Preoperative left ventricular dimensions predict reverse remodeling following restrictive mitral annuloplasty in ischemic mitral regurgitation.

OBJECTIVE: Ischemic mitral regurgitation can be treated with a restrictive mitral annuloplasty, with or without coronary revascularization. In this study, the extent of reverse remodeling of the left ventricle following this strategy is assessed, as well as the factors that influence it. METHODS: Eighty-seven consecutive patients with ischemic mitral regurgitation and a mean ejection fraction of 32+/-10% underwent restrictive mitral annuloplasty (downsizing by two ring sizes, median ring size 26), with additional coronary revascularization in 75 patients. All underwent transthoracic echocardiography 18 months after surgery to assess residual mitral regurgitation, mitral valve gradient and left ventricular end-systolic and end-diastolic dimensions. Univariate and multivariate analysis was performed to identify predictors for reverse remodeling, defined as a 10% reduction in left ventricular dimension. Receiver-operating characteristic analysis was used to identify cut-off values for preoperative left ventricular dimensions in predicting reverse remodeling. RESULTS: Early mortality was 8.0% (seven patients, three non-cardiac), late mortality was 7.5% (six patients, four non-cardiac). There were two reoperations (redo annuloplasty), and four readmissions for heart failure. At 29 months follow-up, NYHA class improved from 3.0+/-0.9 to 1.3+/-0.5 (P<0.01). Mitral regurgitation grade decreased from 3.1+/-0.5 to 0.6+/-0.6 at 18 months, left ventricular end-systolic dimension decreased from 52+/-8 to 44+/-11 mm (P<0.01), and end-diastolic dimension from 64+/-8 to 58+/-10mm (P<0.01). Multivariate analysis identified preoperative left ventricular end-diastolic dimension as the single best factor in predicting occurrence of reverse remodeling. For end-systolic dimension, 51mm was the optimal cut-off value to predict reverse remodeling (specificity and sensitivity 81%, area under curve 0.85); for end-diastolic dimension, the cut-off value was 65mm (specificity and sensitivity 89%, area under curve 0.92). CONCLUSIONS: Stringent restrictive mitral annuloplasty with or without revascularization provides excellent clinical results with acceptable mortality. At 18 months follow-up, there is no significant residual mitral regurgitation. Reverse remodeling occurs in the majority of patients, but is limited by preoperative left ventricular dimensions. In patients with a left ventricular end-diastolic dimension exceeding 65mm, additional surgical procedures are necessary to try and obtain reverse remodeling in this subgroup.     

Surgical treatment of left ventricular aneurysm associated with mitral regurgitation

The purpose of this study is to analyze the early and late results of left ventricular aneurysmectomy in patients with mitral regurgitation secondary to myocardial infarction. Twenty patients who had left ventricular aneurysm combined with mitral regurgitation underwent the isolated or combined aneurysmectomy during the last 10 years. There were 18 male cases and 2 female cases, and their age ranged from 31 to 64 (mean age 52.6 years). In 19 cases, the left ventricular aneurysm were caused secondary to antero-septal infarction due to the occlusion of the left anterior descending coronary artery. In one case, the coronary spasm of circumflex artery provoked the posterolateral myocardial infarction and the tendon rupture of posterior papillary muscle. The isolated left ventricular aneurysmectomy were performed in 6 cases and the combined operations were coronary artery bypass grafting in 11 cases, mitral annuloplasty in 1 case, mitral annuloplasty and bypass grafting in 1 case, and mitral replacement in 1 case. There were no operative death cases. The preoperative mean functional class (NYHA classification) was 2.9 and the postoperative class was 1.4. The preoperative mitral regurgitation of grade 1 in Sellers' classification was observed in 11 cases. Grade 2 regurgitation was observed in 6 cases, grade 3 in 2 and grade 4 in 1. After surgery, mitral regurgitation more than grade 2 was recognized in 3 cases (group A) and regurgitation less than grade 1 was seen in 17 cases (group B).(ABSTRACT TRUNCATED AT 250 WORDS)     

Late development of mitral regurgitation after left ventricular reconstruction surgery.

PURPOSE: Late presence of mitral regurgitation (MR) after the Dor procedure (left ventricular (LV) reconstruction associated with coronary artery bypass grafting) for postinfarction patients carries a poor prognosis. The aim of this study was to review our experience with the Dor procedure and to analyze the correlation of surgical results with late MR. METHODS: The study group comprised 19 patients with previous anterior transmural myocardial infarction (MI). Ten patients were classified as New York Heart Association (NYHA) functional class III or IV at surgery. MR was moderate in 2 patients and mild in 15 patients. RESULTS: Myocardial revascularization was performed in all patients, with a mean of 3.7+/-1.2 grafts. Mitral valve was repaired in 6 patients. Four patients with mild MR underwent posterior annuloplasty, and 2 with moderate MR underwent rigid annular remodeling. Early postoperative NYHA functional class improved from 2.7+/-0.9 to 1.3+/-0.5; however, MR deteriorated to moderate in 5 patients with worsening NYHA functional class 3 months after surgery. Although the valve was not repaired during surgery in 4 patients with preoperative mild MR, 1 patient with moderate MR underwent annuloplasty with a rigid ring. All patients with late MR underwent more than 30-mL/m2 reduction of end-diastolic volume index at surgery. Cumulative 4-year survival including hospital deaths was 89.5%. CONCLUSION: To prevent the risk of late MR, a more than 30-mL/m2 reduction of end-diastolic volume index should be avoided and mitral valve repair should be performed even if preoperative functional MR is only mild.     

Off-pump mitral valve repair using the Coapsys device: a pilot study in a pacing-induced mitral regurgitation model

PURPOSE: The purpose of this study was to evaluate the ability of the Myocor Coapsys device to restore leaflet apposition and valve competency off-pump in a canine model of functional mitral regurgitation (MR). DESCRIPTION: The Coapsys device was surgically implanted in 10 dogs after MR induction by rapid ventricular pacing. The Coapsys consists of anterior and posterior epicardial pads connected by a subvalvular chord. The annular head of the posterior pad was positioned at the annular level to draw the posterior leaflet and annulus toward the anterior leaflet. Final device size was selected when MR was minimized or eliminated as assessed by color flow Doppler echocardiography. EVALUATION: All implants were placed off-pump without atriotomy, and mean MR grade was reduced from 2.9 +/- 0.7 to 0.6 +/- 0.7 (p < 0.001) acutely. No hemodynamic compromise was noted. CONCLUSIONS: The Coapsys device consistently and significantly reduced or eliminated functional MR acutely. Further study will be required to assess the chronic stability of the repair in this animal model.     

Experimental mitral regurgitation: effects on left ventricular function before and after elimination of chronic regurgitation in the dog.

Chronic left ventricular-atrial regurgitation (LVAR) was created in 8 dogs by means of an external conduit so that the effects of acute correction of regurgitation on the mechanics of left ventricular performance could be studied in detail. LVAR of 46 to 77 per cent of the total left ventricular (LV) output was associated with a depression of the LV inotropic state (downward displacement of the stress-velocity relationship, reduction in V max), reduced forward flow, and signs of cardiac failure. Acute occlusion of the shunt (analogous to return of mitral valvular competence) in the anesthetized, open-chest animal resulted in a statistically significant increase in the integrated LV systolic wall stress (afterload), which averaged 18 per cent. In the dog with greatest depression of the LV inotropic state, the increase in afterload was associated with a decrease in forward flow. Occlusion of the shunt had no significant effect on the inotropic state. This model of mitral regurgitation appears to be useful in assessing the effect of chronic LVAR on cardiac performance and may explain the hemodynamic deterioration observed in some patients with severe mitral regurgitation following valve replacement.     

Concomitant mitral valve repair and left ventricular reconstruction in a patient with chronic ischemic mitral regurgitation and inferior left ventricular aneurysm

The surgical approach to ischemic mitral regurgitation with concomitant inferior left ventricular aneurysm remains uncertain in terms of the indication for operation and the short-and long-term outcomes. We performed concomitant mitral valve repair, left ventricular reconstruction, and aortic valve replacement on a 71-year-old male with severe ischemic mitral regurgitation, inferior left ventricular aneurysm, and degenerative aortic regurgitation. Postoperative status was in New York Heart Association functional class I without mitral regurgitation 8 months after operation. We discuss, and review the procedures reported in the literature.     

Selecting patients with mitral regurgitation and left ventricular dysfunction for isolated mitral valve surgery

Background

American College of Cardiology/American Heart Association (ACC/AHA) Guidelines state that patients with an ejection fraction (EF) of 30% or less should not undergo mitral valve replacement for mitral regurgitation (MR). We sought to establish, using a national cardiac surgery database, whether patients with left ventricular dysfunction may safely undergo mitral valve surgery for MR, and if so, which ones.

Methods

We queried the Society of Thoracic Surgeons (STS) National Database to identify patients who had isolated mitral valve replacement or repair for MR between 1998 and 2001. Mortality and morbidity outcomes were compared by EF category (≤ 30% vs > 30%), and observed mortality compared by EF group, stratified by predicted risk for mortality. A classification and regression tree (CART) model was then used to determine which patient characteristics contributed most to designate the high-risk patient.

Results

Of the 14,582 patients who had mitral valve surgery, 727 had an EF of 30% or less and 13,855 had an EF of more than 30%. Observed mortality rates were higher for patients with an EF of 30% or less (5.4% vs 3.1%). However, for low-risk to medium-risk patients, mortality rates remained fairly constant across levels of EF. Mortality is notably increased in the high-risk patients (predicted risk > 10%). A classification tree identifies three key characteristics for high risk: age more than 75 years, renal failure, and emergent or salvage procedure.

Conclusions

When the predicted mortality risk is less than 10%, EF has minimal impact on operative mortality for mitral regurgitation. In contrast to the ACC/AHA Guidelines, our data show that operative risk for mitral valve surgery is not prohibitive for most patients with ventricular dysfunction.     

经左心房或左心室室壁瘤切口行二尖瓣成形术的疗效评价

目的 评价经左心房（LA）或左心室（LV）室壁瘤切口行二尖瓣成形术的手术疗效.方法 1997年1月至2005年4月,23例病人因冠状动脉粥样硬化性心脏病伴室壁瘤形成行冠状动脉旁路移植及室壁瘤手术,同时因缺血性二尖瓣关闭不全行二尖瓣成形术.其中经房间隔左心房切口行二尖瓣成形术10例（A组）,经左心室室壁瘤切口行二尖瓣成形术13例（B组）.手术在全麻低温体外循环下,首先完成冠状动脉旁路移植术,然后行二尖瓣成形术和室壁瘤手术.结果 B组体外循环和主动脉阻断时间较A组缩短,但差异无统计学意义（P＞0.05）,气管插管、住ICU及术后住院时间、术后LA大小、LV大小、EF值两组间差异均无统计学意义（P＞0.05）.但与术前相比,两组术后左心房、室大小均显著减小（P＜0.05）,EF显著改善（P＜0.05）.全组死亡2例,A组、B组各1例,病死率8.7%（2/23例）.远期随访A组1例术后7个月因应激性溃疡出血、肝功能衰竭死亡,另1例术后4个月因严重的二尖瓣关闭不全行二尖瓣置换术;B组无死亡及二次手术病例.生存者心功能Ⅰ～Ⅱ级,症状明显改善,二尖瓣结构、功能正常或仅轻-中度关闭不全.结论 经左心室室壁瘤切口入路行二尖瓣成形术疗效满意,该术式可将二尖瓣和左心室形态、功能的恢复同时设计,整体构思,相同的术野和同时兼顾手术操作,实现二尖瓣与左心室结构和功能快速有效的重建;且避免了常规右心房、房间隔或房间沟切口,简化手术操作,减轻心肌损伤,缩短手术时间.     

Dor procedure for left ventricular diverticulum with mitral regurgitation in an infant

Congenital left ventricular diverticulum accompanied by MR is a rare abnormality. A 5-month-old female infant with this clinical combination underwent a procedure comprising exclusion of a large diverticulum by using an endoventricular circular patch (Dor procedure). This technique allowed us to avoid restriction of the left ventricular cavity and to improve the orientation of the papillary muscles, thus leading to successful mitral valve repair.     

The degree of newly emerging mitral regurgitation during off-pump coronary artery bypass is predicted by preoperative left ventricular function

Purpose During off-pump coronary artery bypass (OPCAB), the displacement of the heart causes mitral regurgitation. We hypothesized that patients with impaired left ventricle (LV) function would be more prone to develop mitral regurgitation, due to further LV end-diastolic pressure elevation and mitral annulus distortion. Therefore, in this study, we examined the relationship between LV function and the severity of mitral regurgitation. Methods We studied 41 patients undergoing elective OPCAB. LV function was evaluated by LV ejection fraction (LVEF), serum brain natriuretic peptide (BNP) levels, the Tei index (myocardial performance index) and mitral inflow propagation velocity (Vp). Results Among all of the anastomoses performed mitral regurgitation was most severe during anastomosis of the left circumflex artery (LCX) territory (P < 0.001). Twenty-five patients (61%) had no to mild mitral regurgitation during anastomosis of the LCX territory (M-MR group) and 16 patients (39%) had moderate to severe mitral regurgitation during anastomosis of the LCX territory (S-MR group). There were significant differences between these groups in preoperative serum BNP levels (median, 26 pg·ml⁻¹ interquartile range [IQR, 14 to 75 pg·ml⁻¹] versus median, 173 pg·ml⁻¹ [IQR, 91 to 296 pg·ml⁻¹]; P < 0.001), Tei index values (median, 0.35; [IQR, 0.27 to 0.41] versus median, 0.53 [IQR, 0.47 to 0.57]; P < 0.001), and Vp (median, 63 cm·s⁻¹; [IQR, 57 to 72 cm·s⁻¹] versus median, 47 cm·s⁻¹; [IQR, 40 to 57 cm·c⁻¹]; P = 0.008), while there was no significant difference in LVEF between the patients in the M-MR group and those in the S-MR group. Conclusion Preoperative LV dysfunction is a predictor of severe mitral regurgitation during OPCAB. When poor LV function is suggested, it is necessary to be prepared for further hemodynamic deterioration caused by mitral regurgitation.