual estimation during real-time two-dimensional echocardiography. Am Heart J. 1982;104:603-606. [Medline] [Order article via Infotrieve]
  20. Salomon NW, Stinson EB, Griepp RB, Shumway NE. Patient-related risk factors as predictors of results following isolated mitral valve replacement. Ann Thorac Surg. 1977;24:519-530. [Abstract]
  21. Fernandez J, Joyce DH, Hirschfeld KJ, Chen C, Yang SS, Laub GW, Adkins MS, Anderson WA, Mackenzie JW, McGrath LB. Valve-related events and valve-related mortality in 340 mitral valve repairs: a late phase follow-up study. Eur J Cardiothorac Surg. 1993;7:263-270. [Abstract]
  22. Crawford MH, Souchek J, Oprian CA, Miller DC, Rahimtoola S, Giacomini JC, Sethi G, Hammermeister KE. Determinants of survival and left ventricular performance after mitral valve replacement: Department of Veterans Affairs Cooperative Study on Valvular Heart Disease. Circulation. 1990;81:1173-1181. [Abstract/Free Full Text]
  23. Goldman ME, Mora F, Guarino T, Fuster V, Mindich BP. Mitral valvuloplasty is superior to valve replacement for preservation of left ventricular function: an intraoperative two-dimensional echocardiographic study. J Am Coll Cardiol. 1987;10:568-575. [Abstract]
  24. Hultgren H, Hubis H, Shumway N. Cardiac function following mitral valve replacement. Am Heart J. 1968;75:302-312. [Medline] [Order article via Infotrieve]
  25. Enriquez-Sarano M, Hannachi M, Jais JM, Acar J. Hemodynamic and angiographic results following surgical correction of mitral insufficiency: apropos of 51 repeated catheterizations. Arch Mal Coeur Vaiss. 1983;76:1194-1203. [Medline] [Order article via Infotrieve]
  26. The SOLVD Investigators. Effect of enalapril on mortality and the development of heart failure in asymptomatic patients with reduced left ventricular ejection fractions. N Engl J Med. 1992;327:685-691. [Abstract]
  27. Marwick TH, Stewart WJ, Currie PJ, Cosgrove DM. Mechanisms of failure of mitral valve repair: an echocardiographic study. Am Heart J. 1991;122:149-156. [Medline] [Order article via Infotrieve]
  28. Obarski TP, Loop FD, Cosgrove DM, Lytle BW, Stewart WJ. Frequency of acute myocardial infarction in valve repairs versus valve replacement for pure mitral regurgitation. Am J Cardiol. 1990;65:887-890. [Medline] [Order article via Infotrieve]
  29. Schuler G, Peterson KL, Johnson A, Francis G, Dennish G, Utley J, Daily PO, Ashburn W, Ross J Jr. Temporal response of left ventricular performance to mitral valve surgery. Circulation. 1979;59:1218-1231. [Free Full Text]
  30. Zile MR, Gaasch WH, Carroll JD, Levine HJ. Chronic mitral regurgitation: predictive value of preoperative echocardiographic indexes of left ventricular function and wall stress. J Am Coll Cardiol. 1984;3:235-242. [Abstract]
  31. Phillips HR, Levine FH, Carter JE, Boucher CA, Osbakken MD, Okada RD, Akins CW, Daggett WM, Buckley MJ, Pohost GM. Mitral valve replacement for isolated mitral regurgitation: analysis of clinical course and late postoperative left ventricular ejection fraction. Am J Cardiol. 1981;48:647-654.[Medline] [Order article via Infotrieve]
  32. Wisenbaugh T. Does normal pump function belie muscle dysfunction in patients with chronic severe mitral regurgitation? Circulation. 1988;77:515-525. [Abstract/Free Full Text]
  33. Corin WJ, Monrad ES, Murakami T, Nonogi H, Hess OM, Krayenbuehl HP. The relationship of afterload to ejection performance in chronic mitral regurgitation. Circulation. 1987;76:59-67. [Abstract/Free Full Text]
  34. Mirsky I, Corin WJ, Murakami T, Grimm J, Hess OM, Krayenbuehl HP. Correction for preload in assessment of myocardial contractility in aortic and mitral valve disease: application of the concept of systolic myocardial stiffness. Circulation. 1988;78:68-80. [Abstract/Free Full Text]
  35. Reed D, Abbott RD, Smucker ML, Kaul S. Prediction of outcome after mitral valve replacement in patients with symptomatic chronic mitral regurgitation: the importance of left atrial size. Circulation. 1991;84:23-34. [Abstract/Free Full Text]
  36. van Herwerden LA, Tjan D, Tijssen JG, Quaegebeur JM, Bos E. Determinants of survival after surgery for mitral valve regurgitation in patients with and without coronary artery disease. Eur J Cardiothorac Surg. 1990;4:329-335. [Abstract]
  37. Hickey MS, Smith LR, Muhlbaier LH, Harrell FE Jr, Reves JG, Hinohara T, Califf RM, Pryor DB, Rankin JS. Current prognosis of ischemic mitral regurgitation: implications for future management. Circulation. 1988;78(suppl I):I-51-I-59.
  38. Pinson CW, Cobanoglu A, Metzdorff MT, Grunkemeier GL, Kay PH, Starr A. Late surgical results for ischemic mitral regurgitation: role of wall motion score and severity of regurgitation. J Thorac Cardiovasc Surg. 1984;88:663-672. [Abstract]
  39. Rankin JS, Feneley MP, Hickey MS, Muhlbaier LH, Wechsler AS, Floyd RD, Reves JG, Skelton TN, Califf RM, Lowe JE, Sabiston DC Jr. A clinical comparison of mitral valve repair versus valve replacement in ischemic mitral regurgitation. J Thorac Cardiovasc Surg. 1988;95:165-177. [Abstract]
  40. Freeman WK, Schaff HV, Khandheria BK, Oh JK, Orszulak TA, Abel MD, Seward JB, Tajik AJ. Intraoperative evaluation of mitral valve regurgitation and repair by transesophageal echocardiography: incidence and significance of systolic anterior motion. J Am Coll Cardiol. 1992;20:599-609. [Abstract]
  41. Hammermeister KE, Fisher L, Kennedy W, Samuels S, Doge HT. Prediction of late survival in patients with mitral valve disease from clinical, hemodyamic, and quantitative angiographic variables. Circulation. 1978;57:341-349. [Abstract/Free Full Text]
  42. Hochreiter C, Niles N, Devereux RB, Kligfield P, Borer JS. Mitral regurgitation: relationship of noninvasive descriptors of right and left ventricular performance to clinical and hemodynamic findings and to prognosis in medically and surgically treated patients. Circulation. 1986;73:900-912. [Abstract/Free Full Text]
  43. Perier P, Deloche A, Chauvaud S, Fabiani JN, Rossant P, Bessou JP, Relland J, Bourezak H, Gomez F, Blondeau P, d'Allaines C, Carpentier A. Comparative evaluation of mitral valve repair and replacement with Starr, Björk, and porcine valve prostheses. Circulation. 1984;70(suppl I):I-187-I-192.
  44. Sakai K, Nakano S, Taniguchi K, Sakaki S, Hirata N, Shintani H, Shimazaki Y, Kawashima Y, Matsuda H. Global left ventricular performance and regional systolic function after suture annuloplasty for chronic mitral regurgitation. Circulation. 1992;86(suppl II):II-39-II-45.
  45. Chavez AM, Cosgrove DM III, Lytle BW, Gill CC, Loop FD, Stewart RW, Golding LR, Taylor PC. Applicability of mitral valvuloplasty techniques in a North American population. Am J Cardiol. 1988;62:253-256. [Medline] [Order article via Infotrieve]
  46. Enriquez-Sarano M, Bailey KR, Seward JB, Tajik AJ, Krohn MJ, Mays JM. Quantitative Doppler assessment of valvular regurgitation. Circulation. 1993;87:841-848. [Abstract/Free Full Text]
  47. Enriquez-Sarano M, Seward JB, Bailey KR, Tajik AJ. Effective regurgitant orifice area: a noninvasive Doppler development of an old hemodynamic concept. J Am Coll Cardiol. 1994;23:443-451. [Abstract]
  48. Vandervoort PM, Rivera JM, Mele D, Palacios IF, Dinsmore RE, Weyman AE, Levine RA, Thomas JD. Application of color Doppler flow mapping to calculate effective regurgitant orifice area: an in vitro study and initial clinical observations. Circulation. 1993;88:1150-1156.[Abstract/Free Full Text]



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