Impact of early surgery on survival of patients with severe mitral regurgitation

Eligibility to COAPT trial in the daily practice: A real-world experience

BACKGROUND

The COAPT Trial was the first ever to demonstrate a survival benefit in treating functional mitral regurgitation (FMR). That was achieved through transcatheter mitral repair in selected patients. The exact proportion of patients fulfilling COAPT selection criteria in the real-world is unknown.

AIMS

To assess the applicability of COAPT criteria in real world and its impact on patients' survival.

METHODS

We assessed the clinical data and follow-up results of all consecutive patients admitted for FMR at our Department between January 2016 and May 2021 according to COAPT eligibility. COAPT eligibility was retrospectively assessed by a cardiac surgeon and a cardiologist.

RESULTS

Among 394 patients, 56 (14%) were COAPT eligible. The most frequent reasons for exclusion were MR ≤ 2 (22%), LVEF < 20% or >50% (19%), and non-optimized GDMT (21.3%). Among Non-COAPT patients, weighted 4-year survival was higher in patients who received MitraClip compared to those who were left in optimized medical therapy (91.5% confidence interval [CI: 0.864, 0.96] vs. 71.8% [CI: 0.509, 0.926], respectively, p = 0.027).

CONCLUSIONS

Only a minority (14%) of real-world patients with FMR referred to a tertiary hospital fulfilled the COAPT selection criteria. Among Non-COAPT patients, weighted 4-year survival was higher in patients who received MitraClip compared to those who were left in optimized medical therapy (91.5% [0.864, 0.96] vs. 71.8% [0.509, 0.926], respectively, p = 0.027).

Heart Valve Abnormalities in Systemic Sclerosis Patients: A Multicenter Cohort Study and Review of the Literature

BACKGROUND

Systemic sclerosis (SSc) is a chronic autoimmune disease that is characterized by vasculopathy and fibrosis of the skin and visceral organs. Heart valve diseases are poorly described and generally not considered typical of SSc. We aimed to describe valvular abnormalities in a multicenter cohort of SSc patients and to investigate their correlation with SSc features.

METHODS

We recruited 118 consecutive SSc patients (male/female, 14/104; mean age, 55.2 ± 12.1 years) in 3 rheumatology centers in Sicily, Italy, from January to October 2019.

RESULTS

Mitral and tricuspid valve insufficiency was found in 85% and 91% of patients, respectively; regurgitations were generally mild and never severe. Mitral stenosis was rare (2%), and tricuspid stenosis was not observed. Sclerosis and calcification were present in 30% of mitral valves and in only 4% of tricuspid valves. The aortic valve was affected in 25% of cases, and it generally presented as regurgitation or sclerosis, whereas stenosis was rare (3%). Finally, 11% of SSc patients showed regurgitation of the pulmonary valve. No specific associations between SSc features and valve alterations were found.

CONCLUSIONS

Valvular diseases are frequently observed in SSc patients, with a predominant pattern of valvular regurgitations. Therefore, echocardiography should be routinely performed during SSc patient follow-up, considering the potential influence of additional cardiac involvement in the prognosis of these patients.

Percutaneous mitral valve repair: the necessity to redefine secondary mitral regurgitation

Interest in percutaneous mitral valve repair has increased during recent years. This is mainly driven by the significant number of patients being declined for mitral valve surgery because of a high risk of surgery-related complications or death. In this subset of patients, percutaneous edge-to-edge repair using the MitraClip device (Abbott, Menlo Park, CA, USA) has become an established treatment option, proven to be safe, efficient and associated with improved functional status. In contrast to primary mitral regurgitation (MR), clinical outcomes after mitral valve surgery appear to be less favourable as regards secondary MR due to heart failure. In the MITRA-FR and COAPT trials, patients with moderate to severe and severe secondary MR with reduced left ventricular function received either medical treatment (control group) or MitraClip implantation plus medical treatment (device group). Results were conflicting, with only the COAPT trial showing better clinical outcomes in the device group. However, both trials are now seen as complementary and provide useful information especially regarding patient selection for MitraClip therapy. The goal of this review is to delineate which subset of patients with secondary MR will potentially benefit from percutaneous mitral valve repair.

Evaluation of Carbon Nanotube Incorporation in Cementitious Composite Materials

Over the last decades, new materials with outstanding performance have been introduced in the construction industry. Considering these new technologies, it is worth mentioning that nanotechnology has revolutionized various areas of engineering. In the area of civil engineering and construction, cement is used for various purposes and the search to improve its performance has been receiving growing interest within the scientific community. The objective of this research was to evaluate the behavior of cement mortar produced by the addition of multi-walled carbon nanotubes (MWCNTs) in different concentrations by comparing their physical and mechanical properties with the properties of the nanotube-free composite. Motivated by the lack of consensus in the literature concerning to the optimal dosage of CNTs in cementitious matrices, three different carbon nanotube ratios, 0.20, 0.40 and 0.60 wt % Portland cement, were investigated with the aim of evaluating the mechanical properties. Destructive tests were carried out to determine the compressive strength, flexural strength and split tensile strength. Additionally, a non-destructive test was performed to determine the dynamic elastic modulus and density. Scanning electron microscopy (SEM) images showed the interaction between the MWCNTs and the hydration products of Portland cement mortar. The results indicated the potential contribution of 0.40 wt % cement CNTs to the enhancement of the mechanical properties of the cement composite as a promising construction material.

Left ventricular remodelling in chronic primary mitral regurgitation: implications for medical therapy

Surgical repair or replacement of the mitral valve is currently the only recommended therapy for severe primary mitral regurgitation. The chronic elevation of wall stress caused by the resulting volume overload leads to structural remodelling of the muscular, vascular and extracellular matrix components of the myocardium. These changes are initially compensatory but in the long term have detrimental effects, which ultimately result in heart failure. Understanding the changes that occur in the myocardium due to volume overload at the molecular and cellular level may lead to medical interventions, which potentially could delay or prevent the adverse left ventricular remodelling associated with primary mitral regurgitation. The pathophysiological changes involved in left ventricular remodelling in response to chronic primary mitral regurgitation and the evidence for potential medical therapy, in particular beta-adrenergic blockers, are the focus of this review.

Novel mitral valve technologies-transcatheter mitral valve implantation: a systematic review

Background

Valvular heart disease is an important cause of morbidity and mortality throughout the world; in industrialized nations, mitral regurgitation (MR) is the most common valvular lesion. Untreated, severe MR has a poor prognosis, with a 5-year mortality rate of up to 50%. Surgical repair of symptomatic, severe primary MR has been demonstrated to improve survival. The aim of this review is to assess the early outcomes of newly developed transcatheter mitral valve implantation technologies for the treatment of secondary native valve disease. Furthermore, the outcomes of patients receiving transcatheter treatment of regurgitant failure of surgically repaired or replaced mitral valve has also been addressed.

Methods

A systematic review of twenty-five studies assessing the outcomes of patients undergoing transcatheter mitral valve implantation for native mitral regurgitation or failed prior surgical repair or bioprosthetic replacement was carried out.

Results

The outcomes of 112 patients undergoing transcatheter mitral valve replacement for secondary mitral regurgitation using six different valve systems were assessed. There were 15 early deaths and 24 deaths over the follow-up period. The outcomes of 44 patients undergoing transcatheter valve-in-valve replacement were assessed with an overall mortality of ten patients. There were 20 patients included who had valve-in-ring transcatheter mitral replacement for previous failed repair. The total mortality was five patients during the follow-up period.

Conclusions

Transcatheter mitral valve implantation represents a new evolution in management of valvular disease and affords management options to patients who historically may not have been offered treatment. Early results have demonstrated some promise and improvements in technology, imaging modalities and patient selection will surely result in a reliable and durable valve.

Almanac 2013: novel non-coronary cardiac interventions

Recent innovations in interventional cardiology have dramatically expanded the therapeutic options for patients with cardiac conditions. Interventional cardiology is no longer limited to the treatment of coronary artery disease but allows also treatment of valvular disease, stroke prevention, hypertension, etc. One of the most important new treatment options is the percutaneous treatment for aortic valve stenosis (transcatheter aortic valve implantation), since aortic valve disease is a rather common problem in elderly patients, with many of them at high risk for surgery. Similarly, mitral regurgitation is often associated with comorbidities which make surgery high risk. The MitraClip is a promising percutaneous alternative to surgical valve repair or replacement. Other procedures discussed in this review are the percutaneous left atrial appendage closure as a non-pharmacologic therapy to prevent strokes, and renal denervation for resistant hypertension. This review explains the basic principles of these procedures, the most important clinical evidence, and also provides additional recent clinical data on each of these them.

Almanac 2013: novel non-coronary cardiac interventions

Recent innovations in interventional cardiology have dramatically expanded the therapeutic options for patients with cardiac conditions. Interventional cardiology is no longer limited to the treatment of coronary artery disease but allows also treatment of valvular disease, stroke prevention, hypertension, etc. One of the most important new treatment options is the percutaneous treatment for aortic valve stenosis (transcatheter aortic valve implantation), since aortic valve disease is a rather common problem in elderly patients, with many of them at high risk for surgery. Similarly, mitral regurgitation is often associated with comorbidities which make surgery high risk. The MitraClip is a promising percutaneous alternative to surgical valve repair or replacement. Other procedures discussed in this review are the percutaneous left atrial appendage closure as a non-pharmacologic therapy to prevent strokes, and renal denervation for resistant hypertension. This review explains the basic principles of these procedures, the most important clinical evidence, and also provides additional recent clinical data on each of these them.

The state of surgical ablation for atrial fibrillation in patients with mitral valve disease

PURPOSE OF REVIEW

Atrial fibrillation has been shown to be associated with less favorable short and long-term outcomes in patients having mitral valve surgery. Despite the growing evidence related to the potential benefits of surgical ablation for atrial fibrillation at the time of the mitral valve operation, there is a significant variability among surgeons in their approaches to atrial fibrillation. The purpose of this review is to discuss the current state of surgical ablation for atrial fibrillation as reported in the literature, as well as to discuss the significance of atrial fibrillation and the different surgical approaches to treat patients with mitral valve disease who may also concurrently suffer from tricuspid valve disease and atrial fibrillation.

RECENT FINDINGS

Increased mortality and morbidity are expected when atrial fibrillation is left untreated in patients undergoing mitral valve surgery. Modern surgical ablations resulted in a shift from the cut and sew maze procedure to the vast majority of cases being performed using different ablation technologies. The use of ablation technology simplifies the procedure. The expectation is that the vast majority of patients with atrial fibrillation will be ablated at the time of their mitral valve surgery.

SUMMARY

Patients who have mitral valve with or without tricuspid valve disease with a significant history of atrial fibrillation may benefit from surgical ablation to eliminate atrial fibrillation. No increased perioperative morbidity or mortality has been documented with an improved long-term survival and very low incidence of thromboembolic events.

Posterior ventricular anchoring neochordal repair of degenerative mitral regurgitation efficiently remodels and repositions posterior leaflet prolapse

OBJECTIVES

Mitral valve repair techniques for degenerative disease typically entail leaflet resection or neochordal construction, which may require extensive resection, leaflet detachment/reattachment, reliance on diseased native chords or precise neochordal measuring. Occasionally, impaired leaflet mobility, reduced coaptation surface and systolic anterior motion (SAM) may result. We describe a novel technique for addressing posterior leaflet prolapse/flail, which both simplifies repair and addresses these issues.

METHODS

Fifty-four patients (age 62 ± 11 years) with degenerative MR underwent this new repair, 36 of whom minimally-invasively. A CV5 Gore-Tex suture was placed into the posterior left ventricular myocardium underneath the prolapsing segment as an anchor. This suture was then used to imbricate a portion of the prolapsed segment into the ventricle, creating a smooth, broad, non-prolapsed coapting surface on a leaflet with preserved mobility, additional neochordal support and posteriorly positioned enough to preclude SAM.

RESULTS

Repair was successful in all patients. The mean MR grade was reduced from +3.8 to +0.1 with 50 of 54 patients having zero MR and 4 of the 54 having trace or mild MR. All patients had proper antero-posterior location of the coaptation line of a mean length of 10.2 mm, and preserved posterior leaflet mobility. No patients had SAM or mitral stenosis. All patients were discharged and are currently doing well.

CONCLUSION

This new technique facilitated efficient single-suture repair of the prolapsed posterior leaflet mitral regurgitation without the need for resection or sliding annuloplasty. It precluded the need for precise neochordal measurement and preserved the leaflet coaptation surface.

Comparison of need for operative therapy in patients with mitral valve prolapse involving both leaflets versus posterior leaflet only

Mitral valve prolapse may involve 1 leaflet or 2 leaflets, yet management guidelines do not differentiate posterior leaflet (PML) from bileaflet (BML) prolapse. We hypothesized that patients with BML have a prolonged natural history with more severe atrial and ventricular enlargement but less severe mitral regurgitation (MR) compared to patients with PML. Patients with mitral valve prolapse undergoing mitral repair were identified and preoperative characteristics were recorded. Patients with predominant PML prolapse (n = 304) versus BML prolapse (n = 131) were identified based on preoperative echocardiographic and intraoperative findings. Timing of operation was based on standard guidelines. Despite being equally symptomatic, patients with BML differed significantly from those with PML in being younger (54 vs 60 years, p <0.0001), more likely to be women (51% vs 24%, p <0.0001), and having a larger valve (37 vs 32 mm, p <0.0001). Despite similar cardiac function and dimensions, patients with BML had less severe MR (24% vs 13% with <4+ MR, p = 0.01) and less severe pulmonary hypertension (14% vs 31%, p <0.0001) at time of operation. In conclusion, patients with BML often meet indications for mitral valve repair with similar cardiac enlargement but less MR than patients with PML prolapse. Patients with BML prolapse may benefit from timing mitral repair based more on symptomatic 3+ MR or cardiac enlargement and less on presence of severe MR.

Magnetic resonance imaging with 3-dimensional analysis of left ventricular remodeling in isolated mitral regurgitation: implications beyond dimensions

BACKGROUND

Although surgery is indicated in patients with mitral regurgitation (MR) when left ventricular (LV) end-systolic (LVES) dimension is >40 mm, LV ejection fraction may decrease after mitral valve surgery. We hypothesize that significant LV remodeling before surgery is not reflected by standard echocardiographic parameters measured at the base of the heart.

METHODS AND RESULTS

Ninety-four patients (age, 54 ± 11 years; 38% female) with degenerative isolated MR underwent cine magnetic resonance imaging with tissue tagging and 3-dimensional analysis. In 51 control subjects (age, 44 ± 14 years; 53% female), the relation between LVES volume (LVESV) and LVES dimension was quadratic, whereas in 94 MR patients, this relation was cubic, indicating a greater increase in LVESV per LVES dimension among MR patients. Moreover, magnetic resonance imaging LVESV from summated serial short-axis slices was significantly greater than LVESV assessed with the Bullet formula in MR patients, attributed to a more spherical remodeling distal to the tips of the papillary muscles (P<0.001). Thirty-five patients underwent mitral valve repair per current guideline recommendations. LV ejection fraction decreased from 61 ± 7% to 54 ± 8% (P<0.0001) and maximum shortening decreased significantly below normal at 1 year postoperatively (P<0.0001). Despite normalization of LV stroke volume and LV end-diastolic volume/mass ratio, there was a persistent significant increase in distal LVES 3-dimensional radius/wall thickness ratio and LVESV index after surgery.

CONCLUSIONS

Despite apparently preserved LVES dimension, MR patients demonstrate significant spherical mid to apical LVES remodeling that contributes to higher LVESV than predicted by standard geometry-based calculations. Decreased LV strain after surgery suggests that a volumetric analysis of LV remodeling and function may be preferred to evaluate disease progression in isolated MR.

Oxidative stress and myocardial remodeling in chronic mitral regurgitation

Mechanisms of left ventricular (LV) dysfunction in isolated mitral regurgitation (MR) are not well understood. Vasodilator therapy in other forms of LV dysfunction reduces LV wall stress and improves LV function; however, studies in isolated MR show no beneficial effect on LV remodeling using vasodilator drugs or renin-angiotensin system blockade. Therefore, the search for new therapies that improve LV remodeling and function in isolated MR is clinically significant. Recent work in the authors' laboratory has demonstrated increased oxidants from a number of sources including the enzyme xanthine oxidase (XO) in the LV of patients with isolated MR. In addition to being a major source of reactive oxygen species, XO is linked to bioenergetic dysfunction because its substrates derive from adenosine triphosphate catabolism. Correspondingly, there was also evidence of aggregates of small mitochondria in cardiomyocytes, which is generally considered a response to bioenergetic deficit in cells. Future studies are required to determine whether XO and persistent oxidative stress are causative in maladaptive LV remodeling and offer potential therapeutic targets in ameliorating LV damage in patients with isolated MR.