Neutrophil degranulation biomarkers characterize restrictive echocardiographic pattern with diastolic dysfunction in patients with diabetes.

OBJECTIVE: To investigate the potential association between neutrophil degranulation and patterns of myocardial dysfunction in a cohort of patients with type 2 diabetes mellitus (T2DM). BACKGROUND: Two distinct phenotypes of diabetic cardiomyopathy have been described: a restrictive phenotype with diastolic dysfunction (restrictive/DD) and a dilative phenotype with systolic dysfunction (dilative/SD). However, the underlying determinants of these two patterns are not yet recognized. METHODS: In this single-centre, observational, cross-sectional study, 492 patients were recruited. Ultrasonographic measurements were performed by two experienced sonographers, blinded to the clinical data of the participants. Serum biomarkers of neutrophil degranulation were measured by enzyme-linked immunosorbent sandwich assay (ELISA). RESULTS: After adjustment for confounders, resistin, myeloperoxidase, matrix metalloproteinase 8 and matrix metalloproteinase 9/tissue inhibitor of metalloproteinases 1 complex were positively associated with the restrictive/DD pattern compared with the normal pattern. Similarly, MPO was positively associated with the dilative/SD pattern compared with the normal pattern, and resistin was negatively associated with the dilative/SD pattern compared with the restrictive/DD pattern. CONCLUSIONS: Neutrophil degranulation is associated with the restrictive/DD echocardiographic pattern in patients with T2DM, but not with the normal pattern and dilative/SD patterns. Neutrophils could have a pivotal role in the pathogenesis of myocardial dysfunction, and particularly diastolic dysfunction, in patients with T2DM.

Hemodynamics of constrictive pericarditis and restrictive cardiomyopathy.

Constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM) are indolent disabling diseases of diastolic function. The two conditions share common pathophysiologic features, resulting in similar and overlapping clinical presentations, echocardiographic findings, and hemodynamic characteristics. However, their clinical course differs, as CP is surgically curable whereas RCM is a chronic condition managed medically. Separating these two entities is based on delineation of anatomic and physiologic derangements employing multimodality hemodynamic interrogation by advanced imaging techniques (Echo-Doppler, CT, and especially MRI) combined with sophisticated invasive hemodynamics.

Cardiovascular magnetic resonance (CMR) in restrictive cardiomyopathies.

The restrictive cardiomyopathies constitute a heterogeneous group of myocardial diseases with a different pathogenesis and overlapping clinical presentations. Diagnosing them frequently poses a challenge. Echocardiography, electrocardiograms and laboratory tests may show non-specific changes. In this context, cardiac magnetic resonance (CMR) may play a crucial role in defining the diagnosis and guiding treatments, by offering a robust myocardial characterization based on the inherent magnetic properties of abnormal tissues, thus limiting the use of endomyocardial biopsy. In this review article, we explore the role of CMR in the assessment of a wide range of myocardial diseases causing restrictive patterns, from iron overload to cardiac amyloidosis, endomyocardial fibrosis or radiation-induced heart disease. Here, we emphasize the incremental value of novel relaxometric techniques such as T1 and T2 mapping, which may recognize different storage diseases based on the intrinsic magnetic properties of the accumulating metabolites, with or without the use of gadolinium-based contrast agents. We illustrate the importance of these CMR techniques and their great support when contrast media administration is contraindicated. Finally, we describe the useful role of cardiac computed tomography for diagnosis and management of restrictive cardiomyopathies when CMR is contraindicated.

Dysregulated autophagy in restrictive cardiomyopathy due to Pro209Leu mutation in BAG3.

Myofibrillary myopathies (MFM) are hereditary myopathies histologically characterized by degeneration of myofibrils and aggregation of proteins in striated muscle. Cardiomyopathy is common in MFM but the pathophysiological mechanisms are not well understood. The BAG3-Pro209Leu mutation is associated with early onset MFM and severe restrictive cardiomyopathy (RCM), often necessitating heart transplantation during childhood. We report on a young male patient with a BAG3-Pro209Leu mutation who underwent heart transplantation at eight years of age. Detailed morphological analyses of the explanted heart tissue showed intracytoplasmic inclusions, aggregation of BAG3 and desmin, disintegration of myofibers and Z-disk alterations. The presence of undegraded autophagosomes, seen by electron microscopy, as well as increased levels of p62, LC3-I and WIPI1, detected by immunohistochemistry and western blot analyses, indicated a dysregulation of autophagy. Parkin and PINK1, proteins involved in mitophagy, were slightly increased whereas mitochondrial OXPHOS activities were not altered. These findings indicate that altered autophagy plays a role in the pathogenesis and rapid progression of RCM in MFM caused by the BAG3-Pro209Leu mutation, which could have implications for future therapeutic strategies.

Incremental Value of the Tissue Motion of Annular Displacement Derived From Speckle-Tracking Echocardiography for Differentiating Chronic Constrictive Pericarditis From Restrictive Cardiomyopathy.

OBJECTIVES: The tissue motion of annular displacement provides an accurate and rapid assessment of left ventricular (LV) systolic function. However, it has rarely been used in patients with chronic constrictive pericarditis and restrictive cardiomyopathy. This study aimed to assess the differences in LV systolic function in patients with constrictive pericarditis and restrictive cardiomyopathy using tissue motion of annular displacement derived from speckle-tracking echocardiography. METHODS: Twenty-four patients with constrictive pericarditis, 24 with restrictive cardiomyopathy, and 25 healthy volunteers (controls) were enrolled. The septal and lateral mitral annular longitudinal displacements, displacement at the midpoint, and normalized midpoint displacement of the mitral ring were calculated. RESULTS: Mitral annular tracking and quantification of the tissue motion of annular displacement were achieved within 10 seconds. In patients with constrictive pericarditis, the lateral mitral annular longitudinal displacement, displacement at the midpoint, and midpoint displacement of the mitral ring were decreased, whereas the septal mitral annular longitudinal displacement was preserved compared to controls, indicating that the reduction of systolic function in constrictive pericarditis was caused by pericardial adhesion and calcium. In patients with restrictive cardiomyopathy, tissue motion of annular displacement was more reduced compared to patients with constrictive pericarditis and controls. The correlation between the septal mitral annular longitudinal displacement and left ventricular ejection fraction was 0.67 (P < .001). A cutoff value of 8.45 mm for the septal mitral annular longitudinal displacement could effectively differentiate constrictive pericarditis from restrictive cardiomyopathy with 95.2% sensitivity and 91.7% specificity. CONCLUSIONS: The tissue motion of annular displacement was decreased in patients with constrictive pericarditis, which indicated early impairment of longitudinal function in constrictive pericarditis; adhesion and calcium in the pericardium might account for the reduction. The septal mitral annular longitudinal displacement provides a fast and effective method for the assessment of LV systolic function in patients with constrictive pericarditis and restrictive cardiomyopathy.

New Cardiac Imaging Algorithms to Diagnose Constrictive Pericarditis Versus Restrictive Cardiomyopathy.

PURPOSE OF REVIEW: Echocardiography is the mainstay in the diagnostic evaluation of constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM), but no single echocardiographic parameter is sufficiently robust to accurately distinguish between the two conditions. The present review summarizes the recent advances in echocardiography that promise to improve its diagnostic performance for this purpose. The role of other imaging modalities such as cardiac computed tomography, magnetic resonance imaging, and invasive hemodynamic assessment in the overall diagnostic approach is also discussed briefly. RECENT FINDINGS: A recent study has demonstrated improved diagnostic accuracy of echocardiography with integration of multiple conventional echocardiographic parameters in to a step-wise algorithm. Concurrently, the studies using speckle-tracking echocardiography have revealed distinct and disparate patterns of myocardial mechanical abnormalities in CP and RCM with their ability to distinguish between the two conditions. The incorporation of machine-learning algorithms into echocardiography workflow permits easy integration of the wealth of the diagnostic data available and promises to further enhance the diagnostic accuracy of echocardiography. New imaging algorithms are continuously being evolved to permit accurate distinction between CP and RCM. Further research is needed to validate the accuracy of these newer algorithms and to define their place in the overall diagnostic approach for this purpose.

A Challenging Differential Diagnosis: Distinguishing between Endomyocardial Fibrosis and Apical Hypertrophic Cardiomyopathy.

Endomyocardial fibrosis, which is a cause of restrictive cardiomyopathy, is characterized by the deposition of fibrous tissue in the apical region of 1 or both ventricles. The condition not only affects the diastolic dynamics of the ventricles, but also the function of the atrioventricular valves. The disease occurs predominantly in tropical regions worldwide and in sub-Saharan Africa. This condition is not well understood, with varied manifestations, from subclinical presentations to chronic and progressive edematous syndromes. Here, we present the challenging case of a patient with an indeterminate echocardiographic image, suggesting apical hypertrophy, plus severe aortic stenosis and fibrosis of the left ventricular outflow tract. An electrocardiogram revealed symmetrical T-wave inversion, which is a characteristic manifestation of apical hypertrophy. The importance of cardiac imaging examinations such as echocardiography and cardiac magnetic resonance for differentiating between endomyocardial fibrosis and apical hypertrophy is highlighted in this patient's case.

Fetal critical aortic stenosis with natural improvement of hydrops fetalis due to spontaneous relief of severe restrictive atrial communication.

We describe a rare case of fetal critical aortic stenosis with spontaneous relief of severe restrictive atrial communication, resulting in complete resolution of hydrops fetalis in utero. Fetal ultrasonography showed hydrops fetalis caused by critical aortic stenosis with a severely restrictive foramen ovale and severe mitral regurgitation at 23 weeks of gestation. Hydrops fetalis, however, spontaneously resolved, showing an obvious increase of flow through the foramen ovale and pulmonary vein at 26 weeks of gestation. The neonate required balloon dilation of the aortic valve and balloon atrioseptostomy immediately after birth and also received bilateral pulmonary artery banding and arterial duct stenting 1 week later. The patient was in good condition after conversion to biventricular circulation via Ross procedure at 8 months old. The present case suggests that atrioseptostomy as a fetal intervention may improve outcome in even a hydropic condition.

Applicability of published guidelines for assessment of left ventricular diastolic function in adults to children with restrictive cardiomyopathy: an observational study.

Guidelines for diagnosis and grading of diastolic dysfunction (DD) in children have not been established. The applicability of adult parameters of DD to children has been questioned by recent studies. Although normal diastolic parameters in children have been published, the data to support application of these indices for the non-invasive diagnosis of DD and quantifying its degree are still being developed. Restrictive cardiomyopathy (RCM) is the only recognized disease entity in children that presents with isolated, irreversible DD as the predominant finding. The aim of this study was to investigate the applicability of current diastolic indices used for assessment of diastolic function in adults as reliable indicators of DD in children with established RCM. Retrospective review of institutional clinical database for the period of 2002-2010 was performed to identify patients with RCM who had had a comprehensive echocardiographic assessment of diastolic function. The following parameters were obtained from apical four chamber view: mitral valve (MV) inflow Doppler early filling velocity (E), late filling velocity (A), deceleration time (DT), color M-mode flow propagation from MV to apex (Vp), Doppler tissue imaging derived early diastolic velocity E' and late diastolic velocity A' at the LV lateral wall at MV annulus, RV at the tricuspid valve annulus, septum, and LA area. All parameters were compared to age and gender matched controls using student t test. : LA area/BSA was significantly larger in RCM group than the control group, median 22.8 cm(2)/m(2) (range 16.9-28.6) versus 10.3 cm(2)/m(2) (range 8.3-12.3), p value <0.001. MV inflow E and A were lower, and DT was shorter in the RCM group (p = 0.04, 0.02, and 0.005, respectively). A wave was absent in 3 of 9 patients in the RCM group. Ratio of E to A (E/A) was not different between the two groups. E' was significantly lower at all three sites in RCM group; however, there was some overlap between the two groups. E/septal E' ratio was statistically significantly higher in RCM group. A' was absent either at lateral wall or at septum in five patients. 7 of 9 patients in RCM group had L' wave (at lateral wall or septum) defined as negative deflection during diastasis. Vp was higher in RCM group than in the control group 81.4 ± 44.5 versus 52.9 ± 10.9, p value <0.01. Combination of increased left atrial size, septal E/E', and lack of A wave and presence of mid-diastolic L'-wave are the noted abnormalities in this group. Individual cut-offs for Doppler indices have very poor sensitivity in identifying restrictive physiology. These findings suggest that poor LV compliance is the hallmark of restrictive cardiomyopathy in children even in the presence of normal early relaxation and ventricular filling. These findings support the need for development of guidelines for diagnosis and physiologic grading of diastolic dysfunction in children.

Subtle echocardiogram findings requiring further investigation: restrictive cardiomyopathy in a rare genetic condition.

Mulibrey nanism (MN) is a extremely rare genetic condition first described in 1973, with around 150 cases reported worldwide. MN is characterised by growth delay and multiorgan manifestations, the most fatal being a combination restrictive-constrictive, perimyocardial heart disease that results in diastolic heart failure. We present a male toddler with MN who presented with recurrent episodes of hypoxia, feeding intolerance, and generalised swelling (anasarca) in the setting of subtle echocardiographic findings. A multidisciplinary and systematic diagnostic approach was used to determine the underlying aetiology. Invasive cardiac testing via right heart catheterisation revealed the final diagnosis of restrictive cardiomyopathy. Transplant decision-making was limited due to hepatic involvement. This case highlights the limitations of echocardiography in diagnosing restrictive cardiomyopathy, which has a preserved ejection fraction, as well the need for multidisciplinary involvement and a family-centred approach in treating patients with this rare condition.

Echocardiography-Based Deep Learning Model to Differentiate Constrictive Pericarditis and Restrictive Cardiomyopathy.

BACKGROUND: Constrictive pericarditis (CP) is an uncommon but reversible cause of diastolic heart failure if appropriately identified and treated. However, its diagnosis remains a challenge for clinicians. Artificial intelligence may enhance the identification of CP. OBJECTIVES: The authors proposed a deep learning approach based on transthoracic echocardiography to differentiate CP from restrictive cardiomyopathy. METHODS: Patients with a confirmed diagnosis of CP and cardiac amyloidosis (CA) (as the representative disease of restrictive cardiomyopathy) at Mayo Clinic Rochester from January 2003 to December 2021 were identified to extract baseline demographics. The apical 4-chamber view from transthoracic echocardiography studies was used as input data. The patients were split into a 60:20:20 ratio for training, validation, and held-out test sets of the ResNet50 deep learning model. The model performance (differentiating CP and CA) was evaluated in the test set with the area under the curve. GradCAM was used for model interpretation. RESULTS: A total of 381 patients were identified, including 184 (48.3%) CP, and 197 (51.7%) CA cases. The mean age was 68.7 ± 11.4 years, and 72.8% were male. ResNet50 had a performance with an area under the curve of 0.97 to differentiate the 2-class classification task (CP vs CA). The GradCAM heatmap showed activation around the ventricular septal area. CONCLUSIONS: With a standard apical 4-chamber view, our artificial intelligence model provides a platform to facilitate the detection of CP, allowing for improved workflow efficiency and prompt referral for more advanced evaluation and intervention of CP.

Long-term prognostic value of big endothelin-1 and its combination with late gadolinium enhancement in patients with idiopathic restrictive cardiomyopathy.

BACKGROUND AND AIMS: Idiopathic restrictive cardiomyopathy (RCM) has a low incidence. This study aimed to determine the prognostic value of big endothelin-1 (ET-1) in idiopathic RCM. MATERIALS AND METHODS: We prospectively enrolled patients with idiopathic RCM from 2009 to 2017 and followed them up. The primary outcome was a composite of all-cause mortality and cardiac transplantation, and the secondary outcome was a composite of cardiac death and cardiac transplantation. RESULTS: Ninety-one patients were divided into the high big ET-1 (>0.85 pmol/L, n = 56) and low big ET-1 (≤0.85 pmol/L, n = 35) groups, and 87 of them completed the follow-up. Big ET-1 concentrations (hazard ratio: 1.756, 95 % confidence interval [CI]: 1.117-2.760) and late gadolinium enhancement (LGE) (hazard ratio: 3.851, 95 % CI: 1.238-11.981) were independent risk factors for the primary outcome. Big ET-1 concentrations (C-statistic estimation: 0.764, 95 % CI: 0.657-0.871) and the combination of LGE and big ET-1 concentrations (C-statistic estimation: 0.870, 95 % CI: 0.769-0.970) could accurately predict the 5-year transplant-free survival rate, and 0.85 pmol/L was a suitable cutoff for big ET-1. CONCLUSION: Big ET-1 and its combination with LGE may be useful to predict an adverse prognosis in patients with idiopathic RCM.

A novel multi-task machine learning classifier for rare disease patterning using cardiac strain imaging data.

To provide accurate predictions, current machine learning-based solutions require large, manually labeled training datasets. We implement persistent homology (PH), a topological tool for studying the pattern of data, to analyze echocardiography-based strain data and differentiate between rare diseases like constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM). Patient population (retrospectively registered) included those presenting with heart failure due to CP (n = 51), RCM (n = 47), and patients without heart failure symptoms (n = 53). Longitudinal, radial, and circumferential strains/strain rates for left ventricular segments were processed into topological feature vectors using Machine learning PH workflow. In differentiating CP and RCM, the PH workflow model had a ROC AUC of 0.94 (Sensitivity = 92%, Specificity = 81%), compared with the GLS model AUC of 0.69 (Sensitivity = 65%, Specificity = 66%). In differentiating between all three conditions, the PH workflow model had an AUC of 0.83 (Sensitivity = 68%, Specificity = 84%), compared with the GLS model AUC of 0.68 (Sensitivity = 52% and Specificity = 76%). By employing persistent homology to differentiate the "pattern" of cardiac deformations, our machine-learning approach provides reasonable accuracy when evaluating small datasets and aids in understanding and visualizing patterns of cardiac imaging data in clinically challenging disease states.

Multimodality Imaging in Differentiating Constrictive Pericarditis From Restrictive Cardiomyopathy: A Comprehensive Overview for Clinicians and Imagers.

In the evaluation of heart failure, 2 differential diagnostic considerations include constrictive pericarditis and restrictive cardiomyopathy. The often outwardly similar clinical presentation of these 2 pathologic entities routinely renders their clinical distinction difficult. Consequently, initial assessment requires a keen understanding of their separate pathophysiology, epidemiology, and hemodynamic effects. Following a detailed clinical evaluation, further assessment initially rests on comprehensive echocardiographic investigation, including detailed Doppler evaluation. With the combination of mitral inflow characterization, tissue Doppler assessment, and hepatic vein interrogation, initial differentiation of constrictive pericarditis and restrictive cardiomyopathy is often possible with high sensitivity and specificity. In conjunction with a compatible clinical presentation, successful differentiation enables both an accurate diagnosis and subsequent targeted management. In certain cases, however, the diagnosis remains unclear despite echocardiographic assessment, and additional evaluation is required. With advances in noninvasive tools, such evaluation can often continue in a stepwise, algorithmic fashion noninvasively, including both cross-sectional and nuclear imaging. Should this additional evaluation itself prove insufficient, invasive assessment with appropriate expertise may ultimately be necessary.

Pediatric restrictive cardiomyopathy: a case report.

Restrictive cardiomyopathy (RCM) is a rare childhood cardiomyopathy that is a challenging diagnostic problem for clinicians. We describe a case of an 8-year-old girl with a 2-year history of shortness of breath on exertion. Electrocardiogram and echocardiography showed biatrial enlargement, while cardiac magnetic resonance showed biatrial dilation and normal pericardial thickness. Left and right heart catheterization revealed a left ventricular (LV) end-diastolic pressure (EDP) of 20 mmHg, right ventricular (RV) EDP of 13 mmHg, and pulmonary arterial systolic pressure of 51 mmHg. LV and RV pressure traces showed that LV and RV pressures moved concordantly with respiration, and that the systolic area index was 0.98. Cardiac catheterization data were therefore supportive of RCM. Next-generation sequencing identified a heterozygous variant of the troponin I gene (TNNI3; c.574C>T). Combining these findings led to a diagnosis of RCM. The patient's parents chose conservative treatment, but at the 12-month follow-up she died of worsening heart failure and cerebral infarction. This case emphasizes the need for cardiac catheterization and genetic testing in RCM, and suggests that anticoagulants should be recommended to reduce the risk of thromboembolic events.

Right ventricular endomyocardial fibrosis.

Endomyocardial fibrosis is a variety of restrictive cardiomyopathy, in which endocardium of one or both ventricles is thickened markedly with involvement of underlying myocardium. Partial obliteration of ventricular cavities by fibrous tissue and thrombus causes diastolic dysfunction with increased resistance to ventricular filling. Systolic function is well preserved till late stages. Biventricular or isolated left ventricular involvement is common. Isolated right ventricular involvement is relatively uncommon. Case reports on endomyocardial fibrosis have declined in literature. In India, endomyocardial fibrosis is mainly reported from Kerala. A case of right ventricular endomyocardial fibrosis from West Bengal is reported here. Isolated right sided endomyocardial fibrosis, massive right atrial enlargement, complete disorganization of tricuspid valve, massive pericardial effusion, normal absolute eosinophil count and its sporadic occurrence outside 15 degrees of the equatorial belt were interesting features in this case of endomyocardial fibrosis. X-ray features were typical of pericardial effusion masking underlying endomyocardial fibrosis. Endomyocardial fibrosis is a neglected research field. It needs more attention from biomedical researchers.

Restrictive cardiomyopathy caused by diffuse calcification of the left ventricle after 20 years of haemodialysis.

Valvular and vascular calcifications are common among patients with end-stage renal disease, but diffuse calcification of the left ventricle is rarely reported. We report on a rare case of restrictive cardiomyopathy resulting from severe myocardial calcification and review the literature. A 77-year-old man was diagnosed with end-stage renal disease after having received regular haemodialysis for 20 years. He was referred to our emergency room due to exertional dyspnoea and exacerbated shortness of breath. A chest X-ray revealed severe pulmonary oedema and bilateral massive pleural effusion. Transthoracic echocardiography revealed impaired diastolic function of the left ventricle but preserved systolic function with a 50% ejection fraction. Repeat chest computed tomography demonstrated exacerbation of the calcification from the mitral annulus to the whole circular left ventricle. A coronary angiogram revealed non-significant stenosis, and right heart catheterisation demonstrated elevated pulmonary capillary wedge pressure. He was discharged after two weeks of conservative medication.

Coffin-Lowry syndrome and left ventricular noncompaction cardiomyopathy with a restrictive pattern.

Coffin-Lowry syndrome (CLS) is an X-linked dominant condition characterized by moderate to severe mental retardation, characteristic facies, and hand and skeletal malformations. The syndrome is due to mutations in the gene that encodes the ribosomal protein S6 kinase-2, a growth factor-regulating protein kinase located on Xp22.2. Cardiac anomalies are known to be associated with CLS. Left ventricular noncompaction (LVNC) is a clinically heterogeneous disorder characterized by left ventricular (LV) myocardial trabeculations and intertrabecular recesses that communicate with the LV cavity. Patients may present with a variety of clinical phenotypes, ranging from a complete absence of symptoms to a rapid, progressive decline in LV systolic and diastolic function, resulting in congestive heart failure, malignant ventricular tachyarrhythmias, and systemic thromboembolic events. Restrictive cardiomyopathy is an uncommon primary cardiomyopathy characterized by biatrial enlargement, normal or decreased biventricular volume, impaired ventricular filling, and normal or near-normal systolic function. We describe a patient with CLS and LVNC with a restrictive pattern, as documented by echocardiography and cardiac catheterization. To our knowledge, there have been no previous reports of concomitant CLS and LVNC. On the basis of our case, we suggest that patients with CLS be screened not only for congenital structural heart defects but also for LVNC cardiomyopathy.