Impact of impinging wall jet on color Doppler quantification of mitral regurgitation

Utilization of Engineering Advances for Detailed Biomechanical Characterization of the Mitral-Ventricular Relationship to Optimize Repair Strategies: A Comprehensive Review

The geometrical details and biomechanical relationships of the mitral valve-left ventricular apparatus are very complex and have posed as an area of research interest for decades. These characteristics play a major role in identifying and perfecting the optimal approaches to treat diseases of this system when the restoration of biomechanical and mechano-biological conditions becomes the main target. Over the years, engineering approaches have helped to revolutionize the field in this regard. Furthermore, advanced modelling modalities have contributed greatly to the development of novel devices and less invasive strategies. This article provides an overview and narrative of the evolution of mitral valve therapy with special focus on two diseases frequently encountered by cardiac surgeons and interventional cardiologists: ischemic and degenerative mitral regurgitation.

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed "moderate" MR.

Characterization of Primary Mitral Regurgitation With Flail Leaflet and/or Wall-Impinging Flow

BACKGROUND

Echocardiography guidelines note that a flail leaflet is a specific criterion for severe mitral regurgitation (MR) and that regurgitant severity is underestimated in wall-impinging jets (Coandă effect). Both findings are often considered to be pathognomonic of severe MR.

OBJECTIVES

In this study, the authors sought to determine the association of flail leaflet and Coandă effect with MR severity quantified by means of cardiac magnetic resonance (CMR).

METHODS

The authors enrolled 158 consecutive patients with primary MR according to echocardiography and CMR. The presence of a flail leaflet or Coandă was determined for each patient. CMR regurgitant volume (RV) and regurgitant fraction (RF) were quantified for all patients.

RESULTS

There were 55 patients (35%) with a flail leaflet, 52 (33%) with Coandă, and 22 (14%) with a flail leaflet and Coandă. The mean CMR mitral RV and RF progressively increased in patients without a Coandă or flail, a Coandă, a flail, or a Coandă and a flail (RV: 28 ± 21 mL vs 43 ± 23 mL vs 58 ± 29 mL vs 64 ± 25 mL [P < 0.001]; RF: 25% ± 16% vs 34% ± 14% vs 41% ± 12% vs 45% ± 12% [P < 0.001]). With the use of CMR RV, 35%, 46%, and 59% of patients had severe MR with the presence of a Coandă, flail leaflet, or both, respectively. With the use of CMR RF, 25%, 31%, and 40% of patients had severe MR with the presence of a Coandă, flail leaflet, or both, respectively.

CONCLUSIONS

While the presence of a flail leaflet and Coandă effect on echocardiography are associated with higher regurgitant volumes and fractions, they are frequently not associated with severe MR as assessed by means of CMR. (Comparison Study of Echocardiography and Cardiovascular Magnetic Resonance Imaging in the Assessment of Mitral and Aortic Regurgitation; NCT04038879).

Echocardiographic Advances in Dilated Cardiomyopathy

Although the overall survival of patients with dilated cardiomyopathy (DCM) has improved significantly in the last decades, a non-negligible proportion of DCM patients still shows an unfavorable prognosis. DCM patients not only need imaging techniques that are effective in diagnosis, but also suitable for long-term follow-up with frequent re-evaluations. The exponential growth of echocardiography’s technology and performance in recent years has resulted in improved diagnostic accuracy, stratification, management and follow-up of patients with DCM. This review summarizes some new developments in echocardiography and their promising applications in DCM. Although nowadays cardiac magnetic resonance (CMR) remains the gold standard technique in DCM, the echocardiographic advances and novelties proposed in the manuscript, if properly integrated into clinical practice, could bring echocardiography closer to CMR in terms of accuracy and may certify ultrasound as the technique of choice in the follow-up of DCM patients. The application in DCM patients of novel echocardiographic techniques represents an interesting emergent research area for scholars in the near future.

Transcatheter Repair of the Mitral Valve: Relevant Pathophysiology, Investigation, and Management

Mitral regurgitation (MR) is a common condition causing significant morbidity and mortality in the Western world. Although surgical therapy has developed over 5 decades to provide solutions, only a minority of patients undergo surgery. The last decade has seen the emergence and application of multiple transcatheter techniques in attempts to address this undertreated population with the large clinical experience of MitraClip providing the most insight. Clear understanding of the pathophysiology of different MR types as well as the role of particularly secondary MR on patient's clinical syndrome allow for better prediction as to which patient subgroups will benefit from different repair techniques or intervention at all. Most of the techniques are based on surgical technique and are applied as single-device/technique solutions, whether leaflet, chordal, or annular solutions, but with broadening experience, combination therapies are likely to find a place in creating a more complete and surgical-like solution.

Acquired von Willebrand syndrome and factor VIII in patients with moderate to severe mitral regurgitation undergoing transcatheter mitral valve repair

Background and Hypothesis

The acquired von Willebrand syndrome (AvWS), which predisposes to bleeding events, is often related to valvular heart diseases. We investigated possible implications of AvWS and factor VIII levels in patients with moderate to severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR).

Methods and Results

123 patients with moderate to severe MR were prospectively enrolled. Complete measurements of von Willebrand Factor activity (vWFAct), von Willebrand Factor antigen (vWFAg), and factor VIII expression before and 4 weeks after TMVR were available in 85 patients. At baseline, seven patients had a history of gastrointestinal bleeding, two patients suffered bleeding events during their hospital stay, and one patient had a bleeding 4 weeks after TMVR. Even though vWFAct, vWFAct/vWFAg ratio and vWFAg values did not change after TMVR, we observed a significantly lower vWFAct/vWFAg ratio in patients with primary MR as compared to patients with secondary MR both at baseline (p = 0.022) and 4 weeks following the TMVR procedure (p = 0.003). Additionally, patients with a mean mitral valve gradient ≥4 mmHg after TMVR had significantly lower vWFAct/vWFAg ratios as compared to patients with a mean mitral valve gradient <4 mmHg (p = 0.001).

Conclusions

MR of primary etiology was associated with lower vWFAct/vWFAg ratio, hinting toward HMWM loss due to shear stress caused by eccentric regurgitation jets. In addition, morphological changes leading to postprocedural transmitral gradients ≥4 mmHg were related to lower vWFAct/vWFAg ratio 4 weeks after the procedure. Alterations of the vWFAct/vWFAg ratio in turn did not translate into a greater risk for bleeding events.

The impact of different geometric assumption of mitral annulus on the assessment of mitral regurgitation volume by Doppler method

Background

Mitral regurgitation volume (MRvol) by quantitative pulsed Doppler (QPD) method previously recommended suffers from geometric assumption error because of circular geometric assumption of mitral annulus (MA). Therefore, the aim of this study was to evaluate the impact of different geometric assumption of MA on the assessment of MRvol by two-dimensional transthoracic echocardiographic QPD method.

Methods

This study included 88 patients with varying degrees of mitral regurgitation (MR). The MRvol was evaluated by QPD method using circular or ellipse geometric assumption of MA. MRvol derived from effective regurgitant orifice area by real time three-dimensional echocardiography (RT3DE) multiplied by MR velocity-time integral was used as reference method.

Results

Assumption of a circular geometry of MA, QPD-MA_A4C and QPD-MA_PLAX overestimated the MRvol by a mean difference of 10.4 ml (P < 0.0001) and 22.5 ml (P < 0.0001) compared with RT3DE. Assumption of an ellipse geometry of MA, there was no significant difference of MRvol (mean difference = 1.7 ml, P = 0.0844) between the QPD-MA_{A4C + A2C} and the RT3DE.

Conclusions

Assuming that the MA was circular geometry previously recommended, the MRvol by QPD-MA_A4C was overestimated compared with the reference method. However, assuming that the MA was ellipse geometry, the MRvol by the QPD-MA_{A4C + A2C} has no significant difference with the reference method.

Advanced cardiac MRI techniques for evaluation of left-sided valvular heart disease

The most common types of left‐sided valvular heart disease (VHD) in the Western world are aortic valve stenosis, aortic valve regurgitation, and mitral valve regurgitation. Comprehensive clinical evaluation entails both hemodynamic analysis and structural as well as functional characterization of the left ventricle. Cardiac magnetic resonance imaging (MRI) is an established diagnostic modality for assessment of left‐sided VHD and is progressively gaining ground in modern‐day clinical practice. Detailed flow visualization and quantification of flow‐related biomarkers in VHD can be obtained using 4D flow MRI, an imaging technique capable of measuring blood flow in three orthogonal directions over time. In addition, recent MRI sequences enable myocardial tissue characterization and strain analysis. In this review we discuss the emerging potential of state‐of‐the‐art MRI including 4D flow MRI, tissue mapping, and strain quantification for the diagnosis and prognosis of left‐sided VHD.

Level of Evidence: 1

Technical Efficacy Stage: 1

J. Magn. Reson. Imaging 2018. J. MAGN. RESON. IMAGING 2018;48:318–329.

Identification and Quantification of Degenerative and Functional Mitral Regurgitation for Patient Selection for Transcatheter Mitral Valve Repair

Chronic mitral regurgitation (MR), whether due to valve degeneration or secondary to myocardial disease, affects an increasing proportion of the aging population. Percutaneous mitral valve interventions, including edge-to-edge repair, are emerging as feasible and effective therapy for patients with severe MR at high or prohibitive surgical risk. Imaging with echocardiography is crucial for patient selection by evaluating mitral anatomy, the mechanism of dysfunction, and MR severity. In this article, the authors review the imaging characteristics for identifying and quantifying degenerative and functional MR for transcatheter mitral valve repair.

Intravascular hemolysis in patients with mitral regurgitation: Evaluation by erythrocyte creatine

BACKGROUND

Intravascular hemolysis has been reported in patients with cardiac valve prostheses, but intravascular hemolysis in patients with mitral regurgitation with native valve has not been evaluated in detail. We designed a study to elucidate the impact of regurgitation flow on intravascular hemolysis in patients with primary mitral regurgitation by measuring erythrocyte creatine.

METHODS

Erythrocyte creatine was enzymatically assayed in 29 patients with moderate to severe primary mitral regurgitation and 12 age-matched healthy volunteers. The size and characteristics of mitral regurgitation were determined by color Doppler echocardiography.

RESULTS

Erythrocyte creatine was significantly higher in patients with eccentric jet (n=17, 2.64±0.77μmol/g Hb) than that of central jet (n=12, 1.68±0.13μmol/g Hb) and control subjects (1.39±0.25μmol/g Hb). Patients with eccentric jet had a significantly lower erythrocyte count and hemoglobin (385±58 x10⁴/μL and 116±19g/l) compared to those with central jet (450±47×10⁴/μL and 137±14g/l) and control subjects (433±31×10⁴/μL and 134±19g/l). There were no significant differences in age, estimated glomerular filtration rate, pulmonary artery systolic pressure, left atrial size and left ventricular end-diastolic dimension between patients with eccentric jet and central jet.

CONCLUSIONS

Intravascular hemolysis associated with subclincal anemia in patients with eccentric jet was due to the destruction of erythrocyte by collision of the eccentric jet to the atrial wall.

Assessment of the severity of native mitral valve regurgitation

Mitral regurgitation (MR) is a major cause of cardiovascular morbidity and mortality. MR is classified as primary (organic) if it is due to an intrinsic valve abnormality, or secondary (functional) if the etiology is because of remodeling of left ventricular geometry and/or valve annulus. Transthoracic echocardiography (TTE) is the initial modality for MR evaluation. Parameters used for the assessment of MR include valve structure, cardiac remodeling, and color and spectral Doppler. Quantitative measurements include effective regurgitant orifice area, regurgitant volume, and regurgitant fraction. Knowledge of advantages and limitations of echo-Doppler parameters is essential for accurate results. An integrative approach is recommended in overall grading of MR as mild, moderate, or severe since singular parameters may be affected by several factors. When the mechanism and/or grade of MR is unclear from the TTE or is discrepant with the clinical scenario, further evaluation with transesophageal echocardiography or cardiac magnetic resonance imaging is recommended, the latter emerging as a powerful MR quantitation tool.

2017 ACC Expert Consensus Decision Pathway on the Management of Mitral Regurgitation: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways

Mitral regurgitation (MR) is a complex valve lesion that can pose significant management challenges for the cardiovascular clinician. This Expert Consensus Document emphasizes that recognition of MR should prompt an assessment of its etiology, mechanism, and severity, as well as indications for treatment. A structured approach to evaluation based on clinical findings, precise echocardiographic imaging, and when necessary, adjunctive testing, can help clarify decision making. Treatment goals include timely intervention by an experienced heart team to prevent left ventricular dysfunction, heart failure, reduced quality of life, and premature death.

Outcome of Significant Functional Tricuspid Regurgitation Late After Mitral Valve Replacement for Predominant Rheumatic Mitral Stenosis

Significant tricuspid regurgitation (TR) can contribute to increased morbidity and mortality in patients undergoing mitral valve surgery for mitral stenosis. The aim of this study was to evaluate the association between the severity of preoperative functional TR and late adverse outcomes in patients undergoing mitral valve replacement (MVR). The study group comprised 68 patients (54 women, 14 men; mean age 45 ±10 years) with rheumatic mitral stenosis (MS) who had undergone MVR without tricuspid valve surgery between 4 and 13 years (mean 8.1 ±2.6 years) before their last clinical examination. All patients underwent a complete preoperative and late postoperative color-Doppler echocardiographic examination. The severity of TR was assessed echocardiographically by using color-Doppler flow images and flow direction in the inferior vena cava or hepatic veins. Patients were classified into 2 groups; 42 with mild (62%) and 26 with significant (38%) TR. Patients with significant TR showed longer preoperative symptomatic period and more atrial fibrillation than those with mild TR. All patients had medical treatment. Functional capacity and NYHA class of the patients in both groups improved significantly after MVR. Freedom from symptomatic heart failure (functional class III or IV) was higher (86% vs 54%) and the need for hospitalization was significantly lower for the mild TR group. Significant preoperative functional TR diagnosed by echocardiography was associated with an adverse outcome. Therefore, further studies are needed to evaluate the effect of concomitant tricuspid valve repair on the late outcome of patients undergoing mitral valve surgery in order to prevent significant late morbidity.

Predicting Left Ventricular Dysfunction after Surgery in Patients with Chronic Mitral Regurgitation: Assessment of Myocardial Deformation by 2-Dimensional Multilayer Speckle Tracking Echocardiography

Background and Objectives

The development of postoperative left ventricular (LV) dysfunction is a frequent complication in patients with chronic severe mitral valve regurgitation (MR) and portends a poor prognosis. Assessment of myocardial deformation enables myocardial contractility to be accurately estimated. The aim of the present study was to evaluate the predictive value of preoperative regional LV contractile function assessment using two-dimensional multilayer speckle-tracking echocardiography (2D MSTE) analysis in patients with chronic severe MR with preserved LV systolic function.

Subjects and Methods

Forty-three consecutive patients with chronic severe MR with preserved LV systolic function scheduled for mitral valve replacement (MVR) or MV repair were prospectively enrolled. Serial echocardiographic studies were performed before surgery, at 7 days follow-up, and at least 3 months follow-up postoperatively. The conventional echocardiographic parameters were analyzed. Global longitudinal strain (GLS) was obtained quantitatively by 2D MSTE.

Results

The mean age of patients was 51.7±14.3 years and 25 (58.1%) were male. In receiver-operating characteristic curve analysis, the most useful cutoff value for discriminating postoperative LV remodeling in severe MR with normal LV systolic function was -20.5% of 2D mid-layer GLS. Patients were divided into two groups by the baseline GLS -20.5%. Preoperative GLS values strongly predicted postoperative LV remodeling or LV dysfunction. The postoperative degree of decrease in LV end-diastolic dimension might be an additive predictive factor.

Conclusion

STE can be used to predict a decrease in LV function after MVR in patients with chronic severe MR. This promising method could be of use in the clinic when trying to decide upon the optimum time to schedule surgery for such patients.

The clinical impact of valvular heart disease in a population-based cohort of subjects aged 80 and older

BACKGROUND

In our ageing society, valvular heart diseases (VHD) have become an increasing public health problem. However, the lack of studies describing the impact of these diseases on the outcome of very old subjects makes it difficult to appreciate their real clinical burden.

METHODS

Prospective, observational, population-based cohort study in Belgium. Five hundred fifty six subjects aged 80 years and older were followed up for 5.1 ± 0.25 years for mortality and 3.0 ± 0.25 years for hospitalization. Echocardiograms were performed at baseline. The Cumulative Illness Rating Scale (CIRS) was calculated for each subject.

RESULTS

The prevalence of moderate-to-severe VHD was 17% (n = 97). Mitral stenosis was more prevalent in women and an age-dependent increase of the prevalence of severe aortic stenosis was seen. The overall disease burden was higher in participants with VHD (median CIRS 3 [IQR 3-5] vs 4 [IQR 3-6] (P = 0.008)). Moderate-to-severe VHD, and more specifically mitral stenosis and aortic stenosis, was found to be an independent predictor of both all-cause (HR 1.42 (95% CI 1.04-1.95)) and cardiovascular mortality (HR 2.13 (95% CI 1.38-3.29)). Moderate-to-severe VHD was also found to be an independent predictor of the need for a first unplanned hospitalization (HR 1.43 (95% CI 1.06-1.94)).

CONCLUSIONS

A high prevalence of moderate-to-severe VHD was found in the very old. Moderate-to-severe VHD was identified as an independent risk factor for all-cause and cardiovascular mortality and as well for unplanned hospitalizations, independent of other structural cardiac abnormalities, ventricular function and major co-morbidities.

Left ventricular early inflow-outflow index: a novel echocardiographic indicator of mitral regurgitation severity

BACKGROUND

No gold standard currently exists for quantification of mitral regurgitation (MR) severity. Classification by echocardiography is based on integrative criteria using color and spectral Doppler and anatomic measurements. We hypothesized that a simple Doppler left ventricular early inflow-outflow index (LVEIO), based on flow velocity into the left ventricle (LV) in diastole and ejected from the LV in systole, would add incrementally to current diagnostic criteria. LVEIO was calculated by dividing the mitral E-wave velocity by the LV outflow velocity time integral.

METHODS AND RESULTS

Transthoracic echocardiography reports from Montefiore Medical Center and its referring clinics from July 1, 2011, to December 31, 2011 (n=11 235) were reviewed. The MR severity reported by a cardiologist certified by the National Board of Echocardiography was used as a reference standard. Studies reporting moderate or severe MR (n=550) were reanalyzed to measure effective regurgitant orifice area by the proximal isovelocity surface area method, vena contracta width, MR jet area, and left-sided chamber volumes. LVEIO was 9.3±3.9, 7.0±3.2, and 4.2±1.7 among those with severe, moderate, and insignificant MR, respectively (ANOVA P<0.001). By receiver operating characteristic analysis, area under the curve for LVEIO was 0.92 for severe MR. Those with LVEIO ≥8 were likely to have severe MR (likelihood ratio 26.5), whereas those with LVEIO ≤4 were unlikely to have severe MR (likelihood ratio 0.11). LVEIO performed better in those with normal LV ejection fraction (≥50%) compared with those with reduced LV ejection fraction (<50%) (area under the curve 0.92 versus 0.80, P<0.001). By multivariate logistic regression analysis, LVEIO was independently associated with severe MR when compared with vena contracta width, MR jet area, and effective regurgitant orifice area measured by the proximal isovelocity surface area method.

CONCLUSION

LVEIO is a simple-to-use echocardiographic parameter that accurately identifies severe MR, particularly in patients with normal LV ejection fraction.

Echocardiographic predictors of survival in dogs with myxomatous mitral valve disease

OBJECTIVES

To evaluate vena contracta and other echocardiographic measures of myxomatous mitral valve disease (MMVD) severity in a multivariable analysis of survival in dogs.

ANIMALS

70 dogs diagnosed with MMVD from stored echocardiographic images that met study inclusion criteria.

METHODS

Left heart dimensions were measured as well as mitral regurgitant jet area/left atrial area (JAR), early mitral filling velocity (Evel), extent of mitral valve prolapse in right and left views (ProlR, ProlL), Prol indexed to aortic diameter (ProlR:Ao, ProlL:Ao), presence of a flail leaflet (FlailR, FlailL), and mitral regurgitation vena contracta diameter (VCR, VCL) indexed to aortic diameter (VCR:Ao, VCL:Ao). Follow-up from referring veterinarians was obtained by questionnaire or telephone to determine survival times. Inter- and intra-observer agreement was evaluated with Bland-Altman plots and weighted Kappa analysis. Survival was analyzed using Kaplan-Meier curves, logrank tests and Cox's proportional hazards.

RESULTS

Logrank analysis showed VCL:Ao, VCR:Ao, FlailL, ProlR:Ao, ProlL:Ao, left ventricular internal dimension in diastole indexed to aortic diameter (LVIDD:Ao) >2.87, left atrium to aorta ratio (LA/Ao) >1.6, and Evel >1.4 m/s were predictors of cardiac mortality. In a multivariable analysis, the independent predictors of cardiac mortality were Evel >1.4 m/s [hazard ratio (HR) 5.0, 95% confidence interval (CI) 2.5-10.3], FlailL (HR 3.1, 95% CI 1.3-7.9), and ProlR:Ao (HR 2.8, 95% CI 1.3-6.3).

CONCLUSIONS

Echocardiographic measures of mitral regurgitation severity and mitral valve pathology provide valuable prognostic information independent of chamber enlargement in dogs with MMVD.

Cardiac structure and function and prognosis in heart failure with preserved ejection fraction: findings from the echocardiographic study of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) Trial

BACKGROUND

Abnormalities in cardiac structure and function in heart failure with preserved ejection fraction may help identify patients at particularly high risk for cardiovascular morbidity and mortality.

METHODS AND RESULTS

Cardiac structure and function were assessed by echocardiography in a blinded core laboratory at baseline in 935 patients with heart failure with preserved ejection fraction (left ventricular ejection fraction ≥45%) enrolled in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial and related to the primary composite outcome of cardiovascular death, heart failure hospitalization, or aborted cardiac arrest, and its components. At a median follow-up of 2.9 years, 244 patients experienced the primary outcome. Left ventricular hypertrophy (adjusted hazard ratio, 1.52; 95% confidence interval, 1.16-2.00), elevated left ventricular filling pressure (E/E'; adjusted hazard ratio 1.05 per 1 integer increase; 95% confidence interval, 1.02-1.07), and higher pulmonary artery pressure assessed by the tricuspid regurgitation velocity (hazard ratio, 1.23 per 0.5 m/s increase; 95% confidence interval, 1.02-1.49) were associated with the composite outcome and heart failure hospitalization alone after adjusting for clinical and laboratory variables. The risk of adverse outcome associated with left ventricular hypertrophy was additive to the risk associated with elevated E/E'.

CONCLUSIONS

Among heart failure with preserved ejection fraction patients enrolled in TOPCAT, left ventricular hypertrophy, higher left ventricular filling pressure, and higher pulmonary artery pressure were predictive of heart failure hospitalization, cardiovascular death, or aborted cardiac arrest independent of clinical and laboratory predictors. These features, both alone and in combination, identify heart failure with preserved ejection fraction patients at particularly high risk for cardiovascular morbidity and mortality.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00094302.

Cardiac structure and function in heart failure with preserved ejection fraction: baseline findings from the echocardiographic study of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is associated with substantial morbidity and mortality. Existing data on cardiac structure and function in HFpEF suggest significant heterogeneity in this population.

METHODS AND RESULTS

Echocardiograms were obtained from 935 patients with HFpEF (left ventricular ejection fraction ≥45%) enrolled in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial before initiation of randomized therapy. Average age was 70±10 years, 49% were women, 14% were of African descent, and comorbidities were highly prevalent. Centralized quantitative analysis in a blinded core laboratory demonstrated a mean left ventricular ejection fraction of 59.3±7.9%, with prevalent concentric left ventricular remodeling (34%) and hypertrophy (43%), and left atrial enlargement (53%). Diastolic dysfunction was present in 66% of gradable participants and was significantly associated with greater left ventricular hypertrophy and a higher prevalence of left atrial enlargement. Doppler evidence of pulmonary hypertension was present in 36%. At least 1 measure of structural heart disease was present in 93% of patients.

CONCLUSIONS

Patients enrolled in TOPCAT demonstrated heterogeneous patterns of ventricular remodeling, with high prevalence of structural heart disease, including left ventricular hypertrophy and left atrial enlargement, in addition to pulmonary hypertension, each of which has been associated with adverse outcomes in HFpEF. Diastolic function was normal in approximately one third of gradable participants, highlighting the heterogeneity of the cardiac phenotype in this syndrome. These findings deepen our understanding of the TOPCAT trial population and expand our knowledge of the diversity of the cardiac phenotype in HFpEF.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00094302.

Pre-operative echocardiographic features associated with persistent mitral regurgitation after left ventricular assist device implantation

BACKGROUND

Previous studies have shown remarkable decrease in size of the left ventricle after left ventricular assist device (LVAD) implantation due to mechanical unloading. However, a certain number of patients continue to have significant mitral regurgitation (MR) under LVAD support. We investigated pre-operative echocardiographic features associated with persistent MR after LVAD implantation.

METHODS

We retrospectively reviewed 82 consecutive patients undergoing continuous-flow LVAD implantation between 2007 and 2010. We obtained echocardiograms performed within 2 weeks before and 1 week after surgery. We investigated the pre-operative echocardiographic findings associated with significant MR post-LVAD and compared 1-year mortality after LVAD surgery between patients with and without significant MR post-LVAD.

RESULTS

MR was significant in 43 patients (52.4%) before LVAD surgery. Among those, 5 underwent concomitant mitral valve repair (MVr) at the time of LVAD implantation. Of the remaining 38 patients, 25 (65.8%) showed improvement of MR, whereas 13 patients (34.2%) continued to have significant MR post-LVAD. Multivariate analysis revealed that posterior displacement of the coaptation point of mitral leaflets was significantly associated with significant MR post-LVAD (hazard ratio, 1.335; 95% confidence interval, 1.035-1.721; p = 0.026) even after adjusting for the amount of pre-operative MR flow. Post-LVAD 1-year survival of patients with and without significant MR post-LVAD was not significantly different (92.3% vs 89.1%, p = 0.826).

CONCLUSIONS

Pre-LVAD posterior displacement of mitral leaflets may be indicative of post-operative significant MR, which would help identify echocardiographic features of functional MR refractory to simple volume reduction of the ventricle.

Left atrial eccentricity in chronic mitral regurgitation: relation to left atrial function

AIMS

The aim of this study was to assess the changes in the left atrial (LA) shape and to identify the determinants of these changes in chronic mitral regurgitation (MR).

METHODS AND RESULTS

We enrolled 125 consecutive patients (56 ± 16 years, 51% men) with chronic MR caused by myxomatous mitral valve disease in sinus rhythm and 45 control patients (54 ± 15 years, 55% men) undergoing transthoracic Doppler echocardiography. The LA eccentricity index (LAEi) and the LA volume index (LAVi) were used to estimate the LA shape and size, respectively. There were significant decreases in LAEi (r= -0.723, P< 0.001) and increases in LAVi (r= 0.642, P< 0.001) with increasing severity of MR. In multivariate stepwise linear regression analysis, regurgitant fraction (RF) was an independent determinant of the LAE, whereas RF, left ventricular (LV) mass index and LV diastolic dysfunction grade were independent determinants of the LA volume. The LAEi was positively related to the velocity of A' in the entire population (r = 0.238, P = 0.002). On the receiver operating characteristic (ROC) curve analysis, LAEi ≤1.30 was the best cut-off value to reflect the LA systolic dysfunction (A' velocity <7 cm/s; area under the curve was 0.78, P < 0.001).

CONCLUSION

LA becomes more spherical with increasing severity of MR, suggesting a decrease in LAE, which is mainly determined by the volume overload. LAE might be closely related to the LA systolic function in chronic MR.

Mechanisms and predictors of mitral regurgitation after high-risk myocardial infarction

BACKGROUND

Mitral regurgitation (MR) has been associated with adverse outcomes after myocardial infarction (MI). Without structural valve disease, functional MR has been related to left ventricular (LV) remodeling and geometric deformation of the mitral apparatus. The aims of this study were to elucidate the mechanistic components of MR after high-risk MI and to identify predictors of MR progression during follow-up.

METHODS

The Valsartan in Acute Myocardial Infarction Echo substudy prospectively enrolled 610 patients with LV dysfunction, heart failure, or both after MI. MR at baseline, 1 month, and 20 months was quantified by mapping jet expansion in the left atrium in 341 patients with good-quality echocardiograms. Indices of LV remodeling, left atrial size, and diastolic function and parameters of mitral valve deformation, including tenting area, coaptation depth, anterior leaflet concavity, annular diameters, and contractility, were assessed and related to baseline MR. The progression of MR was further analyzed, and predictors of worsening among the baseline characteristics were identified.

RESULTS

Tenting area, coaptation depth, annular dilatation, and left atrial size were all associated with the degree of baseline MR. Tenting area was the only significant and independent predictor of worsening MR; a tenting area of 4 cm(2) was a useful cutoff to identify worsening of MR after MI and moderate to severe MR after 20 months.

CONCLUSIONS

Increased mitral tenting and larger mitral annular area are determinants of MR degree at baseline, and tenting area is an independent predictor of progression of MR after MI. Although LV remodeling itself contributes to ischemic MR, this influence is directly dependent on alterations in mitral geometry.

Cardiac structure and function, remodeling, and clinical outcomes among patients with diabetes after myocardial infarction complicated by left ventricular systolic dysfunction, heart failure, or both

AIMS

The mechanisms responsible for the increased risk of heart failure (HF) post-myocardial infarction (MI) may differ between patients with versus without diabetes. We hypothesized that after high-risk MI, patients with diabetes would demonstrate patterns of remodeling that are suggestive of reduced ventricular compliance and that are associated with an increased risk of death or HF.

METHODS AND RESULTS

We performed quantitative echocardiographic analysis in 153 patients with diabetes and 451 patients without diabetes enrolled in the VALIANT Echo study. Diabetes was associated with a higher risk of death or HF in age-adjusted models (hazard ratio 1.44, 95% CI 1.04-2.00, P = .028). Diabetic patients were similar to nondiabetic patients with respect to left ventricular (LV) volume and ejection fraction but had higher LV mass index (104.1 ± 27.5 vs 97.1 ± 28.6 g/m(2), P = .009), relative wall thickness (0.41 ± 0.08 vs 0.38 ± 0.07, P < .0001), and left atrial volume index (LAVi) (26.2 ± 8.1 vs 24.0 ± 8.2 mL/m(2), P = .008)-all parameters that were significantly related to the risk of death or HF hospitalization. Changes in LV volume and ejection fraction from baseline to 20 months were not different, although diabetic patients demonstrated greater increase in LAVi (4.4 ± 7.7 vs 2.2 ± 6.7 mL/m(2), P = .01).

CONCLUSIONS

After high-risk MI, diabetic patients were at higher risk of death or HF and demonstrated greater baseline LV mass index, relative wall thickness, and LAVi as well as greater left atrial enlargement at 20-month follow-up. These findings suggest greater baseline concentric remodeling and long-term elevation in LV diastolic pressure post-MI among diabetic patients, which may partially mediate this risk.

Left atrial distensibility and left ventricular filling pressure in acute versus chronic severe mitral regurgitation

Echocardiograms and left ventricular (LV) filling pressure were obtained from 95 patients with chronic severe mitral regurgitation (MR) and 16 patients with acute severe MR. All patients underwent catheterization for preoperative examinations and LV filling pressure measurements. A total of 52 age-, gender- and co-morbidity-matched patients with negative coronary angiographic results served as the controls. Echocardiography, including assessment of left atrial (LA) distensibility, was performed simultaneously. LA distensibility correlated logarithmically with the LV filling pressure. However, the early-diastolic mitral inflow velocity divided by the early-diastolic mitral annular velocity (mitral E/E') correlated linearly with the LV filling pressure. Bivariate correlation analysis revealed that LV filling pressure correlated positively with the maximum and minimum indexed LA volume, as well as the E/E', but the LV filling pressure correlated negatively with LA distensibility, LA ejection fraction, and LV ejection fraction. However, the MR regurgitation volume was associated only with the maximum and minimum indexed LA volume. Receiver operating characteristic curve analysis indicated that LA distensibility was not inferior to E/E' for identifying a LV filling pressure >15 mm Hg. However, to identify acute severe MR, LA distensibility was superior to E/E'. In conclusion, LA distensibility, as is E/E', is a valuable diastolic parameter. In patients with severe MR, it offers adequate power to assess the LV filling pressure and to identify acute severe MR.

Left atrial remodelling in patients with myocardial infarction complicated by heart failure, left ventricular dysfunction, or both: the VALIANT Echo study

AIMS

To assess the relationship between left atrial (LA) size and outcome after high-risk myocardial infarction (MI) and to study dynamic changes in LA size during long-term follow-up.

METHODS AND RESULTS

The VALIANT Echocardiography study prospectively enrolled 610 patients with left ventricular (LV) dysfunction, heart failure (HF), or both following MI. We assessed LA volume indexed to body surface area (LAVi) at baseline, 1 month, and 20 months after MI. Baseline LAVi was an independent predictor of all-cause death or HF hospitalization (P = 0.004). In patients who survived to 20 months, LAVi increased a mean of 3.00 +/- 7.08 mL/m(2) from baseline. Hypertension, lower estimated glomerular filtration rate, and LV mass were the only baseline independent predictors of LA remodelling. Changes in LA size were related to worsening in MR and increasing in LV volumes. LA enlargement during the first month was significantly greater in patients who subsequently died or were hospitalized for HF than in patients without events.

CONCLUSION

Baseline LA size is an independent predictor of death or HF hospitalization following high-risk MI. Moreover, LA remodelling during the first month after infarction is associated with adverse outcome.

Coexistence of coronary cameral fistulae and cor triatriatum sinister in an elderly patient

Coronary cameral fistulae are unusual congenital or acquired anomalous communications between an epicardial coronary artery and a cardiac chamber. There are no reported cases of the association of coronary cameral fistulae and cor triatriatum, a rare congenital cardiac anomaly in which a fibromuscular membrane divides the left atrium into two chambers. We report the case of an 82-year-old man presenting with recurrent anterior chest pain. Echocardiographic examination identified non-obstructive cor triatriatum, mitral valve prolapse resulting in significant mitral regurgitation, dilated coronary arteries, and established the entry site of coronary artery fistulae at the apex of the left ventricle (Figure 1). Coronary angiography confirmed the existence of a plexiform fistula between the left anterior descending coronary artery and the left ventricle. Tetrofosmine scintigraphy revealed the presence of stress-induced ischaemia in the apex. To our knowledge, we report the oldest person with coronary cameral fistulae presenting with angina only at this stage, and the interesting case of the coexistence of two, although unconnected, congenital conditions in an elderly patient. In addition, this report highlights the important role of transthoracic and transoesophageal echocardiography to the characterization of these unusual anomalies, and the complementary information offered by three-dimensional transthoracic echocardiography.

The Relationship Between Renal Function and Cardiac Structure, Function, and Prognosis After Myocardial Infarction

OBJECTIVES

The purpose of this study was to determine whether alterations in cardiac structure or function contribute to the increased risk associated with renal impairment after myocardial infarction (MI).

BACKGROUND

Renal impairment is associated with adverse cardiovascular outcomes after MI.

METHODS

Echocardiography was performed on 603 patients with left ventricular (LV) dysfunction, heart failure (HF), or both after MI. Patients were grouped according to their estimated glomerular filtration rate (eGFR), and measures of cardiac structure and function were related to baseline eGFR. The relationship between eGFR and cardiac structure and function and clinical outcomes of death or HF was assessed with multivariable Cox regression.

RESULTS

Ejection fraction, infarct segment length, right ventricular function, and mitral deceleration time were not influenced by renal function. Patients with reduced eGFR had smaller LV and larger left atrial (LA) volumes and higher left ventricular mass index (LVMI) and LV mass/LV volume ratio. A greater proportion of the patients with reduced eGFR had LV hypertrophy. The relationship between eGFR and the outcome of death or HF was attenuated by including baseline differences in LVMI, and both LVMI and LA volume conferred additional prognostic information in a multivariable model.

CONCLUSIONS

Renal impairment was associated with smaller LV and larger LA volumes and increased LVMI. Systolic function was similar when compared with patients with normal renal function. Thus, reduced systolic function cannot account for worse outcomes in patients with renal impairment after MI. Indirect measures of diastolic function suggest that diastolic dysfunction might be an important mediator of increased risk in this population.

Valvular heart disease: what does cardiovascular MRI add?

Although ischemic heart disease remains the leading cause of cardiac-related morbidity and mortality in the industrialized countries, a growing number of mainly elderly patients will experience a problem of valvular heart disease (VHD), often requiring surgical intervention at some stage. Doppler-echocardiography is the most popular imaging modality used in the evaluation of this disease entity. It encompasses, however, some non-negligible constraints which may hamper the quality and thus the interpretation of the exam. Cardiac catheterization has been considered for a long time the reference technique in this field, however, this technique is invasive and considered far from optimal. Cardiovascular magnetic resonance imaging (MRI) is already considered an established diagnostic method for studying ventricular dimensions, function and mass. With improvement of MRI soft- and hardware, the assessment of cardiac valve function has also turned out to be fast, accurate and reproducible. This review focuses on the usefulness of MRI in the diagnosis and management of VHD, pointing out its added value in comparison with more conventional diagnostic means.

Assessment of functional anatomy of the mitral valve in patients with mitral regurgitation with cine magnetic resonance imaging: comparison with transesophageal echocardiography and surgical results

The ability of magnetic resonance imaging (MRI) to accurately define the functional anatomy of mitral regurgitation was assessed. Transesophageal echocardiography (TEE) and cine MRI were performed on 43 patients with mitral regurgitation and were compared for the jet number, location, direction and presence of a prolapse (atrial displacement, malapposition or a flail). In 36 patients, diagnostic accuracy in reference to surgery was assessed. Comparing TEE and MRI the jet number and location were judged in concordance in 86% of patients. Jet location did not show a significant difference (Wilcoxon: P = 0.66) and both modalities correlated strongly (Spearman: r = 0.68, P<0.0001). Jet direction was judged with high concordance (kappa=0.63). Additionally, prolapse evaluation showed high concordance (kappa: valve, 0.63; anterior mitral leaflet, 0.70; posterior mitral leaflet, 0.73). Compared with surgery, the sensitivity for the detection of malapposition of any leaflet or one of both leaflets ranged between 75% and 93% for TEE and 71% and 89% for MRI. Specificities ranged between 88 and 96% for TEE and 88 and 100% for MRI. TEE detected torn chordae in all ten patients, six of which were missed by MRI. MRI is comparable with TEE in prolapse and jet evaluation. MRI is inferior to TEE in depicting anatomical details such as torn chordae.

Proximal Flow Convergence Region as Assessed by Real-time 3-Dimensional Echocardiography: Challenging the Hemispheric Assumption

OBJECTIVE

Traditionally, a hemispheric assumption for the proximal flow convergence region (PFCR) is used when calculating mitral regurgitant (MR) effective orifice area (EROA). However, 2-dimensional (2D) echocardiography limits evaluation of the complete PFCR contour. Real-time 3-dimensional (3D) echocardiography (RT3D) allows direct assessment of the true PFCR contour. We hypothesized that the PFCR contour is not necessarily hemispheric, but rather hemielliptic, and aimed to apply a hemielliptic calculation, based on the 3D contour of the PFCR for more accurate MR quantification.

METHODS

In all, 50 patients with MR underwent RT3D to characterize PFCR contour as hemispheric or hemielliptic. MR EROA by RT3D-derived PFCR was calculated using a hemielliptic formula using 3D data. The 2D EROA was computed using standard hemispheric assumption. EROAs calculated from 2D and RT3D data were compared with quantitative Doppler EROA (mitral inflow--aortic outflow/MR time-velocity integral), used as an independent comparison.

RESULTS

Only 1 of 50 patients (2%) had a hemispheric PFCR contour by RT3D. The remaining had hemielliptic PFCR contours. Compared with Doppler method, 2D echocardiography significantly underestimated EROA (0.34 +/- 0.14 vs 0.48 +/- 0.25 cm(2), P < .001). RT3D EROA was not significantly different from Doppler EROA (0.52 +/- 0.17 vs 0.48 +/- 0.25, P = not significant). Of 33 patients with Doppler EROA greater than 0.3 cm(2) (> or =moderate-severe MR), 45% (15 of 33) were underestimated as having mild to moderate MR by 2D EROA.

CONCLUSIONS

The true PFCR contour as shown by RT3D is generally not hemispheric but hemielliptic, tracking the orifice contour. Based on this 3D shape, a hemielliptic approach can be used for practical clinical application with improved MR quantification.