Surgical intervention for ischemic mitral regurgitation: how can we achieve better outcomes?

Long-term follow-up of posterior mitral leaflet extension for Type IIIb ischemic mitral regurgitation

Objective

Ischemic mitral regurgitation (MR) is generally associated with very poor outcomes and disappointing results, despite a seemingly perfect initial repair and optimal revascularization. We previously published our intermediate-term results of posterior leaflet augmentation without follow-up extending beyond 4 years. Our objective is to assess long-term durability of the repair, survival, and the causes of late mortality.

Methods

Ninety-one patients with severe (4+) Carpentier Type IIIb ischemic MR underwent repair in a single center between 2003 and 2022 by method of posterior leaflet extension using a patch of bovine pericardium and a true-sized remodeling annuloplasty ring, with or without surgical revascularization. Serial echocardiography was performed over the years to ascertain valve competence and degree of ventricular remodeling, in addition to telephone follow-up and chart reviews.

Results

The average age of patients was 67 ± 9.6 years. Mean follow-up was 8 ± 5 years with some extending to almost 20 years. One-, 5-, and 10-year freedom from recurrent significant MR, characterized as moderate or severe MR, was 98.6%, 85.5%, and 71.3%, respectively. Thirty-day mortality was 6.5%. One-, 5-, and 10-year survival was 85.5%, 64.4%, and 43.3%, respectively. Of all the mortalities, only 17.5% were proven to be directly cardiac related.

Conclusions

The suggested repair technique offers satisfactory long-term outcomes with minimal residual regurgitation in surviving patients when used in context of ischemic MR. Despite durable repair, we have discovered that poor long-term survival is not directly related to cardiovascular causes.

Long-term outcomes of left ventricular posterior wall plication for ischemic mitral regurgitation

Purpose

To evaluate the early and long-term outcomes of left ventricular posterior wall plication for ischemic mitral regurgitation.

Methods

Patients with ischemic mitral regurgitation who underwent left ventricular posterior wall plication via right-sided left atriotomy at our institution between 2010 and 2020 were retrospectively reviewed. Cases with normal cardiac function, left ventricular end-systolic diameter < 50 mm, and left ventriculotomy approach were excluded.

Results

The mean follow-up period was 5.3 years [standard deviation (SD) = 3.5], with a maximum of 10 years. Among the 21 patients enrolled, 9 had New York Heart Association (NYHA) class ≥ III. Three patients required preoperative inotrope support, while two preoperative ventilator support. The mean left ventricular ejection fraction was 31.4% (SD: 8.6), and 16 patients had mitral regurgitation grade ≥ III. All patients underwent coronary artery bypass grafting and mitral annuloplasty. Concomitant surgeries included 11 chordae cutting and 3 tricuspid annuloplasties. One in-hospital death occurred due to sepsis. At the follow-up, echocardiographic data showed significant improvement in cardiac dilation and function and good control of mitral regurgitation. The serum brain natriuretic peptide level was significantly reduced, and 85% of patients improved to NYHA class I. Four deaths occurred later due to sudden, unknown causes. The 5- and 8-year survival rates were 60.2% and 46.8%, respectively, and the 5- and 8-year hospitalization rates due to heart failure were 14.9% and 21.3%, respectively.

Conclusion

The long-term outcomes of left ventricular posterior wall plication were satisfactory for controlling heart failure and improving survival rate and patient prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01527-2.

New Perspective on Pathophysiology and Management of Functional Mitral Regurgitation

Functional mitral regurgitation (FMR) occurs as a result of global or segmental left ventricular (LV) dysfunction or left atrial dilatation, leading to mitral annular dilatation, papillary muscle displacement, mitral valve (MV) leaflet tethering, and leaflet remodeling. The prevalence of FMR continues to rise in the United States. Even mild FMR is associated with adverse clinical outcomes. Echocardiography is the primary imaging modality used to assess the type and severity of mitral regurgitation. FMR treatment depends on the etiology. Evidence-based pharmacologic and cardiac resynchronization therapies for underlying LV dysfunction remain the mainstay of treatment. Patients who remain symptomatic despite optimal medical therapy can be considered for surgical or percutaneous MV intervention. This article reviews the pathophysiology, imaging evaluation, and therapeutic options of FMR, highlighting the most recent developments in a rapidly evolving field.

Mitral valve repair versus replacement in severe ischemic mitral regurgitation systematic review and meta-analysis

BACKGROUND AND AIM

Ischemic mitral regurgitation (IMR) is a serious consequence of coronary artery disease. The choice of the optimal surgical strategy remains debatable. The aim of the present meta-analysis is to compare the outcomes of mitral valve repair (RPR) versus replacement (RPL) regarding perioperative mortality, overall mortality, reoperation, recurrence of MR, and reverse remodeling after surgery.

METHODS

Electronic searches were performed using the searchable databases of Google Scholar, Pubmed, and Embase, and the search terms mitral valve, IMR, RPR, RPL, and coronary artery bypass grafting. The main outcomes of interest are perioperative mortality, overall mortality, reoperation, recurrence of MR, and reverse remodeling after surgery. Perioperative mortality was defined as death during the surgery or within 30 days after the operation.

RESULTS

There was a trend towards better perioperative survival in the RPR arm. However, the difference fell short of statistical significance [odds ratio (OR) (95% confidence interval [CI]): 0.66 (0.41-1.07), p = 0.09]. Patients submitted to RPR experienced a significantly higher MR recurrence rate when compared with their counterparts submitted to RPL [OR (95% CI): 16.8 (5.07-55.7, p = 0.00001)].

CONCLUSION

There is a trend towards lower perioperative mortality in RPR in comparison to RPL. On the other hand, RPL was associated with significantly lower recurrence rates.

Effect of left ventricular hyperenhancement in magnetic resonance imaging on reverse remodeling after mitral valve repair for moderate ischemic mitral regurgitation

We aimed to investigate cardiac magnetic resonance imaging (MRI)-derived predictors of a lack of left ventricular (LV) reverse remodeling after undersized mitral annuloplasty (uMAP) for moderate ischemic mitral regurgitation (IMR). We retrospectively reviewed 31 patients who underwent uMAP for moderate IMR and cardiac MRI evaluation between 2004 and 2017. Cardiac MRI evaluation included cine MRI LV and right ventricular volumetric measurements and gadolinium-enhanced MRI assessment of myocardial scarring. LV dimensions were assessed preoperatively, postoperatively, and at follow-up using serial transthoracic echocardiography, and the mid-term (median, 49 months) predictors of a lack of LV reverse remodeling were analyzed. At the mid-term follow-up (mean follow-up period: 85 ± 40 months), 15 patients exhibited reverse LV remodeling. The relative reduction in LV dimension at follow-up was negatively correlated with the preoperative number of LV segments with myocardial infarction (MI) (defined as an LV segment with >25% enhancement). The optimal cut-off for predicting a lack of reverse LV remodeling at follow-up was >5 LV segments with MI, with a sensitivity and specificity of 92% and 92%, respectively. This cut-off value also predicted all-cause mortality at follow-up, with a sensitivity and specificity of 88% and 67%, respectively. The presence of >5 LV segments with MI on gadolinium-enhanced MRI might be a useful predictor of lack of reverse LV remodeling and all-cause mortality outcomes after undersized mitral annuloplasty for moderate IMR.

Left ventricular posterior wall plication for ischemic mitral regurgitation and cardiogenic shock

Ischemic mitral regurgitation, a known complication of myocardial infarction that results from left ventricular remodeling, causes heart failure and has a poor prognosis. While recent reports have revealed that surgical techniques utilizing a subvalvular or left ventricular approach might be effective in controlling mitral regurgitation, these methods are not yet established. We report the successful surgical management of a 73-year-old man who suffered from severe ischemic mitral regurgitation, experienced cardiogenic shock, and could not be weaned off mechanical support. We performed left ventriculoplasty from within the left ventricle over the mitral valve through a left atriotomy from the right side, along with coronary artery bypass grafting, ring annuloplasty, and basal chordal resection. The mitral regurgitation improved, and he finally could be weaned off mechanical support. Left ventriculoplasty might lead left ventricular reverse remodeling, improve the cardiac ejection efficiency by changing the left ventricular shape from spherical to oval, and secondarily control mitral regurgitation. Furthermore, performing left ventriculoplasty from inside the left ventricle precludes incising through the remaining healthy left ventricular myocardium, regardless of the position of the papillary muscles, and might be more effective in reducing the infarcted area responsible for ischemic mitral regurgitation.