Cardiovascular Magnetic Resonance, Fibrosis, and Prognosis in Dilated Cardiomyopathy

T1 Mapping and Extracellular Volume Fraction in Dilated Cardiomyopathy: A Prognosis Study

OBJECTIVES

The aim of this study is to examine the prognostic value of T1 mapping and the extracellular volume (ECV) fraction in patients with dilated cardiomyopathy (DCM).

BACKGROUND

Patients with DCM with functional left ventricular remodeling have poorer prognoses. Noninvasive assessment of myocardial fibrosis using T1 mapping and the ECV fraction may improve risk stratification of patients with DCM; however, this has not yet been systematically evaluated.

METHODS

A total of 659 consecutive patients with DCM (498 men; 45 ± 15 years) who underwent cardiac magnetic resonance with T1 mapping and late gadolinium enhancement (LGE) imaging with a 1.5-T magnetic resonance scanner were enrolled in this study. Primary endpoints were cardiac-related death and heart transplantation. Secondary endpoints were hospitalization for heart failure, ventricular arrhythmias, and implantable cardioverter-defibrillator or cardiac resynchronization therapy implantation. Survival estimates were calculated by Kaplan-Meier curves with the log-rank test.

RESULTS

During a mean follow-up of 66.3 ± 20.9 months, 122 and 205 patients with DCM reached the primary and secondary endpoints, respectively. The presence of LGE had an association with both of the primary and secondary endpoints observed in the patients with DCM (both P < 0.001). The maximum native T1 (HR: 1.04; 95% CI: 1.02-1.09) and maximum ECV fraction (HR: 1.14; 95% CI: 1.08-1.21) had associations with the primary endpoints in the patients with positive LGE (both P < 0.001), whereas the mean native T1 (HR: 1.13; 95% CI: 1.10-1.36) and mean ECV fraction (HR: 1.32; 95% CI: 1.12-1.53) had the best associations in the patients with negative LGE (all P < 0.001).

CONCLUSIONS

T1 mapping and the ECV fraction had prognostic value in patients with DCM and were particularly important in patients with DCM without LGE. Using a combination of T1 mapping, ECV fraction, and LGE provided optimal risk stratification for patients with DCM.

Clinical Characteristics, Cardiac Magnetic Resonance Features, and Outcomes of Patients with Dilated Cardiomyopathy - An Experience from a South Asian Country

Objectives:

The objectives of the study were to evaluate the clinical presentation, cardiac magnetic resonance (CMR) features, and outcomes of patients with dilated cardiomyopathy (DCM).

Material and Methods:

A retrospective study was conducted at a tertiary care center of Pakistan. All patients who underwent CMR for further evaluation of DCM during the period of 2011–2019 and in whom CMR confirmed the diagnosis of DCM, were included in the study. Patients were followed up in the year 2020 for all-cause mortality and cardiovascular hospitalizations.

Results:

A total of 75 patients were included in the study. The mean age was 38.7 ± 13 with the majority (n = 57, 76%) being male. Dyspnea was the most common presenting symptom (n = 68, 90.7%). The mean left ventricle ejection fraction (LVEF) by CMR was 29.3 ± 12 and mean left ventricle stroke volume (LVSV) was 66.5 ± 31. Late gadolinium enhanced (LGE) was present in 28 (37.3%) patients. Follow-up was available in 61 patients with the mean follow-up duration of 39.7 ± 27 months. Most patients (40, 65.6%) experienced all-cause major adverse cardiovascular events (MACE) during the follow-up and mortality was observed in 10 (16.4%) patients. LVSV by CMR (P = 0.03), LVEF by CMR (P = 0.02), and presence of pericardial effusion (PE) (P = 0.01) were significantly associated with all-cause MACE. On multiregression analysis, SV by CMR was associated with all cause MACE (P = 0.048). The presence of LGE was associated with higher mortality (P = 0.03).

Conclusion:

LVSV, LVEF by CMR, and PE were significantly associated with all-cause MACE. LGE was associated with higher mortality. Our cohort had a relatively younger age of presentation and diagnosis, and a greater mortality on follow-up, when compared with other regions of the world.

CMR-Based Risk Stratification of Sudden Cardiac Death and Use of Implantable Cardioverter-Defibrillator in Non-Ischemic Cardiomyopathy

Non-ischemic cardiomyopathy (NICM) is one of the most important entities for arrhythmias and sudden cardiac death (SCD). Previous studies suggest a lower benefit of implantable cardioverter–defibrillator (ICD) therapy in patients with NICM as compared to ischemic cardiomyopathy (ICM). Nevertheless, current guidelines do not differentiate between the two subgroups in recommending ICD implantation. Hence, risk stratification is required to determine the subgroup of patients with NICM who will likely benefit from ICD therapy. Various predictors have been proposed, among others genetic mutations, left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume (LVEDD), and T-wave alternans (TWA). In addition to these parameters, cardiovascular magnetic resonance imaging (CMR) has the potential to further improve risk stratification. CMR allows the comprehensive analysis of cardiac function and myocardial tissue composition. A range of CMR parameters have been associated with SCD. Applicable examples include late gadolinium enhancement (LGE), T1 relaxation times, and myocardial strain. This review evaluates the epidemiological aspects of SCD in NICM, the role of CMR for risk stratification, and resulting indications for ICD implantation.

Acute myocarditis: prognostic role of speckle tracking echocardiography and comparison with cardiac magnetic resonance features

To evaluate longitudinal systolic function in patients with myocarditis, its correlation with cardiac magnetic resonance (CMR) features, and its predictive value in functional recovery and arrhythmias onset during follow-up (FU) on optimized medical therapy (OMT). Patients with acute myocarditis, confirmed through CMR criteria, and age- and sex-matched healthy controls were enrolled. Two-dimensional (2D) transthoracic echocardiography, including speckle tracking analysis, was performed at admission and after 6 months of FU. Patients of myocarditis group also underwent 24 h ECG Holter monitoring during FU. 115 patients with myocarditis (mean age 41 ± 17, 70% males) and 70 healthy subjects were enrolled. Global longitudinal strain (GLS) and sub-epicardial strain were markedly lower in the myocarditis group than in controls (mean GLS%: - 14.1 ± 5.1 vs - 23.1 ± 3.6, p < 0.001). A strong positive correlation between total scar burden (TSB) on CMR and baseline LV GLS was found (r = 0.67, p < 0.0001). GLS improved after 6 months of FU in myocarditis on OMT (mean GLS%: - 14.1 ± 5.1 vs - 16.5 ± 4.8, p < 0.01). By bivariate correlation analysis, baseline LVEF, GLS, and TSB were all associated with LVEF at 6 months of FU. Moreover, by multivariable linear regression analysis, these parameters confirmed to be independent predictors of functional recovery at 6 months (LVEF β 0.38, p < 0.01; GLS β - 0.35, p < 0.01; total scar burden β - 0.52, p < 0.0001). Segmental peak systolic strain was significantly different between segments with and without late gadolinium enhancement on CMR (- 13.2 ± 3.1% vs - 18.1 ± 3.5%, p < 0.001). A segmental strain of - 12% identified scar with a sensitivity of 79% and a specificity of 84% (AUC = 0.91; 95% CI 0.73-0.97; p < 0.001). In addition, baseline LV GLS in myocarditis resulted predictive of non-sustained ventricular tachycardias (cut-off value > - 12%; sensitivity84%; specificity74.4%; AUC = 0.75). Parameters of myocardial longitudinal deformation are importantly associated with the presence of a scar on CMR and are predictors of functional outcome and ventricular arrhythmias in patients with acute myocarditis. Their assessment during ultrasound examination should be considered to get more information about the prognosis and risk stratification of this subset of patients.

Influence of Fibrosis Amount and Patterns on Ventricular Arrhythmogenesis and Pumping Efficacy: Computational Study

Myocardial fibrosis is an integral component of most forms of heart failure. Clinical and computational studies have reported that spatial fibrosis pattern and fibrosis amount play a significant role in ventricular arrhythmogenicity. This study investigated the effect of the spatial distribution of fibrosis and fibrosis amount on the electrophysiology and mechanical performance of the human ventricles. Seventy-five fibrosis distributions comprising diffuse, patchy, and compact fibrosis types that contain 10-50% fibrosis amount were generated. The spatial fibrosis distribution was quantified using the fibrosis entropy (FE) metric. Electrical simulations under reentry conditions induced using the S1-S2 protocol were conducted to investigate the fibrosis arrhythmogenicity. We also performed mechanical simulations to examine the influence of the fibrosis amount and the spatial distribution of fibrosis on the pumping efficacy of the LV. We observed that the mean FE of the compact type is the largest among the three types. The electrical simulation results revealed that the ventricular arrhythmogenicity of diffuse fibrosis depends on the fibrosis amount and marginally on the spatial distribution of fibrosis. Meanwhile, the ventricular arrhythmogenicity of the compact and patchy fibrosis pattern is more reliant on the spatial distribution of fibrosis than on the fibrosis amount. The average number of phase singularities (PSs) in the compact fibrosis pattern was the highest among the three patterns of fibrosis. The diffuse type of fibrosis has the lowest average number of PSs than that in the patchy and compact fibrosis. The reduction in the stroke volume (SV) showed high influence from the electrical instabilities induced by the fibrosis amount and pattern. The compact fibrosis exhibited the lowest SV among the three patterns except in the 40% fibrosis amount. In conclusion, the fibrosis pattern is as crucial as the fibrosis amount for sustaining and aggravating ventricular arrhythmogenesis.

Global longitudinal strain evaluated by speckle-tracking echocardiography as a surrogate marker for predicting replacement fibrosis detected by magnetic resonance-late gadolinium enhancement in patients with nonischemic cardiomyopathy

PURPOSE

This study aimed to investigate whether left ventricular (LV) global longitudinal strain (GLS) evaluated by speckle-tracking echocardiography (STE) can be used as a surrogate marker for the detection of replacement fibrosis by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) in patients with nonischemic cardiomyopathy (NICM).

METHODS

This study analyzed 41 NICM patients who successfully underwent both STE and CMR, and were divided into those with (Group A, n = 18) and those without CMR-LGE (Group B, n = 23). Echocardiographic indexes, including GLS, were compared between the two groups.

RESULTS

No significant differences were observed in LV end-diastolic and end-systolic volume indexes, LV ejection fraction, mitral E/A, deceleration time, E/e', left atrial volume index, and the systolic trans-tricuspid pressure gradient between Groups A and B. STE-GLS was significantly worse in Group A than in Group B (-7.6% ± 3.0% vs -9.9% ± 3.2%, P = .01). Receiver operating characteristic curve analysis showed that STE-GLS of -7.9% was the best cut-off value for detection of CMR-LGE (sensitivity, 78%; specificity, 74%; and area under the curve, 0.74).

CONCLUSIONS

STE-GLS may be a potential surrogate marker for the detection of CMR-LGE-derived replacement fibrosis in patients with NICM.

Tenascin-C in Heart Diseases-The Role of Inflammation

Tenascin-C (TNC) is a large extracellular matrix (ECM) glycoprotein and an original member of the matricellular protein family. TNC is transiently expressed in the heart during embryonic development, but is rarely detected in normal adults; however, its expression is strongly up-regulated with inflammation. Although neither TNC-knockout nor -overexpressing mice show a distinct phenotype, disease models using genetically engineered mice combined with in vitro experiments have revealed multiple significant roles for TNC in responses to injury and myocardial repair, particularly in the regulation of inflammation. In most cases, TNC appears to deteriorate adverse ventricular remodeling by aggravating inflammation/fibrosis. Furthermore, accumulating clinical evidence has shown that high TNC levels predict adverse ventricular remodeling and a poor prognosis in patients with various heart diseases. Since the importance of inflammation has attracted attention in the pathophysiology of heart diseases, this review will focus on the roles of TNC in various types of inflammatory reactions, such as myocardial infarction, hypertensive fibrosis, myocarditis caused by viral infection or autoimmunity, and dilated cardiomyopathy. The utility of TNC as a biomarker for the stratification of myocardial disease conditions and the selection of appropriate therapies will also be discussed from a clinical viewpoint.

Ventricular tachycardia with epicardial and pericardial fibrosis 6 months after resolution of subclinical COVID-19: a case report

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been shown to have extensive effects on the cardiovascular system. Its long-term cardiac manifestations, however, remain unclear.

CASE PRESENTATION

We report the case of a Caucasian patient with a mild and self-limited presentation of COVID-19, with subsequent development, months later, of exertional dyspnea and non-sustained ventricular tachycardia, long after resolution of his illness and after returning to aerobic exercise. The patient had normal screening tests including electrocardiogram (ECG) and echocardiogram 4 months after his illness. Cardiac magnetic resonance imaging demonstrated epicardial and pericardial fibrosis of the right ventricle free wall and outflow tract and the pericardium over the anterior wall, 6 months following the initial infection. First abnormal ECG was recorded at month 7 following illness.

CONCLUSIONS

This case suggests an insidious and possible long-term cardiac involvement and reflects the challenges in traditional workups and screening modalities in identifying cardiac involvement in COVID-19.

Immune Cells and Immunotherapy for Cardiac Injury and Repair

Cardiac injury remains a major cause of morbidity and mortality worldwide. Despite significant advances, a full understanding of why the heart fails to fully recover function after acute injury, and why progressive heart failure frequently ensues, remains elusive. No therapeutics, short of heart transplantation, have emerged to reliably halt or reverse the inexorable progression of heart failure in the majority of patients once it has become clinically evident. To date, most pharmacological interventions have focused on modifying hemodynamics (reducing afterload, controlling blood pressure and blood volume) or on modifying cardiac myocyte function. However, important contributions of the immune system to normal cardiac function and the response to injury have recently emerged as exciting areas of investigation. Therapeutic interventions aimed at harnessing the power of immune cells hold promise for new treatment avenues for cardiac disease. Here, we review the immune response to heart injury, its contribution to cardiac fibrosis, and the potential of immune modifying therapies to affect cardiac repair.

Risk stratification for sudden cardiac death in patients with heart failure : Emerging role of imaging parameters

BACKGROUND

Heart failure with reduced ejection fraction is a common condition that has a poor prognosis. Accurate selection of patients with ischemic heart disease and idiopathic dilated cardiomyopathy, who are at risk of sudden cardiac death (SCD), remains a challenge. In these cases, current indications for implantable cardioverter-defibrillators (ICD) rely almost entirely on left ventricular ejection fraction. However, this parameter is insufficient. Recently, noninvasive imaging has provided insight into the mechanism underlying SCD using myocardial deformation on echocardiography and magnetic resonance imaging. The aim of this review article was to underline the emerging role of these novel parameters in identifying high-risk patients.

METHODS

A literature search was carried out for reports published with the following terms: "sudden cardiac death," "heart failure," "noninvasive imaging," "echocardiography," "deformation," "magnetic resonance imaging," and "ventricular arrhythmia." The search was restricted to reports published in English.

RESULTS

The findings of this analysis suggest that cardiac magnetic resonance imaging and strain assessment by echocardiography, particularly longitudinal strain, can be promising techniques for cardiovascular risk stratification in patients with heart failure.

CONCLUSION

In future, risk stratification of arrhythmia and patient selection for ICD placement may rely on a multiparametric approach using combinations of imaging modalities in addition to left ventricular ejection fraction.

Novel Approaches in Cardiac Imaging for Non-invasive Assessment of Left Heart Myocardial Fibrosis

In the past, the identification of myocardial fibrosis was only possible through invasive histologic assessment. Although endomyocardial biopsy remains the gold standard, recent advances in cardiac imaging techniques have enabled non-invasive tissue characterization of the myocardium, which has also provided valuable insights into specific disease processes. The diagnostic accuracy, incremental yield and prognostic value of speckle tracking echocardiography, late gadolinium enhancement and parametric mapping modules by cardiac magnetic resonance and cardiac computed tomography have been validated against tissue samples and tested in broad patient populations, overall providing relevant clinical information to the cardiologist. This review describes the patterns of left ventricular and left atrial fibrosis, and their characterization by advanced echocardiography, cardiac magnetic resonance and cardiac computed tomography, allowing for clinical applications in sudden cardiac death and management of atrial fibrillation.

Myocardial Injury and Fibrosis From Acute Carbon Monoxide Poisoning: A Prospective Observational Study

OBJECTIVES

This study sought to evaluate the prevalence and patterns of late gadolinium enhancement (LGE) after carbon monoxide (CO) poisoning using cardiac magnetic resonance (CMR) imaging (CMRI) and transthoracic echocardiography (TTE).

BACKGROUND

In acute CO poisoning, cardiac injury can predict mortality. However, it remains unclear why increased mortality and cardiovascular events occur despite normalization of CO-induced elevated troponin I (TnI) and cardiac dysfunction.

METHODS

Patients with acute CO poisoning with elevated TnI were evaluated. CMRI was performed within 7 days of CO exposure and after 4 to 5 months. Patients were divided into LGE (n = 72; 69.2%) and no-LGE (n = 32; 30.8%) groups.

RESULTS

In the LGE group, 39.4%, 4.8%, and 25.0% of patients exhibited midwall, subendocardial, and right ventricular insertion point injury, respectively. Diffuse injury was observed in 22.1% of patients, and 67.6% of the 37 patients who underwent follow-up CMRI showed no interval change. On TTE, baseline left ventricular ejection fraction and global longitudinal strain were significantly deteriorated in the LGE group; serial TTE within 7 days indicated that only left ventricular global longitudinal strain remained significantly deteriorated. Three cases of mortality occurred in the LGE group during the 1-year follow-up.

CONCLUSIONS

The LGE prevalence in patients with acute CO poisoning with elevated TnI levels, with no underlying cardiovascular diseases and eligible for CMRI, was 69.2%; this proportion primarily comprised patients with a midwall injury. Of the 37 patients who underwent follow-up CMRI, most chronic phase images showed no interval change. Myocardial fibrosis detected on CMR images was related to acute myocardial dysfunction and subacute deterioration of myocardial strain on TTE. (Cardiac Magnetic Resonance Image in Acute Carbon Monoxide Poisoning; NCT04419298).

Left and right ventricular strain using fast strain-encoded cardiovascular magnetic resonance for the diagnostic classification of patients with chronic non-ischemic heart failure due to dilated, hypertrophic cardiomyopathy or cardiac amyloidosis

AIMS

To compare the ability of left ventricular (LV) and right ventricular (RV) strain measured by fast-strain encoded cardiovascular magnetic resonance (CMR) (fast-SENC) with LV- and RV-ejection fraction for the diagnostic classification of patients with different stages of chronic heart failure (stages A-D based on American College of Cardiology/American Heart Association guidelines) due to non-ischemic cardiomyopathies.

METHODS

Our study population consisted of 276 consecutive patients who underwent CMR for clinical reasons, and 19 healthy subjects. Wall motion score index and non-infarct related late gadolinium enhancement (LGE), LV ejection fraction (LVEF) and RV ejection fraction (RVEF) and global LV- and RV-longitudinal (GLS) and circumferential strain (GCS) based on fast-SENC acquisitions, were calculated in all subjects. The percentage of LV and RV myocardial segments with strain ≤ - 17% (%normal LV and RV myocardium) was determined in all subjects.

RESULTS

LVEF and RVEF, LV-GLS, LV-GCS, RV-GLS, RV-GCS and %normal LV- and RV myocardium depressed with increasing heart failure stage (p < 0.001 for all by ANOVA). By multivariable analysis, %normal LV and RV myocardium exhibited closer associations to heart failure stages than LVEF and RVEF (r_partial = 0.79 versus r_partial = 0.21 for %normal LV myocardium versus LVEF and r_partial = 0.64 versus r_partial = 0.20 for %normal RV myocardium versus RVEF, respectively). Furthermore, %normal LV and RV myocardium exhibited incremental value for the identification of patients (i) with subclinical myocardial dysfunction and (ii) with symptomatic heart failure, surpassing that provided by LVEF and RVEF (ΔAUC = 0.22 for LVEF and ΔAUC = 0.19 for RVEF with subclinical dysfunction, and ΔAUC = 0.19 for LVEF and ΔAUC = 0.22 for RVEF with symptomatic heart failure, respectively, p < 0.001 for all). %normal LV myocardium reclassified 11 of 31 (35%) patients judged as having no structural heart disease by clinical and imaging data to stage B, i.e., subclinical LV-dysfunction.

CONCLUSIONS

In patients with non-ischemic cardiomyopathy, %normal LV and RV myocardium, by fast-SENC, enables improved identification of asymptomatic patients with subclinical LV-dysfunction. This technique may be useful for the early identification of such presumably healthy subjects at risk for heart failure and for monitoring LV and RV deformation during pharmacologic interventions in future studies.

Left and right ventricular strain using fast strain-encoded cardiovascular magnetic resonance for the diagnostic classification of patients with chronic non-ischemic heart failure due to dilated, hypertrophic cardiomyopathy or cardiac amyloidosis

AIMS

To compare the ability of left ventricular (LV) and right ventricular (RV) strain measured by fast-strain encoded cardiovascular magnetic resonance (CMR) (fast-SENC) with LV- and RV-ejection fraction for the diagnostic classification of patients with different stages of chronic heart failure (stages A-D based on American College of Cardiology/American Heart Association guidelines) due to non-ischemic cardiomyopathies.

METHODS

Our study population consisted of 276 consecutive patients who underwent CMR for clinical reasons, and 19 healthy subjects. Wall motion score index and non-infarct related late gadolinium enhancement (LGE), LV ejection fraction (LVEF) and RV ejection fraction (RVEF) and global LV- and RV-longitudinal (GLS) and circumferential strain (GCS) based on fast-SENC acquisitions, were calculated in all subjects. The percentage of LV and RV myocardial segments with strain ≤ - 17% (%normal LV and RV myocardium) was determined in all subjects.

RESULTS

LVEF and RVEF, LV-GLS, LV-GCS, RV-GLS, RV-GCS and %normal LV- and RV myocardium depressed with increasing heart failure stage (p < 0.001 for all by ANOVA). By multivariable analysis, %normal LV and RV myocardium exhibited closer associations to heart failure stages than LVEF and RVEF (rpartial = 0.79 versus rpartial = 0.21 for %normal LV myocardium versus LVEF and rpartial = 0.64 versus rpartial = 0.20 for %normal RV myocardium versus RVEF, respectively). Furthermore, %normal LV and RV myocardium exhibited incremental value for the identification of patients (i) with subclinical myocardial dysfunction and (ii) with symptomatic heart failure, surpassing that provided by LVEF and RVEF (ΔAUC = 0.22 for LVEF and ΔAUC = 0.19 for RVEF with subclinical dysfunction, and ΔAUC = 0.19 for LVEF and ΔAUC = 0.22 for RVEF with symptomatic heart failure, respectively, p < 0.001 for all). %normal LV myocardium reclassified 11 of 31 (35%) patients judged as having no structural heart disease by clinical and imaging data to stage B, i.e., subclinical LV-dysfunction.

CONCLUSIONS

In patients with non-ischemic cardiomyopathy, %normal LV and RV myocardium, by fast-SENC, enables improved identification of asymptomatic patients with subclinical LV-dysfunction. This technique may be useful for the early identification of such presumably healthy subjects at risk for heart failure and for monitoring LV and RV deformation during pharmacologic interventions in future studies.

Physiology, pathophysiology and (mal)adaptations to chronic apnoeic training: a state-of-the-art review

Breath-hold diving is an activity that humans have engaged in since antiquity to forage for resources, provide sustenance and to support military campaigns. In modern times, breath-hold diving continues to gain popularity and recognition as both a competitive and recreational sport. The continued progression of world records is somewhat remarkable, particularly given the extreme hypoxaemic and hypercapnic conditions, and hydrostatic pressures these athletes endure. However, there is abundant literature to suggest a large inter-individual variation in the apnoeic capabilities that is thus far not fully understood. In this review, we explore developments in apnoea physiology and delineate the traits and mechanisms that potentially underpin this variation. In addition, we sought to highlight the physiological (mal)adaptations associated with consistent breath-hold training. Breath-hold divers (BHDs) are evidenced to exhibit a more pronounced diving-response than non-divers, while elite BHDs (EBHDs) also display beneficial adaptations in both blood and skeletal muscle. Importantly, these physiological characteristics are documented to be primarily influenced by training-induced stimuli. BHDs are exposed to unique physiological and environmental stressors, and as such possess an ability to withstand acute cerebrovascular and neuronal strains. Whether these characteristics are also a result of training-induced adaptations or genetic predisposition is less certain. Although the long-term effects of regular breath-hold diving activity are yet to be holistically established, preliminary evidence has posed considerations for cognitive, neurological, renal and bone health in BHDs. These areas should be explored further in longitudinal studies to more confidently ascertain the long-term health implications of extreme breath-holding activity.

Implications of multiple late gadolinium enhancement lesions on the frequency of left ventricular reverse remodeling and prognosis in patients with non-ischemic cardiomyopathy

BACKGROUND

Non-ischemic cardiomyopathy (NICM) is a heterogeneous disease, and its prognosis varies. Although late gadolinium enhancement (LGE)-cardiovascular magnetic resonance (CMR) demonstrates a linear pattern in the mid-wall of the septum or multiple LGE lesions in patients with NICM, the therapeutic response and prognosis of multiple LGE lesions have not been elucidated. This study aimed to investigate the frequency of left ventricular (LV) reverse remodeling (LVRR) and prognosis in patients with NICM who have multiple LGE lesions.

METHODS

This single-center retrospective study included 101 consecutive patients with NICM who were divided into 3 groups according to LGE-CMR results: patients without LGE (no LGE group = 48 patients), patients with a typical mid-wall LGE pattern (n = 29 patients), and patients with multiple LGE lesions (n = 24 patients). LVRR was defined as an increase in LV ejection fraction (LVEF) ≥ 10 % and a final value of LVEF > 35 %, which was accompanied by a decrease in LV end-systolic volume ≥ 15 % at 12-month follow-up using echocardiography. The frequency of composite cardiac events, defined as sudden cardiac death (SCD), aborted SCD (non-fatal ventricular fibrillation, sustained ventricular tachycardia, or adequate implantable cardioverter-defibrillator therapies), and heart failure death or hospitalization for worsening heart failure, were summarized and compared between the groups.

RESULTS

Among the 3 groups, the frequency of LVRR was significantly lower in the multiple lesions group than in the no LGE and mid-wall groups (no LGE vs. mid-wall vs. multiple lesions: 49 % vs. 52 % vs. 19 %, p = 0.03). There were 24 composite cardiac events among the patients: 2 in patients without LGE (hospitalization for worsening heart failure; 2), 7 in patients of the mid-wall group (SCD; 1, aborted SCD; 1 and hospitalization for worsening heart failure; 5), and 15 in patients of the multiple lesions group (SCD; 1, aborted SCD; 8 and hospitalization for worsening heart failure; 6). The multiple LGE lesions was an independent predictor of composite cardiac events (hazard ratio: 11.40 [95 % confidence intervals: 1.49-92.01], p = 0.020).

CONCLUSIONS

Patients with multiple LGE lesions have a higher risk of cardiac events and poorer LVRR. The LGE pattern may be useful for an improved risk stratification in patients with NICM.

Multimodality imaging predictors of sudden cardiac death

Sudden cardiac death (SCD) is the worst clinical event occurring in the clinical context of cardiomyopathies. Current guidelines recommend using LV ejection fraction as the only imaging-derived parameter to identify patients who may benefit from ICD implantation in cardiomyopathies with reduced ejection fraction; however, a relevant proportion of high-risk population is left with unmet therapeutic goal. In case of dilated, hypertrophic, or arrhythmogenic cardiomyopathies, there is still a room for more sensitive and specific risk markers for identifying a cluster at higher risk of SCD. In this paper, we reviewed the evidence supporting the use of advanced echocardiography, CMR, and nuclear cardiology for SCD stratification in patients with the most common cardiomyopathies. The added value of these modalities may be explained on the basis of tissue characterization, especially scar detection, a central player in the pathogenesis of arrhythmias. Therefore, integration of these modalities to our everyday clinical practice may help in dealing with the gray zones where current guidelines are still ineffective for patient selection.

Native T1 mapping in diffuse myocardial diseases using 3-Tesla MRI: An institutional experience

Aims:

Newer cardiac magnetic resonance techniques like native T1 mapping are being used increasingly as an adjunct to diagnose myocardial diseases with fibrosis. However, its full clinical utility has not been tested extensively, especially in the Indian population. The purpose of this study was to find native T1 values in healthy individuals without cardiac disease in our 3-Tesla MRI system and examine whether native myocardial T1 values can be used to differentiate between normal and diffuse myocardial disease groups.

Subjects and Methods:

After approval from the institutional ethics committee, native T1 mapping was performed in 12 healthy individuals without cardiac disease who served as controls and in 26 patients with diffuse myocardial diseases (acute myocarditis (n = 5), hypertrophic cardiomyopathy (HCM) (n = 8), nonischemic dilated cardiomyopathy (DCM) (n = 7), restrictive cardiomyopathy (RCM) due to amyloidosis (n = 6)) in a 3-Tesla MRI system in short axis slices and four-chamber view using a modified Look-Locker inversion recovery sequence. The mean native T1 values and standard deviations were calculated for control and disease groups and compared. The ability of native myocardial T1 mapping to differentiate between normal and diffuse myocardial disease groups was assessed. One-way ANOVA with Tukey's Post-Hoc test was used to find significant difference in the multivariate analysis and Chi-Square test was used to find the significance in categorical data.

Results:

The native T1 values for the healthy group in our 3-Tesla MRI system was 1186.47 ± 45.67 ms. The mean T1 values of the groups acute myocarditis (1418.68 ± 8.62 ms), HCM (1355.86 ± 44.67 ms), nonischemic DCM (1341.31 ± 41.48 ms), and RCM due to amyloidosis (1370.37 ± 90.14 ms) were significantly higher (P = 0.0005) than that of the healthy control group.

Conclusion:

Native myocardial T1 mapping is a promising tool for differentiating between healthy and diffuse myocardial disease groups.

Cardiovascular Magnetic Resonance Imaging and Heart Failure

Purpose of Review

The purpose of this review is to summarize the application of cardiac magnetic resonance (CMR) in the diagnostic and prognostic evaluation of patients with heart failure (HF).

Recent Findings

CMR is an important non-invasive imaging modality in the assessment of ventricular volumes and function and in the analysis of myocardial tissue characteristics. The information derived from CMR provides a comprehensive evaluation of HF. Its unique ability of tissue characterization not only helps to reveal the underlying etiologies of HF but also offers incremental prognostic information.

Summary

CMR is a useful non-invasive tool for the diagnosis and assessment of prognosis in patients suffering from heart failure.

Prognostic Value of Feature-Tracking Circumferential Strain in Dilated Cardiomyopathy Patients with Severely Reduced Ejection Fraction Incremental to Late Gadolinium Enhancement

Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction. However, few studies have addressed the prognostic value of global circumferential strain (GCS) in dilated cardiomyopathy (DCM) patients with severely impaired systolic function. This study aimed to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived GCS in DCM patients with severely reduced ejection. Consecutive DCM patients with severely reduced ejection fraction (EF <35%) who underwent CMR were included. GCS was calculated from CMR cine images. The clinical endpoint was a composite of all-cause mortality, heart transplantation, implantable cardioverter defibrillator (ICD) implantation and aborted sudden cardiac death (SCD). A total of 129 patients with a mean EF of 15.33% (11.36%-22.27%) were included. During a median follow-up of 518 days, endpoint events occurred in 50 patients. Patients with GCS ≥ the median (-5.17%) had significantly reduced event-free survival as compared with those with GCS < the median (P<0.01). GCS was independently associated with adverse events after adjusting for clinical and imaging risk factors including extent of late gadolinium enhancement (LGE) (P<0.05). Adding GCS into the model including the extent of LGE resulted in significant improvements in the C-statistic (from 0.706 to 0.742; P<0.05) with a continuous net reclassification improvement (NRI) of 29.71%. It was concluded that GCS derived from CMR could be useful for risk stratification in DCM patients with severely reduced EF, which may increase common imaging risk factors including LGE.

Resveratrol and cardiac fibrosis prevention and treatment

Cardiovascular diseases are some of the major causes of morbidity and mortality in developed or developing countries but in developed countries as well. Cardiac fibrosis is one of the most often pathological changes of heart tissues. It occurs as a result of extracellular matrix proteins accumulation at myocardia. Cardiac fibrosis results in impaired cardiac systolic and diastolic functions and is associated with other effects. Therapies with medicines have not been sufficiently successful in treating chronic diseases such as CVD. Therefore, the interest for therapeutic potential of natural compounds and medicinal plants has increased. Plants such as grapes, berries and peanuts contain a polyphenolic compound called "resveratrol" which has been reported to have various therapeutic properties for a variety of diseases. Studies on laboratory models that show that resveratrol has beneficial effects on cardiovascular diseases including myocardial infarction, high blood pressure cardiomyopathy, thrombosis, cardiac fibrosis, and atherosclerosis. In vitro animal models using resveratrol indicated protective effects on the heart by neutralizing reactive oxygen species, preventing inflammation, increasing neoangiogenesis, dilating blood vessels, suppressing apoptosis and delaying atherosclerosis. In this review, we are presenting experimental and clinical results of studies concerning resveratrol effects on cardiac fibrosis as a CVD outcome in humans.

Importance of Myocardial Fibrosis in Functional Mitral Regurgitation: From Outcomes to Decision-Making

Functional mitral regurgitation (FMR) is a common and complex valve disease, in which severity and risk stratification is still a conundrum. Although risk increases with FMR severity, it is modulated by subjacent left ventricular (LV) disease. The extent of LV remodeling and dysfunction is traditionally evaluated by echocardiography, but a growing body of evidence shows that myocardial fibrosis (MF) assessment by cardiac magnetic resonance (CMR) may complement risk stratification and inform treatment decisions. This review summarizes the current knowledge on the comprehensive evaluation that CMR can provide for patients with FMR, in particular for the assessment of MF and its potential impact in clinical decision-making.

Role of Cardiac Magnetic Resonance Imaging in Heart Failure

This review describes the current role and potential future applications of cardiac magnetic resonance (CMR) for the management of heart failure (HF). CMR allows noninvasive morphologic and functional assessment, tissue characterization, blood flow, and perfusion evaluation. CMR overcomes echocardiography limitations (geometric assumptions, interobserver variability and poor acoustic window) and provides incremental information in relation to cause, prognosis, and treatment monitoring of patients with HF.

The value of cardiac magnetic resonance imaging and programmed ventricular stimulation in patients with ventricular noncompaction and ventricular arrhythmias

INTRODUCTION

Left ventricular noncompaction (LVNC) is associated with ventricular arrhythmias (VA) including premature ventricular complexes, and ventricular tachycardia (VT). The value of imaging with delayed enhancement cardiac magnetic resonance (DE-CMR) and programmed ventricular stimulation (PVS) for risk stratification in patients with VA and LVNC is unknown. The purpose of this study was to determine whether DE-CMR and PVS are beneficial for risk stratification and whether CMR helps to identify VA target sites.

METHODS AND RESULTS

Consecutive patients with LVNC undergoing ablation for VAs were included, all patients had preprocedure DE-CMR. A total of 23 patients (7 women, 46 ± 14 years, ejection fraction 35 ± 14) were included and followed for 2.9 ± 2.2 years. DE-CMR scar was present in 12/23 patients (52%). PVS was performed in 20/23 patients, 8/10 patients (80%) with scar were inducible for VT compared to 0/10 (0%) patients without scar (p < .001). VA target sites in patients with scarring were located adjacent to areas of scarring in all but 1 patient and ablation was successful in 15/23 patients (65%). Patients with scar had worse survival free of VT than those without scar (log rank p = .01) and patients with inducible VT had worse survival free of VT than those who were noninducible (log rank p < .001).

CONCLUSIONS

The presence of CMR defined scar in patients with LVNC was associated with inducible VT and worse outcomes. Inducibility for VT was associated with VT recurrence. Furthermore, CMR is beneficial in localizing the arrhythmogenic substrate in LVNC and therefore can aid in procedural planning.

Relationship of LVEF and Myocardial Scar to Long-Term Mortality Risk and Mode of Death in Patients With Nonischemic Cardiomyopathy

BACKGROUND

Nonischemic cardiomyopathy is a leading cause of reduced left ventricular ejection fraction (LVEF) and is associated with high mortality risk from progressive heart failure and arrhythmias. Myocardial scar on cardiovascular magnetic resonance imaging is increasingly recognized as a risk marker for adverse outcomes; however, left ventricular dysfunction remains the basis for determining a patient's eligibility for primary prophylaxis with implantable cardioverter-defibrillator. We investigated the relationship of LVEF and scar with long-term mortality and mode of death in a large cohort of patients with nonischemic cardiomyopathy.

METHODS

This study is a prospective, longitudinal outcomes registry of 1020 consecutive patients with nonischemic cardiomyopathy who underwent clinical cardiovascular magnetic resonance imaging for the assessment of LVEF and scar at 3 centers.

RESULTS

During a median follow-up of 5.2 (interquartile range, 3.8, 6.6) years, 277 (27%) patients died. On survival analysis, LVEF ≤35% and scar were strongly associated with all-cause (log-rank test P=0.002 and P<0.001, respectively) and cardiac death (P=0.001 and P<0.001, respectively). Whereas scar was strongly related to sudden cardiac death (SCD; P=0.001), there was no significant association between LVEF ≤35% and SCD risk (P=0.57). On multivariable analysis including established clinical factors, LVEF and scar are independent risk markers of all-cause and cardiac death. The addition of LVEF provided incremental prognostic value but insignificant discrimination improvement by C-statistic for all-cause and cardiac death, but no incremental prognostic value for SCD. Conversely, scar extent demonstrated significant incremental prognostic value and discrimination improvement for all 3 end points. On net reclassification analysis, the addition of LVEF resulted in no significant improvement for all-cause death (11.0%; 95% CI, -6.2% to 25.9%), cardiac death (9.8%; 95% CI, -5.7% to 29.3%), or SCD (7.5%; 95% CI, -41.2% to 42.9%). Conversely, the addition of scar extent resulted in significant reclassification improvement of 25.5% (95% CI, 11.7% to 41.0%) for all-cause death, 27.0% (95% CI, 11.6% to 45.2%) for cardiac death, and 40.6% (95% CI, 10.5% to 71.8%) for SCD.

CONCLUSIONS

Myocardial scar and LVEF are both risk markers for all-cause and cardiac death in patients with nonischemic cardiomyopathy. However, whereas myocardial scar has strong and incremental prognostic value for SCD risk stratification, LVEF has no incremental prognostic value over clinical measures. Scar assessment should be incorporated into patient selection criteria for primary prevention implantable cardioverter-defibrillator placement.

MiR-223-3p in Cardiovascular Diseases: A Biomarker and Potential Therapeutic Target

Cardiovascular diseases, involving vasculopathy, cardiac dysfunction, or circulatory disturbance, have become the major cause of death globally and brought heavy social burdens. The complexity and diversity of the pathogenic factors add difficulties to diagnosis and treatment, as well as lead to poor prognosis of these diseases. MicroRNAs are short non-coding RNAs to modulate gene expression through directly binding to the 3′-untranslated regions of mRNAs of target genes and thereby to downregulate the protein levels post-transcriptionally. The multiple regulatory effects of microRNAs have been investigated extensively in cardiovascular diseases. MiR-223-3p, expressed in multiple cells such as macrophages, platelets, hepatocytes, and cardiomyocytes to modulate their cellular activities through targeting a variety of genes, is involved in the pathological progression of many cardiovascular diseases. It participates in regulation of several crucial signaling pathways such as phosphatidylinositol 3-kinase/protein kinase B, insulin-like growth factor 1, nuclear factor kappa B, mitogen-activated protein kinase, NOD-like receptor family pyrin domain containing 3 inflammasome, and ribosomal protein S6 kinase B1/hypoxia inducible factor 1 α pathways to affect cell proliferation, migration, apoptosis, hypertrophy, and polarization, as well as electrophysiology, resulting in dysfunction of cardiovascular system. Here, in this review, we will discuss the role of miR-223-3p in cardiovascular diseases, involving its verified targets, influenced signaling pathways, and regulation of cell function. In addition, the potential of miR-223-3p as therapeutic target and biomarker for diagnosis and prediction of cardiovascular diseases will be further discussed, providing clues for clinicians.

Assessment of Myocardial Fibrosis Using Two-Dimensional and Three-Dimensional Speckle Tracking Echocardiography in Dilated Cardiomyopathy With Advanced Heart Failure

BACKGROUND

This study aimed to depict strain parameters derived from 2-dimensional (2D)- and 3-dimensional (3D) speckle tracking echocardiography and to explore which may best reflect myocardial fibrosis (MF) in dilated cardiomyopathy with advanced heart failure by comparing with histologic fibrosis.

METHODS AND RESULTS

We analyzed 75 patients with dilated cardiomyopathy with advanced heart failure who underwent echocardiographic examination before heart transplantation. Strain parameters derived from 2D- and 3D speckle tracking echocardiography were as follows: left ventricular global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS) and tangential strain (TS). The degree of MF was quantified using Masson's staining in left ventricular myocardial samples obtained from all patients. Seventy-five patients were divided into 3 groups according to the tertiles of histologic MF (mild, moderate, and severe MF groups). Patients with severe MF had lower 3DGLS, 3DGRS, 3DTS, and 2DGLS than those with mild and moderate MF. MF strongly correlated with 3DGLS (r = 0.72, P < .001), weakly with 3DGRS (r = -0.39, P = .001), 3DGCS (r = 0.30, P = .009), 3DTS (r = 0.47, P < .001), and 2DGLS (r = 0.44, P < .001), but did not correlate with 2DGCS and 2DGRS. Receiver operating characteristic analysis revealed that the area under the curve of 3DGLS for detecting severe MF was significantly larger than that of other strain parameters (0.86 vs 0.59-0.70, P < .05 for all). The multivariate linear regression models using 3DGLS (R² = 0.76; Akaike information criterion = 331) was found to be a more accurate indicator to predict MF than that with 3DTS (R² = 0.65, Akaike information criterion = 354) and 2DGLS (R² = 0.66, Akaike information criterion = 352).

CONCLUSIONS

Three-dimensional GLS may be an optimal surrogate marker for reflecting MF in patients with dilated cardiomyopathy with advanced heart failure.

Progression of Myocardial Fibrosis in Nonischemic DCM and Association With Mortality and Heart Failure Outcomes

OBJECTIVES

The purpose of this study was to assess whether the presence and extent of fibrosis changes over time in patients with nonischemic, dilated cardiomyopathy (DCM) receiving optimal medical therapy and the implications of any such changes on left ventricular ejection fraction (LVEF) and clinical outcomes.

BACKGROUND

Myocardial fibrosis on cardiovascular magnetic resonance (CMR) imaging has emerged as important risk marker in patients with DCM.

METHODS

In total, 85 patients (age 56 ± 15 years, 45% women) with DCM underwent serial CMR (median interval 1.5 years) for assessment of LVEF and fibrosis. The primary outcome was all-cause mortality; the secondary outcome was a composite of heart failure hospitalization, aborted sudden cardiac death, left ventricular (LV) assist device implantation, or heart transplant.

RESULTS

On CMR-1, fibrosis (median 0.0 [interquartile range: 0% to 2.6%]) of LV mass was noted in 34 (40%) patients. On CMR-2, regression of fibrosis was not seen in any patient. Fibrosis findings were stable in 70 (82%) patients. Fibrosis progression (increase >1.8% of LV mass or new fibrosis) was seen in 15 patients (18%); 46% of these patients had no fibrosis on CMR-1. Although fibrosis progression was on aggregate associated with adverse LV remodeling and decreasing LVEF (40 ± 7% to 34 ± 10%; p < 0.01), in 60% of these cases the change in LVEF was minimal (<5%). Fibrosis progression was associated with increased hazards for all-cause mortality (hazard ratio: 3.4 [95% confidence interval: 1.5 to 7.9]; p < 0.01) and heart failure-related complications (hazard ratio: 3.5 [95% confidence interval: 1.5 to 8.1]; p < 0.01) after adjustment for clinical covariates including LVEF.

CONCLUSIONS

Once myocardial replacement fibrosis in DCM is present on CMR, it does not regress in size or resolve over time. Progressive fibrosis is often associated with minimal change in LVEF and identifies a high-risk cohort.

Mitochondrial Function and Dysfunction in Dilated Cardiomyopathy

Cardiac tissue requires a persistent production of energy in order to exert its pumping function. Therefore, the maintenance of this function relies on mitochondria that represent the “powerhouse” of all cardiac activities. Mitochondria being one of the key players for the proper functioning of the mammalian heart suggests continual regulation and organization. Mitochondria adapt to cellular energy demands via fusion-fission events and, as a proof-reading ability, undergo mitophagy in cases of abnormalities. Ca²⁺ fluxes play a pivotal role in regulating all mitochondrial functions, including ATP production, metabolism, oxidative stress balance and apoptosis. Communication between mitochondria and others organelles, especially the sarcoplasmic reticulum is required for optimal function. Consequently, abnormal mitochondrial activity results in decreased energy production leading to pathological conditions. In this review, we will describe how mitochondrial function or dysfunction impacts cardiac activities and the development of dilated cardiomyopathy.

Myocardial Fibrosis Among Antiretroviral Therapy-Treated Persons With Human Immunodeficiency Virus in South Africa

BACKGROUND

Heart failure is a prominent cardiovascular disease (CVD) manifestation in sub-Sarahan Africa. Myocardial fibrosis is a central feature of heart failure that we aimed to characterize among persons with human immunodeficiency virus (PWH) in South Africa.

METHODS

Cardiovascular magnetic resonance (CMR) imaging was performed among PWH with viral suppression and uninfected controls, both free of known CVD. Plasma levels of N-terminal pro B-type natriuretic peptide (NT-proBNP) were measured. Comparisons by human immunodeficiency virus (HIV) status were made using linear and logistic regression, adjusted for age, sex, and hypertension.

RESULTS

One hundred thirty-four PWH and 95 uninfected persons completed CMR imaging; age was 50 and 49 years, with 63% and 67% female, respectively. Compared with controls, PWH had greater myocardial fibrosis by extracellular volume fraction ([ECV] absolute difference, 1.2%; 95% confidence interval [CI], 0.1-2.3). In subgroup analyses, the effect of HIV status on ECV was more prominent among women. Women (vs controls) were also more likely to have elevated NT-proBNP levels (>125 pg/mL; odds ratio, 2.4; 95% CI, 1.0-6.0). Among all PWH, an elevated NT-proBNP level was associated with higher ECV (3.4% higher; 95% CI, 1.3-5.5).

CONCLUSIONS

Human immunodeficiency virus disease may contribute to myocardial fibrosis, with an effect more prominent among women. Research is needed to understand heart failure risk among PWH within sub-Saharan Africa.

The use of MRI in quantification of the atrial fibrosis in patients with rheumatic mitral disease

Background

Atrial fibrillation (AF) is a common type of arrhythmia with higher incidence in countries with increased prevalence of rheumatic heart disease (RHD), where AF contributes to significant morbidity and mortality in young population. Atrial fibrosis is a common feature of AF. Delayed enhancement MRI (DE-MRI) is a well-established method for characterizing fibrosis in ventricles. The use of DE-MRI to detect left atrial fibrosis helps to evaluate the extent of atrial structural remodeling non-invasively. The aim of this study is to evaluate the atrial fibrosis in patients with mitral valve disease, using the DE MRI, regarding its amount, distribution, and relation to AF.

Results

Patients with AF were older and have longer duration of symptoms, smaller valve area, larger LA size, and more fibrosis at the left atrium (with the posterior wall most frequently involved) in comparison to those with sinus rhythm. Patients with atrial fibrosis were older and have longer duration of symptoms, smaller valve area, and larger LA, and most of them had AF compared to those without fibrosis. The comparison between types of AF showed a significant difference in the amount of atrial fibrosis that increases across the spectrum of AF.

Conclusion

In patients with rheumatic mitral valve diseases, AF is associated with more atrial fibrosis as assessed by DE-MRI. Atrial fibrosis is the best independent predictor of AF.

Myocardial Fibrosis in Heart Failure: Anti-Fibrotic Therapies and the Role of Cardiovascular Magnetic Resonance in Drug Trials

All heart muscle diseases that cause chronic heart failure finally converge into one dreaded pathological process that is myocardial fibrosis. Myocardial fibrosis predicts major adverse cardiovascular events and death, yet we are still missing the targeted therapies capable of halting and/or reversing its progression. Fundamentally it is a problem of disproportionate extracellular collagen accumulation that is part of normal myocardial ageing and accentuated in certain disease states. In this article we discuss the role of cardiovascular magnetic resonance (CMR) imaging biomarkers to track fibrosis and collate results from the most promising animal and human trials of anti-fibrotic therapies to date. We underscore the ever-growing role of CMR in determining the efficacy of such drugs and encourage future trialists to turn to CMR when designing their surrogate study endpoints.

Multimodality imaging in the diagnosis, risk stratification, and management of patients with dilated cardiomyopathies: an expert consensus document from the European Association of Cardiovascular Imaging

Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular or biventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to explain these changes. This is a heterogeneous disease frequently having a genetic background. Imaging is important for the diagnosis, the prognostic assessment and for guiding therapy. A multimodality imaging approach provides a comprehensive evaluation of all the issues related to this disease. The present document aims to provide recommendations for the use of multimodality imaging according to the clinical question. Selection of one or another imaging technique should be based on the clinical condition and context. Techniques are presented with the aim to underscore what is 'clinically relevant' and what are the tools that 'can be used'. There remain some gaps in evidence on the impact of multimodality imaging on the management and the treatment of DCM patients where ongoing research is important.

Factors predictive for delayed enhancement in cardiac resonance imaging in patients undergoing catheter ablation of premature ventricular complexes

Background

Patients undergoing ablation of premature ventricular complexes (PVCs) can have cardiac scar. Risk factors for the presence of scar are not well defined.

Objectives

To determine the prevalence of scarring detected by delayed enhancement cardiac magnetic resonance imaging (DE-CMR) in patients undergoing ablation of PVCs, to create a risk score predictive of scar, and to explore correlations between the scoring system and long-term outcomes.

Methods

DE-CMR imaging was performed in consecutive patients with frequent PVCs referred for ablation. The full sample was used to develop a prediction model for cardiac scar based on demographic and clinical characteristics, and internal validation of the prediction model was done using bootstrap samples.

Results

The study consisted of 333 patients (52% male, aged 53.2 ± 14.5 years, preablation ejection fraction 50.9% ± 12.2%, PVC burden 20.7 ± 13.14), of whom 112 (34%) had DE-CMR scarring. Multiple logistic regression analysis showed age (odds ratio [OR] 1.02 [1.01–1.04]/year, P = .019) and preablation ejection fraction (OR 0.92 [0.89–0.94]/%, P < .001) to be predictive of scar. A weighted risk score incorporating age and ejection fraction was used to stratify patients into low-, medium-, and high-risk groups. Scar prevalence was around 86% in the high-risk group and 12% in the low-risk group; high-risk patients had worse survival free of arrhythmia.

Conclusions

Cardiac scar was present in one-third of patients referred for PVC ablation. A weighted risk score based simply on patient age and preprocedural ejection fraction can help discriminate between patients at high and low risk for the presence of cardiac scar and worse arrhythmia outcomes.

SCMR Position Paper (2020) on clinical indications for cardiovascular magnetic resonance

The Society for Cardiovascular Magnetic Resonance (SCMR) last published its comprehensive expert panel report of clinical indications for CMR in 2004. This new Consensus Panel report brings those indications up to date for 2020 and includes the very substantial increase in scanning techniques, clinical applicability and adoption of CMR worldwide. We have used a nearly identical grading system for indications as in 2004 to ensure comparability with the previous report but have added the presence of randomized controlled trials as evidence for level 1 indications. In addition to the text, tables of the consensus indication levels are included for rapid assimilation and illustrative figures of some key techniques are provided.

Cardiovascular Magnetic Resonance in Heritable Cardiomyopathies

Cardiovascular magnetic resonance represents the imaging modality of choice for the investigation of patients with heritable cardiomyopathies. The combination of gold-standard volumetric analysis with tissue characterization can deliver precise phenotypic evaluation of both cardiac morphology and the underlying myocardial substrate. Cardiovascular magnetic resonance additionally has an established role in risk-stratifying patients with heritable cardiomyopathy and an emerging role in guiding therapies. This article explores the application and utility of cardiovascular magnetic resonance techniques with specific focus on the major heritable cardiomyopathies.

Circulating exosomal microRNAs as emerging non-invasive clinical biomarkers in heart failure: Mega bio-roles of a nano bio-particle

Exosomes are nano-sized extracellular vesicles containing a cell-specific biologically active cargo of proteins and genetic materials. Exosomes are constitutively released from almost all cell-types and affect neighboring or distant cells through a complex intercellular exchange of the genetic information and/or regulation of certain gene expressions that change the function and behavior of recipient cells. Those released into body fluids are the major mediators of intercellular communications. The success of the biological functions of exosomes is highly mediated by the effective transfer of microRNAs (miRs). Exosomes secreted by a damaged or diseased heart can exhibit alterations in the miRs' profile that may reflect the cellular origin and (patho)physiological state, as a "signature" or "fingerprint" of the donor cell. It has been shown that the transportation of cardiac-specific miRs in exosomes can be rapidly detected and measured, holding great potential as biomarkers in heart diseases. Currently, the search for new biomarkers of heart diseases remains a large and increasing enterprise. Notably, circulating exosomal miRs (Exo-miRs) have successfully gained huge interests for their diagnostic and prognostic potentials. The present review highlights circulating Exo-miRs explored for diagnosis/prognosis and outcome prediction in patients with heart failure (HF). To this end, we explain the feasibility of exosomes as clinical biomarkers, discuss the priority of circulating Exo-miRs over non-exosomal ones as a biomarker, and then outline reported circulating Exo-miRs having the biomarker function in HF patients, together with their mechanism of action. In conclusion, circulating Exo-miRs represent emerging diagnostic (Exo-miR-92b-5p, Exo-miR-146a, Exo-miR-181c, and Exo-miR-495) and prognostic (Exo-miR-192, Exo-miR-194, Exo-miR-34a, Exo-miR-425, Exo-miR-744) biomarkers for HF.

Prognostic value of multiple cardiac magnetic resonance imaging parameters in patients with idiopathic dilated cardiomyopathy

PURPOSE

Our study aimed to comprehensively explore efficient prognostic indicators in idiopathic dilated cardiomyopathy (IDCM) patients with reduced left ventricular ejection fraction (LVEF<40%).

BACKGROUND

Prognostic value of cardiac magnetic resonance(CMR) parameters for IDCM have been inconsistent.

METHODS

126 IDCM patients with reduced LVEF (<40%) were retrospectively enrolled. Cardiac function parameters, myocardial strain indices and myocardial fibrosis were evaluated. Laboratory data also were analyzed. The endpoint was a combination of major adverse cardiac events (MACEs), including cardiac death, heart transplantation, and rehospitalization. Prognostic value was evaluated by the Kaplan-Meier method and Cox regression.

RESULTS

During a median follow-up of 31 months, 44 patients experienced MACEs, including 9 deaths, 1 heart transplantation, and 34 rehospitalizations due to heart failure. Univariate and multivariate Cox analyses showed that cardiac function and myocardial strain indexes were not associated with the prognosis of IDCM (all p>0.05). NT-proBNP (HR 1.5, 95%CI: 1.053 to 2.137), Late‑gadolinium enhancement(LGE) mass (HR 1.022, 95%CI: 1.005 to 1.038), and LGE mass/left ventricle mass were significant predictors (HR 1.027, 95%CI: 1.007 to 1.046) for MACEs, all p < 0.05. Besides, poorest prognosis was observed in IDCM patients with positive LGE combined with NT-proBNP (log-rank = 27.261, p ≤ 0.001).

CONCLUSION

NT-proBNP and extent of LGE were reliable predictors in IDCM patients with reduced LVEF. Additionally, presence of LGE combined with NT-proBNP showed the strongest prognostic value in IDCM with reduced LVEF. Myocardial strain parameters seemed to have no prognostic value in IDCM patients with reduced LVEF.

Late-gadolinium enhancement in a subject with normal left ventricular function

A 27-year-old man visited our hospital after experiencing palpitations. His 12-lead electrocardiogram and chest radiograph were unremarkable. Blood test results showed normal plasma brain natriuretic peptide level (<5.8 pg/mL). Transthoracic echocardiography revealed normal left ventricular structure and function by demonstrating left ventricular wall thickness of 10 mm, end-diastolic dimension of 46 mm, end-systolic dimension of 31 mm, and ejection fraction of 64%. Pulsed-wave Doppler echocardiography demonstrated normal E/e’ ratio of 7.5. Cardiac magnetic resonance imaging showed normal coronary artery. However, there was massive late-gadolinium enhancement at the mid-layer wall, suggesting massive left ventricular fibrosis. This case reveals that left ventricular function may be normal even in massive late-gadolinium enhancement. Pathophysiology other than fibrosis might have contributed to this specific finding in late-gadolinium enhancement.

Galactin-3 and soluble ST2 as complementary tools to cardiac MRI for sudden cardiac death risk stratification in heart failure: A review

Heart failure (HF) is recognized as one of the leading causes of morbidity and mortality worldwide. Every year about 500,000 new cases of HF are diagnosed in the United States. The predominant etiology of death in HF patients include sudden cardiac death (SCD) and pump failure. Prediction of mode of death may help in devising management decisions. In patients with HF, the presence of myocardial fibrosis has been a known risk factor for SCD and thus it could be used as a criterion in risk stratification for SCD. However, the underlying pathophysiology of SCD is uncertain and controversial, which makes it necessary to develop newer tools to enhance SCD risk stratification. The newer tools should be innovative enough either to complement or to replace the currently available tools. In this scoping review, we highlighted the utilization of novel biomarkers galectin-3 (gal-3) and soluble ST2 (sST2) and discussed that how they might complement currently available tools such as, cardiac MRI (CMR) for SCD risk stratification in HF patients.

Cardiac magnetic resonance in hypertrophic and dilated cardiomyopathies

Cardiomyopathies are a heterogeneous entity. The progress in the field of genetics has allowed over the years to determine its origin more and more often. The classification of these pathologies has changed over the years; it has been updated with new knowledge. Imaging allows to define the phenotypic characteristics of the different forms of cardiomyopathy. Cardiac magnetic resonance (CMR) allows a morphological evaluation of the associated (and sometimes pathognomonic) cardiac findings of any form of cardiomyopathy. The tissue characterization sequences also make magnetic resonance imaging unique in its ability to detect changes in myocardial tissue. This review aims to define the features that can be highlighted by CMR in hypertrophic and dilated forms and the possible differential diagnoses. In hypertrophic forms, CMR provides: precise evaluation of wall thickness in all segments, ventricular function and size and evaluation of possible presence of areas of fibrosis as well as changes in myocardial tissue (measurement of T1 mapping and extracellular volume values). In dilated forms, cardiac resonance is the gold standard in the assessment of ventricular volumes. CMR highlights also the potential alterations of the myocardial tissue.

What is the mid-wall linear high intensity "lesion" on cardiovascular magnetic resonance late gadolinium enhancement?

BACKGROUND

Cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) is a valuable technique for detecting myocardial disorders and fibrosis. However, we sometimes observe a linear, mid-wall high intensity signal in the basal septum in the short axis view, which often presents diagnostic difficulties in the clinical setting. The purpose of this study was to compare the linear, mid-wall high intensity in the basal septum identified by LGE with the anterior septal perforator arteries identified by coronary computed tomography angiography (CorCTA).

METHODS

We retrospectively selected 148 patients who underwent both CorCTA and CMR LGE within 1 year. In the interpretation of LGE, we defined a positive linear high intensity (LHI+) as follows: ① LHI in the basal septum and ② observable for 1.5 cm or more. All other patients were defined as a negative LHI (LHI-). In LHI+ patients, we assessed the correlation between the LHI length and the septal perforator artery length on CorCTA. We also compared the length of the septal perforator artery on CorCTA between LHI+ patients and LHI- patients.

RESULTS

A population of 111 patients were used for further analysis. Among these , there were 55 LHI+ patients and 56 LHI- patients. In LHI+ patients, linear regression analysis revealed that there was a good agreement between LGE LHI and septal perforator arteries by CorCTA in terms of length measurements. The measured length of the anterior septal perforator arteries was significantly shorter in LHI- patients than in LHI+ patients (10 ± 8 mm vs. 21 ± 8 mm; P < 0.05).

CONCLUSIONS

The LHI observed in the basal septum on short axis LGE may reflect contrast enhancement of the anterior septal perforator arteries. It is important to interpret this septal LHI against knowledge of anatomic structure, to avoid misinterpretations of LGE and prevent misdiagnosis.

The Extent of Late Gadolinium Enhancement Can Predict Adverse Cardiac Outcomes in Patients with Non-Ischemic Cardiomyopathy with Reduced Left Ventricular Ejection Fraction: A Prospective Observational Study

OBJECTIVE

The clinical course of an individual patient with heart failure is unpredictable with left ventricle ejection fraction (LVEF) only. We aimed to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived myocardial fibrosis extent and to determine the cutoff value for event-free survival in patients with non-ischemic cardiomyopathy (NICM) who had severely reduced LVEF.

MATERIALS AND METHODS

Our prospective cohort study included 78 NICM patients with significantly reduced LV systolic function (LVEF < 35%). CMR images were analyzed for the presence and extent of late gadolinium enhancement (LGE). The primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, heart transplantation, implantable cardioverter-defibrillator discharge for major arrhythmia, and hospitalization for congestive heart failure within 5 years after enrollment.

RESULTS

A total of 80.8% (n = 63) of enrolled patients had LGE, with the median LVEF of 25.4% (19.8-32.4%). The extent of myocardial scarring was significantly higher in patients who experienced MACE than in those without any cardiac events (22.0 [5.5-46.1] %LV vs. 6.7 [0-17.1] %LV, respectively, p = 0.008). During follow-up, 51.4% of patients with LGE ≥ 12.0 %LV experienced MACE, along with 20.9% of those with LGE ≤ 12.0 %LV (log-rank p = 0.001). According to multivariate analysis, LGE extent more than 12.0 %LV was independently associated with MACE (adjusted hazard ratio, 6.71; 95% confidence interval, 2.54-17.74; p < 0.001).

CONCLUSION

In NICM patients with significantly reduced LV systolic function, the extent of LGE is a strong predictor for long-term adverse cardiac outcomes. Event-free survival was well discriminated with an LGE cutoff value of 12.0 %LV in these patients.

Cardiac Magnetic Resonance in Nonischemic Cardiomyopathies

Cardiovascular magnetic resonance (CMR) has emerged as a key modality to assess nonischemic cardiomyopathies. Its ability to detect cardiac morphology and function with fast cine imaging, myocardial edema with T2-based techniques, and fibrosis with late gadolinium enhancement techniques has enabled noninvasive characterization of cardiac tissue, thus helping clinicians assess cardiovascular risk and determine the most effective management strategy. Active investigations into parametric imaging techniques will further expand the potential clinical applications of CMR for cardiac tissue characterization. This review discusses the use of CMR techniques in characterizing the major morphofunctional phenotypes of nonischemic cardiomyopathies.

Positron emission tomography/MRI for cardiac diseases assessment

Functional imaging tools have emerged in the last few decades and are increasingly used to assess the function of the human heart in vivo. Positron emission tomography (PET) is used to evaluate myocardial metabolism and blood flow. Magnetic resonance imaging (MRI) is an essential tool for morphological and functional evaluation of the heart. In cardiology, PET is successfully combined with CT for hybrid cardiac imaging. The effective integration of two imaging modalities allows simultaneous data acquisition combining functional, structural and molecular imaging. After PET/CT has been successfully accepted for clinical practices, hybrid PET/MRI is launched. This review elaborates the current evidence of PET/MRI in cardiovascular imaging and its expected clinical applications for a comprehensive assessment of cardiovascular diseases while highlighting the advantages and limitations of this hybrid imaging approach.

Aortic valve stenosis-multimodality assessment with PET/CT and PET/MRI

Aortic valve disease is the most common form of heart valve disease in developed countries and a growing healthcare burden with an ageing population. Transthoracic and transoesophageal echocardiography remains central to the diagnosis and surveillance of patients with aortic stenosis, providing gold standard assessments of valve haemodynamics and myocardial performance. However, other multimodality imaging techniques are being explored for the assessment of aortic stenosis, including combined PET/CT and PET/MR. Both approaches provide unique information with respect to disease activity in the valve alongside more conventional anatomic assessments of the valve and myocardium in this condition. This review investigates the emerging use of PET/CT and PET/MR to assess patients with aortic stenosis, examining how the complementary data provided by each modality may be used for research applications and potentially in future clinical practice.

Tenascin-C in cardiac disease: a sophisticated controller of inflammation, repair, and fibrosis

Tenascin-C (TNC) is a large extracellular matrix glycoprotein classified as a matricellular protein that is generally upregulated at high levels during physiological and pathological tissue remodeling and is involved in important biological signaling pathways. In the heart, TNC is transiently expressed at several important steps during embryonic development and is sparsely detected in normal adult heart but is re-expressed in a spatiotemporally restricted manner under pathological conditions associated with inflammation, such as myocardial infarction, hypertensive cardiac fibrosis, myocarditis, dilated cardiomyopathy, and Kawasaki disease. Despite its characteristic and spatiotemporally restricted expression, TNC knockout mice develop a grossly normal phenotype. However, various disease models using TNC null mice combined with in vitro experiments have revealed many important functions for TNC and multiple molecular cascades that control cellular responses in inflammation, tissue repair, and even myocardial regeneration. TNC has context-dependent diverse functions and, thus, may exert both harmful and beneficial effects in damaged hearts. However, TNC appears to deteriorate adverse ventricular remodeling by proinflammatory and profibrotic effects in most cases. Its specific expression also makes TNC a feasible diagnostic biomarker and target for molecular imaging to assess inflammation in the heart. Several preclinical studies have shown the utility of TNC as a biomarker for assessing the prognosis of patients and selecting appropriate therapy, particularly for inflammatory heart diseases.

Predictors of Mortality in Patients With Biopsy-Proven Viral Myocarditis: 10-Year Outcome Data

Background

There is scarce data about the long‐term mortality as well as the prognostic value of cardiovascular magnetic resonance and late gadolinium enhancement (LGE) in patients with biopsy‐proven viral myocarditis. We sought to investigate: (1) mortality and (2) prognostic value of LGEcardiovascular magnetic resonance (location, pattern, extent, and distribution) in a >10‐year follow‐up in patients with biopsy‐proven myocarditis.

Methods and Results

Two‐hundred three consecutive patients with biopsy‐proven viral myocarditis and cardiovascular magnetic resonance were enrolled; 183 patients were eligible for standardized follow‐up. The median follow‐up was 10.1 years. End points were all‐cause death, cardiac death, and sudden cardiac death (SCD). We found substantial long‐term mortality in patients with biopsy‐proven myocarditis (39.3% all cause, 27.3% cardiac, and 10.9% SCD); 101 patients (55.2%) demonstrated LGE. The presence of LGE was associated with a more than a doubled risk of death (hazard ratio [HR], 2.40; 95% CI], 1.30–4.43), escalating to a HR of 3.00 (95% CI, 1.41–6.42) for cardiac death, and a HR of 14.79 (95% CI, 1.95–112.00) for SCD; all P≤0.009. Specifically, midwall, (antero‐) septal LGE, and extent of LGE were highly associated with death, all P<0.001. Septal LGE was the best independent predictor for SCD (HR, 4.59; 95% CI, 1.38–15.24; P=0.01).

Conclusions

In patients with biopsy‐proven viral myocarditis, the presence of midwall LGE in the (antero‐) septal segments is associated with a higher rate of mortality (including SCD) compared with absent LGE or other LGE patterns, underlining the prognostic benefit of a distinct LGE analysis in these patients.