Left ventricular dysfunction after mitral valve repair—the fallacy of “normal” preoperative myocardial function

Renal function improvement correlates with 3D echocardiographic findings: Effect of surgical mitral valve repair

BACKGROUND

The association between surgical treatment of mitral regurgitation (MR) and renal function is not sufficiently well-known. We tried to evaluate renal function before and after the procedure of surgical mitral valve repair (SMVR) in degenerative severe MR.

METHODS

Patients with primary severe (4+) MR and normal left ventricular ejection fraction (LVEF) that underwent SMVR, examined by a cutting-edge 3-dimensional (3D) echocardiographic probe were enrolled in this study. We took three CKD-EPI equations to measure estimated glomerular filtration rate (eGFR) before SMVR and shortly before patients discharge. A total of 40 patients with baseline lower mean eGFR were evaluated.

RESULTS

Measurements substantiated statistically significant improvements in eGFR (p < 0.001), multivariable linear regression modeling indicating prominent associations between increase in eGFR and decrease of MR (p = 0.003), decline of pulmonary arterial systolic pressure (p = 0.018), as well as increment of forward stroke volume (p = 0.02), in spite of LVEF reduction, left ventricular global longitudinal strain worsening and left atrial ejection fraction impairment.

CONCLUSIONS

Renal function improves after SMVR in patients with degenerative significant MR and preserved LVEF, regardless of cardiac functional worsening.

Left ventricular ejection fraction: clinical, pathophysiological, and technical limitations

Risk stratification of cardiovascular death and treatment strategies in patients with heart failure (HF), the optimal timing for valve replacement, and the selection of patients for implantable cardioverter defibrillators are based on an echocardiographic calculation of left ventricular ejection fraction (LVEF) in most guidelines. As a marker of systolic function, LVEF has important limitations being affected by loading conditions and cavity geometry, as well as image quality, thus impacting inter- and intra-observer measurement variability. LVEF is a product of shortening of the three components of myocardial fibres: longitudinal, circumferential, and oblique. It is therefore a marker of global ejection performance based on cavity volume changes, rather than directly reflecting myocardial contractile function, hence may be normal even when myofibril's systolic function is impaired. Sub-endocardial longitudinal fibers are the most sensitive layers to ischemia, so when dysfunctional, the circumferential fibers may compensate for it and maintain the overall LVEF. Likewise, in patients with HF, LVEF is used to stratify subgroups, an approach that has prognostic implications but without a direct relationship. HF is a dynamic disease that may worsen or improve over time according to the underlying pathology. Such dynamicity impacts LVEF and its use to guide treatment. The same applies to changes in LVEF following interventional procedures. In this review, we analyze the clinical, pathophysiological, and technical limitations of LVEF across a wide range of cardiovascular pathologies.

Determinants of post-operative left ventricular dysfunction in degenerative mitral regurgitation

AIMS

Chronic degenerative mitral regurgitation leads to volume overload causing left ventricular (LV) enlargement and eventually LV impairment. Current guidelines determining thresholds for intervention are based on LV diameters and ejection fraction (LVEF). There are sparse data examining the value of LV volumes and newer markers of LV performance on outcomes of surgery in mitral valve prolapse. The aim of this study is to identify the best marker of LV impairment after mitral valve surgery.

METHODS AND RESULTS

Prospective, observational study of patients with mitral valve prolapse undergoing mitral valve surgery. Pre-operative LV diameters, volumes, LVEF, global longitudinal strain (GLS), and myocardial work measured. Post-operative LV impairment defined as LVEF < 50% at 1 year post-surgery. Eighty-seven patients included. Thirteen percent developed post-operative LV impairment. Patients with post-operative LV dysfunction showed significantly larger indexed LV end-systolic diameters, indexed LV end-systolic volumes (LVESVi), lower LVEF, and more abnormal GLS than patients without post-operative LV dysfunction. In multivariate analysis, LVESVi [odds ratio 1.11 (95% CI 1.01-1.23), P = 0.039] and GLS [odds ratio 1.46 (95% CI 1.00-2.14), P = 0.054] were the only independent predictors of post-operative LV dysfunction. The optimal cut-off of 36.3 mL/m2 for LVESVi had a sensitivity of 82% and specificity of 78% for detection of post-operative LV impairment.

CONCLUSION

Post-operative LV impairment is common. Indexed LV volumes (36.3 mL/m2) provided the best marker of post-operative LV impairment.

Clinical and Prognostic Implications of Cardiopulmonary Exercise Stress Echocardiography in Asymptomatic Degenerative Mitral Regurgitation

The current guidelines recommend intervention in severe degenerative mitral regurgitation (MR) in symptomatic patients or asymptomatic patients with left ventricular dilatation or dysfunction. The insidious onset of symptoms may mean that patients do not report their symptoms. The role of systematic exercise testing for symptoms in MR is not clearly defined. A total of 97 patients with moderate to severe asymptomatic MR underwent exercise echocardiography combined with cardiopulmonary exercise testing. The predictors of exercise-induced dyspnea, symptom-free survival, and mitral valve intervention were identified. A total of 18 patients (19%) developed limiting dyspnea on exercise. Spontaneous symptom-free survival at 24 months was significantly higher in those without exercise-induced symptoms than those with exercise-induced symptoms, p <0.0001. The only independent predictors of spontaneous symptoms at 2 years were effective regurgitant orifice area (odds ratio 27.45, 95% confidence interval [CI] 1.43 to 528.40, p = 0.03) and exercise-induced symptoms (odds ratio 11.56, 95% CI 1.71 to 78.09, p = 0.01). The only independent predictor of surgery was indexed left ventricular systolic volumes (odds ratio 1.17, 95% CI 1.04 to 1.30, p = 0.006). Where only the patients who underwent surgery due to symptoms were included, the only independent predictor was exercise-induced symptoms (odds ratio 13.94, 95% CI 1.39 to 140.27, p = 0.025). In conclusion, in patients with primary asymptomatic degenerative MR, 1/5 develop revealed symptoms during exercise. This predicts a subsequent development of spontaneous symptoms and mitral valve intervention due to symptoms.

Biology of mitral valve prolapse: from general mechanisms to advanced molecular patterns-a narrative review

Mitral valve prolapse (MVP) represents the most frequent cause of primary mitral regurgitation. For several years, biological mechanisms underlying this condition attracted the attention of investigators, trying to identify the pathways responsible for such a peculiar condition. In the last ten years, cardiovascular research has moved from general biological mechanisms to altered molecular pathways activation. Overexpression of TGF-β signaling, for instance, was shown to play a key role in MVP, while angiotensin-II receptor blockade was found to limit MVP progression by acting on the same signaling pathway. Concerning extracellular matrix organization, the increased valvular interstitial cells density and dysregulated production of catalytic enzymes (matrix metalloproteinases above all) altering the homeostasis between collagen, elastin and proteoglycan components, have been shown to possibly provide a mechanistic basis contributing to the myxomatous MVP phenotype. Moreover, it has been observed that high levels of osteoprotegerin may contribute to the pathogenesis of MVP by increasing collagen deposition in degenerated mitral leaflets. Although MVP is believed to represent the result of multiple genetic pathways alterations, it is important to distinguish between syndromic and non-syndromic conditions. In the first case, such as in Marfan syndrome, the role of specific genes has been clearly identified, while in the latter a progressively increasing number of genetic loci have been thoroughly investigated. Moreover, genomics is gaining more interest as potential disease-causing genes and loci possibly associated with MVP progression and severity have been identified. Animal models could be of help in better understanding the molecular basis of MVP, possibly providing sufficient information to tackle specific mechanisms aimed at slowing down MVP progression, therefore developing non-surgical therapies impacting on the natural history of this condition. Although continuous progress has been made in this field, further translational studies are advocated to improve our knowledge of biological mechanisms underlying MVP development and progression.

Ventricular Remodeling and Outcomes After Mitral Transcatheter Edge-to-Edge Repair in Heart Failure: The COAPT Trial

BACKGROUND

The relationship between left ventricular (LV) remodeling and clinical outcomes after treatment of severe mitral regurgitation (MR) in heart failure (HF) has not been examined.

OBJECTIVES

The aim of this study was to evaluate the association between LV reverse remodeling and subsequent outcomes and assess whether transcatheter edge-to-edge repair (TEER) and residual MR are associated with LV remodeling in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial.

METHODS

Patients with HF and severe MR who remained symptomatic on guideline-directed medical therapy (GDMT) were randomized to TEER plus GDMT or GDMT alone. Baseline and 6-month core laboratory measurements of LV end-diastolic volume index and LV end-systolic volume index were examined. Change in LV volumes from baseline to 6 months and clinical outcomes from 6 months to 2 years were evaluated using multivariable regression.

RESULTS

The analytical cohort comprised 348 patients (190 treated with TEER, 158 treated with GDMT alone). A decrease in LV end-diastolic volume index at 6 months was associated with reduced cardiovascular death between 6 months and 2 years (adjusted HR: 0.90 per 10 mL/m² decrease; 95% CI: 0.81-1.00; P = 0.04), with consistent results in both treatment groups (P_interaction = 0.26). Directionally similar but nonsignificant relationships were present for all-cause death and HF hospitalization and between reduced LV end-systolic volume index and all outcomes. Neither treatment group nor MR severity at 30 days was associated with LV remodeling at 6 or 12 months. The treatment benefits of TEER were not significant regardless of the degree of LV remodeling at 6 months.

CONCLUSIONS

In patients with HF and severe MR, LV reverse remodeling at 6 months was associated with subsequently improved 2-year outcomes but was not affected by TEER or the extent of residual MR. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] and COAPT CAS [COAPT]; NCT01626079).

Understanding post-surgical decline in left ventricular function in primary mitral regurgitation using regression and machine learning models

Background

Class I echocardiographic guidelines in primary mitral regurgitation (PMR) risks left ventricular ejection fraction (LVEF) < 50% after mitral valve surgery even with pre-surgical LVEF > 60%. There are no models predicting LVEF < 50% after surgery in the complex interplay of increased preload and facilitated ejection in PMR using cardiac magnetic resonance (CMR).

Objective

Use regression and machine learning models to identify a combination of CMR LV remodeling and function parameters that predict LVEF < 50% after mitral valve surgery.

Methods

CMR with tissue tagging was performed in 51 pre-surgery PMR patients (median CMR LVEF 64%), 49 asymptomatic (median CMR LVEF 63%), and age-matched controls (median CMR LVEF 64%). To predict post-surgery LVEF < 50%, least absolute shrinkage and selection operator (LASSO), random forest (RF), extreme gradient boosting (XGBoost), and support vector machine (SVM) were developed and validated in pre-surgery PMR patients. Recursive feature elimination and LASSO reduced the number of features and model complexity. Data was split and tested 100 times and models were evaluated via stratified cross validation to avoid overfitting. The final RF model was tested in asymptomatic PMR patients to predict post-surgical LVEF < 50% if they had gone to mitral valve surgery.

Results

Thirteen pre-surgery PMR had LVEF < 50% after mitral valve surgery. In addition to LVEF (P = 0.005) and LVESD (P = 0.13), LV sphericity index (P = 0.047) and LV mid systolic circumferential strain rate (P = 0.024) were predictors of post-surgery LVEF < 50%. Using these four parameters, logistic regression achieved 77.92% classification accuracy while RF improved the accuracy to 86.17%. This final RF model was applied to asymptomatic PMR and predicted 14 (28.57%) out of 49 would have post-surgery LVEF < 50% if they had mitral valve surgery.

Conclusions

These preliminary findings call for a longitudinal study to determine whether LV sphericity index and circumferential strain rate, or other combination of parameters, accurately predict post-surgical LVEF in PMR.

Abnormal Mechanics Relate to Myocardial Fibrosis and Ventricular Arrhythmias in Patients With Mitral Valve Prolapse

BACKGROUND

The relation between ventricular arrhythmia and fibrosis in mitral valve prolapse (MVP) is reported, but underlying valve-induced mechanisms remain unknown. We evaluated the association between abnormal MVP-related mechanics and myocardial fibrosis, and their association with arrhythmia.

METHODS

We studied 113 patients with MVP with both echocardiogram and gadolinium cardiac magnetic resonance imaging for myocardial fibrosis. Two-dimensional and speckle-tracking echocardiography evaluated mitral regurgitation, superior leaflet and papillary muscle displacement with associated exaggerated basal myocardial systolic curling, and myocardial longitudinal strain. Follow-up assessed arrhythmic events (nonsustained or sustained ventricular tachycardia or ventricular fibrillation).

RESULTS

Myocardial fibrosis was observed in 43 patients with MVP, predominantly in the basal-midventricular inferior-lateral wall and papillary muscles. Patients with MVP with fibrosis had greater mitral regurgitation, prolapse, and superior papillary muscle displacement with basal curling and more impaired inferior-posterior basal strain than those without fibrosis (P<0.001). An abnormal strain pattern with distinct peaks pre-end-systole and post-end-systole in inferior-lateral wall was frequent in patients with fibrosis (81 versus 26%, P<0.001) but absent in patients without MVP with basal inferior-lateral wall fibrosis (n=20). During median follow-up of 1008 days, 36 of 87 patients with MVP with >6-month follow-up developed ventricular arrhythmias associated (univariable) with fibrosis, greater prolapse, mitral annular disjunction, and double-peak strain. In multivariable analysis, double-peak strain showed incremental risk of arrhythmia over fibrosis.

CONCLUSIONS

Basal inferior-posterior myocardial fibrosis in MVP is associated with abnormal MVP-related myocardial mechanics, which are potentially associated with ventricular arrhythmia. These associations suggest pathophysiological links between MVP-related mechanical abnormalities and myocardial fibrosis, which also may relate to ventricular arrhythmia and offer potential imaging markers of increased arrhythmic risk.

Clinical significance of myocardial contraction fraction in significant primary mitral regurgitation

BACKGROUND

The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains a matter of debate. Myocardial contraction fraction (MCF) - the ratio of the left ventricular (LV) stroke volume to that of the myocardial volume - is a volumetric measure of LV myocardial shortening independent of size or geometry.

AIM

To assess the relationship between MCF and outcome in patients with significant chronic primary MR due to prolapse managed in contemporary practice.

METHODS

Clinical, Doppler-echocardiographic and outcome data prospectively collected in 174 patients (mean age 62 years, 27% women) with significant primary MR and no or mild symptoms were analysed. The impact of MCF< or ≥30% on cardiac events (cardiovascular death, acute heart failure or MV surgery) was studied.

RESULTS

During an estimated median follow-up of 49 (22-77) months, cardiac events occurred in 115 (66%) patients. The 4-year estimates of survival free from cardiac events were 21±5% for patients with MCF <30% and 40±6% for those with ≥30% (P<0.001). MCF <30% was associated with a considerable increased risk of cardiac events after adjustment for established clinical risk factors, MR severity and current recommended class I triggers for MV surgery (adjusted hazard ratio: 2.33, 95% confidence interval: 1.51-3.58; P<0.001). Moreover, MCF<30% improved the predictive performance of models, with better global fit, reclassification and discrimination.

CONCLUSIONS

MCF<30% is strongly associated with occurrence of cardiac events in patients with significant primary MR due to prolapse. Further studies are needed to assess the direct impact of MCF on patient management and outcomes.

Research Opportunities in the Treatment of Mitral Valve Prolapse: JACC Expert Panel

In light of the adverse prognosis related to severe mitral regurgitation, heart failure, or sudden cardiac death in a subset of patients with mitral valve prolapse (MVP), identifying those at higher risk is key. For the first time in decades, researchers have the means to rapidly advance discovery in the field of MVP thanks to state-of-the-art imaging techniques, novel omics methodologies, and the potential for large-scale collaborations using web-based platforms. The National Heart, Lung, and Blood Institute recently initiated a webinar-based workshop to identify contemporary research opportunities in the treatment of MVP. This report summarizes 3 specific areas in the treatment of MVP that were the focus of the workshop: 1) improving management of degenerative mitral regurgitation and associated left ventricular systolic dysfunction; 2) preventing sudden cardiac death in MVP; and 3) understanding the mechanisms and progression of MVP through genetic studies and small and large animal models, with the potential of developing medical therapies.

Mitral and tricuspid valve disease: diagnosis and management. Consensus document of the Section on Valvular Heart Disease and the Cardiovascular Imaging, Clinical Cardiology, and Interventional Cardiology Associations of the Spanish Society of Cardiology

The diagnosis and management of mitral and tricuspid valve disease have undergone major changes in the last few years. The expansion of transcatheter interventions and widespread use of new imaging techniques have altered the recommendations for the diagnosis and treatment of these diseases. Because of the exponential growth in the number of publications and clinical trials in this field, there is a strong need for continuous updating of local protocols. The recently published 2021 European Society of Cardiology guidelines for the management of valvular heart disease did not include some of the new data on these new therapies and, moreover, the number of mitral and tricuspid interventions varies widely across Europe. Therefore, all this information must be summarized to facilitate its use in each specific country. Consequently, we present the consensus document of the Section on Valvular Disease, Cardiovascular Imaging, Clinical Cardiology, and Interventional Cardiology Associations of the Spanish Society of Cardiology for the diagnosis and management of mitral and tricuspid valve disease.

Interstitial Collagen Loss, Myocardial Remodeling, and Function in Primary Mitral Regurgitation

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The stretch of volume overload in PMR initiates interstitial collagen loss and decrease in LV sphericity index.

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LV chamber diastolic function is normal whereas LA function, LV twist/volume slope, early LV untwist, and myocardial circumferential strain are impaired.

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There is increased oxidative stress in the cardiomyocyte with cytoskeletal breakdown and myofibrillar loss in PMR.

Interstitial collagen loss and cardiomyocyte ultrastructural damage accounts for left ventricular (LV) sphericity and decrease in LV twist and circumferential strain. Normal LV diastolic function belies significantly abnormal left atrial (LA) function and early LV diastolic untwist rate. This underscores the complex interplay of LV and LA myocardial remodeling and function in the pathophysiology of primary mitral regurgitation. In this study, we connect LA function with LV systolic and diastolic myocardial remodeling and function using cardiac magnetic resonance tissue tagging in primary mitral regurgitation.

Late plasma exosome microRNA-21-5p depicts magnitude of reverse ventricular remodeling after early surgical repair of primary mitral valve regurgitation

Introduction

Primary mitral valve regurgitation (MR) results from degeneration of mitral valve apparatus. Mechanisms leading to incomplete postoperative left ventricular (LV) reverse remodeling (Rev-Rem) despite timely and successful surgical mitral valve repair (MVR) remain unknown. Plasma exosomes (pEXOs) are smallest nanovesicles exerting early postoperative cardioprotection. We hypothesized that late plasma exosomal microRNAs (miRs) contribute to Rev-Rem during the late postoperative period.

Methods

Primary MR patients (n = 19; age, 45-71 years) underwent cardiac magnetic resonance imaging and blood sampling before (T0) and 6 months after (T1) MVR. The postoperative LV Rev-Rem was assessed in terms of a decrease in LV end-diastolic volume and patients were stratified into high (HiR-REM) and low (LoR-REM) LV Rev-Rem subgroups. Isolated pEXOs were quantified by nanoparticle tracking analysis. Exosomal microRNA (miR)-1, -21-5p, -133a, and -208a levels were measured by RT-qPCR. Anti-hypertrophic effects of pEXOs were tested in HL-1 cardiomyocytes cultured with angiotensin II (AngII, 1 μM for 48 h).

Results

Surgery zeroed out volume regurgitation in all patients. Although preoperative pEXOs were similar in both groups, pEXO levels increased after MVR in HiR-REM patients (+0.75-fold, p = 0.016), who showed lower cardiac mass index (-11%, p = 0.032). Postoperative exosomal miR-21-5p values of HiR-REM patients were higher than other groups (p < 0.05). In vitro, T1-pEXOs isolated from LoR-REM patients boosted the AngII-induced cardiomyocyte hypertrophy, but not postoperative exosomes of HiR-REM. This adaptive effect was counteracted by miR-21-5p inhibition.

Summary/Conclusion

High levels of miR-21-5p-enriched pEXOs during the late postoperative period depict higher LV Rev-Rem after MVR. miR-21-5p-enriched pEXOs may be helpful to predict and to treat incomplete LV Rev-Rem after successful early surgical MVR.

Myocardial fibrosis in asymptomatic patients undergoing surgery for mitral and aortic valve regurgitation

BACKGROUND

Chronic heart valve regurgitation induces left ventricular (LV) volume overload, leading to the development of hypertrophy and progressive dilatation of the ventricle to maintain physiological cardiac output. In order to prevent potential irreversible LV structural changes, the identification of the best timing for treatment is pivotal.

OBJECTIVE

To assess the presence and extent of fibrosis in myocardial tissue in asymptomatic patients with valvular heart disease (VHD) and preserved LV dimensions and function undergoing cardiac surgery.

METHODS

Thirty-nine patients were enrolled. Sixteen patients were affected by aortic or mitral regurgitation: they were all asymptomatic, undergoing valve surgery according to VHD European Society of Cardiology guidelines. Twenty-three patients with end-stage nonischemic dilated cardiomyopathy (DCM) and severe LV dysfunction undergoing cardiac surgery for implantation of a durable left ventricular assist device (LVAD) served as controls. During surgery, VHD patients underwent three myocardial biopsies at the level of the septum, the lateral wall and LV apex, while in LVAD patients the coring of the apex of the LV was used. For both groups, the tissue samples were analyzed on one section corresponding to the apical area. All slides were stained with hematoxylin and eosin and Masson's trichrome staining and further digitalized. The degree of fibrosis was then calculated as a percentage of the total area.

RESULTS

Of 39 patients, 23 met the inclusion criteria: 12 had mitral or aortic insufficiency with a preserved ejection fraction and 11 had idiopathic dilated cardiomyopathy. Quantitative analysis of apical sections revealed a myocardial fibrosis amount of 10 ± 6% in VHD patients, while in LVAD patients the mean apical myocardial fibrosis rate was 38 ± 9%. In VHD patients, fibrosis was also present in the lateral wall (9 ± 4%) and in the septum (9 ± 6%).

CONCLUSION

Our case series study highlights the presence of tissue remodeling with fibrosis in asymptomatic patients with VHD and preserved LV function. According to our results, myocardial fibrosis is present at an early stage of the disease, well before developing detectable LV dysfunction and symptoms. Since the relationship between the progressive magnitude of myocardial fibrosis and potential prognostic implications are not yet defined, further studies on this topic are warranted.

Heterotopic Transcatheter Tricuspid Valve Replacement in Severe Tricuspid Regurgitation and Refractory Right Heart Failure

Torrential tricuspid regurgitation may lead to heart failure and poor survival and quality of life. Heterotopic transcatheter tricuspid replacement is increasingly offered to patients unsuitable for direct valve repair or replacement. We describe 1 patient treated by transcatheter implantation of 2 self-expanding valves in the venae cavae with a multimodality imaging approach. (Level of Difficulty: Advanced.)

ARNI or ARB Treats Residual Left Ventricular Remodelling after Surgery for Valvular Regurgitation: ReReRe study protocol

AIMS

Patients with persistent or de novo left ventricular (LV) dilation and/or reduced ejection fraction (EF) after correction for primary aortic (AR) or mitral (MR) regurgitation (i.e. residual LV remodelling) have not been well studied with regard to guideline-directed medical therapy after successful aetiology-reversing surgery. We aim to (i) compare the effectiveness of sacubitril/valsartan vs. valsartan in promoting LV reverse remodelling and (ii) explore the safety of medication withdrawal after LV recovery.

METHODS AND RESULTS

The ReReRe study is a multicentre, randomized, open-label, parallel trial that consists of two consecutive parts. A total of 371 patients with an LV end-diastolic diameter (LVEDD) > 60 mm or LVEF < 50%, assessed by transthoracic echocardiography (TTE) 7-14 days after valve surgery for significant AR or primary MR will be enrolled. The 1^st randomization into the sacubitril/valsartan or valsartan groups and structured follow-up (1, 3, 6, 9, and 12 months after randomization) will be conducted to observe the primary objective as the rate of complete recovery of LV remodelling (i.e. LVEDD < 55 mm and LVEF ≥ 60% by TTE at two consecutive visits). Those who have complete recovery of LV remodelling will be enrolled in Study Part 2; consequently, they will receive the 2^nd randomization into the medication withdrawal or maintenance group and 6-monthly visits for the observation of the primary objective as the rate of LV remodelling relapse (LVEDD > 60 mm or LVEF < 50%). The secondary objectives include the rate of composite clinical outcomes and the degree of change in 6-min walk distance and Kansas City Cardiomyopathy Questionnaire scores.

CONCLUSIONS

The ReReRe study will provide new evidence for the treatment of patients with residual LV remodelling after curable unloaded surgery, as well as the duration of treatment. The study results will fill the gap in identifying an appropriate medical therapy regimen for this group of patients and perhaps for those with reversible aetiologies of heart failure.

Institution representation in publications reporting mitral valve repair durability: A scoping review

BACKGROUND

Mitral valve repair durability currently plays a key role in operative decision making and in defining optimal surgical practice. However, mitral valve durability outcomes measures are not captured by national registries and limited to centers that publish their outcomes. In this study, we aim to describe the scope of institutions represented by reports describing durability outcomes after mitral valve repair within the contemporary literature.

METHODS AND RESULTS

A scoping review of the literature was performed to extract abstracts potentially reporting mitral valve operation outcomes published between 2000-2019. 370 full text articles reporting mitral valve durability outcomes by either reoperation rate or rate of recurrent mitral regurgitation met criteria for analysis. Study characteristics including case volume, country and institution of origin, and surgeon volume were extracted and used to calculate the proportion of total cases in the top 3, 5, and 10 represented countries and institutions by the sum of reported mitral valve repairs described. The top 5 of 21 countries represented 78.9% of the mitral valve repair cases described. The top 3 most represented institutions described 20,120 (37.3%) of all mitral valve repairs in 58 (33.9%) single-center studies.

CONCLUSION

Published mitral valve repair durability data must be interpreted with caution when used to derive policies and practice recommendations that govern the cardiovascular community at large.

Mitral Valve Prolapse Induces Regionalized Myocardial Fibrosis

Background Mitral valve prolapse (MVP) is one of the most common forms of cardiac valve disease and affects 2% to 3% of the population. Previous imaging reports have indicated that myocardial fibrosis is common in MVP and described its association with sudden cardiac death. These data combined with evidence for postrepair ventricular dysfunction in surgical patients with MVP support a link between fibrosis and MVP. Methods and Results We performed histopathologic analysis of left ventricular (LV) biopsies from peripapillary regions, inferobasal LV wall and apex on surgical patients with MVP, as well as in a mouse model of human MVP (Dzip1S14R/+). Tension-dependent molecular pathways were subsequently assessed using both computational modeling and cyclical stretch of primary human cardiac fibroblasts in vitro. Histopathology of LV biopsies revealed regionalized fibrosis in the peripapillary myocardium that correlated with increased macrophages and myofibroblasts. The MVP mouse model exhibited similar regional increases in collagen deposition that progress over time. As observed in the patient biopsies, increased macrophages and myofibroblasts were observed in fibrotic areas within the murine heart. Computational modeling revealed tension-dependent profibrotic cellular and molecular responses consistent with fibrosis locations related to valve-induced stress. These simulations also identified mechanosensing primary cilia as involved in profibrotic pathways, which was validated in vitro and in human biopsies. Finally, in vitro stretching of primary human cardiac fibroblasts showed that stretch directly activates profibrotic pathways and increases extracellular matrix protein production. Conclusions The presence of prominent regional LV fibrosis in patients and mice with MVP supports a relationship between MVP and progressive damaging effects on LV structure before overt alterations in cardiac function. The regionalized molecular and cellular changes suggest a reactive response of the papillary and inferobasal myocardium to increased chordal tension from a prolapsing valve. These studies raise the question whether surgical intervention on patients with MVP should occur earlier than indicated by current guidelines to prevent advanced LV fibrosis and potentially reduce residual risk of LV dysfunction and sudden cardiac death.

Longitudinal change in postoperative right ventricular systolic function in patients undergoing surgery for isolated tricuspid regurgitation

Right ventricular (RV) dysfunction is an indication for tricuspid valve (TV) surgery in patients with severe isolated tricuspid regurgitation (TR). Postoperative RV dysfunction is associated with poor outcome; however, the longitudinal changes in RV function before and after surgery have not been established. We retrospectively analyzed 24 patients who underwent TV surgery for isolated severe TR. For assessing RV systolic function, we measured the RV fractional area change (RVFAC) at baseline, and 1 (immediate) and 4-20 (late) months after surgery. We divided patients into 2 groups according to the RVFAC late after surgery (<35%, post-op. reduced; and ≥35%, post-op. preserved). The mean RVFAC was significantly decreased immediately after surgery compared to baseline (41.5 ± 10.1% vs. 32.2 ± 9.6%; p < 0.001). The RVFAC reduction was still observed late after surgery (35.5 ± 7.4%; p = 0.002). Of 24 patients, 12 patients (50%) had preserved RV systolic function late after surgery. Although there was no significant difference in the preoperative RVFAC between the 2 groups, the preoperative RV end-systolic area (RVESA) /body surface area (BSA) was significantly less in the post-op. preserved RV systolic function group (13.8 ± 4.3 cm2/m2 vs. 8.6 ± 2.6 cm2/m2; p = 0.001). The optimal cut-off value for the preoperative RVESA/BSA in detecting postoperative preserved RV systolic function was 10.8 cm2/m2 (AUC, 0.85; sensitivity, 91.7%; and specificity, 75.0%). In patients undergoing surgery for isolated severe TR, the RVFAC was significantly decreased immediately after surgery and the reduction continued late after surgery. The preoperative RVESA/BSA might be helpful to predict preserved RV function after surgery.

Robotic Mitral Valve Repair: A Decade of Experience with Echocardiographic Follow-up

BACKGROUND

Surgical approaches for mitral valve (MV) disease have evolved with the aim of developing minimally invasive techniques. While the safety of robotic procedures has been documented, there are limited data on long-term echocardiographic follow-up. This review demonstrates outcomes of 11 years of robotic MV repair at a single, tertiary institution.

METHODS

From 2008 to 2019, 843 patients underwent robotic MV repair at our institution. Repeated measures generalized least squares (GLS) modelling was used to assess the echocardiographic changes over time.

RESULTS

The median age was 58 years (IQR 50.8, 65.5) (591 males, 70.1%). Mechanism of MR was posterior leaflet prolapse in 479 (56.8%), bileaflet prolapse in 325 (38.6%), and anterior leaflet prolapse in 36 (4.3%). There were 3 early deaths (0.4%) and 24 early reoperations (2.8%). Echocardiographic follow up demonstrated left ventricular end systolic and diastolic dimensions, left atrial volume index and pulmonary pressure all continuously improvement up to 2 years postoperatively. Ejection fraction immediately declined postoperatively but then gradually improved to near normal over 2 years. Survival and freedom from reoperation at 10 years were 93% and 92.6%, respectively. When surveyed after dismissal, 93.4% reported their activity level at or above their peers and 93.3% reported no activity limitation from cardiac symptoms.

CONCLUSIONS

Robotic MV repair is safe and effective with excellent long-term results, including echocardiographic parameters that demonstrated early improvement in cardiac chamber size and maintenance of postoperative cardiac function. Exceedingly low mortality rates and freedom from reoperation are comparable to those of the standard open repair.

Transcatheter Mitral Valve Repair Using MitraClip in Secondary Mitral Valve Regurgitation Guided by Real-Time Pressure-Volume Loops

Worsening of left ventricular (LV) function is a potential complication after repair of secondary mitral valve regurgitation, and one which has limited methods for predicting its risk of occurrence. We present a case utilizing real-time pressure–volume loops intraprocedurally to monitor hemodynamic changes before and after application of a trancatheter MitraClip device in a patient with severe symptomatic secondary mitral regurgitation (MR). Worsening of LV function is a potential complication after repair of secondary mitral valve regurgitation. We present a case utilizing real-time pressure–volume loops intraprocedurally to monitor hemodynamic changes before and after application of a transcatheter MitraClip device in a patient with severe symptomatic secondary MR.

Mitral valve repair in chronic severe mitral regurgitation: short-term results and analysis of mortality predictors

Introduction

Mitral valve repair is the accepted treatment for mitral regurgitation (MR) but lack of resources and socioeconomic concerns delay surgical referral and intervention in developing countries. We evaluated immediate and short-term results of mitral valve repair for non-ischemic MR at our centre and aimed to identify the predictors of in-hospital and follow-up mortality.

Materials and methods

The study was conducted at a tertiary-level hospital in South India. All patients >18 years with severe non-ischemic MR who underwent mitral valve repair over a period of 6 years were included. Perioperative data was collected from hospital records and follow-up data was obtained by prospective methods.

Results

There were 244 patients (170 males). Most of the patients were in the age group 31-60 years (76.6%). Aetiology of MR was degenerative (n = 159; 65.2%), rheumatic (n = 34; 13.9%), structural (n = 42; 17.2%), or miscellaneous (n = 9; 3.7%). All patients underwent ring annuloplasty with various valve repair techniques. One hundred patients (44.7%) underwent additional cardiac procedures. At discharge, MR was moderate in 4 patients; the rest had no or mild MR. The mean hospital stay of survivors was 7.1 days (SD 2.52, range 5-25 days). There were 9 in-hospital deaths (3.68%) and 10 deaths during follow-up (4.2%). The mean follow-up period was 1.39 years, complete for 87.6%. Pre-operative left ventricle ejection fraction (LVEF) <60% (p = 0.04) was found to be significantly associated with immediate mortality. Logistic regression analysis detected age (p = 0.019), female sex (p = 0.015), and left ventricular (LV) dysfunction at discharge (p = 0.025) to be significantly associated with follow-up mortality.

Conclusion

Pre-operative LV dysfunction was identified as a significant risk factor for in-hospital mortality. Female sex, age greater than 45 years, and LV dysfunction at discharge were found to be significantly associated with follow-up mortality. Hence, it is important to perform mitral valve repair in severe regurgitation patients before significant LV dysfunction sets in for a better outcome.

Postoperative changes in left ventricular systolic function after combined mitral and aortic valve replacement in patients with rheumatic heart disease

BACKGROUNDS

We sought to identify short- and long-term changes in postoperative left ventricular systolic function in patients with rheumatic heart disease (RHD) who underwent combined aortic and mitral valve replacement.

METHODS

We analyzed 146 patients according to their preoperative left ventricular ejection fraction (LVEF) (113 with preoperative LVEF ≥50% and 33 with preoperative LVEF <50%). A restricted cubic spline model was used to assess the effect of time on the postoperative changes in echocardiographic parameters.

RESULTS

There were no significant difference in preoperative and immediately postoperative LVEF before discharge in either group. During median follow-up of 3.2 years (interquartile range: 1.3-4.7 years) after surgery, postoperative LVEF increased slightly and then plateaued in patients with preoperative LVEF ≥50%, whereas it increased over 3-4 years after surgery and then gradually decreased in patients with preoperative LVEF <50% (p < .001).

CONCLUSION

Long-term postoperative LVEF showed a downward trend in RHD patients with reduced preoperative LVEF, whereas it reached a plateau in RHD patients with normal preoperative LVEF.

Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition

Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Forward Left Ventricular Ejection Fraction as a Predictor of Postoperative Left Ventricular Dysfunction in Patients with Degenerative Mitral Regurgitation

Background: Left ventricular dysfunction (LVD) can occur immediately after mitral valve repair (MVr) for degenerative mitral regurgitation (DMR) in some patients with normal preoperative left ventricular ejection fraction (LVEF). This study investigated whether forward LVEF, calculated as left ventricular outflow tract stroke volume divided by left ventricular end-diastolic volume, could predict LVD immediately after MVr in patients with DMR and normal LVEF. Methods: Echocardiographic and clinical data were retrospectively evaluated in 234 patients with DMR ≥ moderate and preoperative LVEF ≥ 60%. LVD and non-LVD were defined as LVEF < 50% and ≥50%, respectively, as measured by echocardiography after MVr and before discharge. Results: Of the 234 patients, 52 (22.2%) developed LVD at median three days (interquartile range: 3–4 days). Preoperative forward LVEF in the LVD and non-LVD groups were 24.0% (18.9–29.5%) and 33.2% (26.4–39.4%), respectively (p < 0.001). Receiver operating characteristic (ROC) analyses showed that forward LVEF was predictive of LVD, with an area under the ROC curve of 0.79 (95% confidence interval: 0.73–0.86), and an optimal cut-off was 31.8% (sensitivity: 88.5%, specificity: 58.2%, positive predictive value: 37.7%, and negative predictive value: 94.6%). Preoperative forward LVEF significantly correlated with preoperative mitral regurgitant volume (correlation coefficient [CC] = −0.86, p < 0.001) and regurgitant fraction (CC = −0.98, p < 0.001), but not with preoperative LVEF (CC = 0.112, p = 0.088). Conclusion: Preoperative forward LVEF could be useful in predicting postoperative LVD immediately after MVr in patients with DMR and normal LVEF, with an optimal cut-off of 31.8%.

Changes in Left Ventricular Ejection Fraction after Mitral Valve Repair for Primary Mitral Regurgitation

This study sought to identify the short- and long-term changes in left ventricular ejection fraction (LVEF) after mitral valve repair (MVr) in patients with chronic primary mitral regurgitation according to preoperative LVEF (pre-LVEF) and preoperative left ventricular end-systolic diameter (pre-LVESD). This study evaluated 461 patients. Restricted cubic spline regression models were constructed to demonstrate the long-term changes in postoperative LVEF (post-LVEF). The patients were divided into four groups according to pre-LVEF (<50%, 50–60%, 60–70%, and ≥70%). The higher the pre-LVEF was, the greater was the decrease in LVEF immediately after MVr. In the same pre-LVEF range, immediate post-LVEF was lower in patients with pre-LVESD ≥ 40 mm than in those with pre-LVESD < 40 mm. The patterns of long-term changes in post-LVEF differed according to pre-LVEF (p for interaction < 0.001). The long-term post-LVEF reached a plateau of approximately 60% when the pre-LVEF was ≥50%, but it seemed to show a downward trend after reaching a peak at approximately 3–4 years after MVr when the pre-LVEF was ≥70%. The patterns of short- and long-term changes in post-LVEF differed according to pre-LVEF and pre-LVESD values in patients with chronic primary mitral regurgitation after MVr.

Myocardial protection: a forgotten modality

The goals of a cardiac surgical procedure are both technical excellence and complete protection of cardiac function. Cardioplegia is used almost universally to protect the heart and provide a quiet bloodless field for surgical accuracy. Yet, despite the importance of myocardial protection in cardiac surgery, manuscripts or dedicated sessions at major meetings on this subject have become relatively rare, as though contemporary techniques now make them unnecessary. Nevertheless, septal dysfunction and haemodynamic support (inotropes, intra-aortic balloon pump, assist devices) are common in postoperative patients, indicating that myocardial damage following cardiac surgery is still prevalent with current cardioplegic techniques and solutions. This article first describes why cardiac enzymes and septal function are the ideal markers for determining the adequacy of myocardial protection. It also describes the underappreciated consequences of postoperative cardiac enzyme release or septal dysfunction (which currently occurs in 40-80% of patients) from inadequate protection, and how they directly correlate with early and especially late mortality. Finally, it reviews the various myocardial protection techniques available to provide a detailed understanding of the cardioplegic methods that can be utilized to protect the heart. This will allow surgeons to critically assess their current method of protection and, if needed, make necessary changes to provide their patients with optimal protection.

Multimodality imaging in valvular heart disease: how to use state-of-the-art technology in daily practice

Our understanding of the complexities of valvular heart disease (VHD) has evolved in recent years, primarily because of the increased use of multimodality imaging (MMI). Whilst echocardiography remains the primary imaging technique, the contemporary evaluation of patients with VHD requires comprehensive analysis of the mechanism of valvular dysfunction, accurate quantification of severity, and active exclusion extravalvular consequences. Furthermore, advances in surgical and percutaneous therapies have driven the need for meticulous multimodality imaging to aid in patient and procedural selection. Fundamental decision-making regarding whom, when, and how to treat patients with VHD has become more complex. There has been rapid technological advancement in MMI; many techniques are now available in routine clinical practice, and their integration into has the potential to truly individualize management strategies. This review provides an overview of the current evidence for the use of MMI in VHD, and how various techniques within each modality can be used practically to answer clinical conundrums.

The analysis of left ventricular ejection fraction after minimally invasive surgery for primary mitral valve regurgitation

BACKGROUND

Although minimally invasive mitral valve surgery (MIMVS) has become the first choice for primary mitral regurgitation (MR) in recent years, clinical evidence in this field is yet limited. The main focus of this study was the analysis of preoperative (Pre), postoperative (Post), and 1-year follow-up (Fu) data in our series of MIMVS to identify factors that have an impact on the left ventricular ejection fraction (LVEF) evolution after MIMVS.

METHODS

We reviewed the perioperative and 1-year follow-up data from 436 patients with primary MR (338 isolated MIMVS und 98 MIMVS combined with tricuspid valve repair) to analyze patients' baseline characteristics, the change of LV size, the postoperative evolution of LVEF and its factors, and the clinical outcomes.

RESULTS

The overall mean value of ejection fraction (EF) slightly decreased at 1-year follow-up (mean change of LVEF: -2.63 ± 9.00%). A significant correlation was observed for preoperative EF (PreEF) und EF evolution, the higher PreEF the more pronounced decreased EF evolution (in all 436 patients; r = -.54, p < .001, in isolated MIMVS; r = -.54, p < .001, in combined MIMVS; r = -.53, p < .001). Statistically significant differences for negative EF evolution were evident in patients with mild or greater tricuspid valve regurgitation (TR) (in all patients; p < .05, odds ratio [OR] = 1.64, in isolated MIMVS; p < .01, OR = 1.93, respectively). Overall clinical outcome in New York Heart Association classification at 1 year was remarkably improved.

CONCLUSIONS

Our results suggest an excellent clinical outcome at 1 year, although mean LVEF slightly declined over time. TR could be a predictor of worsened follow-up LVEF in patients undergoing MIMVS.

A review of the pivotal role of cardiac MRI in mitral valve regurgitation

Cardiac imaging is the cornerstone of defining the etiology, quantification, and management of mitral regurgitation (MR). This continues to be even more so the case with emerging transcatheter techniques to manage MR. Transthoracic echocardiography remains the first-line imaging modality to assess MR but has limitations. Cardiac MRI(CMR) provides the advantages of quantitative nonvisual estimation, 3D volumetric data, late gadolinium, T1, and extracellular volume measurements to comprehensively assess mitral valvular pathology, cardiac remodeling, and the prognostic impact of therapies. This review describes the superiority, technical aspects and growing evidence behind CMR, and lays the roadmap for the future of CMR in MR.

An Analysis of Myocardial Efficiency in Patients with Severe Asymptomatic Mitral Regurgitation

BACKGROUND

It is difficult to determine left ventricular systolic performance in patients with severe mitral regurgitation (MR) since left ventricular ejection fraction (EF) could be preserved until the end stages of the disease. Myocardial efficiency (MEf) describes the amount of external work (EW) done by the left ventricle per unit of oxygen consumed (mVO₂). In the present study, we aimed to investigate MEf in patients with asymptomatic severe MR using a novel echocardiographic method.

METHODS

A total of 27 patients with severe asymptomatic MR and 26 healthy volunteers were included in this cross-sectional study. EW was measured using stroke volume and blood pressure, while mVO₂ was estimated using double product and left ventricular mass.

RESULTS

There were no differences between the groups with regards to EF (66% ± 5% vs. 69% ± 7%), while MEf was significantly reduced in patients with severe MR (25% ± 11% vs. 44% ± 12%, p < 0.001). This difference was maintained even after adjustment for age, gender and body surface area (adjusted x-: 0.44, 95% CI: 0.39–0.49 for controls and adjusted x-: 0.24, 95% CI: 0.19–0.29 for patients with severe MR). Further analysis showed that this reduction was due to an increase in total mVO₂ in the severe MR group. MEf of thepatients who were both on β-blockers and angiotensin converting enzyme inhibitors/angiotensin receptor blockers were higher than those who were not on any drugs, but this difference was not statistically significant (32% ± 15% vs. 23% ± 9%, p = 0.41).

CONCLUSIONS

MEf was significantly lower in patients with asymptomatic severe MR and preserved EF.

Mitigating cardiac dysfunction by TOE-guided cardioplegia and mitral valve repair

Based on current guidelines, 15% to 20% of patients undergoing mitral valve repair for regurgitation develop left ventricular dysfunction (ejection fraction < 50%-55%) despite a normal baseline. Two schools of thought have been debated: preexisting myocardial disease or suboptimal intraoperative myocardial protection. In our view, they could be reconciled. It is well recognized that left ventricular ejection fraction with a standard cut off at 50%-55% has limited sensitivity in detecting early systolic impairment in mitral regurgitation patients. Mitral regurgitation also leads to mitochondrial oxidative stress, thus rendering the myocardium more susceptible to ischemia-reperfusion injury and precipitating postoperative cardiac dysfunction. The fall in left ventricular ejection fraction early after mitral valve repair was shown to be caused by the reduction in both myocardial contractility and left ventricular stroke volume. To mitigate the risk to myocardial reperfusion injury, appropriate cardioplegia volume and distribution and well-defined surgical repair processes are equally important. We use transesophageal echocardiography-guided cardioplegia delivery, imaging the intramyocardial flow and ensuring adequate protection of the subendocardium during mitral valve repair. Mild aortic regurgitation on a beating heart often leads to left ventricular dilatation with diminished cardioplegia flow in the myocardium, thus requiring direct ostia cardioplegia. Systematic transesophageal echocardiography assessment before surgery is essential for establishing the mitral regurgitation mechanisms and translating them into precise surgical repair strategies. The benefits of transesophageal echocardiography-guided cardioplegia delivery warrant further clinical trials in order to evolve into part of a high surgical standard.

Mitral valve repair for degenerative mitral regurgitation in patients with left ventricular systolic dysfunction: early and mid-term outcomes

Background

This study aims to evaluate the early and mid-term outcomes of mitral valve repair for degenerative mitral regurgitation (MR) in patients with left ventricular systolic dysfunction.

Methods

From January 2005 to December 2016, the profiles of patients with degenerative MR who underwent mitral valve repair at our institution were analyzed. Left ventricular systolic dysfunction was defined as an ejection fraction < 60% or left ventricular end-systolic dimension > 40 mm. Finally, 322 patients with left ventricular systolic dysfunction were included in this study. The prognosis of left ventricular function during follow-up was evaluated and preoperative factors associated with deteriorated left ventricular systolic function during follow-up were analyzed.

Results

The in-hospital mortality rate was 1.6%. The rate of eight-year overall survival, freedom from reoperation for mitral valve and freedom from recurrent MR were 96.9, 91.2 and 73.4%, respectively. Intraoperative residual mild MR (hazard ratio 4.82) and an isolated anterior leaflet lesion (hazard ratio 2.48) were independent predictive factors for recurrent MR. During follow-up, 212 patients underwent echocardiography examinations at our institution. Among them, 132 patients had improved left ventricular systolic function, and 80 patients had deteriorated left ventricular systolic. Freedom from recurrent MR was found in 75.9% of the improved left ventricular systolic function group and 56.2% of the deteriorated left ventricular systolic function group (P = 0.047). An age > 50 years (odds ratio 2.40), ejection fraction≤52% (odds ratio 2.79) and left ventricular end-systolic dimension≥45 mm (odds ratio 2.31) were independent risk factors for deteriorated left ventricular systolic function during follow-up.

Conclusions

Mitral valve repair could be safely performed for degenerative MR in patients with left ventricular systolic dysfunction. Intraoperative residual mild MR and an isolated anterior leaflet lesion were independent predictive factors for recurrent MR. An age > 50 years, ejection fraction≤52% and left ventricular end-systolic dimension≥45 mm were independent risk factors for deteriorated left ventricular systolic function during follow-up.

Mitral valve annulus and circumflex artery: In vivo study of anatomical zones

Objective

To provide, with the use of preoperative coronary computed tomography angiography, an in vivo anatomical characterization of the relationship between the circumflex artery and mitral valve annulus to identify different risk classes and to increase the surgical awareness of those anatomical relations.

Methods

Ninety-five (mean age: 64.2 ± 11.7) consecutive patients, initially referred for elective minimally invasive mitral valve surgery, underwent preoperative coronary computed tomography angiography. The distance between the circumflex artery and mitral annulus was assessed using 6 points designed on the posterior mitral annulus, starting from the anterolateral to the posteromedial commissure; this design created an ideal 5-zone system. High-risk anatomy was defined as a distance less than 3 mm between the circumflex artery and the mitral valve annulus.

Results

The shortest distance between the circumflex artery and mitral valve annulus was observed at the area between the anterolateral commissure and the midpoint of P1 scallop, so-called zone 1 (5.49 ± 3.13 mm), whereas the longest distance occurred at zone 5 (12.03 ± 4.93). Twenty-four patients (25%) were identified with high-risk anatomy (mean distance 1.94 ± 0.8 mm). Left dominant and co-dominant hearts demonstrated a shorter circumflex artery-mitral valve annulus distance at all the zones. At multinomial logistic regression, the pattern of coronary dominance and the size of the circumflex artery were independent factors for high-risk anatomy.

Conclusions

Coronary computed tomography angiography is a useful investigation to identify patients at risk of circumflex artery flow disturbance; for high-risk anatomy, this knowledge may enhance a safer operative technique.

Aggressive treatment of afterload mismatch to address left ventricular dysfunction after mitral valve repair: A case report

Mitral regurgitation (MR), one of the most common valvulopathies, occurs in at least 10% of the individuals older than 75 years. The long-standing volume overload occurring in severe MR inevitably leads to left ventricular (LV) enlargement and dysfunction; untreated, severe MR can progress to heart failure and death. Hypotension following separation from cardiopulmonary bypass after mitral valve intervention should alert an anesthesiologist to consider a myriad of differential diagnoses. This includes, but is not limited to, afterload mismatch, which can contribute to severe LV dysfunction, even in patients with seemingly normal preoperative ejection fraction. We present a case of acute on chronic biventricular failure after mitral valve repair due to afterload mismatch and discuss its management intraoperatively. Admittedly, identifying the causes of hypotension to guide treatment after mitral valve surgery in patients with severe MR is challenging. High index of suspicion and transesophageal echocardiogram guidance are important for prompt diagnosis, increasing the likelihood of successful outcomes with appropriate clinical management.

Improvement in Left Cardiac Function Following Mitral Valve Repair: Analyses Based on Cardiac Magnetic Resonance Imaging

AIM

This study aimed to evaluate the structural and functional changes of left-sided cardiac chambers by cardiac magnetic resonance imaging (CMRI) in patients with chronic mitral regurgitation after mitral valve repair (MVR).

PATIENTS AND METHODS

Among 103 patients who underwent MVR, 21 showed normal left ventricular (LV) function; their pre- and postoperative left atrial (LA) and LV functions were examined by CMRI.

RESULTS

LV end-diastolic volume, LV end-systolic volume, and LV mass significantly were reduced postoperatively (p<0.01) and postoperative LV ejection fraction tended to decrease. LA volume parameters also significantly decreased postoperatively (p<0.01). The conduit function positively affected the LV filling volume postoperatively (p<0.01); however, no effect on the booster pump function was noted (p=0.01).

CONCLUSION

Restoration of LA and LV functions after a successful MVR was not associated with structural improvement in LA and LV.