Reparative operations for mitral valve incompetence: an emerging treatment of choice

Prediction of surgical strategy in mitral valve regurgitation based on echocardiography. Interuniversity Cardiology Institute of The Netherlands

The purpose of this prospective multicenter study of 350 consecutive patients who were accepted for mitral valve surgery because of severe regurgitation, was to assess the value of preoperative transthoracic and transesophageal echocardiography in predicting the surgical strategy in severe mitral regurgitation: repair or replacement. The cardiologist predicted the surgical strategy on the basis of the echocardiographic examination, according to predefined guidelines for repair and replacement. The predicted strategy and motivation thereof were compared with the surgical findings and procedure that was performed. Agreement on the basis of transthoracic echocardiography was reached in 86% of the repair patients and on the basis of transesophageal echocardiography in 89%. Agreement on the basis of transthoracic echocardiography was reached in 74% of the replacement patients and on the basis of transesophageal echocardiography in 75%. This study underlines the potential role of echocardiography in predicting the surgical procedure to be applied, provided that both surgeon and cardiologist use the same nomenclature and that the guidelines for replacement/repair are adhered to. Both transthoracic and transesophageal echocardiography appear to be equally accurate in predicting the optimal surgical procedure in this respect.

Regression of left ventricular mass after mitral valve repair of pure mitral regurgitation

To evaluate the effect of mitral valve repair on the regression of left ventricular mass, we studied 50 consecutive patients with severe, pure mitral regurgitation undergoing mitral valve repair. Two-dimensional echocardiograms were recorded a mean 2.5 +/- 2.0 weeks before and 6.5 +/- 2.5 months after valve operation. Postoperative significant mitral regurgitation was present in 3 patients. After mitral valve repair there were significant decreases in left ventricular end-diastolic volume index (133 +/- 39 mL/m2 to 79 +/- 35 mL/m2; p < 0.001), end-systolic volume index (44 +/- 26 mL/m2 to 30 +/- 26 mL/m2; p < 0.001), stroke volume index (89 +/- 29 mL/m2 to 49 +/- 19 mL/m2; p < 0.001), and mass index (211 +/- 82 g/m2 to 134 +/- 52 g/m2; p < 0.001). There also were significant decreases in left atrial dimension (47 +/- 9 mm to 38 +/- 9 mm; p < 0.001), left ventricular end-diastolic dimension (61 +/- 8 mm to 48 +/- 7 mm; p < 0.001), and end-systolic dimension (39 +/- 8 mm to 32 +/- 7 mm; p < 0.001). Left ventricular ejection fraction decreased slightly from 0.69 +/- 0.12 to 0.64 +/- 0.12; p < 0.01) after repair. Thus, correction of pure mitral regurgitation leads to reduction of the cardiac chamber size and left ventricular volumes as well as regression of the left ventricular mass.

Natural history of the asymptomatic/minimally symptomatic patient with severe mitral regurgitation secondary to mitral valve prolapse and normal right and left ventricular performance

The natural history of patients with severe nonischemic mitral regurgitation (MR) from mitral valve prolapse, who are asymptomatic or minimally symptomatic and have normal right ventricular (RV) and left ventricular (LV) performance, has not been evaluated previously. To define natural history in this population and to determine if any objective variables could predict disease progression, 31 patients were followed annually with severe MR due to prolapse, who at entry were asymptomatic or minimally symptomatic and had normal RV and LV performance at rest by radionuclide cineangiography. Average follow-up in patients not reaching surgical end point was 4.7 years. The Kaplan-Meier product limit estimates were used to determine the rate of progression to either "operable" symptoms or to previously defined "high risk" ventricular performance descriptors, if the latter occurred first. Univariate comparisons of Kaplan-Meier curves and multivariate Cox proportional hazards analyses were used to define prognostically important variables measured at entry. Fourteen patients developed symptoms warranting referral for operation; none developed high-risk ventricular performance descriptors. The annual end point risk was 10.3%. Of all covariates, only change in RV ejection fraction from rest to exercise was significantly associated with disease progression. Annual risk of progression to surgical end point was 4.9% in the subgroup in which this parameter increased with exercise and 14.7% in the subgroup without an increase (p = 0.04). Patients with severe MR due to mitral valve prolapse, who are asymptomatic or minimally symptomatic with normal ventricular performance, can be expected to progress to surgical indications at an annual rate of 10.3%.(ABSTRACT TRUNCATED AT 250 WORDS)

Late outcome of unsupported annuloplasty for rheumatic mitral regurgitation

OBJECTIVES

The aim of this study was to evaluate medium- and long-term (range 4 months to 17 years) clinical results in a series of patients treated surgically by unsupported mitral annuloplasty.

BACKGROUND

Mitral valve regurgitation has usually been treated by valve replacement or ring annuloplasty. A few series have reported plastic repair procedures without annular support or remodeling. Furthermore, in rheumatic lesions the results have been inferior to those in degenerative mitral insufficiency, and the majority of previous reports have provided information on short- or medium-term follow-up.

METHODS

One hundred fifty-four patients were operated on (55 male [36%] and 99 female [64%]). The mean age +/- SD was 36 +/- 16 years (range 5 to 73). Associated lesions comprised 47 aortic and 21 tricuspid valve lesions and 2 atrial septal defects. Patients with concomitant mitral stenosis were not included. Preoperative functional class was I or II in 19% and III or IV in 81%. The cardiothoracic ratio was 0.61 +/- 0.10. All patients underwent an unsupported mitral annuloplasty procedure in which the mural portion of the annulus was reduced by applying two buttressed mattress sutures at the commissures without compromising the width of the septal leaflet. When necessary, additional chordal procedures were performed. No patients received ring or posterior annular support.

RESULTS

The early mortality rate was 1.9% (three patients; one of the three died of myocardial failure and two of pulmonary thromboembolism). The late mortality rate was 5.8% (nine patients; three of the nine died of myocardial failure, one each of septicemia, pulmonary thromboembolism and sudden arrhythmic death and three of unknown causes). Twenty-eight patients (18.2%) were reoperated on because of mitral valve dysfunction and 2 (1.3%) because of prosthetic aortic valve dysfunction. A residual late systolic murmur was present in 48% of patients. Late complications were systemic thromboembolism in 5.8% (one third with an aortic valve prosthesis), infective endocarditis in 1.3% and pulmonary thromboembolism in 0.6%. Postoperative functional class was I or II in 84% and III or IV in 16%. Cardiothoracic ratio was 0.58 +/- 0.10. Actuarial probability of late survival was 79.5 +/- 5.3% at 10 years and 71.0 +/- 7.4% at 14 years. Event-free survival was 67.9 +/- 8.9% at 10 years and 56.1 +/- 11.7% at 14 years.

CONCLUSIONS

Rheumatic mitral regurgitation can be effectively treated by annuloplasty without prosthetic annular support, with late results comparable to those obtained with more complicated procedures. This observation is particularly important for treatment of children and young adult patients.

Repair of the anterior mitral leaflet

BACKGROUND

Repair rather than replacement of the diseased mitral valve has been the goal of the cardiac surgeon. Although well accepted for posterior leaflet pathology, a diseased anterior leaflet was believed by some to be irreparable.

AIMS

To assess the result of reconstructive mitral valve surgery involving the anterior mitral leaflet in a selected group of patients.

METHODS

Twenty consecutive patients with degenerative (19), ischaemic (one) and congenital/calcific mitral regurgitation were evaluated. There were five females and 15 males with a mean age of 62 +/- 12 years (41-75 years). The technique used to repair these valves included chordal transposition, leaflet plication commissuroplasty and a new technique we call leaflet repositioning.

RESULT

There were no deaths, follow-up is complete with mean follow-up of 31 +/- five months (two-102) months. All patients have had 2DE and 13 TOE as well. There have been no reoperations due to failure of the repair, 95% of patients are in NYHA Class I-II post operative, while 15% have significant residual regurgitation.

Morphologic characterization and quantitative assessment of mitral regurgitation with ruptured chordae tendineae by transesophageal echocardiography

To compare the accuracy of transesophageal echocardiography (TEE) with that of transthoracic echocardiography (TTE) in the detection of morphologic characteristics and in the quantitative assessment of the severity of mitral regurgitation with ruptured chordae tendineae, 40 patients with ruptured chordae tendineae (group 1) and 20 patients with moderate or severe mitral regurgitation due to other causes (group 2) were studied. All echocardiograms were recorded before cardiac surgery. Cardiac catheterization was performed in 55 patients (92%). TEE showed greater sensitivity and negative predictive value than TTE (100 vs 65%, and 100 vs 56%, respectively; p < 0.005) in the diagnosis of ruptured chordae tendineae. Visualization of the ruptured chordae (termed snake-tongue sign) was highly sensitive and specific (93 and 95%, respectively) for establishing the diagnosis of ruptured chordae tendineae. The severity of mitral regurgitation in group 1 patients evaluated by TTE color flow mapping was underestimated by 2 grades in 1 patient and by 1 grade in 6 patients, and overestimated by 1 grade in 1 patient, compared with left ventriculography. In contrast, by TEE color flow mapping it was underestimated by 1 grade in 1 and overestimated by 1 grade in 1 patient. TEE color flow mapping showed better correlation with angiography than did TTE color flow mapping (r = 0.82 vs r = 0.49).

Mitral valve prolapse, panic disorder, and chest pain

Mitral valve prolapse is a common cardiac disorder that can readily be diagnosed by characteristic auscultatory and echocardiographic criteria. Although many diseases have been associated with mitral valve prolapse, most affected individuals have the primary form of the disorder. Mitral valve prolapse is an inherited condition commonly associated with myxomatous degeneration of the mitral valve and its support structures. Complications of mitral valve prolapse, including cardiac arrhythmias, sudden death, infective endocarditis, severe mitral regurgitation (with or without chordae tendineae rupture), and cerebral ischemic events, occur infrequently considering the wide prevalence of the disorder. Panic disorder is a specific type of anxiety disorder characterized by at least three panic attacks within a 3-week period or one panic attack followed by fear of subsequent panic attacks for at least 1 month. It too is a common condition with a prevalence and age and gender distribution similar to that of mitral valve prolapse. Panic disorder and mitral valve prolapse share many nonspecific symptoms, including chest pain or discomfort, palpitations, dyspnea, effort intolerance, and pre-syncope. Chest pain is the symptom in both conditions that most commonly brings the patient to medical attention. The clinical description of chest pain in patients with mitral valve prolapse is highly variable, possibly reflecting multiple etiologies. Chest pain in panic disorder is usually characterized as atypical angina pectoris and as such bears resemblance to the chest pain commonly described by patients with mitral valve prolapse. Multiple investigative attempts to elucidate the mechanism of chest pain in both conditions have failed to identify a unifying cause. Review of the literature leaves little doubt that mitral valve prolapse and panic disorder frequently co-occur. Given the similarities in their symptomatology, a high rate of co-occurrence is, in fact, entirely predictable. There is, however, no convincing evidence of a cause-effect relationship between the two disorders, nor has a single pathophysiologic or biochemical mechanism been identified that unites these two common conditions. Until specific biologic markers for these disorders are identified, it may be impossible to do so. The lack of a proven cause-and-effect relationship between mitral valve prolapse and panic disorder and the absence of a unifying mechanism do not diminish the clinical significance of the high rate of co-occurrence between the two conditions. Primary care physicians and cardiologists frequently encounter patients with mitral valve prolapse and nonspecific symptoms with no discernible objective cause who fail to respond to beta-blockade. Panic disorder should be considered as a possible explanation for symptoms in such patients.(ABSTRACT TRUNCATED AT 400 WORDS)

The flail mitral valve: echocardiographic findings by precordial and transesophageal imaging and Doppler color flow mapping

To determine the echocardiographic and Doppler characteristics of mitral regurgitation associated with a flail mitral valve, precordial and transesophageal echocardiography with pulsed wave and Doppler color flow mapping was performed in 17 patients with a flail mitral valve leaflet due to ruptured chordae tendineae (Group I) and 22 patients with moderate or severe mitral regurgitation due to other causes (Group II). Echocardiograms were performed before or during cardiac surgery; cardiac catheterization was also performed in 28 patients (72%). Mitral valve disease was confirmed at cardiac surgery in all patients. By echocardiography, the presence of a flail mitral valve leaflet was defined by the presence of abnormal mitral leaflet coaptation or ruptured chordae. Using these criteria, transesophageal imaging showed a trend toward greater sensitivity and specificity than precordial imaging in the diagnosis of flail mitral valve leaflet. By Doppler color flow mapping, a flail mitral valve leaflet was also characterized by an eccentric, peripheral, circular mitral regurgitant jet that closely adhered to the walls of the left atrium. The direction of flow of the eccentric jet in the left atrium distinguished a flail anterior from a flail posterior leaflet. By transesophageal echocardiography with Doppler color flow mapping, the ratio of mitral regurgitant jet arc length to radius of curvature was significantly higher in Group I than Group II patients (5.0 +/- 2.3 versus 0.7 +/- 0.6, p less than 0.001); all of the Group I patients and none of the Group II patients had a ratio greater than 2.5.(ABSTRACT TRUNCATED AT 250 WORDS)

Current management of mitral valve incompetence associated with coronary artery disease

At a time when hospital mortality for adult cardiac operations is continuing to fall, the combined mitral valve coronary bypass subset remains at relatively high risk. Efforts to improve results should be directed toward a more general application of mitral reconstruction in this population, tailoring the type of repair to the pathological anatomy of valve dysfunction. Other promising therapeutic measures include the liberal use of reperfusion therapy in the acute papillary muscle dysfunction group, better selection patients for operation, and perhaps operative recommendation to a greater proportion of the more stable patients that previously were treated medically. Finally increasing the general awareness of this problem should hasten the development of improved management strategies.

Mitral valve prolapse

Mitral valve prolapse is a common mitral valve disorder manifested clinically as a midsystolic click and/or a late systolic murmur (the click-murmur syndrome) and pathologically as billowing or prolapsing mitral leaflets (the floppy valve syndrome). Not only is it one of the two most common congenital heart diseases and the most common valve disorder diagnosed in the United States, but it is also prevalent throughout the world. Mitral valve prolapse may be associated with a variety of other conditions or diseases. Diagnosis of mitral valve prolapse should be made on clinical grounds and, if necessary, supported by echocardiography. The majority of patients with mitral valve prolapse suffer no serious sequelae. However, major complications such as disabling angina-like chest pains, progressive mitral regurgitation, infective endocarditis, thromboembolism, serious arrhythmias, and sudden death may occur. Unless these serious complications occur, most of the patients with mitral valve prolapse need no treatment other than reassurance, including those with atypical chest pain or palpitation unconfirmed by objective data. Therapy with a beta-blocker for disabling chest pain and/or arrhythmias and antiplatelet therapy for cerebral embolic events may be indicated. In occasional patients with significant mitral regurgitation surgery may be necessary.