The Impact of Surgical Ventricular Restoration on Mitral Valve Regurgitation

Results of different therapeutic strategies for left ventricular aneurysm with mitral regurgitation

OBJECTIVE

This study aims to compare the midterm outcomes of left ventricular reconstruction (LVR) added to coronary artery bypass grafting (CABG) with those of CABG alone in patients with left ventricular aneurysm (LVA) and mild or moderate mitral regurgitation (MR). We also assessed the impact of LVR on the degree of MR.

METHODS

A total of 130 patients (77 who underwent CABG plus LVR and 53 who underwent CABG alone) with concomitant mild or moderate MR were included in the study population. All-cause mortality was considered the primary endpoint. Major adverse cardiovascular and cerebrovascular events (MACCEs), including death, myocardial infarction, stroke, and subsequent mitral valve surgery, were considered secondary endpoints. Kaplan-Meier analysis was performed to evaluate event-free survival. MR was graded 0 to 4+ by echocardiogram.

RESULTS

The median follow-up time among all patients was 22 months. There was a significant difference between the CABG plus LVR and CABG alone groups with regard to all-cause mortality ( P = 0.019). However, the statistical difference was not observed in cardiogenic mortality ( P = 0.186) and MACCEs ( P = 0.107). In the grade of MR, the two groups both resulted in the decreased grade of MR, but the CABG plus LVR group had a significant number of patients improving to 0 or 1+ ( P = 0.030).

CONCLUSION

The clinical outcomes of CABG alone are comparable with those of CABG plus LVR in patients with LVA and mild or moderate MR. However, CABG+LVR demonstrated greater reduction in MR severity after surgery than CABG alone.

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Results of Left Ventricular Reconstruction With and Without Mitral Valve Surgery

BACKGROUND

This study aims to compare the midterm outcomes of left ventricular reconstruction with those of left ventricular reconstruction plus mitral valve surgery in patients with left ventricular aneurysm due to anterior myocardial infarction and moderate mitral regurgitation.

METHODS

A total of 523 patients (75 who underwent left ventricular reconstruction plus mitral valve surgery and 448 who underwent left ventricular reconstruction) with concomitant moderate mitral regurgitation were included in the study population. All-cause mortality was considered the primary endpoint. Major adverse cardiovascular and cerebrovascular events, including death, myocardial infarction, stroke, and subsequent mitral valve surgery, were considered secondary endpoints. Multivariable proportional hazards Cox regression models were used to assess the associations between groups and outcomes. In the sensitivity analysis we excluded patients who did not undergo coronary artery bypass graft and repeated the statistical analysis above.

RESULTS

The median follow-up time among all patients was 41 months. There was no significant difference between the left ventricular reconstruction plus mitral valve surgery and the left ventricular reconstruction groups with regard to all-cause mortality (P = .208) and major adverse cardiovascular and cerebrovascular events (P = .817) after adjustment for covariates. In the sensitivity analysis there was no significant difference between the left ventricular reconstruction plus mitral valve surgery and left ventricular reconstruction groups with regard to all-cause mortality (P = .158) and major adverse cardiovascular and cerebrovascular events (P = .651) after adjustment for covariates.

CONCLUSIONS

The clinical outcomes of left ventricular reconstruction are comparable with those of left ventricular reconstruction plus mitral valve surgery in patients with left aneurysm and moderate mitral regurgitation.

The role of papillary muscle approximation in mitral valve repair for the treatment of secondary mitral regurgitation

Secondary mitral regurgitation (MR) is present in up to half of patients with dilated cardiomyopathy, and is associated with a poor prognosis. It primarily results from progressive left ventricular remodelling, papillary muscle displacement and tethering of the mitral valve leaflets. Mitral valve repair with an undersized ring annuloplasty is the reparative procedure of choice in the treatment of secondary MR. However, this technique is associated with a 30-60% incidence of recurrent moderate or greater MR at mid-term follow-up, which results in progressive deterioration of left ventricular function and increased morbidity. Combined mitral valve repair and papillary muscle approximation has been applied in order to address both the annular and subvalvular dysfunction that coexist in secondary MR, which include graft and suture-based techniques. Herein, we provide a systematic review of the published literature regarding the technical aspects, clinical application, and outcomes of mitral valve repair with combined ring annuloplasty and papillary muscle approximation for the treatment of secondary MR.

Influence of procedural differences on mitral valve configuration after surgical repair for functional mitral regurgitation: in which direction should the papillary muscle be relocated?

Background

After restrictive mitral annuloplasty (RMAP) for functional mitral regurgitation (MR), the MR frequently recurs. Papillary muscle relocation (PMR) should reduce the recurrence rate. We assessed the influence of procedural differences in PMR on the postoperative mitral valve configuration.

Methods

Thirty-nine patients who underwent mitral valve repair for functional MR were enrolled. In limited tethering cases, RMAP alone was performed (RMAP group; n = 23). In severe tethering cases, in addition to RMAP, bilateral papillary muscles were relocated in the direction of the posterior annulus (posterior PMR group; n = 10) or anterior annulus (anterior PMR group; n = 6). We performed pre- and postoperative transthoracic echocardiographic studies, introducing a new index, mitral inflow angle (MIA), to assess the diastolic mitral leaflet excursion. MIA was measured as the angle between the mitral annular plane and the bisector of the anterior and posterior leaflets.

Results

Postoperative MR grade was significantly reduced in each group (P < 0.001). Follow-up echocardiography showed recurrent MR in 13% of the patients in RMAP group. In contrast, no recurrent MR was observed in either the anterior PMR or the posterior PMR group. After surgery, MIA was significantly reduced in both the RMAP group (P < 0.01) and the posterior PMR group (P < 0.001), but was preserved in the anterior PMR group (NS). None of the postoperative variables showed any significant difference between the early and late postoperative phases.

Conclusions

In the surgical treatment of functional MR, a PMR procedure in addition to RMAP was effective in reducing systolic MR. However, mitral valve opening assessed by MIA was restricted even after RMAP alone. The restriction was severely augmented after additional posterior PMR, but was attenuated after additional anterior PMR. The papillary muscle should be relocated in the direction of the anterior annulus to preserve the diastolic opening of the mitral valve.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0185-6) contains supplementary material, which is available to authorized users.

[Mitral regurgitation in heart failure. Surgical therapy]

The optimal treatment of mitral regurgitation concomitant to heart failure remains controversial. A lack of consensus between cardiologists and cardiac surgeons, because of limited studies and heterogeneous data, has led to vaguely defined guidelines and different handling in the clinical routine in the past. However, progress in the operative management with excellent results of individual experienced centers suggests that a variety of patients might benefit from surgical therapy. Each patient should be evaluated individually regarding the benefits of surgical therapy which requires an interdisciplinary approach ("heart team") due to the complex pathophysiology and demanding diagnostics.

Management of mitral regurgitation during left ventricular reconstruction for ischemic heart failure

OBJECTIVE

Remodeling of the left ventricle (LV) in ischemic cardiomyopathy frequently leads to functional mitral regurgitation (MR). The indication for correcting MR in patients undergoing LV reconstruction (LVR) is unclear. In this study, we evaluated our strategy of correcting MR≥grade 2+ by restrictive mitral annuloplasty (RMA) during LVR.

METHODS

We studied 92 consecutive patients (76 men, mean age 61±10 years) who underwent LVR for ischemic heart failure (IHF). RMA was performed in all patients with MR≥grade 2+ on preoperative echocardiography and in patients who showed increased MR to ≥grade 2+ immediately after LVR. Patients were attributed to a RMA and no-RMA group, depending on whether or not concomitant RMA had been performed. Mean clinical and structured echocardiographic follow-up was 47±20 months and was 100% complete.

RESULTS

In 38 out of 40 patients (95%) with preoperative MR≥grade 2+, concomitant RMA was planned and performed. In 17 out of 52 patients (33%) with MR<grade 2+ preoperatively, MR increased after LVR to ≥grade 2+ leading to additional RMA during a second period of aortic cross-clamping. Early mortality in the RMA group (n=55) was 12.7% and survival at 36 months 78.2±11.2%. Early mortality in the no-RMA group (n=37) was 5.4% and survival at 36 months 81.1±12.8%. Patients in the RMA group had significantly more reduced LV function with greater LV dimensions and volumes preoperatively. Echocardiography demonstrated sustained improvement in LVEF with reduction of LV volumes in both patient groups. Recurrence of MR at late follow-up was observed in 2 patients (1 patient per group).

CONCLUSIONS

Patients with IHF eligible for LV reconstruction have MR≥grade 2+ in 44% of cases. In one-third of IHF patients with MR<grade 2+ preoperatively, MR increases to ≥grade 2+ after LVR. Concomitant mitral valve repair for MR≥grade 2+, on either preoperative echocardiography or immediately after LVR, results in favorable late clinical and echocardiographic outcome that proved to be similar to patients without concomitant mitral valve repair, despite more advanced disease.

Review of surgical ventricular restoration: A procedure to treat cardiac failure

Severe heart failure refractory to medical treatment necessitates the use of other modalities of treatment. Surgical ventricular restoration (SVR) surgery can provide relief until donour hearts are available or when transplantation is contraindicated. In this review we look at the physiological basis for improvement in cardiac function and cardiac and haemodynamic changes that occur after SVR. We also compile the reported factors affecting surgical outcome, criteria for patient selection and predictors of postoperative mortality. NYHA class, presence of diastolic failure, severe impairment of contractile function and presence of mitral regurgitation were the most important determinants. Various different procedures for achieving SVR are briefly discussed. Importance of mitral valve repair/replacement, coronary artery bypass grafting and intraoperative echocardiography in improving postoperative result is highlighted. Role of perioperative medication (anti-arrhythmics, ACE inhibitors and β-blockers) is briefly studied at the end of the review.