Increased distance between mitral valve coaptation point and mitral annular plane: significance and correlations in patients with heart failure

Challenges of managing anomalous mitral arcade with severe mitral regurgitation and hydrops fetalis in infants

Anomalous mitral arcade (MA) is a rare congenital anomaly. We report a case of MA in a newborn who presented with hydrops fetalis due to severe mitral regurgitation. After birth, he developed severe respiratory failure, congestive heart failure and airway obstruction because an enlarged left atrium from severe mitral regurgitation compressed the distal left main bronchus. There is limited experience in surgical management of this condition in Thailand, and the patient's mitral valve was too small for replacement. Therefore, he was treated with medication to control heart failure and supported with positive pressure ventilation to promote growth. We have followed the patient until the current time of writing this report at the age of 2 years, and his outcome is favourable regarding heart failure symptoms, airway obstruction, growth and development. This case describes a challenging experience in the non-surgical management of MA with severe regurgitation, which presented at birth.

Surgical treatment of functional mitral regurgitation in dilated cardiomyopathy

Functional mitral regurgitation is a significant complication of end-stage cardiomyopathy. Dysfunction of one or more components of the mitral valve apparatus occurs in 39-74% and affects almost all heart failure patients. Survival is decreased in subjects with more than mild mitral regurgitation irrespective of the aetiology of heart failure. The goal of treating functional mitral regurgitation is to slow or reverse ventricular remodelling, improve symptoms and functional class, decrease the frequency of hospitalization for congestive heart failure, slow progression to advanced heart failure (time to transplant) and improve survival. This article reviews the role of mitral valve surgery in patients with heart failure and dilated cardiomyopathy.

Reduction in mitral regurgitation during therapy guided by measured filling pressures in the ESCAPE trial

BACKGROUND

Dynamic mitral regurgitation (MR) contributes to decompensation in chronic dilated heart failure. Reduction of MR was the primary physiological end point in the ESCAPE trial, which compared acute therapy guided by jugular venous pressure, edema, and weight (CLIN) with therapy guided additionally by pulmonary artery catheters (PAC) toward pulmonary wedge pressure

METHODS AND RESULTS

Patients were randomized to PAC or CLIN during hospitalization with chronic heart failure and mean left ventricular ejection fraction 20%, and at least 1 symptom and 1 sign of congestion. MR and mitral flow patterns, measured blinded to therapy and timepoint, were available at baseline and discharge in 133 patients, and at 3 months in 104 patients. Changes in MR and related transmitral flow patterns were compared between PAC and CLIN patients. Jugular venous pressure, edema, and weights decreased similarly during therapy in the hospital for both groups. In PAC but not in CLIN patients, MR jet area, MR/left atrial area ratio, and E velocity were each significantly reduced and deceleration time increased by discharge. By 3 months, patients had clinical evidence of increased jugular venous pressure, edema, and weight since discharge, reaching significance in the PAC arm, and the change in MR was no longer different between the 2 groups, although the change in E velocity remained greater in PAC patients.

CONCLUSIONS

During hospitalization, therapy guided by PAC to reduce left-sided pressures improved MR and related filling patterns more than therapy guided clinically by evidence of systemic venous congestion. This early reduction did not translate into improved outcomes out of the hospital, where volume status reverted toward baseline.

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Key Words

• hemodynamics
• heart failure
• cardiomyopathy
• mitral regurgitation

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MESH Headings

• Adult
• Aged
• Body Weight
• Catheterization, Swan-Ganz
• Central Venous Pressure
• Chronic Disease
• Edema/etiology
• Edema/physiopathology
• Edema/therapy
• Female
• Heart Failure/etiology
• Heart Failure/physiopathology
• Heart Failure/therapy
• Hemodynamics
• Hospitalization
• Humans
• Jugular Veins/physiopathology
• Male
• Middle Aged
• Mitral Valve Insufficiency/complications
• Mitral Valve Insufficiency/physiopathology
• Mitral Valve Insufficiency/therapy
• Patient Discharge
• Predictive Value of Tests
• Pulmonary Artery/physiopathology
• Pulmonary Wedge Pressure
• Stroke Volume
• Time Factors
• Treatment Outcome
• United States
• Ventricular Function, Left

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Grants

• N01HV98177 NHLBI NIH HHS
• R01 HL067691 NHLBI NIH HHS
• R01 HL067691-01 NHLBI NIH HHS
• N01-HV-98177 NHLBI NIH HHS

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Affiliation(s)

Maryse Palardy Brigham and Women's Hospital, Boston, Mass; Duke Medical Center, Durham, NC, USA
Lynne W Stevenson
Gudaye Tasissa
Michele A Hamilton
Robert C Bourge
Thomas G Disalvo
Uri Elkayam
James A Hill
Sharon C Reimold

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Is myocardial performance index an independent echocardiographic marker of death in children with idiopathic dilated cardiomyopathy?

BACKGROUND

Myocardial performance index (MPI) was reported as a parameter of ventricular systolic and diastolic function, as well as a useful tool to predict the outcome in patients with ventricular dysfunction.

HYPOTHESIS

To compare MPI with classical echocardiographic parameters as an independent marker of death in children with idiopathic dilated cardiomyopathy (IDCM).

METHODS

Fifty-five children (13 deaths) underwent 104 echocardiograms from January 1996 to May 2005. Right ventricle (RV) MPI and left ventricle (LV) MPI, and 9 classical echocardiographic parameters (left atrium [LA]/body surface area [BSA], distance between mitral E point and ventricular septum, LV mass/body surface area, RV shortening fraction, LV end-systolic and end-diastolic dimensions/body surface area, LV ejection fraction, fiber circumferential shortening velocity, and mitral deceleration time) were compared. Statistical analysis was performed by chi-square, Pearson's correlation and Student t-test, Kaplan-Meier method, Cox's method, and receiver operating curve (ROC). Statistical significance was considered with alpha<0.05 and p=0.80].

RESULTS

Univariate analysis showed that all studied parameters were markers of death. There was a high correlation between RVMPI and LVMPI (r=0.847]-p=0.0001]); therefore, to avoid bias, RVMPI was discharged from multivariate analysis. In the deceased group, moderate/severe mitral regurgitation was frequent (76.9%; confidence interval [CI[ 95%=46.2%- 94.9%) and it was considered in multivariate analysis. In Cox's multivariate analysis, LVMPI was the only independent marker of death (p=0.0213]). The ideal cut-off was 0.63 with 92.3% sensitivity, 66.7% specificity, and fitted ROC area=0.918].

CONCLUSIONS

In children with IDCM, LVMPI is an independent marker of death.

A computational procedure for prediction of structural effects of edge-to-edge repair on mitral valve

Edge-to-edge technique is a surgical procedure for the correction of mitral valve leaflets prolapse by suturing the edge of the prolapsed leaflet to the free edge of the opposing one. Suture presence modifies valve mechanical behavior and orifice flow area in the diastolic phase, when the valve opens and blood flows into the ventricle. In the present work, in order to support identification of potentially critical conditions, a computational procedure is described to evaluate the effects of changing suture length and position in combination with valve size and shape. The procedure is based on finite element method analyses applied to a range of different mitral valves, investigating for each configuration the influence of repair on functional parameters, such as mitral valve orifice area and transvalvular pressure gradient, and on structural parameters, such as stress in the leaflets and stitch tension. This kind of prediction would ideally require a coupled fluid-structural analysis, where the interactions between blood flows and mitral apparatus deformation are simultaneously considered. In the present study, however, an alternative approach is proposed, in which results obtained by purely structural finite element analyses are elaborated and interpreted taking into account the Bernoulli type equations available in literature to describe blood flow through mitral orifice. In this way, the effects of each parameter in terms of orifice flow area, suture loads, and leaflets stresses can be expressed as functions of atrioventricular pressure gradient and then correlated to blood flow rate. Results obtained by using this procedure for different configurations are finally discussed.

Coronary sinus stent implantation improves acute ischaemic mitral valve regurgitation; an experimental safety and efficacy study

AIMS

Percutaneous implantation of a large stent was performed in the coronary sinus of pigs, to assess safety and immediate efficacy for reduction of acute ischaemic mitral regurgitation.

METHODS AND RESULTS

Acute ischaemic mitral regurgitation (MR) was produced in seven pigs, continuously monitored with echocardiography, during repeated balloon inflations in the proximal left circumflex artery. The protocol was repeated following placement of a stent in the coronary sinus. Five pigs survived the period of acute ischaemia and developed severe mitral regurgitation (>/=3+/4+). Following successful stent implantation, the MR area decreased from 2.4+/-0.4 cm2 to 1.1+/-0.6 cm2 (p=0.016) and the proximal isovelocity surface area (PISA) MR flow from 63.9+/-37.3 ml/sec to 44.0+/-35.0 ml/sec (p=0.029). Coronary sinus stent prevented the ischaemia-induced increase in septal-lateral mitral annulus dimension (p=0.041) and left ventricular dilatation. Three animals were allowed to recover and underwent histological analysis of the coronary sinus stent at 30 days, showing endothelialisation and minimal hyperplasia, without thrombus formation.

CONCLUSIONS

A percutaneously deployed stent in the coronary sinus may help to decrease the severity of acute ischaemic mitral regurgitation.

A New Echocardiographic Index for Assessing Left Ventricular Function and Mechanism of Mitral Regurgitation and Its Relation to Other Echocardiographic Indices

OBJECTIVE

Mitral regurgitation (MR) is a progressive disease of the mitral valve, which can be primary or functional. The assessment of left ventricular function in MR is still troublesome. In this study, we evaluated the validity of a new parameter, total dt, in patients with MR.

METHODS

Forty patients with severe MR constituted the study group. According to the transesophageal echocardiographic evaluation, the patients were dichotomized into two groups: (1) Primary MR; n = 21, (2) Functional MR; n = 19. The total dt was defined as the sum of time intervals from 1 msto 3 ms (positive dt) and from 3 ms to 1 ms (negative dt) on the CW Doppler recording of MR jet. It was compared to other indices of left ventricular function and left ventricular geometry, including ejection fraction, fractional shortening, myocardial performance index, coaptation distance, left ventricular volume and diameter, sphericity index, and parameters of diastolic function.

RESULT

The total dt correlated with myocardial performance index, coaptation distance, and sphericity index. It could differentiate between primary and functional MR with an area under curve of 0.878, followed by myocardial performance index with 0.860. The total dt > 104 ms was 79% sensitive and 81% specific for discrimination.

CONCLUSION

The total dt is useful for assessing left ventricular function and also for differentiating primary MR from functional MR.

Exercise-induced changes in mitral regurgitation in patients with prior myocardial infarction and left ventricular dysfunction: relation to mitral deformation and left ventricular function and shape

AIMS

The aim of this study was to assess the relationship between exercise-induced changes in mitral regurgitation (MR) and echocardiographic characteristics of mitral deformation, global left ventricular (LV) function and shape at rest and after exercise.

METHODS AND RESULTS

Forty consecutive patients with ischaemic MR due to prior myocardial infarction (MI), ejection fraction <45% in sinus rhythm underwent exercise-echocardiographic testing. Exercise-induced changes in effective regurgitant orifice (ERO) were compared with baseline and exercise-induced changes in mitral deformation and global LV function and shape. There was significant correlation between exercise-induced changes in ERO and changes in coaptation distance (r=0.80, P<0.0001), tenting area (r=0.79, P<0.0001) and mitral annular diameter (r=0.65, P<0.0001), as well as in end-systolic sphericity index (r=-0.50, P=0.001, respectively), and wall motion score index (r=0.44, P=0.004). In contrast, exercise-induced changes in ERO were not related to the echocardiographic features at rest. By stepwise multiple regression model, the exercise-induced changes in mitral deformation were found to independently correlate with exercise-induced changes in ERO (generalized r(2)=0.80, P<0.0001).

CONCLUSION

Exercise-induced changes in severity of ischaemic MR in patients with LV dysfunction due to prior MI were independently related to changes in mitral deformation.

Mitral regurgitation in chronic heart failure: more questions than answers?

The presence, implications, and approach to mitral valvular disease in the setting of a cardiomyopathy has recently become a focal issue for discussion. Although recent evidence suggests that mitral regurgitation confers a poor prognosis in heart failure, the true prevalence of mitral regurgitation as well as its pathogenic contribution to prognosis in heart failure remains uncertain. Whereas angiotensin-converting enzyme inhibitors have not been demonstrated to favorably alter mitral regurgitation, treatment with b-blockers or cardiac resynchronization therapy has been shown to induce regression of ventricular dilation, with consequent decrease in mitral regurgitation. Surgical valve reconstruction by undersized ring annuloplasty appears promising, but optimal results require skilled surgical expertise. Even in highly experienced hands, intermediate outcomes appear to be inferior to those of cardiac transplantation. Percutaneous mitral valve repair remains an investigational procedure that warrants further clinical research.