A meta-analysis of mitral valve repair versus replacement for ischemic mitral regurgitation

Surgical Management of Heart Failure

Optimal management of heart failure is collaborative, with the involvement of specialist heart failure physicians, nurses, interventionalists, and surgeons. In addition to medical optimisation and cardiac resynchronisation therapy, surgery plays a valuable role in many patients. We herein study the evidence and the role of surgical intervention in functional mitral regurgitation, coronary revascularisation in ischaemic cardiomyopathy, and surgical ventricular reconstruction. Additionally, we describe techniques of temporary and durable mechanical circulatory support, with their relative advantages and disadvantages, and applications. Finally, we describe the history and nomenclature around heart transplants, their indications, techniques, present-day outcomes, complications, and new developments in the field.

Restrictive mitral valve annuloplasty for chronic ischaemic mitral regurgitation: outcomes of flexible versus semi-rigid rings

Background

Restrictive mitral annuloplasty is the mainstay of surgical correction of chronic ischaemic mitral regurgitation (CIMR). Long-term data on the various types of annuloplasty rings is limited. The aim of this study was to investigate the clinical and echocardiographic outcomes of restrictive mitral annuloplasty in patients with CIMR, comparing the use of flexible versus semi-rigid annuloplasty rings.

Methods

A retrospective review was conducted for 133 patients with CIMR who underwent restrictive mitral annuloplasty at our institution between 1999 and 2015. Patient demographics and postoperative outcomes were analyzed.

Results

Mean age was 61.9±9.2 years and 103 patients (77.4%) were male. All patients underwent coronary artery bypass grafting, with a mean of 3.3±0.8 grafts. Flexible rings was implanted in 39 patients (29.3%, group F) and semi-rigid rings in 94 (70.7%, group R). Preoperative New York Heart Association class was III/IV in 104 patients (78.2%). Mean preoperative left ventricular ejection fraction was 28.8%±10.2%. Preoperative mitral regurgitation was moderate in 51 patients (38.3%) and severe in 82 (61.7%). In-hospital mortality occurred in 11 patients (8.3%). Overall survival at 1, 5 and 10 years were, respectively, 86.4%, 69.7% and 45.9%. At 10 years, overall survival (group F 53.1%, group R 40.0%, P=0.330) and freedom from moderate to severe MR (group F 53.1%, group R 53.8%, P=0.725) did not differ significantly. Freedom from hospitalization for heart failure was 59.3%. Left ventricular reverse remodelling, defined as a reduction of left ventricular end-systolic volume index >15%, occurred more commonly in Group R (51.1%) compared to Group F (23.1%), P=0.003.

Conclusions

Restrictive mitral annuloplasty was associated with an operative mortality of 8.3%. Heart failure symptoms and significant MR recur in approximately 40% of patients after 10 years. Survival remained suboptimal and was not influenced by the type of annuloplasty ring.

Emerging Technologies for Percutaneous Mitral Valve Repair

Mitral regurgitation (MR) is a common disease affecting more than 4 million people in the United States and the European Union. A significant number of percutaneous valves have been developed recently, specifically designed for the mitral anatomy, and with a promising evidence of good procedural and echocardiographic outcomes. However, even if transcatheter mitral valve replacement (TMVR) will have a role in the future of percutaneous treatment of both functional and degenerative mitral regurgitation, percutaneous mitral valve repair will always play a vital role in the treatment of MR because of the favorable safety profile and the fact that it respects the native anatomy. In this review, we will discuss the new emerging technologies under development to treat mitral regurgitation focusing on different devices that aim to target different components of the mitral anatomy.

Cost-Effectiveness of Mitral Valve Repair Versus Replacement for Severe Ischemic Mitral Regurgitation: A Randomized Clinical Trial From the Cardiothoracic Surgical Trials Network

BACKGROUND

The CTSN (Cardiothoracic Surgical Trials Network) recently reported no difference in left ventricular end-systolic volume index or in survival at 2 years between patients with severe ischemic mitral regurgitation (MR) randomized to mitral valve repair or replacement. However, replacement provided more durable correction of MR and fewer cardiovascular readmissions. Yet, costeffectiveness outcomes have not been addressed.

METHODS AND RESULTS

We conducted a cost-effectiveness analysis of the surgical treatment of ischemic MR based on the CTSN trial (n=126 for repair; n=125 for replacement). Patient-level data on readmissions, survival, qualityof- life, and US hospital costs were used to estimate costs and quality-adjusted life years per patient over the trial duration and a 10-year time horizon. We performed microsimulation for extrapolation of outcomes beyond the 2 years of trial data. Bootstrap and deterministic sensitivity analyses were done to address parameter uncertainty. In-hospital cost estimates were $78 216 for replacement versus $72 761 for repair (difference: $5455; 95% uncertainty interval [UI]: −7784–21 193) while 2-year costs were $97 427 versus $96 261 (difference: $1166; 95% UI: −16 253–17 172), respectively. Quality-adjusted life years at 2 years were 1.18 for replacement versus 1.23 for repair (difference: −0.05; 95% UI: −0.17 to 0.07). Over 5 and 10 years, the benefits of reduction in cardiovascular readmission rates with replacement increased, and survival minimally improved compared with repair. At 5 years, cumulative costs and quality-adjusted life years showed no difference on average, but by 10 years, there was a small, uncertain benefit for replacement: $118 023 versus $119 837 (difference: −$1814; 95% UI: −27 144 to 22 602) and qualityadjusted life years: 4.06 versus 3.97 (difference: 0.09; 95% UI: −0.87 to 1.08). After 10 years, the incremental cost-effectiveness of replacement continued to improve.

CONCLUSIONS

Our cost-effectiveness analysis predicts potential savings in cost and gains in quality-adjusted survival at 10 years when mitral valve replacement is compared with repair for severe ischemic MR. These projected benefits, however, were small and subject to variability. Efforts to further delineate predictors of long-term outcomes in patients with severe ischemic MR are needed to optimize surgical decisions for individual patients, which should yield more cost-effective care.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00807040.

Mitral valve repair versus replacement in patients with ischemic mitral regurgitation

Background

The optimal management of ischemic mitral regurgitation (IMR) is controversial. The aim of this study was to examine our eight years' experience of surgical treatment in patients with IMR, and to compare outcomes of mitral valve repair versus replacement with concomitant coronary artery bypass grafting (CABG).

Methods

A retrospective, observational, cohort study was undertaken to collect data on consecutive patients with IMR and coronary artery disease who received CABG and mitral valve surgery in our hospital between January 2008 and December 2015. Basic patient characteristics, operative data, and postoperative clinical outcomes were examined.

Results

The series included 22 consecutive patients (21 male; 1 female). The mean age was 62.1±11.4 years old. The mean preoperative left ventricular ejection fraction (LVEF) was 33.4%±15.4%. The mean cardiopulmonary bypass (CPB) time was 165.4±38.4 minutes, and the mean aortic cross clamp time was 113.8±33.6 minutes. Eighteen patients underwent CABG plus mitral valve repair, and four patients underwent CABG plus mitral valve replacement (MVR). There were three early in-hospital mortalities: two in the mitral valve repair group, and one in the replacement group. The follow-up was complete in all patients, with a mean follow-up duration of 3.1±2.3 years. The mean last LVEF was 35.3%±17.7%. There were 2 late mortalities. Both were from the repair group. The overall late survival rate was 81.6%, with 83.0% in the repair group and 75.0% in the replacement group. In patients with echocardiography follow-up of more than or equal to 1 year duration, the residual or recurrent mitral regurgitation rates were 0.0% in the replacement group and 57.1% in the repair group. One patient in the repair group later underwent MVR due to severe regurgitation postoperatively.

Conclusions

Our preliminary findings showed that the surgical outcome of mitral valve repair might be comparable to that of MVR in terms of early mortality and long-term survival. However, mitral valve repair was associated with a higher residual or recurrent mitral regurgitation rate. According to the latest literature, the role of MVR can justifiably be indicated for severe IMR. As for moderate IMR, CABG alone without mitral valve intervention may provide similar clinical outcomes.

Topographic mapping of left ventricular regional contractile injury in ischemic mitral regurgitation

OBJECTIVE

Restrictive leaflet tethering resulting from regional left ventricular (LV) contractile injury causes ischemic mitral regurgitation (MR). We hypothesized that 3-dimensional LV topographic mapping by MRI-based multiparametric strain analysis could characterize the regional contractile injury patterns that differentiate ischemic coronary artery disease patients who have ischemic MR from those who do not.

METHODS

Magnetic resonance imaging-based multiparametric strain data were calculated for 15,300 LV grid points in 100 normal volunteers. Strain parameters from ischemic MR (n = 10) and ischemic no-MR (n = 36) patients were then normalized to this normal human strain database with z score quantification of standard deviation from the normal mean. Mean multiparametric strain z scores were calculated for 18 LV subregions (basilar/mid/apical levels; 6 LV regions). Mean strain z scores for papillary muscle-related (basilar/mid levels of anterolateral, posterolateral, and posterior) and nonpapillary muscle-related (all other) subregions were compared between ischemic MR and ischemic no-MR groups.

RESULTS

Across all patients, contractile injury was greater in the papillary muscle-related regions compared with the nonpapillary regions (P = .007). In the papillary regions, contractile injury was greater in the ischemic MR group compared with the no-MR group (z scores, 1.91 ± 1.13 vs 1.20 ± 1.01, respectively; P < .001). Strain values in the nonpapillary muscle-related subregions were not different between the 2 groups (1.31 ± 1.04 vs 1.20 ± 1.03; P = .301).

CONCLUSIONS

Multiparametric strain analysis demonstrated severe normalized contractile injury in the papillary muscle-related LV subregions in patients with ischemic MR. The mean degree of normalized injury approached 2 standard deviations and was significantly worse than the levels seen in ischemic no-MR patients.