Anatomy, mechanics, and pathophysiology of the mitral annulus

Impact of Exercise on Atrial Functional Mitral Regurgitation and Its Determinants: An Exercise Echocardiographic Study

Atrial functional mitral regurgitation (AFMR) is a distinct form of mitral regurgitation in patients with atrial fibrillation and heart failure with preserved ejection fraction. Its pathophysiology remains elusive, and data on exercise-related AFMR are scarce. We sought to investigate the impact of acute exercise on AFMR severity and to identify its determinants. In total, 47 patients with heart failure with preserved ejection fraction (n = 39) and/or atrial fibrillation (n = 22) were enrolled. We assessed AFMR severity, mitral annular dimensions, left atrial size, AFMR severity, and parameters of systolic and diastolic function at rest and during maximal exercise by echocardiography. An increase in AFMR severity of ≥1 grade was observed in 20 patients (43%) during exercise and was associated with impaired progression of peak mitral annulus systolic velocity and increased systolic mitral annular diameter during exercise, whereas the systolic annular diameter decreased in patients without AFMR progression. Furthermore, patients with ≥ moderate AFMR during exercise (n = 19, 40%) had lower peak mitral annulus systolic velocity, greater systolic mitral annular diameters, reduced tricuspid annular plane systolic excursion, and more severe tricuspid regurgitation than patients with ≤ mild MR during exercise. In conclusion, AFMR is a dynamic condition which may worsen during exercise. Deterioration of AFMR during exercise was associated with impaired longitudinal left ventricular contractile reserve and greater mitral annular dimensions. Because impaired left ventricular longitudinal function may influence mitral annular dynamics, this attributes to the hypothesis that AFMR results from mitral annulus area/leaflet area imbalance caused by annular dilation and impaired mitral annular dynamics.

Outcomes of mitral transcatheter edge-to-edge repair in patients with mitral annular calcification: A meta-analysis

BACKGROUND

The impact of mitral annular calcification (MAC) on the clinical outcomes of patients undergoing mitral transcatheter edge-to-edge repair (MTEER) remains unclear. This meta-analysis aims to evaluate the clinical outcomes of MTEER among patients with moderate to severe MAC compared to those with mild or no MAC.

METHODS

We systematically searched PubMed, EMBASE, and Cochrane CENTRAL databases through March 31st, 2024, comparing clinical outcomes of MTEER among patients with moderate/severe (MAC+) versus no/mild MAC (MAC-). We assessed pooled estimates for procedural success, all-cause mortality, residual mitral regurgitation (MR) ≤ moderate, and New York Heart Association (NYHA) class III/IV status at one year.

RESULTS

Among five studies (2533 patients; mean age 76.4 ± 10.9 years, 39.8 % women), MAC+ patients were predominantly women (55.7 % vs 37.5 %, p < 0.001), older (87.9 ± 11.1 vs. 75.9 ± 9.1 years; mean difference (MD) = 3.99, p = 0.011) and had higher STS scores (7.7 ± 6.7 % vs. 4.9 ± 4.6 %; MD = 1.34, p < 0.001). MAC+ patients had comparable procedural success rates, residual MR < moderate, and NYHA III/IV at 1 year. However, all-cause mortality at 1 year was higher for MAC+ patients (Relative Risk = 1.56, 95 % CI = 1.06-2.29).

CONCLUSIONS

MTEER is a safe and feasible option for carefully selected patients with MAC and significant MR, offering durable MR reduction and functional status improvement. Significantly higher one-year mortality associated with MAC despite significant MR reduction suggests an increased risk unrelated to valvular dysfunction and highlights the need for further investigation into identifying patients who benefit the most from MTEER.

Characterisation of global and regional mitral annular strains in an acute porcine model

OBJECTIVES

This study aimed to explore regional mitral annular strain using a novel computational method.

METHODS

Eight pigs underwent implantation with piezoelectric transducers around the mitral annulus. Interventions of pre- and afterload were performed by inferior vena cava constriction and endovascular balloon occlusion of the descending aorta. The mitral annulus was reconstructed in a mathematical model and divided into 6 segments. Global and segmental annular strain were calculated from a discrete mathematical representation.

RESULTS

Global annular strain gradually decreased after isovolumetric contraction until late systole. Mitral annular end-systolic strain demonstrated shortening in all segments except the anterior segment, which showed the least deformation. The P2 annular segment demonstrated the most end-systolic shortening (-7.6 ± 1.1% at baseline, P < 0.001 compared to anterior segment). Systolic global annular strain showed no significant change in response to load interventions but correlated positively with left ventricular contractility at baseline and after preload reduction.

CONCLUSIONS

Mitral annular systolic strain demonstrates cyclical variations with considerable regional heterogeneity, with the most pronounced deformation in posterior annular segments. Measurements appear independent of changes to pre- and afterload.

Atrial Functional Mitral Regurgitation: From Diagnosis to Current Interventional Therapies

Mitral regurgitation (MR) is one of the most common valvular pathologies worldwide, contributing to the morbidity and mortality of several cardiovascular pathologies, including heart failure (HF). Novel transcatheter treatment for MR has given the opportunity for a safe and feasible alternative, to surgery, in order to repair the valve and improve patient outcomes. However, after the results of early transcatheter edge-to-edge repair (TEER) trials, it has become evident that subcategorizing the mitral regurgitation etiology and the left ventricular function, in patients due to undergo TEER, is of the essence, in order to predict responsiveness to treatment and select the most appropriate patient phenotype. Thus, a novel MR phenotype, atrial functional MR (AFMR), has been recently recognized as a distinct pathophysiological entity, where the etiology of the regurgitation is secondary to annular dilatation, in a diseased left atrium, with preserved left ventricular function. Recent studies have evaluated and compared the outcomes of TEER in AFMR with ventricular functional MR (VFMR), with the results favoring the AFMR. In specific, TEER in this patient substrate has better echocardiographic and long-term outcomes. Thus, our review will provide a comprehensive pathogenesis and mechanistic overview of AFMR, insights into the echocardiographic approach of such patients and pre-procedural planning, discuss the most recent clinical trials and their implications for future treatment directions, as well as highlight future frontiers of research in the setting of TEER and transcatheter mitral valve replacement (TMVR) in AFMR patients.

Rethinking Mitral Annular Calcification and Its Clinical Significance: From Passive Process to Active Pathology

BACKGROUND

Mitral annulus calcification is a chronic degenerative condition affecting the fibrous base of the mitral valve. Historically viewed as an age-related phenomenon, recent studies suggest it is driven by active mechanisms involving systemic inflammation, hemodynamic stress, abnormal calcium-phosphorus metabolism, and lipid accumulation. Despite often being asymptomatic and incidentally detected, its clinical relevance stems from its strong association with increased cardiovascular disease risk, higher cardiovascular mortality, and elevated overall mortality.

METHODS

This article investigates the complexities and controversies surrounding mitral annular calcification as a potential embolic source, focusing on its diagnosis, its relationship with systemic inflammation, and its links to metabolic and chronic disorders.

RESULTS

The findings highlight that mitral annular calcification is not merely a passive marker of aging but an active indicator of atherosclerotic burden with significant implications for cardiovascular health.

CONCLUSION

Mitral annulus calcification should be recognized as an important factor in cardiovascular risk assessment, offering insight into systemic inflammatory processes and metabolic dysregulation.

Mitral valve early systolic billowing induces following annular expansion and leaflet augmentation in Barlow's disease: sequential analysis using 3D echocardiography

AIMS

Although systolic expansion of the annulus has been recognized in Barlow's disease, the mechanisms of the unique pathological movement of the annulus and its relation to the leaflet augmentation have not yet been clarified. We aimed to investigate the detailed mechanisms of the characteristic mitral apparatus dynamics in Barlow's disease by frame-by-frame sequential geometric analysis using real-time 3D transoesophageal echocardiography.

METHODS AND RESULTS

Fifty-three patients with Barlow's disease and severe mitral regurgitation without torn chordae, as well as 10 controls, were included. We evaluated geometric changes in the mitral complex using 3D transoesophageal echocardiography at five points during systole. To identify early systolic billowing of leaflets, the annulo-leaflet angle was measured. We also performed a more detailed analysis in four consecutive frames just before and after leaflet free-edge prolapse above the annulus plane. The median annulo-leaflet angle of both leaflets in early systole was >0° (above annulus plane) in patients with Barlow's disease, and billowing of the leaflet body was observed from early systole. The prolapse volume of both leaflets increased markedly from early to mid-systole [1.60 (0.85-2.80) to 4.00 (2.10-6.45) mL; analysis of variance (ANOVA), P < 0.001; post hoc, P < 0.05]. With frame-by-frame analysis, dynamic augmentation of the annulus and leaflets developed between frames just before and just after leaflet free-edge prolapse (ANOVA, P < 0.01; post hoc, P < 0.05).

CONCLUSION

In Barlow's disease, early systolic billowing of the mitral leaflet induces systolic annulus expansion followed by leaflet augmentation and leaflet free-edge prolapse.

Echocardiographic manifestations in end-stage renal disease

End-stage renal disease (ESRD) is a common but profound clinical condition, and it is associated with extremely increased morbidity and mortality. ESRD can represent four major echocardiographic findings-myocardial hypertrophy, heart failure, valvular calcification, and pericardial effusion. Multiple factors interplay leading to these abnormalities, including pressure/volume overload, oxidative stress, and neurohormonal imbalances. Uremic cardiomyopathy is characterized by left ventricular (LV) hypertrophy and marked diastolic dysfunction. In ESRD patients on hemodialysis, LV geometry is changeable bidirectionally between concentric and eccentric hypertrophy, depending upon changes in corporal fluid volume and arterial pressure, which eventually results in a characteristic of LV systolic dysfunction. Speckle tracking echocardiography enabling to detect subclinical disease might help prevent future advancement to heart failure. Heart valve calcification also is common in ESRD, keeping in mind which progresses faster than expected. In a modern era, pericardial effusion observed in ESRD patients tends to result from volume overload, rather than pericarditis. In this review, we introduce and discuss those four echocardiography-assessed findings of ESRD, with which known and conceivable pathophysiologies for each are incorporated.

Outcomes of COMBO therapy for severe mitral regurgitation compared with transcatheter edge-to-edge repair

Background

There are different types of transcatheter mitral valve repair (TMVr) currently in clinical use, including leaflet approximation, annular cinching, and restoration of the chordal apparatus of the mitral valve (MV). While the concomitant combination (COMBO) therapy of mitral transcatheter edge-to-edge repair (M-TEER) with another TMVr concept has been proven feasible, potentially offering patient-tailored treatment for severe mitral regurgitation (MR), a comparison with M-TEER alone has not been made.

Aims

To evaluate the procedural and clinical outcome of COMBO therapies compared with M-TEER alone.

Methods

We included consecutive patients undergoing COMBO and M-TEER between March 2015 and April 2018 at our Heart Valve Center, while excluding patients presenting a case of redo or with previous MV surgery. Procedural outcomes and all-cause mortality were compared between COMBO therapy vs. M-TEER alone.

Results

A total of 357 patients (mean age 78.9 ± 7.0 years, 53.2% male, M-TEER n = 322, COMBO n = 35; COMBO: MitraClip and the Carillon mitral contour system n = 26, MitraClip and Cardioband n = 5, and MitraClip and NeoChord n = 4) were analyzed. Patients with COMBO therapy had larger left chamber sizes, a lower left ventricular systolic ejection fraction (LVEF; COMBO: 37.4 ± 13.8%, M-TEER: 47.9 ± 14.3%, p < 0.001), and a more severe MR grade (p < 0.001). There were no significant differences in the prevalence of residual MR ≧2+. However, the need for re-intervention, always employing M-TEER, was more common in the COMBO group. During a mean 3.6-year long-term follow-up, there was no significant difference of all-cause mortality between both groups (Log rank p = 0.921).

Conclusions

COMBO therapy may still be a beneficial therapy option for patients with severe MR who already have a more dilated left ventricle (LV), a more severe MR, and a more pronounced LV systolic dysfunction. The higher need for re-intervention in the COMBO group may signal more complex anatomies and possibly underlines the necessity of treating significant MR earlier. Future research is required to establish the COMBO approach as a toolbox-like treatment option, thus offering a patient-tailored approach depending on the individual anatomy and pathology.

Mitral Annular Calcification-Related Valvular Disease: A Challenging Entity

Mitral valve annular calcification-related valvular disease is increasingly common due to the rising prevalence of age-related mitral annular calcifications. Mitral annular calcification alters the structure and function of the mitral valve annulus, which in turn causes mitral valve regurgitation, stenosis, or both. As it frequently coexists with comorbid conditions and overlapping symptoms, mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges. For instance, left ventricular diastolic dysfunction hinders the assessment of mitral valvular disease. Detection of mitral annular calcifications and assessment of related mitral valve disease hinge on two-dimensional echocardiography. Comprehensive assessment of mitral annular calcifications and related mitral valve disease may require multidetector computed tomography and three-dimensional echocardiography. Invasive hemodynamic testing with exercise helps identify the cause of symptoms in patients with comorbid conditions, and transcatheter interventions have emerged as a viable therapeutic option for older patients. After an outline of the normal mitral annulus, we examine how mitral annular calcifications lead to mitral valve disease and how to accurately assess mitral regurgitation and stenosis. Lastly, we review surgical and transcatheter approaches to the management of mitral annular calcification-related mitral valve regurgitation, stenosis, or both.

Three-dimensional echocardiography reveals early mitral valve alterations in hypertrophic cardiomyopathy genetic mutation carriers

BACKGROUND

The mitral valve undergoes structural modifications in response to cardiac functional changes, often predating cardiac decompensation and overt clinical signs. Our study assessed the potential of mitral valve morphological changes as early indicators for detecting carriers of hypertrophic cardiomyopathy (HCM)-associated gene mutations.

METHODS

We studied 505 participants: 189 without the pathogenic gene mutations and left ventricular hypertrophy (G-/LVH-), 149 carriers without LV hypertrophy (G+/LVH-), and 167 manifest HCM patients (G+/LVH+). We juxtaposed the mitral valve morphology and associated metrics across these groups, emphasizing those carrying MYH7 and MYBPC3 mutations.

RESULTS

We discerned pronounced disparities in the mitral annulus and leaflet structures across the groups. The mitral valve apparatus in mutation carriers exhibited a tendency towards a flattened profile. Detailed analysis spotlighted MYBPC3 mutation carriers, whose mitral valves were notably flatter (with notably lower AHCWR values than non-carriers); this contrast was not evident in MYH7 mutation carriers. This mitral valve flattening, manifest in the mutation carriers, suggests it might be an adaptive response to incipient cardiac dysfunction in HCM's nascent stages.

CONCLUSIONS

Three-dimensional echocardiography illuminates the initial mitral valve structural changes in HCM patients bearing pathogenic gene mutations. These morphological signatures hold promise as sensitive imaging markers, especially for asymptomatic carriers of the MYBPC3 mutation.

Transcatheter mitral valve implantation for native valve disease

Mitral regurgitation is the second most frequent heart valve disease in Europe and the most frequent in the US. Although surgery is the therapy of choice when intervention is indicated, transcatheter mitral valve repair or replacement are alternatives for patients who are not eligible for surgery. However, the development of transcatheter mitral valves is slower than expected. Although several transcatheter heart valves have been developed, only one has been commercialised. Indeed, most of these devices are being evaluated in clinical studies, with promising initial results. In this review, we propose an overview on transcatheter mitral valve replacement for the treatment of native mitral valve disease, from indication to results, including patients with severe annular calcification, and we provide you with a glimpse into the future of these therapies.

Mitral annular calcification in obstructive hypertrophic cardiomyopathy: Incidence, risk factors, and prognostic value after myectomy

BACKGROUND

Mitral annular calcification (MAC) is a risk factor for cardiac surgery, but there is limited study on the prognosis value and the impact for valve function of MAC based on computed tomography (CT) diagnosis after myectomy for hypertrophic obstructive cardiomyopathy (OHCM).

METHODS

Consecutive OHCM patients underwent septal myectomy were compared according to the existence of MAC and its severity in preoperative CT scans. The survival data were evaluated and compared by Kaplan Meier analysis and log rank test. Cox regression analysis was used to evaluate the impact of MAC on endpoint events.

RESULTS

From the entire cohort of 1035 patients, 10.8% had MAC. In multivariate regression, female (OR = 2.23), age (OR = 1.07), aortic annular calcification (OR = 2.52), aortic calcification (OR = 2.56), systolic anterior motion of the mitral valve (SAM) (OR = 0.42), mitral valve thickening (OR = 2.13), and tricuspid regurgitation (OR = 3.12) were independent predictors of MAC. All-cause mortality (3.57% vs. 1.08%, p = 0.031), major adverse cardiovascular and cerebrovascular events (MACCE) (23.32% vs. 13.65%, p = 0.014), recurrent MR > 2+ (8.04% vs. 2.49%, p = 0.001) and NYHA III-IV (11.61% vs. 5.53%, p = 0.012) were more frequent in OHCM patients with MAC after myectomy. MAC was discovered to be an independent predictor of postoperative recurrent MR > 2+ after other risk factors were taken into account (HR 2.47, 95% CI 1.08-5.67, p = 0.0329). Moderate-to-severe MAC was an independent risk factor (HR 2.03, 95% CI 1.09-3.75, p = 0.0244) for long-term major adverse cardiovascular and cerebrovascular events (MACCE).

CONCLUSION

MAC was detected in one-tenth of OHCM patients in preoperative CT scanning and is mainly associated with aging and atherosclerosis. OHCM patients with MAC had a worse prognosis and more recurrent mitral valve regurgitation than those without MAC after septal myectomy.

Noncontrast cardiac computed tomography-derived mitral annular calcification scores in mitral valve disease

BACKGROUND AND AIMS

Mitral annular calcification (MAC) by computed tomography (CT) is reported as an independent predictor of poor outcomes. However, it currently remains unclear if quantitative MAC parameters provide more value for mitral valve disease (MVD) management, therefore, we examined the prognostic value of MAC scores using noncontrast cardiac-CT in MVD patients.

METHODS

Between January 2020 and December 2021, we prospectively enrolled 300 consecutive patients with MVD (MAC-present = 80 and MAC-absent = 220) undergoing preoperative cardiac-CT and mitral valve (MV) surgery. Noncontrast cardiac-CT images were used to qualitatively detect MAC (present or absent) and evaluate MAC scores. For analyses, we also collected baseline clinical data, intraoperative conversion (from MV repair to MV replacement), and follow-up arrhythmia data.

RESULTS

Compared with the MAC-absent group, MAC-present patients were older (62 ± 7 vs. 58 ± 9 years, p < .001), mostly women (55% vs. 39.5%, p = .017), and also had aortic valve calcification (57.5% vs. 23.2%, p < .001), mitral stenosis (82.5% vs. 61.8%, p < .001), atrial fibrillation (30% vs. 11.8%, p < .001), and larger left atrial end-diastolic dimension (LADD, 49 [44-56] versus 46 [41-50], p = .001]. Furthermore, MAC-present patients underwent more MV replacements (61.8% vs. 82.5%, p = .001) and experienced a higher intraoperative conversion prevalence (11.8% vs. 61.3%, p < .001). Multiple logistic regression analyses showed that the female gender (odds ratio [OR]/95% confidence interval [CI]/p = 2.001/1.042-3.841/0.037) and MAC scores (OR/95% CI/p = 10.153/4.434-23.253/p < .001) were independent predictors of intraoperative conversion. During a follow-up of 263 ± 134 days, MAC-present patients had more arrhythmias (42.5% vs. 9.5%, p < .001). Also, MAC-scores (hazard ratio [HR]/95% CI/p = 6.841/3.322-14.089/p < .001) and LADD (HR/95% CI/p = 1.039/1.018-1.060/p < .001) were independently associated with arrhythmias by Cox regression analyses.

CONCLUSIONS

Noncontrast cardiac CT-derived MAC-scores showed a high risk for intraoperative conversion and follow-up arrhythmias in MVD-patients.

Clinical significance of substrate characteristics and ablation outcomes in patients with atrial fibrillation and significant functional mitral regurgitation

Background

Atrial fibrillation (AF) and mitral regurgitation (MR) have a complex interplay. Catheter ablation (CA) of AF may be a potential method to improve the severity of MR in AF patients.

Methods

Patients with symptomatic AF and moderate to severe MR who underwent catheter ablation from 2011 to 2021 were retrospectively included in the study. Patients' baseline characteristics and electrophysiological features were examined. These patients were classified as group 1 with improved MR and group 2 with refractory MR after CA.

Results

Fifty patients (age 60.2 ± 11.6 years, 29 males) were included in the study (32 in group 1 and 18 in group 2). Group 1 patients had a lower CHA2DS2-VASc score (1.7 ± 1.5 vs. 2.7 ± 1.5, P = 0.005) and had a lower incidence of hypertension (28.1% vs. 66.7%, P = 0.007) and diabetes mellitus (3.1% vs. 22.2%, P = 0.031) as compared to group 2 patients. Electroanatomic three-dimensional (3D) mapping showed that group 1 patients demonstrated less scars on the posterior bottom of the left atrium compared to group 2 patients (12.5% vs. 66.7%, P < 0.001). AF recurrence was not different between the two groups. After multivariate logistic regression analysis, a posterior bottom scar in the left atrium independently predicted refractory MR despite successful AF ablation.

Conclusion

Most patients with AF and MR showed improvement of MR after AF ablation. A scar involving the posterior bottom of the left atrium is associated with poor recovery of MR.

Feasibility and Outcomes of Mitral Transcatheter Edge-To-Edge Repair in Patients With Variable Degrees of Mitral Annular Calcification

Background The clinical significance of mitral annular calcification (MAC) in patients undergoing mitral transcatheter edge-to-edge repair is not well understood. There is limited evidence regarding the feasibility, durability of repair, and the prognostic value of MAC in this population. We sought to examine the prognostic value of MAC, its severity, and its impact on procedural success and durability of mitral transcatheter edge-to-edge repair. Methods and Results We reviewed the records of 280 patients with moderate-severe or severe mitral regurgitation who underwent mitral transcatheter edge-to-edge repair with MitraClip from March 2014 to March 2022. The primary end point was cumulative survival at 1 year. Independent factors associated with the primary end point were identified using multivariable Cox regression. Among 280 patients included in the final analysis, 249 had none/mild MAC, and 31 had moderate/severe MAC. Median follow-up was 23.1 months (interquartile range: 11.1-40.4). Procedural success was comparable in the MAC and non-MAC groups (92.6% versus 91.4%, P=0.79) with similar rates of residual mitral regurgitation ≤2 at 1 year (86.7% versus 93.2%, P=0.55). Moderate/severe MAC was associated with less improvement in New York Heart Association III/IV at 30 days when compared with none/mild MAC (45.8% versus 14.3%, P=0.001). The moderate/severe MAC group had lower cumulative 1-year survival (56.8% versus 80.0%, hazard ratio [HR], 1.98 [95% CI, 1.27-3.10], P=0.002). Moderate/severe MAC and Society of Thoracic Surgeons predicted risk of mortality for mitral valve repair were independently associated with the primary end point (HR, 2.20 [1.10-4.41], P=0.02; and HR, 1.014 [1.006-1.078], P=0.02, respectively). Conclusions Mitral TEER is a safe and feasible intervention in selected patients with significant MAC and associated with similar mitral regurgitation reduction at 1 year compared with patients with none/mild MAC. Patients with moderate/severe MAC had a high 1-year mortality and less improvement in their symptoms after TEER.

Primary Mitral Regurgitation and Heart Failure: Current Advances in Diagnosis and Management

Primary mitral regurgitation is a frequent etiology of congestive heart failure and is best treated with intervention when patients are symptomatic or when additional risk factors exist. Surgical intervention improves outcomes in appropriately selected patients. However, for those at high surgical risk, transcatheter intervention provides less invasive repair and replacement options while providing comparable outcomes to surgery. The excess mortality and high prevalence of heart failure in untreated mitral regurgitation illuminate the need for further developments in mitral valve intervention ideally fulfilled by expanding these types of procedures and eligibility to these procedures beyond only those at high surgical risk.

A Systematic Review and Meta-Analysis of Prevalence, Characteristics, and Impact of Mitral Annular Calcification on Outcomes After Transcatheter Aortic Valve Implantation

There is a paucity of data on the prognostic impact of mitral annular calcification (MAC) in patients who underwent transcatheter aortic valve implantation (TAVI) with conflicting results being reported by the studies that are published. Therefore, we performed a meta-analysis to assess the short-term and long-term outcomes of MAC in patients after TAVI. Of 25,407 studies identified after the initial database search, 4 observational studies comprising 2,620 patients (2,030 patients in the nonsevere MAC arm and 590 patients in the severe MAC arm) were included in the final analysis. Compared with patients with nonsevere MAC, the severe MAC group was associated with significantly higher incidences of overall bleeding (0.75 [0.57 to 0.98], p = 0.03, I² = 0%) at 30 days. However, no significant difference was observed between the 2 groups for the rest of the 30-day outcomes: all-cause mortality (0.79 [0.42 to 1.48], p = 0.46, I² = 9%), myocardial infarction (1.62 [0.37 to 7.04], p = 0.52, I² = 0%), cerebrovascular accident or stroke (1.22 [0.53 to 2.83], p = 0.64, I² = 0%), acute kidney injury (1.48 [0.64 to 3.42], p = 0.35, I² = 0%), and pacemaker implantation (0.70 [0.39 to 1.25], p = 0.23, I² = 68%). Similarly, follow-up outcomes also showed no significant difference between the 2 groups: all-cause mortality (0.69 [0.46 to 1.03], p = 0.07, I² = 44%), cardiovascular mortality (0.52 [0.24 to 1.13], p = 0.10, I² = 70%) and stroke (0.83 [0.41 to 1.69], p = 0.61, I² = 22%). The sensitivity analysis, however, demonstrated significant results for all-cause mortality (0.57 [0.39 to 0.84], p = 0.005, I² = 7%) by removing the study by Okuno et al⁵ and cardiovascular mortality (0.41 [0.21 to 0.82], p = 0.01, I² = 66%) by removing the study by Lak et al.⁷ In conclusion, our meta-analysis corroborates the notion that isolated MAC is not an independent predictor of long-term mortality after TAVI and determines severe MAC to be a predictor of mortality at follow-up because of the higher incidence of mitral valve dysfunction associated with it.

Mitral annular dynamics are influenced by left ventricular load and contractility in an acute animal model

The purpose of this study was to investigate the effects of loading conditions and left ventricular (LV) contractility on mitral annular dynamics. In 10 anesthetized pigs, eight piezoelectric transducers were implanted equidistantly around the mitral annulus. High-fidelity catheters measured left ventricular pressures and the slope of the end-systolic pressure-volume relationship (Ees ) determined LV contractility. Adjustments of pre- and afterload were done by constriction of the inferior caval vein and occlusion of the descending aorta. Mitral annulus area indexed to body surface area (MAAi ), annular circularity index (ACI), and non-planarity angle (NPA) were calculated by computational analysis. MAAi was more dynamic in response to loading interventions than ACI and NPA. However, MAAi maximal cyclical reduction (-Δr) and average deformational velocity (-v ¯ $$ \overline{v} $$ ) did not change accordingly (p = 0.31 and p = 0.22). Reduced Ees was associated to attenuation in MAAi -Δr and MAAi -v ¯ $$ \overline{v} $$ (r2  = 0.744; p = 0.001 and r2  = 0.467; p = 0.029). In conclusion, increased cardiac load and reduced LV contractility may cause deterioration of mitral annular dynamics, likely impairing coaptation and increasing susceptibility to valvular incompetence.

3D echocardiography in mitral valve prolapse

Mitral valve prolapse (MVP) is the leading cause of mitral valve surgery. Echocardiography is the principal imaging modality used to diagnose MVP, assess the mitral valve morphology and mitral annulus dynamics, and quantify mitral regurgitation. Three-dimensional (3D) echocardiographic (3DE) imaging represents a consistent innovation in cardiovascular ultrasound in the last decades, and it has been implemented in routine clinical practice for the evaluation of mitral valve diseases. The focus of this review is the role and the advantages of 3DE in the comprehensive evaluation of MVP, intraoperative and intraprocedural monitoring.

Characterization of ventricular arrhythmias and sudden cardiac death in subjects with mitral valve prolapse and mitral annular disjunction

Sudden cardiac death is reported as the leading cause of mortality in developed nations. Arrhythmic mitral valve disease, encompassing mitral valve prolapse and/or mitral annular disjunction, is thought to be responsible in a sizable portion of these deaths. Despite this evidence, there are no reliable methods or clinically useful risk stratification schemes to determine which group of patients are at higher risk or may benefit from interventions such as catheter ablation or prophylactic implantation of a defibrillator. The reasons for this lack of guidance include our incomplete understanding of the mechanisms of ventricular arrhythmias and the fact that mitral valve prolapse and disjunction are frequently diagnosed, yet carry an overall low risk of sudden cardiac death. This heterogeneity makes the development of a reliable prediction model based on the presence of common risk factors very difficult. In this review, we summarize the relevant literature regarding the epidemiology, diagnosis, pathophysiology, and management of mitral valve prolapse and mitral annular disjunction and elucidate their role in sudden cardiac death.

Transcatheter mitral valve repair in a liver transplant candidate

Untreated severe mitral regurgitation (MR) is associated with poor outcomes due to the adverse consequences of long-standing volume overload on the left ventricle and left atrium, which leads to pulmonary hypertension and right-sided heart failure. Early intervention results in favorable long-term outcomes making appropriate timing of intervention very critical. We present a 53-year-old male with severe symptomatic MR and right sided-heart failure which progressed to cardiac cirrhosis necessitating enrollment to the liver transplant list. Transcatheter mitral valve repair (TMVR) using MitraClip implantation resulted in impressive clinical improvement and resolution of cirrhosis. Eventually, the patient was taken off the transplant list. Treatment of severe MR may lead to improvements in congestive hepatopathy.

Automated mitral valve assessment for transcatheter mitral valve replacement planning

Transcatheter mitral valve replacement (TMVR) has emerged as a minimally invasive alternative for treating patients suffering from mitral valve disease. The number of TMVR procedures is expected to rise as devices currently in clinical trials obtain approval for commercialization. Automating the planning of such interventions becomes, therefore, more relevant in an attempt to decrease inter-subject discrepancies and time spent in patient assessment. This study evaluates the performance of an automated method for detection of anatomical landmarks and generation of relevant measurements for device selection and positioning. Cardiac CT scans of 70 patients were collected retrospectively. Fifty scans were used to generate a statistical shape model (SSM) of the left heart chambers at ten different timepoints, whereas the remaining 20 scans were used for validation of the automated method. The clinical measurements resulting from the anatomical landmarks generated automatically were compared against the measurements obtained through the manual indication of the corresponding landmarks by three observers, during systole and diastole. The automatically generated measurements were in close agreement with the user-driven analysis, with intraclass correlation coefficients (ICC) consistently lower for the saddle-shaped (ICCArea = 0.90, ICCPerimeter 2D = 0.95, ICCPerimeter 3D = 0.93, ICCAP-Diameter = 0.71, ICCML-Diameter = 0.90) compared to the D-shaped annulus (ICCArea = 0.94, ICCPerimeter 2D = 0.96, ICCPerimeter 3D = 0.96, ICCAP-Diameter = 0.95, ICCML-Diameter = 0.92). The larger differences observed for the saddle shape suggest that the main discrepancies occur in the aorto-mitral curtain. This is supported by the fact that statistically significant differences are observed between the two annulus configurations for area (p < 0.001), 3D perimeter (p = 0.009) and AP diameter (p < 0.001), whereas errors for 2D perimeter and ML diameter remained almost constant. The mitral valve center deviated in average 2.5 mm from the user-driven position, a value comparable to the inter-observer variability. The present study suggests that accurate mitral valve assessment can be achieved with a fully automated method, what could result in more consistent and shorter pre-interventional planning of TMVR procedures.

DynaRing: A Patient-Specific Mitral Annuloplasty Ring With Selective Stiffness Segments

Annuloplasty ring choice and design are critical to the long-term efficacy of mitral valve (MV) repair. DynaRing is a selectively compliant annuloplasty ring composed of varying stiffness elastomer segments, a shape-set nitinol core, and a cross diameter filament. The ring provides sufficient stiffness to stabilize a diseased annulus while allowing physiological annular dynamics. Moreover, adjusting elastomer properties provides a mechanism for effectively tuning key MV metrics to specific patients. We evaluate the ring embedded in porcine valves with an ex-vivo left heart simulator and perform a 150 million cycle fatigue test via a custom oscillatory system. We present a patient-specific design approach for determining ring parameters using a finite element model optimization and patient MRI data. Ex-vivo experiment results demonstrate that motion of DynaRing closely matches literature values for healthy annuli. Findings from the patient-specific optimization establish DynaRing's ability to adjust the anterior-posterior and intercommissural diameters and saddle height by up to 8.8%, 5.6%, 19.8%, respectively, and match a wide range of patient data.

Mitral Annulus Disjunction and Arrhythmic Mitral Valve Prolapse: Emerging Role of Cardiac Magnetic Resonance Imaging in the Workup

Mitral valve prolapse is a commonly described entity with a highly variable and benign course. However, it is associated with ventricular arrhythmias and sudden cardiac death in a small subset of patients. Recent studies have yielded insight into myocardial mechanics and the causation of ventricular arrhythmias in these groups of patients.

Mitral annular disjunction (MAD) characterized by detachment of mitral annulus from left ventricular myocardium is associated with morphological and functional remodeling of the left ventricular myocardium. Resultant fibrosis acts as a substrate of ventricular arrhythmia and sudden cardiac death.

We present two such cases of arrhythmic mitral valve prolapse associated with MAD. Cardiac magnetic resonance imaging provides excellent morphological information and also helps in the assessment of fibrosis.

Mitral Valve Dysfunction in Patients With Annular Calcification: JACC Review Topic of the Week

Mitral annular calcification (MAC) is a common clinical finding and is associated with adverse clinical outcomes, but the clinical impact of MAC-related mitral valve (MV) dysfunction remains underappreciated. Patients with MAC frequently have stenotic, regurgitant, or mixed valvular disease, and this valvular dysfunction is increasingly recognized to be independently associated with worse prognosis. MAC-related MV dysfunction is a distinct pathophysiologic entity, and importantly much of the diagnostic and therapeutic paradigm from published rheumatic MV disease research cannot be applied in this context, leaving important gaps in our knowledge. This review summarizes the current epidemiology, pathophysiology, diagnosis, and classification of MAC-related MV dysfunction and proposes both an integrative definition and an overarching approach to this important and increasingly recognized clinical condition.

Echocardiographic characteristics of non-resectional ring-only valve repair in mitral valve prolapse

BACKGROUND

Simple mitral valve repair (MVR) using a ring-only approach (ROA) was recently proposed for some complex forms of bileaflet myxomatous mitral valve prolapse (MVP). Nevertheless, few data are available concerning the characteristics of MVP patients that may benefit from this simple repair technique.

METHODS

Based on 39 consecutive patients (28 men; mean age 57 ± 15) with severe primary Mitral regurgitation (MR) caused by bileaflet MVP referred for MVR, we sought to identify the preoperative echocardiographic parameters associated with successful ROA repair.

RESULTS

Twenty-three patients (59%) underwent standard resectional MVR (SMVR) while 16 (41%) underwent ROA. Cardiopulmonary bypass and cross clamp times were lower in ROA than in SMVR (74 ± 27 min vs 99 ± 42 min and 49 ± 19 min vs 70 ± 25 min, respectively, p = 0.03 and p = 0.005). ROA patients were more frequently women (50% vs 13%, p = 0.027). Echocardiographic characteristics of successful ROA were mid-late systolic MR, a paradoxical systolic papillary muscle displacement, and paradoxical systolic annulus expansion (PAE). A prolapsing depth <10 mm, the absence of flail leaflet and ruptured chordae, the presence of multiple jets, more often in the central part of the valve were also associated with ROA. Non hemodynamic systolic anterior motion and residual trivial MR tended to be more frequent in ROA than in SMVR.

CONCLUSION

Simple and fast MVR using a ROA is feasible in 4/10 patients with complex forms of bileaflet MVP. Successful ROA patients were more frequently women, with mid-late systolic central multiple jet, low prolapse depth, absence of chordal rupture or flail leaflet and PAE.

Open transcatheter valve implantation for mitral annular calcification: One-year outcomes

Background

Transcatheter mitral valve implantation (TMVI) for native mitral valve pathology with severe mitral annular calcification has emerged as an alternative treatment option to conventional mitral valve surgery. The objective of this study was to evaluate patients who were referred for TMVI with severe mitral annular calcification and their procedural outcomes.

Methods

Retrospective analysis of patients from 2017 to 2020 referred for TMVI was carried out. Demographic characteristic details; surgical strategy; perioperative complications; and hospital stay, including 30-day and 1-year mortality, were analyzed.

Results

Eleven patients were referred for consideration of TMVI. The 8 patients who underwent TMVI had a median age of 74 years (range, 57-80 years), the median Society of Thoracic Surgeons score was 4.6 (range, 2.4-10.9), and European System for Cardiac Operative Risk Evaluation II score was 5.2% (2%-10.1%). The median cardiopulmonary bypass time and crossclamp times were 170 minutes (range, 150-248 minutes) and 152 minutes (range, 118-214 minutes), respectively. The median hospital stay was 29 days (range, 2-40 days). Thirty-day in hospital mortality was 12%, whereas 1-year mortality was 25%. There was symptomatic improvement with downgrade of New York Heart Association functional class from III or IV to I or II. The 3 patients who were turned down had a median age of 73 years, median Society of Thoracic Surgeons score was 13.4, and median European System for Cardiac Operative Risk Evaluation II score was 5.72%. They were alive at 12 months follow-up from the date of surgical assessment; however, all with New York Heart Association functional class III or IV symptoms.

Conclusions

We describe a series demonstrating the technical consideration and capability of transatrial TMVI to treat mitral annular calcification and native mitral valve disease. Our results are favorable when compared with TMVI global registry data for transseptal or transapical approach.

Mitral Annular Calcification in Obstructive Hypertrophic Cardiomyopathy: Prevalence and Outcomes

BACKGROUND

The prevalence and clinical impact of mitral annular calcification (MAC) in patients with obstructive hypertrophic cardiomyopathy (HCM) are largely unknown.

METHODS

We reviewed 2113 HCM patients who underwent septal myectomy from January 2000 to April 2016. Preoperative and intraoperative echocardiograms along with operative notes were reviewed to identify MAC. Survival was estimated and compared using Kaplan-Meier analysis and log-rank test. Cox regression analysis was used to identify factors independently associated with mortality.

RESULTS

MAC was identified in 390 (18.5%) patients. Older age, female sex, and presence of mitral valve leaflet calcification were strongly associated with higher odds of having MAC. Patients with MAC had higher resting LVOT gradients, more likely to have worse mitral valve regurgitation (MR) preoperatively, and more likely to undergo a concomitant mitral valve replacement (6% vs 1%, P<0.001) compared to those without MAC. Postoperatively, patients with MAC had marginally higher residual MR (13% vs 8%). After a median follow-up of 6.95 (IQR 3.7- 12.1) years, survival of patients with MAC at 1, 5 and 10 years was 99%, 92% and 69% respectively. Adjusted analysis identified MAC as an independent predictor of poor survival (HR 1.46, 95% CI 1.08 to 1.97; P=.014).

CONCLUSIONS

MAC is a frequent finding in older patients with obstructive HCM, more likely to be seen in females, and is associated with higher rates of concomitant mitral valve replacement. Despite higher prevalence of comorbidities, MAC remained an independent predictor for overall mortality following septal myectomy.

Mitral valve prolapse morphofunctional features by cardiovascular magnetic resonance: more than just a valvular disease

INTRODUCTION

Mitral valve (MV) prolapse (MVP) is a primary valvular abnormality. We hypothesized that additionally there are concomitant abnormalities of the left ventricle (LV) and MV apparatus in this entity even in the absence of significant mitral regurgitation (MR).

OBJECTIVE

To characterize MV and LV anatomic and functional features in MVP with preserved LV ejection fraction, with and without significant MR, using cardiovascular magnetic resonance (CMR).

METHODS

Consecutive MVP patients (n = 80, mean 52 years, 37% males) with preserved LV ejection fraction, and 44 controls (46 years, 52% males) by CMR were included, as well as 13 additional patients with "borderline" MVP. From cine images we quantified LV volumes, MV and LV anatomic measurements (including angle between diastolic and systolic annular planes, annular displacement, and basal inferolateral hypertrophy) and, using feature tracking, longitudinal and circumferential peak systolic strains.

RESULTS

Significant MR was found in 46 (56%) MVP patients. Compared with controls, MVP patients had LV enlargement, basal inferolateral hypertrophy, higher posterior annular excursion, and reduced shortening of the papillary muscles. LV basal strains were significantly increased, particularly in several basal segments. These differences remained significant in patients without significant MR, and many persisted in "borderline" MVP.

CONCLUSIONS

In patients with MVP and preserved LV ejection fraction there is LV dilatation, basal inferolateral hypertrophy, exaggerated posterior annular displacement and increased basal deformation, even in the absence of significant MR or overt MVP. These findings suggest that MVP is a disease not only of the MV but also of the adjacent myocardium.

Association between mitral annulus calcification and subtypes of heart failure rehospitalization

BACKGROUND

Mitral annulus calcification (MAC) has been associated with cardiovascular diseases, including heart failure (HF); however, the associations between MAC and both the category and etiology of HF have not been fully elucidated. The aim of this study was to investigate the relationship between MAC and three types of HF rehospitalization: HF with preserved ejection fraction (HFpEF), HF with mid-range EF (HFmrEF), and HF with reduced EF (HFrEF).

METHODS

We enrolled consecutive patients undergoing echocardiography, who were admitted to our hospital for clinically indicated congestive HF between April 2014 and March 2018. Cox proportionalhazards models were used after adjusting for age, gender, and hypertension.

RESULTS

Of 353 patients, 40 (11.3%) had MAC. With a median follow-up of 2.8 years, 100 (28%) patients were rehospitalized for congestive HF (HFpEF 40%, HFmrEF 16%, HFrEF 44%, respectively). According to the Kaplan-Meier method, the estimated incidence of HFpEF rehospitalization in the MAC group was significantly greater than that in the non-MAC group (p < 0.001) whereas the incidences of HFmrEF and HFrEF rehospitalization were comparable between the groups (p = 0.101 and p = 0.291, respectively). In a multivariate analysis, MAC remained significantly associated with HFpEF rehospitalization (hazard ratio: 3.379; 95% confidence interval: 1.651-6.597). At initial HF hospitalization, E/e' was significantly higher in the MAC group (both septum and lateral, p < 0.05), suggesting a possible relationship between MAC and left ventricular diastolic function.

CONCLUSIONS

Mitral annulus calcification was associated with increased HFpEF rehospitalization and might be a cause of left ventricular diastolic dysfunction.

Mitral Annular Dynamics in AF Versus Sinus Rhythm: Novel Insights Into the Mechanism of AFMR

OBJECTIVES

This study aimed to investigate mitral annular dynamics in atrial fibrillation (AF) and after sinus rhythm restoration, and to assess the relationship between annular dynamics and mitral regurgitation (MR).

BACKGROUND

AF can be associated with MR that improves after sinus rhythm restoration. Mechanisms underlying this atrial functional MR (AFMR) are ill-understood and generally attributed to left atrial remodeling.

METHODS

Fifty-three patients with persistent AF and normal left ventricular ejection fraction were prospectively examined by means of 3-dimensional transesophageal echocardiography before, immediately after, and 6 weeks after electric cardioversion to sinus rhythm. Annular motion was assessed during AF and in sinus rhythm with the use of 3-dimensional analysis software, and the relationship with MR severity was explored.

RESULTS

During AF and immediately after sinus rhythm restoration, the mitral annulus behaved relatively adynamically, with an overall change in annular area of 10.3% (95% CI: 8.7%-11.8%) and 12.2% (95% CI: 10.6%-13.8%), respectively. At follow-up, a significant increase in annular dynamics (19.0%; 95% CI: 17.4%-20.6%; P < 0.001) was observed, owing predominantly to an increase in presystolic contraction (P < 0.001). The effective regurgitant orifice area decreased from 0.15 cm² (0.10 cm²-0.23 cm²) during AF to 0.09 cm² (0.05 cm²-0.12 cm²) at follow-up (P < 0.001) in the total cohort, and from 0.27 (0.23-0.33) to 0.16 (0.12-0.29) in the subgroup with effective regurgitant orifice area (EROA) ≥0.20 cm². The change in presystolic annular motion was the only independent determinant of the decrease in MR severity (P = 0.027), by optimizing annular-leaflet imbalance. Patients with more pronounced blunting of presystolic dynamics had a higher EROA (P < 0.001), because of a lower total-to-closed leaflet area ratio (P < 0.001) at each point in time. This ratio was the strongest independent determinant of AFMR severity (adjusted P = 0.003).

CONCLUSIONS

Mitral annular dynamics are impaired in AF, with blunted presystolic narrowing that contributes to AFMR. Sinus rhythm restoration allows gradual recovery of presystolic annular dynamics. Improved annular dynamics decrease AFMR severity by optimizing annular-leaflet imbalance, regardless of LA remodeling.

Valvular calcification and risk of peripheral artery disease: the Multi-Ethnic Study of Atherosclerosis (MESA)

AIMS

The detection of cardiac valvular calcification on routine imaging may provide an opportunity to identify individuals at increased risk for peripheral artery disease (PAD). We investigated the associations of aortic valvular calcification (AVC) and mitral annular calcification (MAC) with risk of developing clinical PAD or a low ankle-brachial index (ABI).

METHODS AND RESULTS

AVC and MAC were measured on cardiac computed tomography in 6778 Multi-Ethnic Study of Atherosclerosis participants without baseline PAD between 2000 and 2002. Clinical PAD was ascertained through 2015. Incident low ABI, defined as ABI <0.9 and decline of ≥0.15, was assessed among 5762 individuals who had an ABI >0.9 at baseline and at least one follow-up ABI measurement 3-10 years later. Adjusted Cox proportional hazards and Poisson regression modelling were used to determine the association of valvular calcification with clinical PAD and low ABI, respectively. There were 117 clinical PAD and 198 low ABI events that occurred over a median follow-up of 14 years and 9.2 years, respectively. The presence of MAC was associated with an increased risk of clinical PAD [hazard ratio 1.79; 95% confidence interval (CI) 1.04-3.05] but not a low ABI (rate ratio 1.28; 95% CI 0.75-2.19). No significant associations were noted for the presence of AVC and risk of either clinical PAD.

CONCLUSION

MAC is associated with an increased risk of developing clinical PAD. Future studies are needed to corroborate our findings and better understand whether MAC holds any predictive value as a risk marker for PAD.

Mitral prolapsing volume is associated with increased cardiac dimensions in patients with mitral annular disjunction

Introduction

In patients with mitral annular disjunction (MAD), it can be difficult to assess the severity of mitral regurgitation (MR), as they present with a prolapsing volume (i.e. volume resulting from mitral valve prolapse, blood volume shift) rather than a regurgitant jet. The influence of the mitral prolapsing volume (MPV) on cardiac dimensions is unknown. We hypothesised that the severity of MR is underestimated in these patients. Our aim was to measure MPV and to investigate its influence on cardiac dimensions in patients with MAD.

Methods

We retrospectively included 131 consecutive patients with MAD from our institution’s echocardiographic database. Transthoracic echocardiography was used to assess MPV. Additionally, we established a control group of 617 consecutive patients with degenerative mitral valve disease and performed propensity score matching.

Results

Median MPV in the MAD group was 12 ml. MPV was an independent predictor for left ventricular end-diastolic (LVEDD) and end-systolic diameter (LVESD) and left atrial volume (all p < 0.001). In patients with large prolapsing volumes (> 15 ml), LVEDD (56 ± 6 mm vs 51 ± 6 mm, p < 0.001), LVESD [38 mm (34–41) vs 34 mm (31–39), p < 0.01] and left atrial volume [105 ml (86–159) vs 101 ml (66–123), p = 0.04] were significantly increased compared to matched patients with degenerative mitral valve disease and similarly assessed severity of MR.

Conclusion

Due to a volume shift based on the MPV rather than an actual regurgitant jet, MR severity cannot be assessed adequately in MAD patients. Increased MPV induces ventricular and atrial enlargement. These findings warrant future studies to focus on MPV as an additional parameter for assessment of the severity of MR in MAD patients.

Supplementary Information

The online version of this article (10.1007/s12471-021-01575-6) contains supplementary material, which is available to authorized users.

Mitral Annular Calcification and Calcific Mitral Stenosis: Role of Echocardiography in Hemodynamic Assessment and Management

As the life expectancy of the population continues to increase, mitral annular calcification has emerged as an important cause of mitral stenosis (MS), commonly referred to as calcific or degenerative MS. Mitral annular calcification results in valvular stenosis when calcification extends into the base of the mitral leaflet(s) and displaces the mitral valve hinge point(s) into the left ventricular inlet. Echocardiographic determination of mitral vale area is fraught with difficulties and often precludes using planimetry or the Hatle formula. Given the numerous confounders that affect transmitral flow in calcific MS, evaluation of lesion severity should incorporate flow-independent methods such as the continuity equation and the mitral valve dimensionless index. In light of the significant risks entailed, there is little enthusiasm for mitral valve replacement in patients with calcific MS. Transcatheter mitral valve replacement is generally offered on a compassionate use basis to patients deemed to be at high surgical risk.

The current diagnosis and treatment of high-risk patients with chronic primary and secondary mitral valve regurgitation

Mitral valve regurgitation (MR) is due primarily to either primary degeneration of the mitral valve with Barlow's or fibroelastic disease or is secondary to ischemic or nonischemic cardiomyopathies. Echocardiography is essential to assess MR etiology and severity, the remodeling of cardiac chambers and to characterize longitudinal chamber changes to determine optimal therapies. Surgery is recommended for severe primary MR if persistent symptoms are present or if left ventricle dysfunction is present with an EF <60% or a left ventricle end-systolic diameter ≥40 mm. For secondary MR, therapy of heart failure with vasodilators and diuretics improves forward cardiac output. Coronary artery bypass grafts (CABG) or percutaneous coronary intervention (PCI) should be considered for severe MR due to ischemia. This review summarizes the pathophysiology, the characteristics, the management and the different interventions for high risk patients with chronic primary and secondary MR.

Arrhythmic Mitral Valve Prolapse: Introducing an Era of Multimodality Imaging-Based Diagnosis and Risk Stratification

Mitral valve prolapse is a common cardiac condition, with an estimated prevalence between 1% and 3%. Most patients have a benign course, but ever since its initial description mitral valve prolapse has been associated to sudden cardiac death. Although the causal relationship between mitral valve prolapse and sudden cardiac death has never been clearly demonstrated, different factors have been implicated in arrhythmogenesis in patients with mitral valve prolapse. In this work, we offer a comprehensive overview of the etiology and the genetic background, epidemiology, pathophysiology, and we focus on the state-of-the-art imaging-based diagnosis of mitral valve prolapse. Going beyond the classical, well-described clinical factors, such as young age, female gender and auscultatory findings, we investigate multimodality imaging features, such as alterations of anatomy and function of the mitral valve and its leaflets, the structural and contractile anomalies of the myocardium, all of which have been associated to sudden cardiac death.

Advances in Rheumatic Mitral Stenosis: Echocardiographic, Pathophysiologic, and Hemodynamic Considerations

Echocardiography is the primary imaging modality used in patients with mitral stenosis. Doppler-derived measurements of mitral pressure half-time are commonly used to calculate mitral valve area, but a number of hemodynamic confounders associated with advanced age limit its utility. Planimetry remains the gold standard for determining mitral valve area and may be performed using two- or three-dimensional imaging. Although the Wilkins score has been used for >30 years to predict balloon mitral valvuloplasty outcomes, newer scoring systems have been proposed to improve predictive accuracy. Some patients undergoing technically successful balloon mitral valvuloplasty may not have satisfactory clinical outcomes. These individuals may be identified by the presence of reduced net atrioventricular compliance, which can be measured echocardiographically. Exercise testing may be useful in patients with mitral stenosis whose symptomatic status is incongruous their mitral valve area. Last, reduced left atrial systolic strain, an indicator of poor left atrial compliance, has been shown to reliably predict adverse outcomes in patients with mitral stenosis. The author discusses the hemodynamics and path ophysiology of mitral stenosis and reviews current and emerging roles of echocardiography in its evaluation.

Mitral annulus is dilated with preserved function in acromegaly regardless of its activity: Insights from the three-dimensional speckle-tracking echocardiographic MAGYAR-Path Study

INTRODUCTION AND OBJECTIVE

Acromegaly is a rare, chronic and slowly developing endocrine disorder caused by hypersecretion of human growth hormone and consequently of insulin-like growth factor-1 during adulthood. The present study was conducted to assess mitral annular (MA) size and function between acromegalic patients and age- and gender-matched healthy controls by three-dimensional speckle-tracking echocardiography (3D-STE). It also aimed to examine whether activity of the disease has any effect on MA parameters.

METHODS

This study included 27 patients with acromegaly, three of whom were excluded due to inferior image quality. The mean age of the remaining 24 patients was 55.7±14.0 years and seven were male. Complete two-dimensional Doppler echocardiography and 3D-STE were performed in all cases.

RESULTS

Significantly increased end-diastolic and end-systolic MA diameter (2.81±0.36 cm vs. 2.44±0.34 cm and 2.00±0.32 cm vs. 1.65±0.37 cm, respectively), area (9.67±2.33 cm² vs. 7.38±1.93 cm² and 5.14±1.62 cm² vs. 3.74±1.19 cm², respectively) and perimeter (11.76±1.42 cm vs. 10.27±1.33 cm and 8.61±1.23 cm vs. 7.36±1.10 cm, respectively) were demonstrated in acromegalic patients compared with control subjects. MA functional parameters were not significantly altered compared to those of healthy individuals.

CONCLUSIONS

MA dilation could be seen in acromegaly regardless of its activity. Acromegaly is not associated with MA functional impairment.

Morphology display and hemodynamic testing using 3D printing may aid in the prediction of LVOT obstruction after mitral valve replacement

AIMS

Left ventricular outflow tract(LVOT) obstruction after mitral valve replacement can be life-threatening once occur. We simulated mitral valve replacement preoperatively using dynamic, three-dimensional(3D) printed models to help predict LVOT obstruction in this study.

METHODS

56 patients who underwent mitral valve replacement were included. Prediction of LVOT obstruction in vitro was based on the data from 4 sources: digital, anatomical, flexible, and dynamic model. Digital 3D models were designed based on computed tomography (CT) image dataset and printed with photopolymer resin to create a 3D anatomical model, which contributed to the morphology display. Then, flexible models were made from specialized silicone, which is similar to cardiac tissue in terms of its softness and elasticity. Dynamic function was achieved by coupling flexible models to a mock circulatory system (MCS). Besides, surgery simulation and hemodynamic testing was done using dynamic 3D printed model and patients were regrouped based on hemodynamic change. Finally, different methods for prediction of LVOT obstruction as well as classification based on two-dimensional image data and dynamic model were compared with surgical results as golden standard.

RESULTS

(1)Qualitatively, the prediction of LVOT obstruction using the dynamic 3D model was the most accurate and was consistent with clinical outcomes. In the four patients who developed LVOT obstruction after surgery, only two were at a high risk based on the other three models. (2)Quantitatively, the area of neo-LVOT predicted by the digital, anatomical, and flexible models was higher compared with the dynamic models and in-vivo after surgery. (3)Classification based on traditional criteria(two-dimensional image data) was different from surgical results. While the difference between dynamic model and surgical results was not statistically different.

CONCLUSIONS

After coupling the flexible model with the mock circulatory system, the dynamic 3D model predicted LVOT obstruction more accurately with hemodynamic testing compared with morphological evaluation. 3D printing can assist surgeons to better plan mitral valve replacement than traditional image data.

Multimodality imaging anatomy of interatrial septum and mitral annulus

The detailed anatomy of the interatrial septum (IAS) and mitral annulus (MA) as observed on cardiac magnetic resonance, computed tomography and two-dimensional/three-dimensional transthoracic and transesophageal echocardiography is reviewed. The IAS comprises of two components: the septum primum that is membrane-like forming the floor of the fossa ovalis (FO) and the septum secundum that is a muscular rim that surrounds the FO. The latter is an enfolding of atrial wall forming an interatrial groove. Named Waterston's groove, it is filled with adipose tissue on the epicardial side. Thus, the safest area for transseptal puncture (TSP) is within the limits of the FO floor, which provides direct interatrial access. While crossing an intact septum is a well-established procedure, TSP is a more complex and time-consuming procedure in the presence of patent foramen ovalis, aneurysmal FO or atrial septal defect closure devices. MA comprises two distinctive segments: an anterior-straight and a posterior-curved segment. The posterior MA is a thin, discontinuous fibrous 'string', interspersed with adipose tissue, where four components converge: the atrial and ventricular musculature, epicardial adipose tissue and the leaflet's hinge line. In parts of where this fibrous string is deficient or absent, the posterior leaflet is inserted directly on ventricular and atrial myocardium rendering the MA less robust and producing an 'asymmetric' dilation. The marked vulnerability of posterior MA to calcifications might be due to its insertion on the crest of ventricular myocardium being subject to friction injury due to the contraction and relaxation of LV.

Randomized, Controlled Trial Comparing Mitral Valve Repair With Leaflet Resection Versus Leaflet Preservation on Functional Mitral Stenosis

Background:

Equipoise exists between the use of leaflet resection and preservation for surgical repair of mitral regurgitation caused by prolapse. We therefore performed a randomized, controlled trial comparing these 2 techniques, particularly in regard to functional mitral stenosis.

Methods:

One hundred four patients with degenerative mitral regurgitation surgically amenable to either leaflet resection or preservation were randomized at 7 specialized cardiac surgical centers. Exclusion criteria included anterior leaflet or commissural prolapse, as well as a mixed cause for mitral valve disease. Using previous data, we determined that a sample size of 88 subjects would provide 90% power to detect a 5–mm Hg difference in mean mitral valve gradient at peak exercise, assuming an SD of 6.7 mm with a 2-sided test with α=5% and 10% patient attrition. The primary end point was the mean mitral gradient at peak exercise 12 months after repair.

Results:

Patient age, proportion who were female, and Society of Thoracic Surgeons risk score were 63.9±10.4 years, 19%, and 1.4±2.8% for those who were assigned to leaflet resection (n=54), and 66.3±10.8 years, 16%, and 1.9±2.6% for those who underwent leaflet preservation (n=50). There were no perioperative deaths or conversions to replacement. At 12 months, moderate mitral regurgitation was observed in 3 subjects in the leaflet resection group and 2 in the leaflet preservation group. The mean transmitral gradient at 12 months during peak exercise was 9.1±5.2 mm Hg after leaflet resection and 8.3±3.3 mm Hg after leaflet preservation ( P =0.43). The participants had similar resting peak (8.3±4.4 mm Hg versus 8.4±2.6 mm Hg; P =0.96) and mean resting (3.2±1.9 mm Hg versus 3.1±1.1 mm Hg; P =0.67) mitral gradients after leaflet resection and leaflet preservation, respectively. The 6-minute walking distance was 451±147 m for those in the leaflet resection versus 481±95 m for the leaflet preservation group ( P =0.27).

Conclusions:

In this adequately powered randomized trial, repair of mitral prolapse with either leaflet resection or leaflet preservation was associated with similar transmitral gradients at peak exercise at 12 months postoperatively. These data do not support the hypothesis that a strategy of leaflet resection (versus preservation) is associated with a risk of functional mitral stenosis.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier NCT02552771.

Automatic estimation of aortic and mitral valve displacements in dynamic CTA with 4D graph-cuts

The location of the mitral and aortic valves in dynamic cardiac imaging is useful for extracting functional derived parameters such as ejection fraction, valve excursions, and global longitudinal strain, and when performing anatomical structures tracking using slice following or valve intervention's planning. Completely automatic segmentation methods are still challenging tasks because of their fast movements and the different positions that prevent good visibility of the leaflets along the full cardiac cycle. In this article, we propose a processing pipeline to track the displacement of the aortic and mitral valve annuli from high-resolution cardiac four-dimensional computed tomographic angiography (4D-CTA). The proposed method is based on the dynamic separation of left ventricle, left atrium and aorta using statistical shape modeling and an energy minimization algorithm based on graph-cuts and has been evaluated on a set of 15 electrocardiography-gated 4D-CTAs. We report a mean agreement distance between manual annotations and our proposed method of 2.52±1.06 mm for the mitral annulus and 2.00±0.69 mm for the aortic valve annulus based on valve locations detected from manual anatomical landmarks. In addition, we show the effect of detecting the valvular planes on derived functional parameters (ejection fraction, global longitudinal strain, and excursions of the mitral and aortic valves).

Relation of Mitral Annulus and Left Atrial Dysfunction to the Severity of Functional Mitral Regurgitation in Patients with Dilated Cardiomyopathy

METHODS

56 patients (58 ± 17 years, 42 men) with DCM and FMR and 52 controls, prospectively enrolled, underwent 3DTTE dedicated for mitral valve (MV), LA, and left ventricle (LV) quantitative analysis.

RESULTS

Patients with FMR vs. controls presented increased MA size and sphericity during the entire systole, whereas MA fractional area change (MAFAC) and MA displacement were decreased (15 ± 5 vs. 28 ± 5%; and 5 ± 3 vs. 10 ± 2 mm, p < 0.001). In patients with moderate/severe FMR, MA diameters correlated with PISA radius, EROA, and regurgitant volume (Rvol), as also did the MA area (with PISA radius, EROA, and Rvol: r = 0.48, r = 0.58, and r = 0.47, p < 0.05). MAFAC correlated inversely with EROA and Rvol (r = -0.32 and r = -0.35, p < 0.05), with both active and total LA emptying fractions and with LV ejection fraction as well. In a stepwise multivariate regression model, decreased MAFAC and increased LA volume independently predicted patients with severe FMR.

CONCLUSIONS

Patients with DCM and FMR have MA geometry remodeling and contractile dysfunction, correlated with the severity of FMR. MA contractile dysfunction correlated with both LA and left LV pumps dysfunctions and predicted patients with severe FMR. Our results provide new insights that might help with better selection of patients for MV transcatheter procedures.

Determinants of Discrepancy in the Left Ventricular Systolic Function Evaluation Between Preoperative and Intraoperative Evaluations

Unexpectedly decreased left ventricular global systolic function can be difficult to manage, even for patients undergoing elective cardiac surgery, and should prompt a multidisciplinary discussion. Therefore, in this review, we discuss the evidence describing key perioperative variables expected to influence left ventricular systolic function to facilitate this discussion.