Assessment of the severity of native mitral valve regurgitation

Presentation and outcomes of women and men undergoing surgery for degenerative mitral regurgitation

OBJECTIVES

Degenerative mitral regurgitation is associated with heart failure, arrhythmia and mortality. The impact of sex on timing of surgical referral and outcomes has not been reported comprehensively. We examined preoperative status and surgical outcomes of male versus female degenerative mitral valve regurgitation patients undergoing surgery.

METHODS

We reviewed our institutional database for all patients undergoing surgery for degenerative mitral regurgitation between 2013 and 2021. Preoperative clinical and echocardiographic variables, surgical characteristics and outcomes were compared, and left atrial strain in available images.

RESULTS

Of 963 patients, 314 (32.6%) were female. Women were older (67 vs 64 years, P = 0.031) and more often had bileaflet prolapse (19.4% vs 13.8%, P = 0.028), mitral annular calcification (12.1% vs 5.4%, P < 0.001) and tricuspid regurgitation (TR; 31.8% vs 22.5%, P = 0.001). Indexed left ventricular end-diastolic and end-systolic diameters were higher in women, with 29.4 vs 26.7 mm/m2 (P < 0.001) and 18.2 vs 17 mm/m2 (P < 0.001), respectively, and left atrial conduit strain lower (17.6% vs, 21.2%, P = 0.001). Predicted risk of mortality was 0.73% vs 0.54% in men (P = 0.023). Women required mechanical circulatory support more frequently (1.3% vs 0%, P = 0.011), had longer intensive care unit stay (29 vs 26 h, P < 0.001), mechanical ventilation (5.4 vs 5 h, P = 0.036), and overall hospitalization (7 vs 6 days, P < 0.001). There was no difference in long-term reoperation-free survival (P = 0.35).

CONCLUSIONS

Women undergoing mitral valve repair are older and show indicators of more advanced disease with long-standing left ventricular impairment. Guidelines may need to be adjusted and address this disparity, to improve postoperative recovery times and outcomes.

Mitral and Tricuspid Valve Disease in Athletes

Observing mitral or tricuspid valve disease in an athlete raises many considerations for the clinician. Initially, the etiology must be clarified, with causes differing depending on whether the athlete is young or a master. Notably, vigorous training in competitive athletes leads to a constellation of structural and functional adaptations involving cardiac chambers and atrioventricular valve systems. In addition, a proper evaluation of the athlete with valve disease is necessary to evaluate the eligibility for competitive sports and identify those requiring more follow-up. Indeed, some valve pathologies are associated with an increased risk of severe arrhythmias and potentially sudden cardiac death. Traditional and advanced imaging modalities help clarify clinical doubts, allowing essential information about the athlete's physiology and differentiating between primary valve diseases from those secondary to training-related cardiac adaptations. Remarkably, another application of multimodality imaging is evaluating athletes with valve diseases during exercise to reproduce the sport setting and better characterize the etiology and valve defect mechanism. This review aims to analyze the possible causes of atrioventricular valve diseases in athletes, focusing primarily on imaging applications in diagnosis and risk stratification.

Survival benefit of overweight patients undergoing MitraClip® procedure in comparison to normal-weight patients

BACKGROUND

The number of MitraClip® implantations increased significantly in recent years. Data regarding the impact of weight class on survival are sparse.

HYPOTHESIS

We hypothesized that weight class influences survival of patients treated with MitraClip® implantation.

METHODS

We investigated in-hospital, 1-year, 3-year, and long-term survival of patients successfully treated with isolated MitraClip® implantation for mitral valve regurgitation (MR) (June 2010-March 2018). Patients were categorized by weight classes, and the impact of weight classes on survival was analyzed.

RESULTS

Of 617 patients (aged 79.2 years; 47.3% females) treated with MitraClip® implantation (June 2010-March 2018), 12 patients were underweight (2.2%), 220 normal weight (40.1%), 237 overweight (43.2%), and 64 obesity class I (11.7%), 12 class II (2.2%), and 4 class III (0.7%). Preprocedural Logistic EuroScore (21.1 points [IQR 14.0-37.1]; 26.0 [18.5-38.5]; 26.0 [18.4-39.9]; 24.8 [16.8-33.8]; 33.0 [25.9-49.2]; 31.6 [13.1-47.6]; p = .291) was comparable between groups. Weight class had no impact on in-hospital death (0.0%; 4.1%; 1.5%; 0.0%; 7.7%; 0.0%; p = .189), 1-year survival (75.0%; 72.0%; 76.9%; 75.0%; 75.0%; 33.3%; p = .542), and 3-year survival (40.0%; 36.8%; 38.2%; 48.6%; 20.0%; 33.3%; p = .661). Compared to normal weight, underweight (hazard ratio [HR]: 1.35 [95% confidence interval [CI]: 0.65-2.79], p = .419), obesity-class I (HR: 0.93 [95% CI: 0.65-1.34], p = .705), class II (HR: 0.39 [95% CI: 0.12-1.24], p = .112), and class III (HR: 1.28 [95% CI: 0.32-5.21], p = .726) did not affect long-term survival. In contrast, overweight was associated with better survival (HR: 1.32 [95% CI: 1.04-1.68], p = .023).

CONCLUSION

Overweight affected the long-term survival of patients undergoing MitraClip® implantation beneficially compared to normal weight.

The mitral regurgitation effects of cardiac structure and function in left ventricular noncompaction

This study evaluated the effects of mitral regurgitation (MR) on cardiac structure and function in left ventricular noncompaction (LVNC) patients. The clinical and cardiovascular magnetic resonance (CMR) data for 182 patients with noncompaction or hypertrabeculation from three institutes were retrospectively included. We analyzed the difference in left ventricular geometry, cardiac function between LVNC patients with and without MR. The results showed that patients with MR had a worse New York Heart Association (NYHA) class and a higher incidence of arrhythmia (P < 0.05). MR occurred in 48.2% of LVNC patients. Compared to LVNC patients without MR, the two-dimensional sphericity index, maximum/minimum end-diastolic ratio and longitudinal shortening in LVNC patients with MR were lower (P < 0.05), and the peak longitudinal strain (PLS) of the global and segmental myocardium were obviously reduced (P < 0.05). No significant difference was found in strain in LVNC patients with different degree of MR; end diastolic volume, end systolic volume, and global PLS were statistically associated with MR and NYHA class (P < 0.05), but the non-compacted to compacted myocardium ratio had no significant correlation with them. In conclusion, the presence of MR is common in LVNC patients. LVNC patients with MR feature more severe morphological and functional changes. Hypertrabeculation is not an important factor affecting structure and function at the heart failure stage.

Radiofrequency ablation alters the microstructural organization of healthy and enzymatically digested porcine mitral valves

BACKGROUND

Myxomatous mitral valve degeneration is a common cause of mitral regurgitation and is often associated with mitral valve prolapse. With no known targets to pharmacologically treat mitral valve prolapse, surgery is often the only treatment option. Recently, radiofrequency ablation has been proposed as a percutaneous alternative to surgical resection for the reduction of mitral valve leaflet area.

OBJECTIVE

Using an in vitro model of porcine mitral valve anterior leaflet enlargement following enzymatic digestion, we sought to investigate mechanisms by which radiofrequency ablation alters the geometry, microstructural organization, and mechanical properties of healthy and digested leaflets.

METHODS

Paired measurements before and after ablation revealed the impact of radiofrequency ablation on leaflet properties. Multiphoton imaging was used to characterize changes in the structure and organization of the valvular extracellular matrix; planar biaxial mechanical testing and constitutive modeling were used to estimate mechanical properties of healthy and digested leaflets.

RESULTS

Enzymatic digestion increased leaflet area and thickness to a similar extent as clinical mitral valve disease. Radiofrequency ablation altered extracellular matrix alignment and reduced the area of digested leaflets to that of control. Additionally, enzymatic digestion resulted in fiber alignment and reorientation toward the radial direction, causing increased forces during ablation and a structural stiffening which was improved by radiofrequency ablation.

CONCLUSION

Radiofrequency ablation induces radial extracellular matrix alignment and effectively reduces the area of enlarged mitral valve leaflets. Hence, this technique may be a therapeutic approach for myxomatous mitral valve disease and is thus an avenue for future study.

Comparison of different transcatheter interventions for treatment of mitral regurgitation: A protocol for a network meta-analysis

BACKGROUND

The arrival of transcatheter mitral valve therapies has provided feasible and safe alternatives to medical and surgical treatments for mitral regurgitation. The aim of this study is to estimate the relative efficacy and safety of different transcatheter mitral valve therapies for mitral regurgitation patients through network meta-analysis.

METHODS

A systematic search will be performed using PubMed, EMBASE, the Cochrane Library, Web of Science, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure to include random controlled trials and nonrandom controlled trials comparing the efficacy and safety of different transcatheter mitral valve techniques. The risk of bias for the included nonrandom controlled studies will be evaluated according to Risk of Bias in Non-randomized Studies - of Interventions. For random controlled trials, we will use Cochrane Handbook version 5.1.0 as the risk of bias tool. A Bayesian network meta-analysis will be conducted using R-4.0.3 software. Grading of recommendations assessment, development, and evaluation will be used to assess the quality of evidence.

RESULTS

The results of this network meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will provide broad evidence of efficacy and safety of different transcatheter mitral valve therapies for treatment of mitral regurgitation and provide suggestions for clinical practice and future research.

PROTOCOL REGISTRATION NUMBER

INPLASY2020110034.

Color Doppler Splay: A Clue to the Presence of Significant Mitral Regurgitation

BACKGROUND

The authors describe a previously unreported Doppler signal associated with mitral regurgitation (MR) as imaged using transthoracic echocardiography. Horizontal "splay" of the color Doppler signal along the atrial surface of the valve may indicate significant regurgitation when the MR jet otherwise appears benign.

METHODS

Splay was defined as a nonphysiologic arc of color centered at the point at which the MR jet emerges into the left atrium. The authors present a series of 10 cases of clinically significant MR (moderately severe or severe as defined by transesophageal echocardiography) that were misclassified on transthoracic echocardiography as less than moderate. The splay signal was present on at least one standard transthoracic view in each case. To better characterize the splay signal, two groups were created from existing clinically driven transthoracic echocardiograms: 100 consecutive patients with severe MR and 100 with mild MR.

RESULTS

Splay was present in the majority of severe MR cases (81%) regardless of vendor machine, ejection fraction, or MR etiology. Splay was particularly prevalent among patients with wall-hugging jets (28 of 30 [93%]). In patients with mild MR, splay was present less often (16%), on fewer frames per clip, and had smaller dimensions compared with severe MR. Color scale did not differ between subjects with and those without splay, but color gain was higher when splay was present (P = .04). Machine settings were further explored in a single subject with prominent splay: increasing transducer frequency reduced splay, while increasing color gain increased it.

CONCLUSIONS

The authors describe a new transthoracic echocardiographic sign of MR. Horizontal splay may be a clue to the presence of severe MR when the main body of the jet is out of the imaging plane. Splay is likely generated as a side-lobe artifact due to a high-flux regurgitant jet.

Impact of obesity on adverse in-hospital outcomes in patients undergoing percutaneous mitral valve edge-to-edge repair using MitraClip® procedure - Results from the German nationwide inpatient sample

BACKGROUND AND AIM

The number of percutaneous edge-to-edge mitral regurgitation (MR) valve repairs with MitraClip® implantations increased exponentially in recent years. Studies have suggested an obesity survival paradox in patients with cardiovascular diseases. We investigated the influence of obesity on adverse in-hospital outcomes in patients with MitraClip® implantation.

METHODS AND RESULTS

We analyzed data on characteristics of patients and in-hospital outcomes for all percutaneous mitral valve repairs using the edge-to-edge MitraClip®-technique in Germany 2011-2015 stratified for obesity vs. normal-weight/over-weight. The nationwide inpatient sample comprised 13,563 inpatients undergoing MitraClip® implantations. Among them, 1017 (7.5%) patients were coded with obesity. Obese patients were younger (75 vs.77 years,P < 0.001), more often female (45.4% vs.39.5%,P < 0.001), had more often heart failure (87.1% vs.79.2%,P < 0.001) and renal insufficiency (67.0% vs.56.4%,P < 0.001). Obese and non-obese patients were comparable regarding major adverse cardiac and cerebrovascular events (MACCE) and in-hospital death. The combined endpoint of cardio-pulmonary resuscitation (CPR), mechanical ventilation and death was more often reached in non-obese than in obese patients with a trend towards significance (20.6%vs.18.2%,P = 0.066). Obesity was an independent predictor of reduced events regarding the combined endpoint of CPR, mechanical ventilation and death (OR 0.75, 95%CI 0.64-0.89,P < 0.001), but not for reduced in-hospital mortality (P = 0.355) or reduced MACCE rate (P = 0.108). Obesity class III was associated with an elevated risk for pulmonary embolism (OR 5.66, 95%CI 1.35-23.77,P = 0.018).

CONCLUSIONS

We observed an obesity paradox regarding the combined endpoint of CPR, mechanical ventilation and in-hospital death in patients undergoing MitraClip® implantation, but our results failed to confirm an impact of obesity on in-hospital survival or MACCE.

Echocardiographic indices and severity of mitral regurgitation in dogs with preclinical degenerative mitral valve disease

Background

Describing severity of mitral regurgitation (MR) in dogs with degenerative mitral valve disease (DMVD) is challenging.

Hypothesis/Objectives

Mitral regurgitant fraction (RF), effective regurgitant orifice area (EROA), and the ratio of mitral regurgitant to aortic flow (Q_MR:Q_Ao) can be calculated from routine echocardiographic measurements and provide additional information regarding MR severity.

Animals

Fifty‐seven dogs with preclinical DMVD including 36 without and 21 with cardiomegaly.

Methods

Prospective observational study. The expected relationships among RF, EROA, and Q_MR:Q_Ao and 1‐dimensional measurements including left atrium to aortic root diameter ratio (LA:Ao) and normalized left ventricular internal dimension at end‐diastole (LVIDdN) were mathematically derived and calculated using echocardiographic data from the study population. Nonlinear goodness of fit was determined by calculation of the root mean standard error. The correlations between 1‐dimensional and multidimensional indices were analyzed using receiver operating characteristic curves.

Results

The relationships among RF, EROA, Q_MR:Q_Ao, and both LA:Ao and LVIDdN were curvilinear, and the multidimensional indices differentiated MR of variable severity. By contrast, 1‐dimensional measurements were insensitive to MR severity until RF equaled or exceeded 50%. Regurgitant fraction ≥50%, EROA to body surface area ≥0.347 and Q_MR:Q_Ao ≥0.79 were strongly associated with LA:Ao ≥1.6 and LVIDdN ≥1.7.

Conclusions and Clinical Importance

Regurgitant fraction, EROA, and Q_MR:Q_Ao quantify MR severity in dogs with preclinical DMVD in a manner that 1‐dimensional measurements do not.

Echocardiography in Athletes in Primary Prevention of Sudden Death

Echocardiography is a noninvasive imaging technique useful to provide clinical data regarding physiological adaptations of athlete's heart. Echocardiographic characteristics may be helpful for the clinicians to identify structural cardiac disease, responsible of sudden death during sport activities. The application of echocardiography in preparticipation screening might be essential: it shows high sensitivity and specificity for identification of structural cardiac disease and it is the first-line imagining technique for primary prevention of SCD in athletes. Moreover, new echocardiographic techniques distinguish extreme sport cardiac remodeling from beginning state of cardiomyopathy, as hypertrophic or dilated cardiomyopathy and arrhythmogenic right ventricle dysplasia. The aim of this paper is to review the scientific literature and the clinical knowledge about athlete's heart and main structural heart disease and to describe the rule of echocardiography in primary prevention of SCD in athletes.

Mitral Prolapse: An Old Mysterious Entity - The Incremental Role of Multimodality Imaging in Sports Eligibility

Mitral valve prolapse is generally a benign condition characterized by fibromyxomatous changes of the mitral leaflet with displacement into the left atrium and late-systolic regurgitation. Although it is an old clinical entity, it still arouses perplexity in diagnosis and clinical management. Complications, such as mitral regurgitation (MR), atrial fibrillation, congestive heart failure, endocarditis, ventricular arrhythmias, and sudden cardiac death (SCD), have been reported. A large proportion of the overall causes of SCD in young competitive athletes is explained by mitral valve prolapse. Recent studies have shown the fibrosis of the papillary muscles and inferobasal left ventricular wall in mitral valve prolapse, suggesting a possible origin of ventricular fatal arrhythmias. Athletes with mitral valve prolapse and MR should undergo annual evaluations including physical examination, echocardiogram, and exercise stress testing to evaluate the cardiovascular risks of competitive sports and obtain the eligibility. In this setting, multimodality imaging techniques - echocardiography, cardiac magnetic resonance, and cardiac computed tomography - should provide a broad spectrum of information, from diagnosis to clinical management of the major clinical profiles of the disease.