Mitral valve surgery in advanced heart failure

Restrictive annuloplasty or replacement on reverse remodeling for nonischemic dilated cardiomyopathy

BACKGROUND

For patients with nonischemic dilated cardiomyopathy (NIDCM), the indications for and results of mitral surgery remain controversial. We reviewed a strategy of mitral repair and replacement for clinically relevant secondary mitral regurgitation (MR) in patients with NIDCM.

METHODS

We retrospectively reviewed 65 patients with advanced NIDCM (LVEF < 40%) who underwent mitral surgery. Of them, 47 (72%) underwent mitral annuloplasty and 18 (28%) replacement for secondary MR. The primary endpoint was postoperative reduction in indexed LV end-systolic volume (LVESVI).

RESULTS

At baseline, there was no intergroup difference in LVESVI (123 ± 47 vs. 147 ± 37 ml/m2, P = 0.055), LVEF (27 ± 8% vs. 25 ± 6%, P = 0.41), incidence of severe MR (57% (27/47) vs. 72% (13/18), P = 0.40), or EuroSCORE II score (6.2% vs. 7.6%, P = 0.90). At 6 months, the annuloplasty group reduced LVESVI to a greater degree than the replacement group (P < 0.001), yielding significantly smaller postoperative LVESVI (96 ± 59 vs. 154 ± 61 ml/m2, P < 0.001) and better LVEF (P < 0.001). The rates of moderate/severe recurrent MR were 17% (8/47) and 0%, respectively. Multivariable analysis demonstrated that mitral annuloplasty (OR 6.10, 95% CI 1.14-32.8, P = 0.035) was significantly associated with postoperative LV reverse remodeling. Cumulative survival was not different between the groups (P = 0.26).

CONCLUSIONS

In patients with NIDCM, mitral annuloplasty reduced LV volume to a greater degree than did mitral replacement. These findings may assist with surgical options for secondary MR associated with NIDCM.

Systolic heart failure induced by butylparaben in zebrafish is caused through oxidative stress and immunosuppression

Due to Butylparaben (BuP) widespread application in cosmetics, food, pharmaceuticals, and its presence as an environmental residue, human and animal exposure to BuP is common, potentially posing hazards to both human and animal health. Congenital heart disease is already a serious problem. However, the effects of BuP on the developing heart and its underlying mechanisms remain unclear. Here, zebrafish embryos were exposed to environmentally and human-relevant concentrations of BuP (0.6 mg/L, 1.2 mg/L, and 1.8 mg/L, calculated but not measured) at 6 h post-fertilization (hpf) and were treated until 72 hpf. Exposure to BuP led to cardiac morphological defects and cardiac dysfunction in zebrafish embryos, manifesting symptoms similar to systolic heart failure. The etiology of BuP-induced systolic heart failure in zebrafish embryos is multifactorial, including cardiomyocyte apoptosis, endocardial and atrioventricular valve damage, insufficient myocardial energy, impaired Ca2+ homeostasis, depletion of cardiac-resident macrophages, cardiac immune non-responsiveness, and cardiac oxidative stress. However, excessive accumulation of reactive oxygen species (ROS) in the cardiac region and cardiac immunosuppression (depletion of cardiac-resident macrophages and cardiac immune non-responsiveness) may be the predominant factors. In conclusion, this study indicates that BuP is a potential hazardous substance that can cause adverse effects on the developing heart and provides evidence and insights into the pathological mechanisms by which BuP leads to cardiac dysfunction. It may help to prevent the BuP-based congenital heart disease heart failure in human through ameliorating strategies and BuP discharge policies, while raising awareness to prevent the misuse of preservatives.

Impact of Mitral Regurgitation Recurrence on Mitral Valve Repair for Secondary Ischemic Mitral Regurgitation

OBJECTIVES

The current guidelines still do not include specific recommendations on the use of subvalvular repair (SV-r) for treatment of ischemic mitral regurgitation (IMR). Therefore, the objective of our study was to evaluate the clinical impact of mitral regurgitation (MR) recurrence and ventricular remodeling on long-term outcomes after SV-r combined with restrictive annuloplasty (RA-r).

METHODS

We performed a subanalysis of the papillary muscle approximation trial, studying 96 patients with severe IMR and coronary artery disease undergoing restrictive annuloplasty alongside subvalvular repair (SV-r + RA-r group) or restrictive annuloplasty alone (RA-r group). We analyzed treatment failure differences, the influence of residual MR, left ventricular remodeling, and clinical outcomes. The primary endpoint was treatment failure (composite of death; reoperation; or recurrence of moderate, moderate-to-severe, or severe MR) within 5 years of follow-up after the procedure.

RESULTS

A total of 45 patients showed failure of the treatment within 5 years, of which 16 patients underwent SV-r + RA-r (35.6%) and 29 underwent RA-r (64.4%, p = 0.006). Patients with significant residual MR presented with a higher rate of all-cause mortality at 5 years compared with trivial MR (HR 9.09, 95% CI 2.08-33.33, p = 0.003). MR progression occurred earlier in the RA-r group, as 20 patients in the RA-r group vs. 6 in SV-r + RA-r group had a significant MR 2 years after surgery (p = 0.002).

CONCLUSIONS

RA-r remains a surgical mitral repair technique with an increased risk of failure and mortality at 5 years compared with SV-r. The rates of recurrent MR are higher, and recurrence occurs earlier, with RA-r alone compared to SV-r. The addition of the subvalvular repair increases the durability of the repair, thus extending all of the benefits of preventing MR recurrence.

Role of the mitral valve in left ventricular assist device pathophysiology

Functional mitral regurgitation (MR) in the setting of heart failure results from progressive dilatation of the left ventricle (LV) and mitral annulus. This leads to leaflet tethering with posterior displacement. Contrary to common assumptions, MR often does not resolve with LVAD decompression of the LV alone. The negative impact of significant (moderate-severe) mitral regurgitation in the LVAD setting is becoming better recognized in terms of its harmful effect on right heart function, pulmonary vascular resistance and hospital readmissions. However, controversies remain regarding the threshold for intervention and management. At present, there are no consensus indications for the repair of significant mitral regurgitation at the time of LVAD implantation due to the conflicting data regarding potential adverse effects of MR on clinical outcomes. In this review, we summarize the current understanding of MR pathophysiology in patients supported with LVAD and potential future management strategies.

Derangements and Reversibility of Energy Metabolism in Failing Hearts Resulting from Volume Overload: Transcriptomics and Metabolomics Analyses

Derangements in cardiac energy metabolism have been shown to contribute to the development of heart failure (HF). This study combined transcriptomics and metabolomics analyses to characterize the changes and reversibility of cardiac energetics in a rat model of cardiac volume overload (VO) with the creation and subsequent closure of aortocaval fistula. Male Sprague–Dawley rats subjected to an aortocaval fistula surgery for 8 and 16 weeks exhibited characteristics of compensated hypertrophy (CH) and HF, respectively, in echocardiographic and hemodynamic studies. Glycolysis was downregulated and directed to the hexosamine biosynthetic pathway (HBP) and O-linked-N-acetylglucosaminylation in the CH phase and was further suppressed during progression to HF. Derangements in fatty acid oxidation were not prominent until the development of HF, as indicated by the accumulation of acylcarnitines. The gene expression and intermediates of the tricarboxylic acid cycle were not significantly altered in this model. Correction of VO largely reversed the differential expression of genes involved in glycolysis, HBP, and fatty acid oxidation in CH but not in HF. Delayed correction of VO in HF resulted in incomplete recovery of defective glycolysis and fatty acid oxidation. These findings may provide insight into the development of innovative strategies to prevent or reverse metabolic derangements in VO-induced HF.

Learning from Controversy and Revisiting the Randomized Trials of Secondary Mitral Regurgitation

Until recently, conventional mitral valve surgery has been the treatment of choice even in secondary mitral regurgitation. Recent evidence, however, advocates the use of transcatheter edge-to-edge mitral valve repair (TEER) of the mitral valve. This has been reflected by the change in guidelines of the American College of Cardiology/American Heart Association. We reviewed the literature to shed light on the risks and benefits of all interventions, surgical, transcatheter and guideline-directed medical therapy. Secondary mitral regurgitation occurs due to an imbalance between closing forces and tethering forces. Given the pathology extends beyond the valve alone, treatment should be directed at restoring the geometrical shape of the left ventricle alongside the valve. Myocardial revascularization plays a pivotal role in preventing recurrence. The role of papillary muscle approximation in addition to restrictive mitral annuloplasty should be considered in a select group of patients. We also reviewed the current literature on TEERs from the COAPT and Mitra-FR trials while highlighting the concept of proportionate/disproportionate MR which may help identify which patients benefit from mitral valve restoration. Treatment of this condition will require robust randomized trials alongside the use of state-of-the-art imaging technologies available with the full complement of the multidisciplinary team to ensure the best outcomes for each patient.

Pre-surgical Prediction of Ischemic Mitral Regurgitation Recurrence Using In Vivo Mitral Valve Leaflet Strains

Ischemic mitral regurgitation (IMR) is a prevalent cardiac disease associated with substantial morbidity and mortality. Contemporary surgical treatments continue to have limited long-term success, in part due to the complex and multi-factorial nature of IMR. There is thus a need to better understand IMR etiology to guide optimal patient specific treatments. Herein, we applied our finite element-based shape-matching technique to non-invasively estimate peak systolic leaflet strains in human mitral valves (MVs) from in-vivo 3D echocardiographic images taken immediately prior to and post-annuloplasty repair. From a total of 21 MVs, we found statistically significant differences in pre-surgical MV size, shape, and deformation patterns between the with and without IMR recurrence patient groups at 6 months post-surgery. Recurrent MVs had significantly less compressive circumferential strains in the anterior commissure region compared to the recurrent MVs (p = 0.0223) and were significantly larger. A logistic regression analysis revealed that average pre-surgical circumferential leaflet strain in the Carpentier A1 region independently predicted 6-month recurrence of IMR (optimal cutoff value - 18%, p = 0.0362). Collectively, these results suggest greater disease progression in the recurrent group and underscore the highly patient-specific nature of IMR. Importantly, the ability to identify such factors pre-surgically could be used to guide optimal treatment methods to reduce post-surgical IMR recurrence.

Ex Vivo Model of Ischemic Mitral Regurgitation and Analysis of Adjunctive Papillary Muscle Repair

Ischemic mitral regurgitation (IMR) is particularly challenging to repair with lasting durability due to the complex valvular and subvalvular pathologies resulting from left ventricular dysfunction. Ex vivo simulation is uniquely suited to quantitatively analyze the repair biomechanics, but advancements are needed to model the nuanced IMR disease state. Here we present a novel IMR model featuring a dilation device with precise dilatation control that preserves annular elasticity to enable accurate ex vivo analysis of surgical repair. Coupled with augmented papillary muscle head positioning, the enhanced heart simulator system successfully modeled IMR pre- and post-surgical intervention and enabled the analysis of adjunctive subvalvular papillary muscle repair to alleviate regurgitation recurrence. The model resulted in an increase in regurgitant fraction: 11.6 ± 1.7% to 36.1 ± 4.4% (p < 0.001). Adjunctive papillary muscle head fusion was analyzed relative to a simple restrictive ring annuloplasty repair and, while both repairs successfully eliminated regurgitation initially, the addition of the adjunctive subvalvular repair reduced regurgitation recurrence: 30.4 ± 5.7% vs. 12.5 ± 2.6% (p = 0.002). Ultimately, this system demonstrates the success of adjunctive papillary muscle head fusion in repairing IMR as well as provides a platform to optimize surgical techniques for increased repair durability.

Successful mitral repair in dogs by mitral annuloplasty using Hegar dilator: two case reports

Mitral regurgitation (MR) is the most common heart disease in small-breed dogs. Mitral repair, which comprise artificial chorda tendineae implantation and mitral annuloplasty, has become the mainstay of treatment in the veterinary field. We report on two small dogs who underwent mitral repair surgery for MR. A Hegar dilator was used during mitral annuloplasty for accurate and reproducible surgery. In both cases, mitral regurgitant flow almost disappeared after surgery, and clinical signs improved. The treatment regimen was terminated 3 months after the surgery. We concluded that using a Hegar dilator may facilitate mitral valve repair surgery.

Nomogram Predicts Improvement of Ischemic Mitral Regurgitation after Coronary Artery Bypass Grafting

BACKGROUND

Developing a nomogram to predict improvement in moderate ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG) is in need.

METHODS

Between 2010 and 2018, data were retrospectively collected from 112 patients with prior myocardial infarction and moderate IMR undergoing CABG. Patients were divided into two groups based on IMR degree 1 year after CABG as follows: Improved Group with no or mild IMR (n=54) and Failure Group with moderate or severe IMR (n=58). To determine the predictors of postoperative IMR improvement, preoperative clinical and echocardiographic data were compared, and a nomogram was formulated based on all independent predictors. Discriminative ability, calibration, and clinical usefulness of the prediction model were assessed.

RESULTS

Independent predictors of IMR improvement after CABG constructing the nomogram included duration between infarction and operation, poster-inferior to left ventricular volume ratio, maximum difference of the time to reach minimum systolic volume of 16 segments, P3 leaflet tethering angle, and annular Non-planar angle. The nomogram exhibited well-fitted calibration curves and excellent discriminative ability. The area under receiver operating characteristic curve was 0.974. Patients with a score > 236 demonstrated a high probability of IMR improvement (sensitivity, 90.7%; specificity, 93.1%). Patients in the Improved Group demonstrated greater actuarial survival rates than those in the Failure Group.

CONCLUSIONS

The nomogram combining 5 preoperative clinical and echocardiographic predictors provides an accurate preoperative estimation of moderate IMR improvement after surgery, with excellent discriminative ability. Based on this nomogram, patients with a higher score predict higher probabilities of IMR improvement.

Functional mitral regurgitation combined with increased early diastolic transmitral velocity to early mitral annulus diastolic velocity ratio is associated with a poor prognosis in patients with shock

BACKGROUND

Functional mitral regurgitation (FMR) is common in critically ill patients and may cause left atrial (LA) pressure elevation. This study aims to explore the prognostic impact of synergistic LA pressure elevation and FMR in patients with shock.

METHODS

We retrospectively screened 130 consecutive patients of 175 patients with shock from April 2016 to June 2017. The incidence and impact of FMR and early diastolic transmitral velocity to early mitral annulus diastolic velocity ratio (E/e') ≥ 4 within 6 h of shock on the prognosis of patients were evaluated. Finally, the synergistic effect of FMR and E/e' were assessed by combination, grouping, and trend analyses.

RESULTS

Forty-four patients (33.8%) had FMR, and 15 patients (11.5%) had E/e' elevation. A multivariate analysis revealed FMR and E/e' as independent correlated factors for 28-day mortality (P = 0.043 and 0.028, respectively). The Kaplan-Meier survival analysis revealed a significant difference in survival between patients with and without FMR (χ2 = 7.672, P = 0.006) and between the E/e' ≥ 14 and E/e' < 14 groups (χ2 = 19.351, P < 0.010). Twenty-eight-day mortality was significantly different among the four groups (χ2 = 30.141, P < 0.010). The risk of 28-day mortality was significantly higher in group 4 (E/e' ≥ 14 with FMR) compared with groups 1 (E/e' < 14 without FMR) and 2 (E/e' < 14 with FMR) (P = 0.001 and 0.046, respectively).

CONCLUSIONS

Patients with shock can be identified by the presence of FMR. FMR and E/e' are independent risk factors for a poor prognosis in these patients, and prognosis is worst when FMR and E/e' ≥ 14 are present. It may be possible to improve prognosis by reducing LA pressure and E/e'.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03082326.

Prognostic impact of transcatheter mitral valve repair in patients with exercise-induced secondary mitral regurgitation

AIMS

Although exercise-induced secondary mitral regurgitation (MR) is known to have a poor prognosis, the therapeutic strategy towards this condition remains to be investigated. In the present study, we aimed to investigate the prognostic impact of transcatheter mitral valve repair (TMVr) using the MitraClip in patients with exercise-induced secondary MR.

METHODS AND RESULTS

Of the 200 consecutive patients with secondary MR who underwent exercise stress echocardiography, 46 (23%) that presented with exercise-induced secondary MR [i.e. increase in effective regurgitant orifice area (EROA) of ≥ 0.13 cm2] were enrolled in the present investigation. The composite endpoints of all-cause mortality and hospitalization for heart failure were evaluated. Of the 46 patients included in the current cohort, 19 (41%) underwent TMVr and 27 (59%) were medically managed (control group). Although the TMVr group tended to present with a greater EROA at rest (0.26 ± 0.10 vs. 0.20 ± 0.08 cm2, P = 0.047), there were no differences in the EROA changes during exercise between the two groups (0.18 ± 0.10 vs. 0.18 ± 0.04 cm2, P = 0.940). While the TMVr group reported a higher event-free survival rate after the 13-month follow-up period (log-rank P = 0.017), the Cox proportional-hazard analysis suggested the TMVr to be associated with clinical outcomes (hazard ratio: 0.419, P = 0.044).

CONCLUSION

As opposed to the medical management, TMVr treatment was associated with a lower risk of composite endpoints in patients with exercise-induced secondary MR. Exercise stress echocardiography is considered to have played an important role in decision-making for secondary MR.

Fate of preoperative moderate mitral regurgitation following left ventricular assist device implantation

OBJECTIVE

We examined for improvements in preoperative moderate mitral regurgitation following continuous-flow left ventricular assist device (cfLVAD) implantation.

METHODS

From 2006 to 2020, 190 patients with moderate MR underwent cfVLAD implant without concomitant mitral valve (MV) surgery. Cardiac dimensions and contractility, as well as valve function, were assessed with an echocardiogram (echo) pre-cfLVAD, and at approximately 1 month post-cfLVAD. Outcomes were determined by retrospective chart review.

RESULTS

Median echo follow-up was 0.94 (0.53, 1.38) months. Residual significant moderate or greater MR was present in 30/190 (15.8%) on follow-up. Patients with significant residual MR had larger preoperative left ventricular internal diameters in diastole (74.4 ± 8.7 vs. 71.1.0 ± 9.1 mm, p = .034). Significant residual MR was associated with higher preoperative mean pulmonary artery pressures (OR = 1.055, p = .035) and pulmonary capillary wedge pressures (OR = 1.060, p = .034). Significant residual MR on echo was not associated with any survival difference (p = .325). The 1, 5, and 10 year survival were 89.9%, 55.2%, and 34.2%, respectively.

CONCLUSIONS

For patients with moderate MR undergoing LVAD implantation, the likelihood of significant residual MR is low and mitral intervention in this population is not recommended. However, select patients with larger preoperative left heart dimensions and pulmonary vascular pressures may be at risk for persistent residual MR.

Transcatheter mitral valve replacement: latest advances and future directions

Mitral regurgitation remains the most common form of valve disease worldwide and given an aging population with a significant proportion of secondary mitral regurgitation, a transcatheter approach to mitral valve replacement has become a major goal of the transcatheter therapeutics field. Mitral regurgitation can be caused by disease of the leaflets (primary) or by diseases of the left atrium or left ventricle (LV) (secondary or functional), and may involve overlap of the two (mixed disease). The location of the mitral valve (and large size), the approach to anchoring a valve replacement, and concerns about left ventricular outflow tract (LVOT) obstruction are all issues that have made the transcatheter delivery of a valve replacement challenging. Despite these challenges, both transapical and transseptal devices are currently being developed, with several in early feasibility trials and several entering pivotal trials. As the field of transcatheter mitral valve replacement (TMVR) improves and develops, a critical part of evaluating patients with mitral valve disease will be utilizing the heart team approach to identify and individualize the most appropriate treatment for each patient.

Individual patient data meta-analysis of the effects of the CARILLON® mitral contour system

AIMS

Functional mitral regurgitation (MR) (FMR) is common in heart failure with reduced ejection fraction and worsens morbidity and mortality, even when mild. The CARILLON® mitral contour system (Cardiac Dimensions, Kirkland, WA, USA), a mitral annuloplasty device delivered percutaneously to the coronary sinus, is designed to reduce the mitral annular dimension by virtue of the close anatomic relationship between the coronary sinus and the posterior mitral annulus. We performed a comprehensive individual patient data meta-analysis of all studies that used CARILLON® device vs. control that have measured mitral regurgitation severity, left ventricular (LV) remodelling, functional status, and heart failure-related outcomes in heart failure with reduced ejection fraction patients.

METHODS AND RESULTS

The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE were searched in July 2020. Primary outcomes of interest were measures of MR severity, LV remodelling, New York Heart Association functional class and heart failure-related outcomes [mortality and heart failure hospitalization (HFH) during follow up]. All data were received as individual patient and individual time point data-points. Mean differences and 95% confidence intervals (CIs) were calculated for continuous data using a fixed-effects model. Three studies (REDUCE FMR, TITAN and TITAN II) enrolling 209 participants were identified and included. Pooled analysis showed that, compared with control, CARILLON® device significantly improved both MR volume (mean difference MD -9.20, 95% C.I. -16.11 to -2.29 mL, P = 0.009) and MR grade (MD -1.12, 95% CI -1.36 to -0.88, P < 0.00001) and this was associated with a significant reduction in LA volume, MD -7.54 mL, 95% CI -14.90 to - 0.18, P = 0.04. Significant LV reverse remodelling was also seen in terms of EDV (MD -16.53, 95% CI -28.61 to -44.4 mL, P = 0.007), and a trend in ESV (MD -8.68, 95% CI -18.69 to -1.34 mL, P = 0.09) but no significant effect on LVEF (MD 0.88, 95% CI -1.52% to 2.38%, P = 0.47), due presumably to the greater residual MR in the control patients falsely elevating the LVEF. In addition, the CARILLON® device significantly improved New York Heart Association functional Class (MD -0.22, 95% CI -0.24 to -0.16, P < 0.00001), associated with a lower rate of HFH compared with controls (45.3% vs. 64%, respectively, P = 0.04). As a sensitivity analysis we also restricted the analyses to those patients with Class 3+/4+ MR at baseline. In this cohort, the echocardiographic results were similar, and the reduction in HFH rates was even more marked (43.9% vs. 82.9%, respectively, P = 0.04).

CONCLUSIONS

This comprehensive meta-analysis of individual patient data has shown that CARILLON® device provides statistically significant and clinically meaningful benefits on MR severity, LA and LV volumes, and remodelling and rates of subsequent heart failure hospitalization.

Transcatheter Mitral Valve Replacement: Rationale and Current Status

Mitral regurgitation (MR) is the most prevalent form of moderate or severe valve disease in the developed world. MR can result from impairment of any part of the mitral valve apparatus and is classified as primary (disease of the leaflets) or secondary (functional). The presence of at least moderate MR is associated with increased morbidity and mortality. With the goal of avoiding the risks of traditional surgery, transcatheter mitral valve therapies have been developed. The current transcatheter repair techniques are limited by therapeutic target and incomplete MR reduction, and thus transcatheter mitral valve replacement (TMVR) has been pursued. Several devices (both transapical and transseptal) are under development, with both early feasibility and pivotal trials under way. As this field develops, the decision to treat with TMVR will require a heart team approach that takes patient-, disease-, and device-specific factors into account.

Impact of Subclinical Congestion on Outcome of Patients Undergoing Mitral Valve Surgery

Since risk assessment prior to cardiac surgery is based on proven but partly unsatisfactory scores, the need for novel tools in preoperative risk assessment taking into account cardiac decompensation is obvious. Even subclinical chronic heart failure is accompanied by an increase in plasma volume. This increase is illustrated by means of a plasma volume score (PVS), calculated using weight, gender and hematocrit. A retrospective analysis of 187 consecutive patients with impaired left ventricular function undergoing mitral valve surgery at a single centre between 2013 and 2016 was conducted. Relative preoperative PVS was generated by subtracting the ideal from actual calculated plasma volume. The study population was divided into two cohorts using a relative PVS score > 3.1 as cut-off. Patients with PVS > 3.1 had a significantly higher need for reoperation for bleeding/tamponade (5.5% vs. 16.7%; p = 0.016) and other non-cardiac causes (9.4% vs. 21.7%; p = 0.022). In-hospital as well as 6-month, 1-year and 5-year mortality was significantly increased in PVS > 3.1 (6.3% vs. 18.3%; p = 0.013; 9.4% vs. 23.3%; p = 0.011; 11.5% vs. 23.3%; p = 0.026; 18.1% vs. 33.3%; p = 0.018). Elevated PVS above the defined cut-off used to quantify subclinical congestion was linked to significantly worse outcome after mitral valve surgery and therefore could be a useful addition to current preoperative risk stratification.

Are recurrence of ischemic mitral regurgitation and left ventricular reverse remodeling after restrictive annuloplasty ring dependent?

OBJECTIVE

This meta-analysis investigates MR recurrence and degree of left ventricular reverse remodeling (LVRR) in CIMR patients in mitral annuloplasty employing different ring designs.

BACKGROUND

The deeper understanding of complex changes caused by chronic ischemic mitral regurgitation (CIMR) have led to new generations of rings that, by maintaining normal 3D annular geometry are supposed to enhance long-term repair durability.

METHODS

A meta-analysis of all available reports in literature of MV repair through different ring design was conducted. Meta-regression was performed to investigate the impact of mitral ring characteristics related to flexibility, planarity, symmetry and single type utilized. Twenty studies encompassing a total of 1876 patients were included at the end of the selection process.

RESULTS

At meta-regression recurrence of MR was not influenced by the ring employed. Nonetheless, the event rate of MR recurrence in planar rings was 19%. Vs. 11% observed with non-planar rings. Recurrence rate in patients implanted with symmetric rings was 14% whereas it was 7% in asymmetric rings. The non-planar asymmetric IMR-ETlogix showed the lowest recurrence rate (6%). Furthermore, in planar group the reduction of pre- and post-operative LVEDD was - 4%. In the non-planar group, the LVEDD was reduced by 8.6%. In patients implanted with symmetric rings LVEDD reduction was 10.8%. LVRR in the asymmetric group was -5.8%.

CONCLUSION

MR recurrence occurred the least with asymmetric rings with less disproportionate asymmetry. In contrast, LVRR occurred at a greater extent in symmetric rings.

Moving object tracking in clinical scenarios: application to cardiac surgery and cerebral aneurysm clipping

BACKGROUND AND OBJECTIVES

Surgical procedures such as laparoscopic and robotic surgeries are popular since they are invasive in nature and use miniaturized surgical instruments for small incisions. Tracking of the instruments (graspers, needle drivers) and field of view from the stereoscopic camera during surgery could further help the surgeons to remain focussed and reduce the probability of committing any mistakes. Tracking is usually preferred in computerized video surveillance, traffic monitoring, military surveillance system, and vehicle navigation. Despite the numerous efforts over the last few years, object tracking still remains an open research problem, mainly due to motion blur, image noise, lack of image texture, and occlusion. Most of the existing object tracking methods are time-consuming and less accurate when the input video contains high volume of information and more number of instruments.

METHODS

This paper presents a variational framework to track the motion of moving objects in surgery videos. The key contributions are as follows: (1) A denoising method using stochastic resonance in maximal overlap discrete wavelet transform is proposed and (2) a robust energy functional based on Bhattacharyya coefficient to match the target region in the first frame of the input sequence with the subsequent frames using a similarity metric is developed. A modified affine transformation-based registration is used to estimate the motion of the features following an active contour-based segmentation method to converge the contour resulted from the registration process.

RESULTS AND CONCLUSION

The proposed method has been implemented on publicly available databases; the results are found satisfactory. Overlap index (OI) is used to evaluate the tracking performance, and the maximum OI is found to be 76% and 88% on private data and public data sequences.

Standardized Subannular Repair Improves Outcomes in Type IIIb Functional Mitral Regurgitation

BACKGROUND

The major drawback of isolated annuloplasty in secondary mitral regurgitation (MR) is the reoccurrence of MR. We prospectively compared the results of isolated annuloplasty vs annuloplasty with simultaneous standardized subannular repair.

METHODS

The study comprised 101 patients with secondary type IIIb MR. Of these, 51 underwent annuloplasty plus standardized subannular repair with realignment of both papillary muscles (subannular repair) and 50 underwent isolated annuloplasty. The primary study end point was the reoccurrence of MR >2 at the 1-year follow-up. Secondary end points were survival, freedom from major adverse cardiac events, and residual leaflet tethering.

RESULTS

Baseline characteristics were comparable in both groups. There was no significant difference in in-hospital mortality (P = .3). Although postrepair MR was comparable between the subannular repair and isolated annuloplasty subgroups, the residual leaflet tethering (tenting area, 127.6 ± 35.8 mm² vs 166.3 ± 47.3 mm², P = .02; posterior mitral leaflet angle, 19.2 ± 4.7 degrees vs 24.8 ± 5.2 degrees, P = .001; anterior mitral leaflet angle, 25.4 ± 5.8 degrees vs 34.1 ± 4.0 degrees, P = .001; and tenting height, 5.9 ± 1.4 mm vs 9.2 ± 2.2 mm, P = .001) were significantly increased in the isolated annuloplasty group (P < .001). At the 1-year follow-up, we found a significant difference between the groups in the freedom from MR >2 of 98% (50 of 51) for subannular repair vs 86.7% (39 of 45) for isolated annuloplasty (P = .045) and mortality of 0% (0 of 51) for subannular repair vs 10% (5 of 50) for isolated annuloplasty (P = .025).

CONCLUSIONS

In secondary MR with reduced leaflet motion, the combination of annuloplasty and standardized subannular repair is associated with a significantly reduced MR reoccurrence, decreased residual leaflet tenting, and significantly improved 1-year outcome compared with annuloplasty alone.

Percutaneous Mitral Valve Repair versus Optimal Medical Therapy in Patients with Functional Mitral Regurgitation: A Systematic Review and Meta-Analysis

Objectives

To compare percutaneous mitral valve repair (PMVR) with optimal medical therapy (OMT) in patients with heart failure (HF) and severe functional mitral regurgitation (FMR).

Background

Many patients with HF and FMR are not suitable for surgical valve replacement and remain symptomatic despite maximal OMT. PMVR has recently emerged as an alternative solution.

Methods

We performed a systematic review and a meta-analysis to address this question. Cochrane CENTRAL, MEDLINE, and Scopus were searched for randomized (RCT) and nonrandomized studies comparing PMVR with OMT in patients with HF and FMR. Primary endpoint was all-cause midterm mortality (at 1 and 2 years). Secondary endpoints were 30-day mortality and cardiovascular mortality and HF hospitalizations, at maximum follow-up. Studies including mixed cohort of degenerative and functional MR were allowed initially but were excluded in a secondary sensitivity analysis for each of the study's end points. This meta-analysis was performed following the publication of two RCTs (MITRA-FR and COAPT).

Results

Eight studies (six observational, two RCTs) comprising 3,009 patients were included in the meta-analysis. In comparison with OMT, PMVR significantly reduced 1-year mortality (RR: 0.70 [0.56, 0.87]; p=0.002; I²=47.6%), 2-year mortality (RR: 0.63 [0.55, 0.73]; p<0.001; I²=0%), and cardiovascular mortality (RR: 0.32 [0.23, 0.44]; p<0.001; I²=0%). No significant difference between PMVR+OMT and OMT was noted in HF hospitalization (HR: 0.69 [0.40, 1.20]; p=0.19; I²=85%) and 30-day mortality (RR: 1.13 [0.68, 1.87]; p=0.16; I²=0%).

Conclusions

In comparison with OMT, PMVR significantly reduces 1-year mortality, 2-year mortality, and cardiovascular mortality in patients with HF and severe MR.

The Year in Perioperative Echocardiography: Selected Highlights from 2018

This article is the third of an annual series reviewing the research highlights of the year pertaining to the subspecialty of perioperative echocardiography for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series. In most cases, these will be research articles targeted at the perioperative echocardiography diagnosis and treatment of patients after cardiothoracic surgery; but in some cases, these articles will target the use of perioperative echocardiography in general.

A meta-analysis of MitraClip combined with medical therapy vs. medical therapy alone for treatment of mitral regurgitation in heart failure patients

AIMS

Survival benefit of percutaneous mitral valve repair with the MitraClip over conservative treatment of functional mitral regurgitation (MR) remains unclear. The purpose of this meta-analysis is to compare survival outcomes of MitraClip with those of medical therapy in patients with functional MR.

METHODS AND RESULTS

A comprehensive literature search of PubMed, MEDLINE, and Google Scholar was conducted including studies evaluating MitraClip vs. medical therapy with multivariate adjustment and with >80% of patients with functional MR. Death from any cause was the primary endpoint, while freedom from readmission was the secondary one, evaluated with random effects. These analyses were performed at study level and at patient level including only functional MR when available, evaluating the effect of MitraClip in different subgroups according to age, ischaemic aetiology, presence of implantable cardioverter defibrillator/cardiac resynchronization therapy, and left ventricular ejection fraction and volumes. We identified six eligible observational studies including 2121 participants who were treated with MitraClip (n = 833) or conservative therapy (n = 1288). Clinical follow-up was documented at a median of 400 days. At study-level analysis, MitraClip, when compared with medical therapy (P = 0.005), was associated with significant reduction of death (P = 0.002) and of readmission due to cardiac disease. At patient-level analysis, including 344 patients, MitraClip confirmed robust survival benefit over medical therapy for all patients with functional MR and among the most important subgroups.

CONCLUSIONS

Compared with conservative treatment, MitraClip is associated with a significant survival benefit. Importantly, this superiority is particularly pronounced among patients with functional MR and across all the main subgroups.

Dynamic cardiac anatomy: the "cypress tree" papillary muscle root

Introduction: The understanding of gross cardiac anatomy has been relatively stable over the last 80 years, reliant on well-established autopsy findings. The advent of dynamic imaging by cardiac MRI and CT provides a window to view anatomic features in vivo, providing insights typically masked at autopsy due to death.

Hypothesis: We hypothesize that cardiac magnetic resonance (CMR) with its high spatial and temporal resolution allows detection of anatomic features not previously appreciated at autopsy.

Methods: Two hundred fifty-five sequential, CMR examinations were retrospectively examined to describe the anatomic features of the LV (left ventricular) PM (papillary muscles). Specifically, the origin of the base of the PM was delineated. The insertion of the PM was seen in 255/255 patients.

Results: In 249 out of 255 patients (97.6%), the appearance of the PM was not a uniform muscle arising from the inner face of the LV myocardium, but was a finger-like series of long, slender trabeculae carneae traversing >1 cm before inserting into the main body of PM challenging our previous understanding of PM anatomy.

Conclusion: The capabilities of dynamic CMR to view cardiac features in vivo non-invasively provides a useful tool to study cardiac anatomy. Unlike the widely accepted representation of papillary muscles, uniformly arising from the floor of the LV, the base resolves into a ‘cypress-tree’ root-like structure with multiple thin projections before coalescing into a thick muscle head. Such observations have far reaching clinical implications in areas such as mitral regurgitation, post-MI remodeling and electrical transmission of the His-Purkinje system, and further work is indicated to delineate the role of non-invasive imaging in these areas.

Long-term outcomes of mitral regurgitation by type and severity

BACKGROUND

We aimed to determine the association of MR severity and type with all-cause death in a large, real-world, clinical setting.

METHODS

We reviewed full echocardiography studies at Duke Echocardiography Laboratory (01/01/1995-12/31/2010), classifying MR based on valve morphology, presence of coronary artery disease, and left ventricular size and function. Survival was compared among patients stratified by MR type and baseline severity.

RESULTS

Of 93,007 qualifying patients, 32,137 (34.6%) had ≥mild MR. A total of 8094 (8.7%) had moderate/severe MR, which was primary myxomatous (14.1%), primary non-myxomatous (6.2%), secondary non-ischemic (17.0%), and secondary ischemic (49.4%). At 10 years, patients with primary myxomatous MR or MR due to indeterminate cause had survival rates of >60%; primary non-myxomatous, secondary ischemic, and non-ischemic MR had survival rates <50%. While mild (HR 1.06, 95% CI 1.03-1.09), moderate (HR 1.31, 95% CI 1.27-1.37), and severe (HR 1.55, 95% CI 1.46-1.65) MR were independently associated with all-cause death, the relationship of increasing MR severity with mortality varied across MR types (P ≤ .001 for interaction); the highest risk associated with worsening severity was seen in primary myxomatous MR followed by secondary ischemic MR and primary non-myxomatous MR.

CONCLUSIONS

Although MR severity is independently associated with increased all-cause death risk for most forms of MR, the absolute mortality rates associated with worse MR severity are much higher for primary myxomatous, non-myxomatous, and secondary ischemic MR. The findings from this study support carefully defining MR by type and severity.

Mitral Valve and Subvalvular Repair for Secondary Mitral Regurgitation: Rationale and Clinical Outcomes of the Papillary Muscle Sling

Secondary mitral regurgitation (MR) is a common finding in patients with dilated cardiomyopathy, and it is associated with poor outcomes. It is the result of incomplete systolic closure of the mitral valve (MV) as a consequence of left ventricular dilatation, papillary muscle displacement with impaired systolic shortening, and mitral leaflet tethering. MV surgery may be performed in cases of significant secondary MR despite guideline-directed medical therapy. However, MV repair, which is most commonly performed with an undersized ring annuloplasty, is associated with a 30-60% recurrence of moderate or greater MR at mid-term follow-up. To improve MV repair durability, several adjunctive subvalvular procedures have been proposed, one of which is the addition of papillary muscle approximation utilizing a papillary muscle sling. Recent studies comparing the outcomes of a conventional undersized ring annuloplasty with a MV repair utilizing a papillary muscle sling have reported a significant reduction in recurrent moderate or severe MR, greater left ventricular reverse remodeling, and improved MV apparatus geometry with the addition of the papillary muscle sling. We present a comprehensive review of the pathophysiology of secondary MR, and the rationale and clinical outcomes of MV repair with papillary muscle sling placement for the treatment of secondary MR.

Therapeutic options for functional mitral regurgitation in chronic heart failure

INTRODUCTION

Mitral regurgitation is a common finding in patients with chronic heart failure and is associated with a progressive worsening of symptoms, reduced survival and increased cost of care. However, the use of mitral valve surgery for these patients remains controversial and has not been shown to improve survival. Consequently, research has been increasingly directed towards the nonsurgical management of this important co-morbidity of heart failure.

AREAS COVERED

The present review will describe the relevance of mitral regurgitation in people with chronic heart failure, the current options for percutaneous treatment and the evidence base for each of these.

EXPERT COMMENTARY

Although at present there are few solid data to guide heart teams in deciding what degree of mitral regurgitation to treat, in which patients, and with what, this situation is likely to change over the next two years with the release of the first large randomised trials of percutaneous interventions.

Long-term outcomes of mitral valve annuloplasty versus subvalvular sparing replacement for severe ischemic mitral regurgitation

BACKGROUND

Although practice guidelines recommend surgery for patients with severe chronic ischemic mitral regurgitation (CIMR), they do not specify whether to repair or replace the mitral valve. The purpose of this study was to evaluate the long-term outcomes in patients with severe CIMR undergoing mitral valve annuloplasty (MVA) versus subvalvular sparing mitral valve replacement (MVR).

METHODS

392 consecutive patients who underwent MVA or subvalvular sparing MVR for treatment of severe CIMR were retrospectively reviewed.

RESULTS

After adjustment for baseline differences with multivariable regression analysis at 53 months follow-up (interquartile range, 34-81 months), there was no significant difference between the two groups for risk of major adverse cardiac or cerebrovascular events (MACCE), cardiac death, or all-cause death. Propensity score matching extracted 77 pairs. During the follow-up, compared with the MVR group, both the left atrium and left ventricle end-diastolic diameter were markedly larger (p = 0.013 and p = 0.033, respectively), and the incidence of mitral regurgitation recurrence was significantly higher in the MVA group (p < 0.001). No significant difference was observed between the two propensity score-matched groups in composite in-hospital outcomes, overall survival, freedom from cardiac death or MACCE, except subvalvular sparing MVR was associated with a lower incidence of hospitalization for heart failure than MVA (p = 0.015).

CONCLUSIONS

Subvalvular sparing MVR is a suitable management of patients with severe CIMR, it is more favorable to ventricular remodeling and is associated with a lower incidence of hospitalization for heart failure than MVA.

Subannular reconstruction in secondary mitral regurgitation: a meta-analysis

OBJECTIVE

Mitral valve repair using an undersized complete annuloplasty ring in secondary mitral regurgitation with restricted leaflet motion during systole (Carpentier's surgical classification of mitral valve pathology: type IIIb) only inadequately addresses the underlying left ventricular disease. This may lead to an ongoing ventricular remodelling and progressive papillary muscle displacement with increasing leaflet tethering. Several subannular techniques have been proposed to counteract the reoccurrence of mitral regurgitation after mitral valve repair. We aimed to evaluate the potential additive effect of such subannular techniques on the late reoccurrence rate of secondary mitral regurgitation.

METHODS

Systematic literature review and meta-analysis were performed on PubMed, Embase and Google Scholar for studies published up to March 2016 and reporting late reoccurrence of mitral regurgitation after mitral valve repair using standard annuloplasty (control group) versus annuloplasty with subannular correction (study group) cohorts. Primary endpoint was late reoccurrence of mitral regurgitation ≥2 after surgical mitral valve repair, as defined by follow-up echocardiography.

RESULTS

The cumulative number of 1093 patients in 12 included studies served as our study population. A total of 743 patients underwent combined mitral valve repair including annuloplasty and subannular manoeuvre (ie, study group), while the remaining 350 patients underwent an isolated ring annuloplasty (ie, control group). Secondary mitral regurgitation was caused by ischaemic heart disease in 733/743 patients in the study group and 334/350 patients in the control group. Mean echocardiographic follow-up was 42.7±13.9 months. Pooled outcome analysis demonstrated that the combination of subannular repair with ring annuloplasty was associated with a significantly lower reoccurrence rate of mitral regurgitation ≥2 as compared with annuloplasty alone (OR 0.27, 95% CI 0.19 to 0.38, P=0.0001).

CONCLUSION

The combination of subannular reconstruction and mitral valve annuloplasty is associated with a lower late reoccurrence of mitral regurgitation after surgical mitral valve repair, as compared with annuloplasty alone.

Torsion Mechanics as an Indicator of More Advanced Left Ventricular Systolic Dysfunction in Secondary Mitral Regurgitation in Patients with Dilated Cardiomyopathy: A 2D Speckle-Tracking Analysis

Left ventricular (LV) twist serves as a compensatory mechanism in systolic dysfunction and its degree of reduction may reflect a more advanced stage of disease. Aim: The aim was to investigate twist alterations depending on the degree of functional mitral regurgitation (MR) by speckle-tracking echocardiography. Methods: Sixty-three patients with symptomatic dilated cardiomyopathy (DCM) were included. Patients were divided according to MR vena contracta width (VCW): group 1 with VCW <7 mm (mild/moderate MR) and group 2 with VCW ≥7 mm (severe MR). Results: There were no differences in LV geometry and function between groups. Group 2 showed lower endocardial basal rotation (BR) (–2.04° ± 1.83° vs. –3.23° ± 1.83°, p = 0.012); epicardial BR (–1.54° ± 1.18° vs. –2.31° ± 1.22°, p = 0.015); endocardial torsion (0.41°/cm ± 0.36°/cm vs. 0.63°/cm ± 0.44°/cm, p = 0.033) and mid-level circumferential strain (CSmid) (–6.12% ± 2.64% vs. –7.75% ± 2.90%, p = 0.028), when compared with group 1. Multivariable linear regression analysis identified endocardial BR, torsion and CSmid, as the best predictors of larger VCW. In the ROC curve analysis, endocardial BR and CSmid values greater than or equal to –3.63° and –9.35%, respectively, can differentiate patients with severe MR. Conclusions: In DCM patients, torsional profile was more altered in severe MR. Endocardial BR, endocardial torsion, and CSmid, can be used as indicators of advanced structural wall architecture damage.

Mitral valve annuloplasty versus replacement for severe ischemic mitral regurgitation

Although practice guidelines recommend surgery for patients with severe chronic ischemic mitral regurgitation (CIMR), they do not specify whether to repair or replace the mitral valve. 436 consecutive patients with severe CIMR were eligible for inclusion in the study, of which 316 (72.5%) underwent mitral valve annuloplasty (MVA) whereas 120 (27.5%) received mitral valve replacement (MVR). At 59 months (interquartile range, 37–85 months) follow-up, though the left ventricle end-diastolic diameter was markedly larger (P = 0.019) in the MVA group than in the MVR group, no significant difference was observed in overall survival, freedom from cardiac death, or avoidance of major adverse cardiac or cerebrovascular events (MACCE). MVA provides better results in freedom from cardiac death in subgroups of age ≥65years and left ventricular ejection fraction (EF) ≥50% (P = 0.014 and P = 0.016, respectively), whereas MVR was associated with a lower risk of MACCE in subgroups of age <65years, EF <50% and left ventricular inferior basal wall motion abnormality (BWMA) (all P < 0.05). In conclusion, MVR is a suitable management of patients with severe CIMR, and it is more favorable to ventricular remodeling. The choice of MVA or MVR should depend on major high-risk clinical factors.

Effect of Mitral Valve Surgery in Patients With Dilated Cardiomyopathy and Severe Functional Mitral Regurgitation

BACKGROUND

Surgical treatment of functional mitral regurgitation (FMR) improves ventricular remodeling in patients with dilated cardiomyopathy (DCM). However, it is unclear whether surgical treatment improves long-term outcomes. We investigated the effects of mitral valve (MV) surgery in patients with DCM and FMR.

METHODS AND RESULTS

Of 525 patients with DCM hospitalized due to heart failure between January 1996 and September 2014, 70 who had severe FMR despite receiving optimal medical therapy were enrolled in the study. Of these patients, 16 underwent surgery for FMR (surgery group; repair=14, replacement=2); the remaining 54 who refused or decided not to undergo surgery were classified as the medication group. There were no differences in age, sex, medication, or echocardiographic parameters between the 2 groups (P>0.05). During the mean follow-up period of 53.6±43.6 months, the occurrence of clinical outcomes (i.e., all-cause death or left ventricular assist device implantation) was 54.3%; the occurrence of clinical outcomes was lower in the surgery group (P=0.008, log-rank test). Multivariate Cox regression analysis using clinical data revealed that MV surgery (hazard ratio [HR] 0.257, 95% confidence interval [CI] 0.103-0.640; P=0.004) and diabetes mellitus (HR 2.924, 95% CI 1.243-6.876; P=0.014) were independent predictors of clinical outcomes after adjusting for age and sex.

CONCLUSIONS

Surgery for severe FMR provides better long-term outcomes in patients with DCM.

Surgical Treatment of Ischemic Mitral Regurgitation: Valve Repair Versus Replacement

PURPOSE OF REVIEW

Ischemic mitral regurgitation (MR), which occurs in about 20-30% patients with a prior myocardial infarction, is associated with worsening heart failure and an increase in cardiovascular mortality. It should be treated surgically if certain hemodynamic severity criteria are met and in patients who continue to experience symptoms of heart failure despite optimal medical therapy. However, current guidelines do not suggest which of the available approaches to mitral valve surgery-mitral valve (MV) repair or replacement (MVR) is superior for this indication. While MV repair is reported to confer improved survival, MVR may provide higher rates of freedom from recurrent MR. This article attempts to provide the reader with a comprehensive review and comparison of current techniques of mitral valve surgery in patients with severe ischemic MR.

RECENT FINDINGS

The first randomized trial to compare MV repair versus MVR in patients with severe ischemic MR, the Cardiothoracic Surgical Trials Network (CTSN) trial, was recently concluded and reported no significant difference in the primary outcome of left ventricular end systolic volume index between the two approaches at either 1- or 2-year follow-ups. Data comparing approaches of MV repair and MVR for ischemic MR is largely limited to small, non-randomized retrospective trials. The only randomized trial data to examine this issue suggested no difference in mortality with either MVR or MV repair; however, MVR was shown to be consistently associated with higher rates of MR recurrence. Certain echocardiographic features have been reported to predict poor outcomes with MVR and may help refine the selection of the surgical approach in the individual patient.

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.

Surgical Management of Severe Ischaemic Mitral Regurgitation

BACKGROUND

Coronary artery bypass graft surgery (CABG) with mitral valve surgery is undisputed in severe ischaemic mitral regurgitation (IMR) treatment, but the controversy is whether mitral valve replacement (MVR) or mitral valvuloplasty (MVP) should be used.

METHODS

Data was collected from 130 cases of severe IMR patients who underwent CABG and MVP or MVR from June 2010 to June 2015 to compare the short-term efficacy of CABG with MVP or MVR in the treatment of severe IMR patients. There were 70 cases in the MVP group and 60 in the MVP group. The postoperative major cardiac cerebral vascular events and left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD) were recorded.

RESULTS

Eleven patients died in hospital, the remaining patients were followed up for 12 months; 18 patients died. The cumulative survival rate and the major cardiac cerebrovascular events were not significantly different. There was no significant change in LVEF, but LVEDD, LVESD and systolic pulmonary artery pressure (sPAP) improved significantly, and there was no difference between the groups. In the MVR group, the rate of postoperative moderate or severe mitral regurgitation patients was significantly less than that in the MVP group.

CONCLUSION

The short-term survival rate, reversal of left ventricular remodelling and major cardiac or cerebrovascular events post-CABG combined with MVP were not significantly different to those with CABG combined with MVR in the treatment of severe IMR, but long-term efficacy remains to be observed.

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.

Impact of Residual Mitral Regurgitation on Right Ventricular Systolic Function After Left Ventricular Assist Device Implantation

Significant mitral regurgitation (MR) is thought to decrease after left ventricular assist device (LVAD) implantation, and therefore repair of mitral valve is not indicated in current practice. However, residual moderate and severe MR leads to pulmonary artery pressure increase, thereby resulting in right ventricular (RV) dysfunction during follow-up. We examined the impact of residual MR on systolic function of the right ventricle by echocardiography after LVAD implantation. This study included 90 patients (mean age: 51.7 ± 10.9 years, 14.4% female) who underwent LVAD implantation (HeartMate II = 21, HeartWare = 69) in a single center between December 2010 and June 2014. Echocardiograms obtained at 3-6 months and over after implantation were analyzed retrospectively. RV systolic function was graded as normal, mild, moderate, and severely depressed. MR (≥moderate) was observed in 43 and 44% of patients at early and late period, respectively. Systolic function of the RV was severely depressed in 16 and 9% of all patients. Initial analysis (mean duration of support 174.3 ± 42.5 days) showed a statistically significant correlation between less MR and improved systolic function of RV (P = 0.01). Secondary echocardiographic analysis (following a mean duration of support of 435.1 ± 203 days) was also statistically significant for MR degree and RV systolic dysfunction (P = 0.008). Residual MR after LVAD implantation may cause deterioration of RV systolic function and cause right-sided heart failure symptoms. Repair of severe MR, in selected patients such as those with severe pulmonary hypertension and depressed RV, may be considered to improve the patient's clinical course during pump support.

Mastering Mitral Leaflets Coaptation After Valve Repair with Adjustable Mitral Annuloplasty Ring: Proof of Concept in Mock Loop Study

This investigation sought to determine the feasibility of a novel mitral ring designed to reshape mitral annulus on beating heart, after surgery. The mitral ring is intended to improve mitral leaflets coaptation to correct residual and recurrent mitral regurgitations. It could also provide progressive correction of mitral regurgitation. The device was tested in ex vivo beating heart model. The novel mitral ring is selectively deformable in P1, P2, and P3 segments using a dedicated angioplasty-type balloon. The deformation should increase leaflets coaptation, reducing distance between the two leaflets. It was implanted using standard surgical techniques. The mock loop is based on passive beating heart. Mitral valve (MV) functioning was evaluated in terms of leaflets coaptation height at P2 level using epicardial echocardiography. The test has been completed on eight swine hearts. Ring size was 30 mm. The balloons were inserted in the connecting line. Each segment of the posterior annulus was independently activated over three progressive positions. Balloon inflation pressures were between 15 and 21 bar. Maximum coaptation height increase was 7 mm. Mean pressure gradient across the MV was 1.7 ± 0.3 mm Hg after complete activation of the device. The device allowed significant increase in coaptation height at P2 level after adjustments at P1, P2, and P3. Results were consistent and reproducible. This feasibility study demonstrates the possibility to reshape the mitral annulus on beating heart to precisely increase MV leaflets coaptation height.

Trans-catheter mitral valve implantation for mitral regurgitation: clinical case description and literature review

Trans-catheter mitral valve implantation (TMVI) is actually the most attractive technique for treating patients with severe mitral regurgitation, who are denied surgical therapy. Recently, trans-catheter implantation of aortic biological prosthesis in mitral position has been done in compassionate cases, and very few experiences of TMVI in native non-calcified valves have been recently reported in very-high-risk patients, mainly with functional mitral regurgitation.Here, we report our case of TMVI using the second-generation CardiAQ prostheisis (CardiAQ Valve Technologies, Irvine, California, USA), reviewing the current state of the art.

Anterior Mitral Leaflet Augmentation for Ischemic Mitral Regurgitation Performed Via a Right Thoracotomy Approach

Ischemic mitral regurgitation (MR) after myocardial infarction is associated with poor long-term survival, and the optimal treatment strategy remains debated. The most common repair technique used is a restrictive annuloplasty. However, up to 15% to 30% of patients experience recurrent MR owing to progressive left ventricular remodeling and geometric distortion of the mitral valve apparatus. Anterior mitral leaflet augmentation using a pericardial patch, in combination with a true-sized mitral annuloplasty, has been proposed as an adjunctive technique to increase the durability of valve repair for ischemic MR. Herein, we describe 2 cases of anterior mitral leaflet augmentation with annuloplasty repair for severe ischemic MR via a minimally invasive right thoracotomy, and review the literature regarding patient selection and clinical outcomes of this technique.

Pre-Operative Left Ventricular Torsion, QRS Width/CRT, and Post-Mitral Surgery Outcomes in Patients With Nonischemic, Chronic, Severe Secondary Mitral Regurgitation

The selection of appropriate candidates for mitral surgery among symptomatic patients with nonischemic, chronic, secondary severe mitral regurgitation (NICSMR) remains a clinical challenge. We studied 50 consecutive symptomatic NICSMR patients for a median follow-up of 2.5 years after mitral surgery and concluded that the pre-operative 2-dimensional speckle tracking echocardiography-derived left ventricular torsional profile and QRS width/cardiac resynchronization therapy are potentially important prognostic indicators for post-surgery survival and reverse remodeling.

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Determining which patients with NICSMR will benefit from MS is a clinical dilemma.

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LV torsion (which is a shear strain, not volume strain such as ejection fraction and originates in LV myocardial architectures) may reveal the myopathic conditions and reflect intra-LV electrical conduction.

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The LV torsional profile predicted post-MS outcomes in NICSMR patients with a narrow QRS but not in those with a wide QRS.

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The findings may help to resolve the clinical dilemma and identify appropriate candidates for mitral surgery (and other resources) in patients with NICSMR.

Is valve repair preferable to valve replacement in ischaemic mitral regurgitation? A systematic review and meta-analysis

Ischaemic mitral regurgitation (MR) is associated with poor survival. The favoured surgical option remains debatable. Our aim was to perform a meta-analysis to compare the outcomes of mitral valve repair (MVRp) with replacement (MVR). A literature search was conducted in PubMed, Medline and Ovid using the terms 'ischaemic mitral regurgitation', 'repair' and 'replacement'. The primary outcome measure was 30-day survival. The secondary outcome measures were MR recurrence and reoperation. Out of 310 articles, 18 fulfilled the inclusion criteria. A total of 3978 patients were included: 2563 (64%) MVRp cases and 1415 (36%) MVR cases. Operative techniques included annuloplasty for MVRp and subvalvular apparatus-sparing MVR techniques. Thirty-day mortality was lower after MVRp compared with MVR [OR 0.42; (95% CI 0.33-0.54; P = 0.0001)]. There was no difference in long-term survival ranging 1-5 years (HR 0.85, 95% CI 0.65-1.12). Recurrence of MR was significantly higher in the MVRp group (OR 4.26, 95% CI 2.52-7.22), as was the rate of reoperation (OR 2.03, 95% CI 1.49-2.77). Although MVR for ischaemic MR has a higher 30-day mortality rate compared with MVRp, MVRp is associated with the higher rate of MR recurrence and the need for reoperation. MVR remains an attractive option for ischaemic MR.