Results of coronary bypass and valve operations for mitral valve regurgitation

Combined coronary bypass grafting and valve procedures for mitral valve regurgitation result in poor outcomes, but the impact of the etiology of valve regurgitation on operative and long-term outcomes is not well defined. A retrospective analysis of 468 patients who had combined coronary bypass grafting and valve operations for mitral regurgitation showed that 78% had valve repairs and 22% had replacements for ischemic (45%) or degenerative (55%) disease. Predictors of operative mortality were ischemic mitral regurgitation, failure to use the internal mammary artery for grafting, severe coronary disease, acute myocardial infarction, low ejection fraction, advanced heart failure, emergency operation, and mitral valve replacement. The 5-year survival rates for propensity-matched patients with ischemic or degenerative disease were similar (66%). Low ejection fraction (< 35%), advanced age (> 67 years), valve replacement surgery, residual mitral regurgitation, and severe coronary artery disease were predictors of poor long-term outcome. Although the operative outcomes of ischemic mitral regurgitation were poor compared to those of degenerative disease, the long-term survival was similar in both groups of propensity-matched patients. Left ventricular remodeling, an optimal valve procedure without residual mitral regurgitation, and left ventricular function are more important determinants of long-term outcome than the etiology of valve regurgitation.     

经食道三维超声分析继发性二尖瓣关闭不全的结构特点

目的:借助经食管实时三维超声心动图及量化分析软件,分析继发性二尖瓣关闭不全(SMR)时二尖瓣结构的特点。方法:选择继发于主动脉关闭不全致二尖瓣重度反流组20例与正常对照组20例均行经食管实时三维超声心动图检查,并使用Tom Tec-Arena 1.0-4D MV-Assessment 2.3软件进行后处理分析。结果:左心室舒张末期内径组间差异显著,慢性继发性二尖瓣关闭不全(CSMR)组较对照组明显增大(P0.01);与正常组相比较,CSMR组的瓣环前后径、左右纤维三角间径、瓣环周长、瓣环面积均增大(P0.05),瓣环球形指数及前后瓣环间角度差异无统计学意义。CSMR组瓣环高度较正常组小(P0.05)。AHCWR即瓣环高度与跨前后交界间径的比值,通常认为其值减低提示二尖瓣环变平。CSMR组AHCWR值较正常组减小(P0.05)。对瓣叶的分析,前叶面积及前叶瓣环至闭合缘的长度较对照组均差异无统计学意义,而后叶面积及后叶瓣环至闭合缘的长度较对照组增大(P0.05)。两组间后叶与瓣环夹角、二尖瓣前叶对合缘长度、二尖瓣后叶对合缘长度均无明显差异。CSMR组二尖瓣前后径与主动脉瓣环间夹角较对照组增大(P0.05)。对瓣环的动态分析发现,CSMR组二尖瓣环最大位移、瓣环面积的压缩比均较对照组减小(P0.05)。结论:重度主动脉关闭不全继发二尖瓣关闭不全,伴随左心室的增大二尖瓣环扩张、变平,二尖瓣瓣叶闭合障碍。     

Troublesome factors in mitral valve repair for mitral valve regurgitation

Limitations in the long-term results of medical treatment for mitral regurgitation are well recognized, but the advances in its surgical repair have produced good results. Therefore, early surgical intervention has been the focus of treatment in Europe and America. Increased surgical intervention depends on the development of technical skills in mitral reconstruction. This study investigated presurgical factors making surgical reconstruction difficult in 103 patients who underwent mitral operations performed from April 1994 to September 1997 in our hospital. Records were reviewed retrospectively for etiology, type of operation, and the immediate result of operation. The etiology of mitral regurgitation was prolapse in 65 patients (63%), restriction in 14, normal in 11, infectious endocarditis in 10, and others in 3. The type of prolapse involved the anterior leaflet in 22 patients (34%), posterior in 28 (43%), and both leaflets in 15 (23%). Valve repair was attempted in 74 patients, of which 16 were switched to valve replacement during operation. These included anterior leaflet prolapse in 9 patients, posterior leaflet in 1, both leaflets in 3, restriction in 2 and infectious endocarditis in 1. The success rate for reconstruction of anterior leaflet prolapse was not high. The cause of mitral regurgitation was mostly prolapse of the mitral valve, in our country as well as in Europe and America. Prolapsed posterior leaflet is much more common in Europe and America, and there is a high success rate reported for its valve reconstruction. In contrast, this study cannot recommend earlier surgical intervention because of difficult repair for anterior leaflet prolapse.     

Mechanical haemolytic anaemia after valve repair operations for non-rheumatic mitral regurgitation.

Two cases are described in which severe mechanical haemolytic anaemia developed shortly after operation for repair of non-rheumatic mitral regurgitation. One patient had a "floppy" valve and the other cleft mitral leaflets, and both had chordal rupture. In both there was residual regurgitation after repair though in one this was initially only trivial. Clinically manifest haemolysis ceased after replacement of the valve by a frame-mounted xenograft. There are two previously reported cases in which haemolytic anaemia followed an unsuccessful mitral valve repair operation. Subclinical haemolysis or mild haemolytic anaemia may occur with unoperated valve lesions, but hitherto frank haemolytic anaemia has been observed only when turbulent blood flow is associated with the presence of a prosthetic valve or patch of prosthetic fabric. In these four cases, however, polyester or Teflon sutures were the only foreign material, and it is suggested that when these are used for the repair of leaflets, particularly in non-rheumatic mitral valve disease, they may increase the damaging effect of turbulence on circulating red blood cells.     

Transient mitral regurgitation due to mitral valve prolapse accompanied by systolic anterior motion of the mitral valve

A grade 4/6 systolic murmur, systolic anterior motion of the mitral valve (SAM), and severe mitral regurgitation (MR) documented by two-dimensional Doppler echocardiography developed suddenly on the structurally normal heart of a patient with idiopathic portal hypertension. The patient did not have signs of congestive heart failure and the aforementioned phenomenon disappeared completely when the patient was in hepatic failure. This could be explained by a change in circulating blood volume either by gastrointestinal hemorrhage or hepatic failure.     

Percutaneous mitral valve repair for mitral regurgitation

Mitral regurgitation (MR) associated with, ischemic, and degenerative (prolapse) disease, contributes to left ventricular (LV) dysfunction due to remodeling, and LV dilation, resulting in worsening of MR. Mitral valve (MV) surgical repair has provided improvement in survival, LV function and symptoms, especially when performed early. Surgical repair is complex, due to diverse etiologies and has significant complications. The Society for Thoracic Surgery database shows that operative mortality for a 1st repair is 2% and for re-do repair is 4 times that. Cardiopulmonary bypass and cardiac arrest are required. The attendant morbidity prolongs hospitalization and recovery. Alfieri simplified mitral repair using an edge-to-edge technique which subsequently has been shown to be effective for multiple etiologies of MR. The MV leaflers are typically brought together by a central suture producing a double orifice MV without stenosis. Umana reported that MR decreased from grade 3.6 +/- 0.5 to 0.8 +/- 0.4 (P < 0.0001) and LV ejection fraction increased from 33 +/- 13% to 45 +/- 11% (P = 0.0156). In 121 patients, Maisano reported freedom from re-operation of 95 +/- 4.8% with up to 6 year follow-up. Oz developed a MV "grasper" that is directly placed via a left ventriculotomy and coapts both leaflets which are then fastened by a graduated spiral screw. An in-vitro model using explanted human valves showed significant reduction in MR and in canine studies, animals followed by serial echo had persistent MV coaptation. At 12 weeks the device was endothelialized. These promising results have paved the way for a percutaneous or minimally invasive-off pump mitral repair. Evalve has developed catheter-based technology, which, by apposing the edges of a regurgitant MV, results in edge-to-edge repair. Release of the device is done after echo and fluoroscopic evaluation under normal loading conditions. If the desired effect is not produced the device can be repositioned or retrieved. Animal studies show excellent healing, with incorporation of the device into the leaflets at 6-10 weeks with persistent coaptation. Another percutaneous approach has been to utilize the proximity of the coronary sinus (CS) to the mitral annulus (MA). Placement of a self-compressing device in the CS along the region of the posterior MA has, in canine models, reduced MR and addresses the issues of MA dilation and its contribution to MR. Ongoing studies are underway for both techniques.     

Floppy mitral valve, mitral valve prolapse, and mitral valvular regurgitation

Opinion statement  

Complex arrhythmias in mitral regurgitation with and without mitral valve prolapse: Contrast to arrhythmias in mitral valve prolapse without mitral regurgitation

Atrial and ventricular arrhythmias were characterized by ambulatory electrocardiography in 31 patients with nonischemic mitral regurgitation (MR), 17 of whom had echocardlographic evidence of mitral valve prolapse (MVP) and 14 of whom had other causes of MR. Frequent and complex arrhythmias were common and equally prevalent in each MR subgroup, whether or not MVP was present. Multiform ventricular ectopy was found in 77%% (24 of 31), ventricular couplets in 61 % (19 of 31), and ventricular salvos or ventricular tachycardia in 35% (11 of 31) of patients with MR. Arrhythmias in patients with MR were significantly more prevalent than in 63 patients with MVP who had no evidence of MR. Among patients with MVP, excess arrhythmias associated with MR were most striking with respect to frequent ventricular premature complexes (41 % with MR vs 3 % without MR), multiform ventricular ectopic activity (88% vs 43%), ventricular couplets (65% vs 6%), and ventricular salvos or ventricular tachycardia (35 vs 5 %) (p <0.005 for each comparison). These data demonstrate that complex arrhythmias are common in patients with nonischemic MR irrespective of etiology, and that these arrhythmias are more strongly associated with hemodynamically important MR than with MVP alone.     

Progression of mitral regurgitation in patients with mitral valve prolapse

Mitral valve prolapse (MVP) is a very common clinical entity which is frequently associated with mild mitral regurgitation (MR) and which most commonly becomes clinically manifest in the third and fourth decades of life. Severe MR associated with MVP, occurs much less frequently and is most commonly seen in patients above the age of 50 years. Relatively little information is available regarding the progression of mild to severe MR in patients with MVP. This report reviews a recent study which investigated the progression from mild to severe MR in patients with MVP. The study included 86 patients, average age 60 years, who presented with cardiac symptoms and severe MR. A high incidence of MVP was seen on echocardiograms (57 of 75 [75%]) and on left ventriculography (61 of 84 [73%]). Mitral valve replacement was performed in 75 patients. Pathologically all valves appeared grossly enlarged, severely floppy and had extensive myxomatous changes with collagen dissolution. 80 patients had a pre-existing heart murmur first detected at average age 34. Patients remained asymptomatic for an average of 25 years at which time clinical symptoms first appeared. After symptoms developed mitral valve surgery was necessary in most patients within one year. This rapid deterioration could partially be attributed to ruptured chordae in 39 of 76 patients (51%) or atrial fibrillation in 48 of 86 patients (56%). 28 patients had one or more serial clinical evaluations including auscultation, chest x-ray, echocardiography, and cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

MitraClip for radiotherapy-related mitral valve regurgitation

ObjectiveOwing to mediastinal and cardiac damage burden, the surgical treatment of radiotherapy-related mitral regurgitation (MR) may be associated with high operative risk or might even contraindicated. We evaluated the feasibility and outcome of MitraClip therapy in patients with radiotherapy-related MR as an alternative to surgery.MethodsBased on Doppler Echocardiography, 15 of 33 screened patients underwent MitraClip implantation.ResultsFollowing MitraClip MR improved (residual MR ≤2+) without significant mitral valve stenosis (planimetric area 2.83 ± 0.8 cm², mean gradient 4.6 ± 1.8 mm Hg). All patients completed a 6-month follow-up, while 14 of 15 patients achieved a longer follow-up, ranging from 12 to 72 months (median 24 months, IQR 42 months). At 6-month follow-up we observed NYHA improvement in 13 patients with an increase of 6-min walking covered distance (from 260 ± 34 to 367 ± 70, p < 0.001), sustained moderate or less MR, mild mitral stenosis in 3 patients, and significant systolic Pulmonary Artery Pressure (PAPs) reduction (from 52.5 ± 14 to 42 ± 9, p < 0.01). Sustained clinical improvement and ≤2+ MR was observed in 13 of 14 patients who completed the 12-month follow-up. Two patients died of acute pneumonia (11 months and 60 months, respectively). One patient developed moderate MV stenosis (MVA 1.4 cm²) at last follow-up (48 months) without related clinical instability. Tricuspid regurgitation improved in 12 patients with further improvement at late follow-up in 2 of 3 patient with 3+.ConclusionMitraClip may be an effective treatment for RT-induced MR, although unexpected late stenosis may occur in the context of sustained reactive mitral apparatus damage following mediastinal radiation.     

Mitral valve repair for mitral regurgitation

We analyzed the results of mitral valve repair in 81 consecutive patients with severe mitral regurgitation. Of these patients, 66.6% had myxomatous degeneration, 11% ischemic disease, 8% chordal rupture, 5% congenital disease, and 3.7% endocarditis. Repair could not be achieved in five patients, and valve replacement was necessary. Six died during surgery (mortality 7%). During follow-up (mean 30 [8] months), there was one death due to refractory ischemic heart failure and mitral regurgitation (>or= 2/4) was observed in 11 patients. A good result (i.e., survival without a prosthesis, major complications, or mitral regurgitation >1/4) was obtained in 78% of patients with myxomatous degeneration versus 48% of those with other etiologies (P=.023). A good result was obtained more frequently in cases of isolated posterior cusp degeneration than in those involving degeneration of both cusps (85% vs 70%; P=.03).