Valvular heart disease: diagnosis and management

The clinical value and safety of ECG-gated dipyridamole myocardial perfusion imaging in patients with aortic stenosis

The role of vasodilator myocardial perfusion imaging (MPI) for aortic stenosis (AS) is controversial due to safety and accuracy concerns. In addition, its utility after aortic valve (AV) interventions remains unclear. Patients with AS who underwent thallium-201-gated dipyridamole MPI using a cadmium-zinc-telluride camera were retrospectively reviewed and divided into three groups: mild AS, moderate-to-severe AS, and prior AV interventions. Patients with coronary artery disease with ≥50% stenosis, severe arrhythmia, left ventricular ejection fraction (LVEF) <40%, left bundle branch block or no follow-up were excluded. Relationships between the severity of AS, clinical characteristics, hemodynamic response, serious adverse events (SAE) and MPI parameters were analyzed. None of the 47 patients had SAE, including significant hypotension or LVEF reduction. The moderate-to-severe AS group had higher summed stress scores (SSSs) and depressed LVEF than the mild AS group, however there were no differences after AV interventions. SSS was positively correlated with AV mean pressure gradient, post-stress lung-heart ratio (LHRs), and post-stress end-diastolic volume (EDVs) (P < 0.05). In multivariate analysis, LHRs and EDVs were independent contributors to SSS. Dipyridamole-induced ischemia and LV dysfunction is common, and dipyridamole stress could be a safe diagnostic tool in evaluation and follow-up in patients with AS.

Immunoproteomic Identification of Noncarbohydrate Antigens Eliciting Graft-Specific Adaptive Immune Responses in Patients with Bovine Pericardial Bioprosthetic Heart Valves

PURPOSE

This case-control retrospective discovery study is to identify antigenic bovine pericardium (BP) proteins that stimulate graft-specific humoral immune response in patients implanted with glutaraldehyde fixed bovine pericardial (GFBP) heart valves.

EXPERIMENTAL DESIGN

Banked serum is collected from age- and sex-matched patients who received either a GFBP or mechanical heart valve replacement. Serum IgG is isolated and used to generate poly-polyclonal antibody affinity chromatography columns from each patient. Native and deglycosylated BP protein extracts are separately added to individual patient affinity chromatography columns, with unbound proteins washed through the column. Proteins captured in the affinity chromatography columns are submitted for proteomic identification. Differences between GFBP and mechanical heart valve replacement recipients are analyzed with Gaussian linearized modeling.

RESULTS

Carbohydrate antigens overwhelm protein capture in the column, requiring BP protein deglycosylation prior to affinity chromatography. Nineteen BP protein antigens, which stimulated graft-specific IgG production, are identified in patients who received GFBP valve replacements. Identified antigens are significantly over-represented for calcium-binding proteins.

CONCLUSIONS AND CLINICAL RELEVANCE

Patients implanted with GFBP valves develop a graft-specific humoral immune response toward BP protein antigens, with 19 specific antigens identified in this work. The molecular functions of over-represented antigens, specifically calcium-binding proteins, may aid in understanding the underlying factors that contribute to structural valve deterioration.

Developmental origins for semilunar valve stenosis identified in mice harboring congenital heart disease-associated GATA4 mutation

Congenital heart defects affect ∼2% of live births and often involve malformations of the semilunar (aortic and pulmonic) valves. We previously reported a highly penetrant GATA4 p.Gly296Ser mutation in familial, congenital atrial septal defects and pulmonic valve stenosis and showed that mice harboring the orthologous G295S disease-causing mutation display not only atrial septal defects, but also semilunar valve stenosis. Here, we aimed to characterize the role of Gata4 in semilunar valve development and stenosis using the Gata4^G295Ski/wt mouse model. GATA4 is highly expressed in developing valve endothelial and interstitial cells. Echocardiographic examination of Gata4^G295Ski/wt mice at 2 months and 1 year of age identified functional semilunar valve stenosis predominantly affecting the aortic valve with distal leaflet thickening and severe extracellular matrix (ECM) disorganization. Examination of the aortic valve at earlier postnatal timepoints demonstrated similar ECM abnormalities consistent with congenital disease. Analysis at embryonic timepoints showed a reduction in aortic valve cushion volume at embryonic day (E)13.5, predominantly affecting the non-coronary cusp (NCC). Although total cusp volume recovered by E15.5, the NCC cusp remained statistically smaller. As endothelial to mesenchymal transition (EMT)-derived cells contribute significantly to the NCC, we performed proximal outflow tract cushion explant assays and found EMT deficits in Gata4^G295Ski/wt embryos along with deficits in cell proliferation. RNA-seq analysis of E15.5 outflow tracts of mutant embryos suggested a disease state and identified changes in genes involved in ECM and cell migration as well as dysregulation of Wnt signaling. By utilizing a mouse model harboring a human disease-causing mutation, we demonstrate a novel role for GATA4 in congenital semilunar valve stenosis.

This article has an associated First Person interview with the joint first authors of the paper.

Summary: Cellular and molecular characterization of a mutant mouse, harboring a human disease-causing GATA4 variant, identifies cellular deficits in endothelial-to-mesenchymal transition and proliferation that cause abnormal valve remodeling and resultant stenosis.

A case report of an unusual cause of mitral stenosis in a young woman

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease, frequently associated with cardiovascular involvement. One of the most frequent complication is mitral valve regurgitation in more than one-third of the patients.

Case summary

A 30-year-old woman with arthralgia, butterfly rash, and Raynaud phenomenon presented with a systolic murmur and renal impairment. Based on the kidney biopsy the diagnosis of SLE was made. Echocardiography revealed the presence of pulmonary hypertension, restrictive mitral valve disease with nodular thickening of the anterior leaflet and moderate regurgitation, compatible with Libman Sacks (LS) endocarditis. Immunosuppressive therapy was started and the patient status improved with normalization of systolic pulmonary artery pressure. After 8 years without follow-up, she presented with fatigue and dyspnoea based on a severe mitral valve stenosis. Subsequently, she underwent a minimal invasive mitral valve replacement and the diagnosis of LS endocarditis could be confirmed upon histopathological examination.

Discussion

This case demonstrates that LS endocarditis can not only lead to mitral regurgitation but occasionally to mitral stenosis due to chronic inflammation with thickening and fusion of mitral valve leaflets. Hereby, comprehensive echocardiography, inclusive stress echocardiography, plays a critical role.

Gentisic acid prevents the transition from pressure overload-induced cardiac hypertrophy to heart failure

We previously reported that gentisic acid attenuates cardiac hypertrophy and fibrosis in transverse aortic constriction (TAC)-induced cardiac hypertrophy. Here, we examined whether gentisic acid prevents the development of heart failure. Heart failure was induced in mice via chronic TAC. Mice were administered the vehicle, gentisic acid (10 and 100 mg∙kg^-1∙day^-1), or bisoprolol (0.5 mg∙kg^-1∙day^-1) orally for 3 weeks, beginning 3 weeks after TAC. After oral administration of gentisic acid (2000 mg∙kg^-1), no significant differences in organ weight, histology, or analyzed serum and hematological parameters were observed between female mice in the control and gentisic acid-treated groups. Gentisic acid administration inhibited cardiac dysfunction in a dose-dependent manner, and reduced cardiac hypertrophy and fibrosis, as was revealed via western blotting, quantitative real-time PCR, and Masson's trichrome staining. Gentisic acid dose-dependently reduced the expression of fibrosis marker genes, suppressed the renin-angiotensin-aldosterone system, and reduced lung size and pulmonary vascular remodeling. Our data indicate that gentisic acid prevents cardiac hypertrophy, fibrosis, cardiac dysfunction, and pulmonary pathology in TAC-induced heart failure. These findings suggest that supplementation with gentisic acid may provide an advantage in preventing the progression from cardiac hypertrophy to heart failure.

Role of Cardiac Computed Tomography in the Diagnosis of Left Ventricular Myocardial Diseases

Multimodality imaging is indicated for the evaluation of left ventricular (LV) myocardial diseases. Cardiac magnetic resonance (CMR) allows morphological and functional assessment of the LV along with soft tissue characterization. Technological advances in cardiac computed tomography (CT) have led to the development of techniques for diagnostic acquisition in LV myocardial disease. Cardiac CT facilitates the characterization of LV myocardial disease based on anatomy, function, and enhancement pattern. LV regional and global functional parameters are evaluated using multi-phasic cine CT images. CT myocardial perfusion facilitates the identification of hemodynamically significant coronary artery stenosis. Cardiac CT with delayed enhancement is used to detect myocardial scarring or fibrosis in myocardial infarction and non-ischemic cardiomyopathy, and for the measurement of extracellular volume fraction in non-ischemic cardiomyopathy. In this review, we review imaging techniques and key imaging features of cardiac CT used for the evaluation of myocardial diseases, along with CMR findings.

Computed Tomography of Cardiac Valves: Review

Valvular heart disease is a common clinical problem. Although echocardiography is the standard technique for the noninvasive evaluation of the valves, cardiac CT has evolved to become a useful tool in the evaluation of the cardiac structures as well. Importantly, CT allows for improved quantification of valvular calcification due to its superior spatial resolution. It may improve the detection of small valvular or perivalvular pathology or the characterization of valvular masses and vegetations. This review describes the assessment of normal and diseased heart valves by cardiac CT and discusses its strengths and weaknesses.

Predictors of Clinically Significant Echocardiography Findings in Older Adults with Syncope: A Secondary Analysis

BACKGROUND

Syncope is a common reason for visiting the emergency department (ED) and is associated with significant healthcare resource utilization.

OBJECTIVE

To develop a risk-stratification tool for clinically significant findings on echocardiography among older adults presenting to the ED with syncope or nearsyncope.

DESIGN

Prospective, observational cohort study from April 2013 to September 2016.

SETTING

Eleven EDs in the United States.

PATIENTS

We enrolled adults (=60 years) who presented to the ED with syncope or near-syncope who underwent transthoracic echocardiography (TTE).

MEASUREMENTS

The primary outcome was a clinically significant finding on TTE. Clinical, electrocardiogram, and laboratory variables were also collected. Multivariable logistic regression analysis was used to identify predictors of significant findings on echocardiography.

RESULTS

A total of 3,686 patients were enrolled. Of these, 995 (27%) received echocardiography, and 215 (22%) had a significant finding on echocardiography. Regression analysis identified five predictors of significant finding: (1) history of congestive heart failure, (2) history of coronary artery disease, (3) abnormal electrocardiogram, (4) high-sensitivity troponin-T >14 pg/mL, and 5) N-terminal pro B-type natriuretic peptide >125 pg/mL. These five variables make up the ROMEO (Risk Of Major Echocardiography findings in Older adults with syncope) criteria. The sensitivity of a ROMEO score of zero for excluding significant findings on echocardiography was 99.5% (95% CI: 97.4%-99.9%) with a specificity of 15.4% (95% CI: 13.0%-18.1%).

CONCLUSIONS

If validated, this risk-stratification tool could help clinicians determine which syncope patients are at very low risk of having clinically significant findings on echocardiography.

REGISTRATION

ClinicalTrials.gov Identifier NCT01802398.

Cell Sources for Tissue Engineering Strategies to Treat Calcific Valve Disease

Cardiovascular calcification is an independent risk factor and an established predictor of adverse cardiovascular events. Despite concomitant factors leading to atherosclerosis and heart valve disease (VHD), the latter has been identified as an independent pathological entity. Calcific aortic valve stenosis is the most common form of VDH resulting of either congenital malformations or senile “degeneration.” About 2% of the population over 65 years is affected by aortic valve stenosis which represents a major cause of morbidity and mortality in the elderly. A multifactorial, complex and active heterotopic bone-like formation process, including extracellular matrix remodeling, osteogenesis and angiogenesis, drives heart valve “degeneration” and calcification, finally causing left ventricle outflow obstruction. Surgical heart valve replacement is the current therapeutic option for those patients diagnosed with severe VHD representing more than 20% of all cardiac surgeries nowadays. Tissue Engineering of Heart Valves (TEHV) is emerging as a valuable alternative for definitive treatment of VHD and promises to overcome either the chronic oral anticoagulation or the time-dependent deterioration and reintervention of current mechanical or biological prosthesis, respectively. Among the plethora of approaches and stablished techniques for TEHV, utilization of different cell sources may confer of additional properties, desirable and not, which need to be considered before moving from the bench to the bedside. This review aims to provide a critical appraisal of current knowledge about calcific VHD and to discuss the pros and cons of the main cell sources tested in studies addressing in vitro TEHV.

320-row CT transcatheter aortic valve replacement planning with a single reduced contrast media bolus injection

OBJECTIVE

To reduce the iodine load required for CT Transcatheter Aortic Valve Replacement (TAVR) planning on a 320-row scanner by acquiring the two CT TAVR steps (ECG-gated aortic root CTA and non-gated aorto-ilio-femoral CTA) within a single contrast media bolus injection.

METHODS

50 consecutive patients (82.6±6.9 years; 56% female) were prospectively enrolled and underwent a TAVR planning using a 320-row CT, with ECG-gated aortic root CTA immediately followed by a non-gated aorto-iliac acquisition, all within a single bolus of 40-70mL of Iohexol 350mgI/mL. The Iodine load, image quality, SNR, CNR and radiation dose were compared using a Mann-Whitney test to that of 24 consecutive patients (84.3±4.8 years, 58% female) previously imaged on a 64-row scanner with a conventional two-step protocol.

RESULTS

Iodine load was reduced by 44%. All examinations were of diagnostic quality, with improvement of the aortic root CTA image quality (4.9±0.3 versus 4.6±0.5, p<0.01) and a non-significant decrease of the aorto-iliac CTA image quality (4.7±0.6 versus 4.9±0.3, p = 0.07). SNR and CNR were significantly improved in the aortic root CTA (14.0±5.3 and 10.4±4.5 versus 10.3±4.2 and 6.8±3.3, p<0.01 for both) and non-significantly higher in the aorto-iliac CTA (16.5±8.0 and 14.1±7.9 versus 14.7±5.5 and 12.5±5.0, p = 0.42 and p = 0.66). Total radiation dose was reduced by 32%.

CONCLUSION

320-row CT scanner enables a 44% reduction of iodine load in TAVR planning, while maintaining excellent aorto-ilio-femoral arterial enhancement and lowering radiation dose.

Is elevation of N-terminal pro-B-type natriuretic peptide at discharge associated with 2-year composite endpoint of all-cause mortality and heart failure hospitalisation after transcatheter aortic valve implantation? Insights from a multicentre prospective OCEAN-TAVI registry in Japan

OBJECTIVES

The aim of this study was to investigate the 2-year prognostic impact of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels at discharge following transcatheter aortic valve implantation (TAVI).

DESIGN

Multicentre prospective observational study.

SETTINGS

Seven institutions from multicentre, observational registry of symptomatic patients with severe aortic stenosis who undergo TAVI.

PARTICIPANTS

We enrolled 500 consecutive patients who underwent TAVI with measurements of NT-proBNP at discharge between 2013 and 2016. Study patients were stratified into two groups according to survival classification and regression tree (CART) analysis: high versus low NT-proBNP groups.

INTERVENTIONS

The impact of high NT-proBNP on a 2-year composite endpoint consisting of all-cause mortality and heart failure hospitalisation was evaluated using a multivariable Cox model.

RESULTS

Median age was 86 years (quartile 82-89), and 24.2% of the study population were men. Median Society of Thoracic Surgeon score was 7.1 (5.1-9.8), and NT-proBNP at discharge was 1381 (653-3136) pg/mL. The composite endpoint incidence was 13.0% (95% CI 9.5% to 16.3%) at 1 year and 22.3% (95% CI 16.1%-27.9%) at 2 years. The survival CART analysis revealed that the NT-proBNP level required to discern the 2-year composite endpoint was 4288 pg/mL. Elevated NT-proBNP had a statistically significant impact on outcomes, with adjusted HR of 2.21 (95% CI 1.21 to 4.04, p=0.010), and with a significant sex difference (P for interaction=0.003).

CONCLUSION

Elevation of NT-proBNP at discharge is associated with higher incidence of the 2-year composite endpoint after TAVI.

TRIAL REGISTRATION NUMBER

000020423.

Three-dimensional transesophageal echocardiography vs cardiac magnetic resonance in the assessment of planimetric mitral valve area in rheumatic mitral stenosis

AIM

Rheumatic heart disease is a common cause of valvular disease, especially in developing countries. Echocardiography is the gold standard investigation modality for cardiac valves. In rheumatic mitral stenosis (MS), three-dimensional transesophageal echocardiography (3D TEE) provides better alignment of the image plane at the mitral tips and more accurate and reproducible planimetric measurement of mitral valve area (MVA). Cardiac magnetic resonance (CMR) is a new method that provides evaluation of cardiac anatomy and function noninvasively. Previous studies showed strong correlation between planimetric MVA measured by two-dimensional transthoracic echocardiography and CMR. We aimed to compare the planimetric MVAs assessed by 3D TEE and CMR in rheumatic MS patients. To best of our knowledge, this is the first study that compares 3D TEE and CMR for the assessment of the planimetric MVA in rheumatic MS.

METHODS

We retrospectively evaluated 28 rheumatic MS patients who underwent 3D TEE and ECG-gated CMR. 3D TEE planimetric MVAs were measured manually by multiplanar reconstruction (MPR) method and CMR planimetric MVAs were measured manually on short-axis cine images. Then, 3D TEE and CMR measurements were compared.

RESULTS

A total of 28 patients' (mean age 44 ± 12, 82.1% female) planimetric 3D TEE MVAs (1.00 ± 0.20 cm² ) and CMR MVAs (1.04 ± 0.17 cm² ) were found to be highly correlated (P < 0.0001, r: 0.744) with Pearson correlation analysis. Bland-Altman analysis showed strong agreement between two techniques.

CONCLUSION

For the diagnosis and the follow-up of rheumatic MS, planimetric CMR MVA is an alternative noninvasive method which highly correlates with planimetric 3D TEE MVA.

Echocardiographic manifestations and chemical composition of stenotic bicuspid aortic valves

Bicuspid aortic valve (BAV) is an inherited form of heart disease with only two aortic valve leaflets via a disorder of cardiac valvulogenesis. We investigated the in vivo echocardiographic features of cardiac morphology in patients with BAV and the ex vivo compositional components of all the excised BAV leaflets isolated from BAV patients. Three BAV patients were randomly selected. All patients underwent 2D transthoracic echocardiography (TTE) with a Doppler ultrasound tool. The compositional components of each respective BAV leaflet for all the excised BAVs were determined by a portable fiber-optic Raman spectroscopy. Preoperative TTE revealed the thickened and calcified BAV leaflets, and stenotic aortic flow for all BAV patients. These BAV patients exhibited severe aortic stenosis (AS) by the lower values of aortic valve area (AVA) index. One patient showed a more significant left ventricle hypertrophy, whereas two patients exhibited a significant aortic regurgitation (AR). In addition, three different Raman spectral patterns were summed up from 121 randomized Raman determinations for all the excised BAV leaflets. The main calcified deposition in each BAV leaflet was formed by large amounts of calcium hydroxyapatite and type-B carbonate apatite (Raman bands at 960 and 1070 cm^-1). The calcified BAV leaflets were composed of different compositional components such as calcium hydroxyapatite, type-B carbonate apatite, lipids, proteins, cholesterol and β-carotene. The rare NL subtype of type 1 BAV morphotype was found in one patient, but two patients had the purely BAV morphotype with two equal-sized leaflets.

Cardiovascular tissue engineering: From basic science to clinical application

Valvular heart disease is an increasing population health problem and, especially in the elderly, a significant cause of morbidity and mortality. The current treatment options, such as mechanical and bioprosthetic heart valve replacements, have significant restrictions and limitations. Considering the increased life expectancy of our aging population, there is an urgent need for novel heart valve concepts that remain functional throughout life to prevent the need for reoperation. Heart valve tissue engineering aims to overcome these constraints by creating regenerative, self-repairing valve substitutes with life-long durability. In this review, we give an overview of advances in the development of tissue engineered heart valves, and describe the steps required to design and validate a novel valve prosthesis before reaching first-in-men clinical trials. In-silico and in-vitro models are proposed as tools for the assessment of valve design, functionality and compatibility, while in-vivo preclinical models are required to confirm the remodeling and growth potential of the tissue engineered heart valves. An overview of the tissue engineered heart valve studies that have reached clinical translation is also presented. Final remarks highlight the possibilities as well as the obstacles to overcome in translating heart valve prostheses into clinical application.

Extracellular Matrix for Myocardial Repair

Multiple strategies have been investigated to restore functional myocardium following injury or disease including the local administration of cytokines or chemokines, stem/progenitor cell therapy, mechanical circulatory support, pharmacologic use, and the use of inductive biomaterials. The use of xenogeneic biologic scaffolds composed of extracellular matrix (ECM) has been shown to facilitate functional restoration of several tissues and organs including the esophagus, skeletal muscle, skin, and myocardium, among others. The present chapter describes the current understanding of specific components of biologic scaffolds composed of ECM, the mechanisms by which ECM bioscaffolds promote constructive cardiac remodeling after injury, determinants of remodeling outcome, and the versatility of ECM as a potential cardiac therapeutic.

Echocardiography in the Evaluation of Chest Pain in the Emergency Department

BACKGROUND

A challenge for clinicians in emergency departments (EDs) is rapid identification of those patients with chest pain who require admission and urgent management and those with low clinical risk who can be discharged safely from the ED. This study was designed with an aim to evaluate the ability of two-dimensional transthoracic echocardiography (2D-TTE) to determine causes of acute chest pain in patients presenting to the ED in order to decide whether hospital admission and further investigations were needed.

MATERIAL/METHODS

A total of 250 consecutive patients admitted with chest pain, were enrolled in this prospective study. Patients were divided into three groups: high risk, moderate risk, and low risk of cardiac events, according to cardiovascular risk factors. 2D-TTE was obtained using the HI vision Avius ultrasound unit (Hitachi). Statistical analysis was performed with the Statistical Package for the Social Sciences (SPSS), version 20.

RESULTS

Ischemic and/or non-ischemic heart diseases (IHD and/or NIHD) were detected in 147 (86.5%), 13 (7.6%), and 10 (5.9%) patients with high, moderate, and low risk, respectively. 2D-TTE was characterized by sensitivity of 85.86%, specificity of 100%, and positive predictive value (PPV) of 100% for detecting causes of chest pain.

CONCLUSIONS

2D-TTE increased specificity and sensitivity of detecting causes of chest pain, when compared to patient history, clinical findings, and electrocardiography (ECG). 2D-TTE can be used to help determine the need for hospital admission, to confirm or exclude diagnosis, and guide urgent therapy.

Expression of the Frizzled receptors and their co-receptors in calcified human aortic valves

The cellular mechanisms that induce calcific aortic stenosis are yet to be unraveled. Wnt signaling is increasingly being considered as a major player in the disease process. However, the presence of Wnt Frizzled (Fzd) receptors and co-receptors LRP5 and 6 in normal and diseased human aortic valves remains to be elucidated. Immunohistochemistry and quantitative polymerase chain reaction were used to determine Fzd receptor expression in normal and calcified human aortic valve tissue, as well as human aortic valve interstitial cells (HAVICs) isolated from calcified and normal human aortic valves. There was significantly higher mRNA expression of 4 out of the 10 Fzd receptors in calcified aortic valve tissues and 8 out of the 10 in HAVICs, and both LRP5/6 co-receptors in calcified aortic valves (P < 0.05). These results were confirmed by immunohistochemistry, which revealed abundant increase in immunoreactivity for Fzd3, 7, and 8, mainly in areas of lipid core and calcified nodules of diseased aortic valves. The findings of abundant expression of Fzd and LRP5/6 receptors in diseased aortic valves suggests a potential role for both canonical and noncanonical Wnt signaling in the pathogenesis of human aortic valve calcification. Future investigations aimed at targeting these molecules may provide potential therapies for aortic valve stenosis.

Valve interstitial cell contractile strength and metabolic state are dependent on its shape

The role of valvular interstitial cell (VIC) architecture in regulating cardiac valve function and pathology is not well understood. VICs are known to be more elongated in a hypertensive environment compared to those in a normotensive environment. We have previously reported that valve tissues cultured under hypertensive conditions are prone to acute pathological alterations in cell phenotype and contractility. We therefore aimed to rigorously study the relationship between VIC shape, contractile output and other functional indicators of VIC pathology. We developed an in vitro model to engineer VICs to take on the same shapes as those seen in normal and hypertensive conditions. VICs with longer cellular and nuclear shapes, as seen in hypertensive conditions, had greater contractile response to endothelin-1 that correlated with increased anisotropy of the actin architecture. These elongated VICs also demonstrated altered cell metabolism through a decreased optical redox ratio, which coincided with increased cellular proliferation. In the presence of actin polymerization inhibitor, however, these functional responses were significantly reduced, suggesting the important role of cytoskeletal actin organization in regulating cellular responses to abnormal shape. Overall, these results demonstrate the relationship between cell shape, cytoskeletal and nuclear organization, with functional output including contractility, metabolism, and proliferation.

An assessment of the safety, hemodynamic response, and diagnostic accuracy of commonly used vasodilator stressors in patients with severe aortic stenosis

BACKGROUND

Increasing numbers of patients are undergoing transcatheter aortic valve replacement, which often involves assessment of coronary artery disease ischemic burden. The safety and diagnostic accuracy of vasodilator stress agents in patients with severe aortic stenosis (AS) undergoing SPECT myocardial perfusion imaging (MPI) has not been established.

METHODS

Patients with severe AS (valve area <1 cm2) on echocardiography who underwent vasodilator stress SPECT MPI at two centers were identified. Patients with aortic valve intervention prior to MPI or who underwent concurrent exercise during stress testing were excluded. AS patients were matched to controls without AS based on age, gender, BMI, ejection fraction, and stress agent. Symptoms, serious adverse events, hemodynamic response, and correlation to invasive angiography were assessed.

RESULTS

A total of 95 cases were identified with 45% undergoing regadenoson, 31% dipyridamole, and 24% adenosine stress. A significant change in systolic blood pressure (BP), cases vs controls, was observed with adenosine [-17.9 ± 20.1 vs -2.6 ± 24.9 P = .03)], with a trend toward significance with regadenoson [-16.8 ± 20.3 vs -9.4 ± 17.9 (P = .08)] and dipyridamole [-17.8 ± 20.6 vs -9.0 ± 12.1 (P = .05)]. The change in heart rate was significantly different only for adenosine [5.3 ± 16.8 vs 14.2 ± 10.8 (P = .04)]. Overall, 45% of cases vs 24% of controls (P = .004) had a >20 mmHg decrease in systolic BP. Age, BMI, and resting systolic BP were related to a >20 mmHg decrease in systolic BP on univariate analysis, although only higher resting systolic BP was a predictor on multivariate analysis. In 33 patients who underwent angiography, the sensitivity, specificity, and diagnostic accuracy of vasodilator stress MPI was 77%, 69%, and 73%, respectively. No serious adverse events occurred in the severe AS patients.

CONCLUSION

Severe AS patients are more likely to have a hemodynamically significant decrease in systolic BP with vasodilator stress. There were no serious adverse events in this severe AS cohort with good diagnostic performance of MPI compared to angiography.

Elevation of B-Type Natriuretic Peptide at Discharge is Associated With 2-Year Mortality After Transcatheter Aortic Valve Replacement in Patients With Severe Aortic Stenosis: Insights From a Multicenter Prospective OCEAN-TAVI (Optimized Transcatheter Valvular Intervention-Transcatheter Aortic Valve Implantation) Registry

Background

In this study, we sought to investigate the 2‐year prognostic impact of B‐type natriuretic peptide (BNP) levels at discharge, following transcatheter aortic valve replacement.

Methods and Results

We enrolled 1094 consecutive patients who underwent transcatheter aortic valve replacement between 2013 and 2016. Study patients were stratified into 2 groups according to survival classification and regression tree analysis (high versus low BNP groups). We evaluated the impact of high BNP on 2‐year mortality compared with that of low BNP using a multivariable Cox model, and assessed whether this stratification would improve predictive accuracy for determining 2‐year mortality by assessing time‐dependent net reclassification improvement and integrated discrimination improvement. The median age of patients was 85 years (quartile 82–88), and 29.2% of the study population were men. The median Society of Thoracic Surgeons score was 6.8 (4.7–9.5), and BNP at discharge was 186 (93–378) pg/mL. All‐cause mortality following discharge was 7.9% (95% CI, 5.8–9.9%) at 1 year and 15.4% (95% CI, 11.6–19.0%) at 2 years. The survival classification and regression tree analysis revealed that the discriminating BNP level to discern 2‐year mortality was 202 pg/mL, and that elevated BNP had a statistically significant impact on outcomes, with an adjusted hazard ratio of 2.28 (1.36–3.82, P=0.002). The time‐dependent net reclassification improvement (P=0.047) and integrated discrimination improvement (P=0.029) analysis revealed that the incorporation of BNP stratification with other clinical variables significantly improved predictive accuracy for 2‐year mortality.

Conclusions

Elevation of BNP at discharge is associated with 2‐year mortality after transcatheter aortic valve replacement.

An Effective Treatment for Heart Failure Caused by Valvular Heart Diseases: Thoracic Sympathetic Block

BACKGROUND

The pilot study is designed to investigate the effect of continuous thoracic sympathetic block (TSB) on cardiac function, reconstruction, and hemodynamic parameters in patients with heart failure resulting from valvular heart disease.

METHOD

The cardiac function parameters, including left ventricle ejection fraction (LVEF), left ventricle end-diastole diameter (LVEDD), fractional shortening (FS), and N-terminal prohormone of brain natriuretic peptide (NT-proBNP), were measured in 19 patients before and after TSB treatment. The patients were also classified on the basis of NYHA classification system.

RESULTS

4 weeks of TSB administration improved cardiac function in 18 of 19 patients (94.74%). The patients' LVEF, LVEDD, and NT-proBNP were all improved significantly after treatment.

CONCLUSIONS

The favorable clinical outcome of TSB administration suggests an alternative treatment for the patients with heart failure caused by valvular dysfunctions.

Radiographic Evaluation of Valvular Heart Disease With Computed Tomography and Magnetic Resonance Correlation

Valvular heart disease is a group of complex entities with varying etiologies and clinical presentations. There are a number of imaging tools available to supplement clinical evaluation of suspected valvular heart disease, with echocardiography being the most common and clinically established, and more recent emergence of computed tomography and magnetic resonance imaging as additional supportive techniques. Yet even with these newer and more sophisticated modalities, chest radiography remains one of the earliest and most common diagnostic examinations performed during the triage of patients with suspected cardiac dysfunction. Recognizing the anatomic and pathologic features of cardiac radiography including the heart's adaptation to varying hemodynamic changes can provide clues to the radiologist regarding the underlying etiology. In this article, we will elucidate several principles relating to chamber modifications in response to pressure and volume overload as well as radiographic appearances associated with pulmonary fluid status and cardiac dysfunction. We will also present a pattern approach to optimize analysis of the chest radiograph for valvular heart disease, which will help guide the radiologist down a differential diagnostic pathway and create a more meaningful clinical report.

Safety and Efficacy of Simultaneous Biplane Mode of 3-Dimensional Transesophageal Echocardiography-Guided Antegrade Multiple-Inflation Balloon Aortic Valvuloplasty in Patients With Severe Aortic Stenosis

BACKGROUND

Balloon aortic valvuloplasty (BAV) is resurging as a bridge treatment in patients with severe aortic stenosis (AS) with a dissemination of transcatheter aortic valve implantation. However, the significantly high periprocedural mortality and complication rates still limit the indications of BAV. Further efforts are needed to improve the safety and efficacy of BAV.

METHODS AND RESULTS

We retrospectively investigated the safety and efficacy of simultaneous biplane mode of 3-dimensional transesophageal echocardiography (biplane-TEE) guided antegrade transseptal multiple-inflation BAV, with gradual upsizing of the balloon, by enrolling 20 consecutive AS patients who underwent BAV. The median age was 83 years, and there were 6 male patients (30.0%). The clinical frailty scale was 4, and the Society of Thoracic Surgeon score was 14.5%. The balloon was inflated at a median of 18 times, which improved the mean aortic valve pressure gradient from 43.0 to 15.2 mmHg (P<0.001). We safely performed BAV in all patients, without periprocedural death or symptomatic stroke, although asymptomatic stroke was detected in 8 patients (42.1%) on diffusion-weighted magnetic resonance imaging. Kaplan-Meier estimates showed that the survival rate was 84.0% and cardiovascular death-free survival was 88.9% at 1-year.

CONCLUSIONS

Biplane-TEE guided antegrade multiple-inflation BAV might have the potential to improve periprocedural survival without increasing complications, compared with conventional retrograde BAV in patients with severe AS.

Epidemiology of valvular heart disease in a Swedish nationwide hospital-based register study

OBJECTIVE

Transitions in the spectrum of valvular heart diseases (VHDs) in developed countries over the 20th century have been reported from clinical case series, but large, contemporary population-based studies are lacking.

METHODS

We used nationwide registers to identify all patients with a first diagnosis of VHD at Swedish hospitals between 2003 and 2010. Age-stratified and sex-stratified incidence of each VHD and adjusted comorbidity profiles were assessed.

RESULTS

In the Swedish population (n=10 164 211), the incidence of VHD was 63.9 per 100 000 person-years, with aortic stenosis (AS; 47.2%), mitral regurgitation (MR; 24.2%) and aortic regurgitation (AR; 18.0%) contributing most of the VHD diagnoses. The majority of VHDs were diagnosed in the elderly (68.9% in subjects aged ≥65 years), but pulmonary valve disease incidence peaked in newborns. Incidences of AR, AS and MR were higher in men who were also more frequently diagnosed at an earlier age. Mitral stenosis (MS) incidence was higher in women. Rheumatic fever was rare. Half of AS cases had concomitant atherosclerotic vascular disease (48.4%), whereas concomitant heart failure and atrial fibrillation were common in mitral valve disease and tricuspid regurgitation. Other common comorbidities were thoracic aortic aneurysms in AR (10.3%), autoimmune disorders in MS (24.5%) and abdominal hernias or prolapse in MR (10.7%) and TR (10.3%).

CONCLUSIONS

Clinically diagnosed VHD was primarily a disease of the elderly. Rheumatic fever was rare in Sweden, but specific VHDs showed a range of different comorbidity profiles . Pronounced sex-specific patterns were observed for AR and MS, for which the mechanisms remain incompletely understood.

Simulation for transthoracic echocardiography of aortic valve

Simulation allows interactive transthoracic echocardiography (TTE) learning using a virtual three-dimensional model of the heart and may aid in the acquisition of the cognitive and technical skills needed to perform TTE. The ability to link probe manipulation, cardiac anatomy, and echocardiographic images using a simulator has been shown to be an effective model for training anesthesiology residents in transesophageal echocardiography. A proposed alternative to real-time reality patient-based learning is simulation-based training that allows anesthesiologists to learn complex concepts and procedures, especially for specific structures such as aortic valve.

Exploratory assessment of left ventricular strain-volume loops in severe aortic valve diseases

KEY POINTS

Severe aortic valve diseases are common cardiac abnormalities that are associated with poor long-term survival. Before any reduction in left ventricular (LV) function, the left ventricle undergoes structural remodelling under the influence of changing haemodynamic conditions. In this study, we combined temporal changes in LV structure (volume) with alterations in LV functional characteristics (strain, ԑ) into a ԑ-volume loop, in order to provide novel insight into the haemodynamic cardiac consequences of aortic valve diseases in those with preserved LV ejection fraction. We showed that our novel ԑ-volume loop and the specific loop characteristics provide additional insight into the functional and mechanical haemodynamic consequences of severe aortic valve diseases (with preserved LV ejection fraction). Finally, we showed that the ԑ-volume loop characteristics provide discriminative capacity compared with conventional measures of LV function.

ABSTRACT

The purpose of this study was to examine left ventricular (LV) strain (ԑ)-volume loops to provide novel insight into the haemodynamic cardiac consequences of aortic valve stenosis (AS) and aortic valve regurgitation (AR). Twenty-seven participants were retrospectively recruited: AR (n = 7), AS (n = 10) and control subjects (n = 10). Standard transthoracic echocardiography was used to obtain apical four-chamber images to construct ԑ-volume relationships, which were assessed using the following parameters: early systolic ԑ (ԑ_ES); slope of ԑ-volume relationship during systole (Sslope); end-systolic peak ԑ (peak ԑ); and diastolic uncoupling (systolic ԑ-diastolic ԑ at same volume) during early diastole (UNCOUP_ED) and late diastole (UNCOUP_LD). Receiver operating characteristic curves were used to determine the ability to detect impaired LV function. Although LV ejection fraction was comparable between groups, longitudinal peak ԑ was reduced compared with control subjects. In contrast, ԑ_ES and Sslope were lower in both pathologies compared with control subejcts (P < 0.01), but also different between AS and AR (P < 0.05). UNCOUP_ED and UNCOUP_LD were significantly higher in both patient groups compared with control subjects (P < 0.05). Receiver operating characteristic curves revealed that loop characteristics (AUC = 0.99, 1.00 and 1.00; all P < 0.01) were better able then peak ԑ (AUC = 0.75, 0.89 and 0.76; P = 0.06, <0.01 and 0.08, respectively) and LV ejection fraction (AUC = 0.56, 0.69 and 0.69; all P > 0.05) to distinguish AS vs control, AR vs control and AS vs AR groups, respectively. Temporal changes in ԑ-volume characteristics provide novel insight into the haemodynamic cardiac impact of AS and AR. Contrary to traditional measures (i.e. ejection fraction, peak ԑ), these novel measures successfully distinguish between the haemodynamic cardiac impact of AS and AR.

Non-invasive measurement of volume-time curves in patients with mitral regurgitation and in healthy volunteers, using a new operator-independent screening tool

Left ventricular volume-time curves (VTCs) provide hemodynamic data, and may help clinical decision making. The generation of VTCs using echocardiography, however, is time-consuming and prone to inter-operator variability. In this study, we used a new non-invasive, operator-independent technique, the hemodynamic cardiac profiler (HCP), to generate VTCs. The HCP, which uses a low-intensity, patient-safe, high-frequency applied AC current, and 12 standard ECG electrodes attached on the thorax in a pre-defined pattern, was applied to five young healthy volunteers, five older healthy volunteers, and five patients with severe mitral regurgitation. From the VTCs generated by the HCP, the presence or absence of an isovolumetric contraction phase (ICP) was assessed, as well as the left ventricular ejection time (LVET), time of the pre-ejection period (tPEP), and ratio of the volumes of the early (E) and late (A) diastolic filling (E _V/A _V ratio), and compared to 2D transthoracic echocardiography (2D TTE) at rest. The reproducibility by two different operators showed good results (RMS  =  5.2%). For intra-patient measurement RMS was 2.8%. Both LVET and the E _V/A _V ratio showed a strong significant correlation between HCP and 2D TTE derived parameters (p  <  0.05). For tPEP, the correlation was still weak (p  =  0.32). In all five patients with mitral regurgitation, the ICP was absent in the VTC from the HCP, whereas it was present in the 10 healthy volunteers, which is in accordance with pathophysiology. We conclude that the HCP seems to be a method for reproducible VTC generation, and may become a useful early screening tool for cardiac dysfunction in the future.

Differences in Aortic Valve and Left Ventricular Parameters Related to the Severity of Myocardial Fibrosis in Patients with Severe Aortic Valve Stenosis

OBJECTIVE

This study investigated the morphological and functional characteristics of the aortic valve and the left ventricular (LV) systolic functional parameters and myocardial mass related to the severity of myocardial fibrosis (MF) in patients with severe aortic valve stenosis (AS).

MATERIALS AND METHODS

We retrospectively enrolled 81 patients (48 men; mean age: 59±12 years) with severe AS who underwent transthoracic echocardiography (TTE), cardiac computed tomography (CCT), and cardiovascular magnetic resonance (CMR) within 1 month and subsequent aortic valve surgery. Degree of MF was determined on delayed contrast-enhanced CMR with visual sub-segmental analysis-based quantification and was classified into three groups (no, mild, and severe) for identifying the differences in LV function and characteristics of the aortic valve. One-way ANOVA, Chi-square test or Fisher's exact test were used to compare variables of the three groups. Univariate multinomial logistic regression analysis was performed to determine the association between the severity of MF and variables on imaging modalities.

RESULTS

Of 81 patients, 34 (42%) had MF (mild, n = 18; severe, n = 16). Aortic valve calcium volume score on CCT, aortic valve area, LV mass index, LV end-diastolic volume index on CMR, presence of mild aortic regurgitation (AR), transaortic mean pressure gradient, and peak velocity on TTE were significantly different among the three groups and were associated with severity of MF on a univariate multinomial logistic regression analysis. Aortic valve calcium grade was different (p = 0.008) among the three groups but not associated with severity of MF (p = 0.375).

CONCLUSIONS

A multi-imaging approach shows that severe AS with MF is significantly associated with more severe calcific AS, higher LV end-diastolic volume, higher LV mass, and higher prevalence of mild AR.

Cohort profile: prevalence of valvular heart disease in community patients with suspected heart failure in UK

PURPOSE

The aim of this study was to evaluate the proportion of suspected heart failure patients with significant valvular heart disease. Early diagnosis of valve disease is essential as delay can limit treatment and negatively affect prognosis for undiagnosed patients. The prevalence of unsuspected valve disease in the community is uncertain.

PARTICIPANTS

We prospectively evaluated 79 043 patients, between 2001 and 2011, who were referred to a community open access echocardiography service for suspected heart failure. All patients underwent a standard transthoracic echocardiogram according to British Society of Echocardiography guidelines.

FINDINGS TO DATE

Of the total number, 29 682 patients (37.5%) were diagnosed with mild valve disease, 8983 patients (11.3%) had moderate valve disease and 2134 (2.7%) had severe valve disease. Of the total number of patients scanned, the prevalence of aortic stenosis, aortic regurgitation, mitral stenosis, mitral regurgitation was 10%, 8.4%, 1%, and 12.5% respectively. 18% had tricuspid regurgitation. 5% had disease involving one or more valves.

CONCLUSIONS

Of patients with suspected heart failure in the primary care setting, a significant proportion have important valvular heart disease. These patients are at high risk of future cardiac events and will require onward referral for further evaluation. We recommend that readily available community echocardiography services should be provided for general practitioners as this will result in early detection of valve disease.

Echocardiographic assessment of long-term hemodynamic characteristics of mechanical mitral valve prostheses with different mitral valvular diseases

Mitral stenosis (MS) and mitral insufficiency (MI) have different pre-operative hemodynamic characteristics. However, it is unclear if there are differences in long-term echocardiographic characteristics of MS and MI patients after mechanical mitral valve replacement. This study is to compare long-term echocardiographic results of mechanical mitral valve prostheses between MS and MI patients. From January 2003 to January 2009, a total of 199 consecutive patients were recruited in this study. Patients were classified as group MS (n = 123) and MI (n = 76) according to the manifestation of mitral valvular disease. The mean age for patients was 50.1 ± 10.5 years and follow-up time was 7.2 ± 2.0 years. The MS after operation were more likely to experience atrial fibrillation (p = 0.002). The New York Heart Association (NYHA) class in MI showed a greater improvement (p = 0.006) than in MS. The left ventricular end-diastolic dimension (LVEDD) (p = 0.010) and stroke volume (SV) (p = 0.000) in MI were still larger than that in MS patients. These differences did not disappear with time after operation. The long-term echocardiographic results of mechanical mitral valve prostheses between MS and MI patients are significantly different. Over a long-term follow up, MI patients still have a larger LVEDD and SV than MS, and associated with a greater improvement of NYHA class.

Asymptomatic heart valve dysfunction in healthy middle-aged companion dogs and its implications for cardiac aging

Heart disease is the leading cause of death in the USA, accounting for about one in every four deaths. Age is the greatest risk factor for heart disease in both people and dogs; however, heart disease is generally not considered as a major cause of morbidity or mortality in dogs. As part of the preliminary selection process for a veterinary clinical trial, 40 companion dogs with no history of cardiac pathology that were at least 6 years old and weighed at least 18 kg underwent a cardiac screening using Doppler echocardiography. Eleven dogs from this cohort were diagnosed with valvular regurgitation by echocardiography, and seven of these cases were of sufficient severity to warrant exclusion from the clinical trial. In only one case was a heart murmur detected by auscultation. Serum alkaline phosphatase levels were significantly higher in the dogs with moderate to severe valvular regurgitation compared to the rest of the cohort. These observations suggest that asymptomatic degenerative valvular disease detectable by echocardiography, but not by a standard veterinary exam including auscultation, may be present in a significant fraction of middle-aged companion dogs, indicating a previously underappreciated similarity between human and canine aging. Further, these data suggest that companion dogs may be a particularly useful animal model for understanding mechanisms of age-related degenerative valve disease and for developing and testing interventions to ameliorate cardiac disease. Future studies should address whether dogs with asymptomatic valve disease are at higher risk for subsequent morbidity or early death.

Transition to palliative care when transcatheter aortic valve implantation is not an option: opportunities and recommendations

PURPOSE OF REVIEW

Transcatheter aortic valve implantation (TAVI) is the recommended treatment for most patients with symptomatic aortic stenosis at high surgical risk. However, TAVI may be clinically futile for patients who have multiple comorbidities and excessive frailty. This group benefits from transition to palliative care to maximize quality of life, improve symptoms, and ensure continuity of health services. We discuss the clinical determination of utility and futility, explore the current evidence guiding the integration of palliative care in procedure-focused cardiac programs, and outline recommendations for TAVI programs.

RECENT FINDINGS

The determination of futility of treatment in elderly patients with aortic stenosis is challenging. There is a paucity of research available to guide best practices when TAVI is not an option. Opportunities exist to build on the evidence gained in the management of end of life and heart failure. TAVI programs and primary care providers can facilitate improved communication and processes of care to provide decision support and transition to palliative care.

SUMMARY

The increased availability of transcatheter options for the management of valvular heart disease will increase the assessment of people with life-limiting conditions for whom treatment may not be an option. It is pivotal to bridge cardiac innovation and palliation to optimize patient outcomes.

Timing of Surgical Intervention for Aortic Regurgitation

OPINION STATEMENT

Aortic regurgitation is a frequently encountered condition, in which traditional measurements of severity have proven to be of limited value in identifying those who would be best served by aortic valve replacement. Novel methods of assessing severity are vital, particularly as an entirely new paradigm of aortic regurgitation has surfaced, with the advent of transcatheter aortic valve replacement (TAVR), and the adverse events that are being observed with varying degrees of aortic regurgitation. With that in mind, a comprehensive assessment of aortic regurgitation should now include indexed left ventricular systolic volumes and a comprehensive assessment of right ventricular function, in addition to the quantitative measures that are currently recommended. Cardiac MRI also provides valuable information and should be strongly considered, particularly in challenging cases. The incremental value of additional echocardiographic parameters such as strain imaging, speckle tracking imaging, and tissue Doppler imaging remains unclear, and evidence for their utility is not, as yet, compelling. However, the field of aortic regurgitation assessment has been reinvigorated by the prevalence of paravalvular regurgitation post-TAVR, and many of the abovementioned parameters may need to be re-visited so that we can more accurately determine prognosis and risk stratify patients in a more reliable and evidence-based manner.

Drug-Induced- or Rheumatic- Valvular Heart Disease in Patients Exposed to Benfluorex?

There is a risk of misdiagnosis between benfluorex-induced VHD and acute rheumatic fever (ARF)-related VHD due to common characteristics of both etiologies. We aimed at estimating the probability for a patient exposed to benfluorex presenting with VHD to have, at the same time, a history of ARF-related VHD. Such epidemiological approach could help at reducing the risk of misdiagnosis. We used INSEE data and related literature as well as various modeling hypotheses to drive and test a formula for calculating the probability of a patient presenting with VHD and a history of benfluorex intake to have a prior history of ARF-related VHD. Different scenarios were estimated by a Markov model on the life course of people born in France between 1940 and 1960. Sensitivity analyses were performed under these scenarios. According to the different scenarios and gender, the probability that a patient born between 1940 and 1960 presenting with VHD and a history of benfluorex intake would have had a prior history of ARF-related VHD varied from 0.2% to 2.7%. The probabilities by the year of birth were as follows: 0.8%-2.7% for a patient born in 1940, < 0.5% in all scenarios for patients born after 1955, and < 0.2% in all scenarios for patients, born in 1960. Our results indicate that the burden of ARF-related VHD is low in the patient population exposed to benfluorex. The probability of ARF related VHD should not be over-estimated in the diagnostic procedure of VHD.