Baseline cardiac magnetic resonance imaging versus baseline endomyocardial biopsy for the prediction of left ventricular reverse remodeling and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy

Impact of late gadolinium-enhanced cardiac MRI on arrhythmic and mortality outcomes in nonischemic dilated cardiomyopathy: updated systematic review and meta-analysis

Risk stratification based mainly on the impairment of left ventricular ejection fraction has limited performance in patients with nonischemic dilated cardiomyopathy (NIDCM). Evidence is rapidly growing for the impact of myocardial scar identified by late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMR) on cardiovascular events. We aim to assess the prognostic value of LGE on long-term arrhythmic and mortality outcomes in patients with NIDCM. PubMed, Scopus, and Cochrane databases were searched from inception to January 21, 2022. Studies that included disease-specific subpopulations of NIDCM were excluded. Data were independently extracted and combined via random-effects meta-analysis using a generic inverse-variance strategy. Data from 60 studies comprising 15,217 patients were analyzed with a 3-year median follow-up. The presence of LGE was associated with major ventricular arrhythmic events (pooled OR: 3.99; 95% CI 3.08, 5.16), all-cause mortality (pooled OR: 2.14; 95% CI 1.81, 2.52), cardiovascular mortality (pooled OR 2.83; 95% CI 2.23, 3.60), and heart failure hospitalization (pooled OR: 2.53; 95% CI 1.78, 3.59). Real-world evidence suggests that the presence of LGE on CMR was a strong predictor of adverse long-term outcomes in patients with NIDCM. Scar assessment should be incorporated as a primary determinant in the patient selection criteria for primary prophylactic implantable cardioverter-defibrillator placement.

Relationship Between Results of Pathological Evaluation of Endomyocardial Biopsy and Echocardiographic Indices in Patients With Non-Ischemic Cardiomyopathy

Background: Endomyocardial biopsy (EMB) is a useful modality in diagnosing the origin of cardiomyopathy and the condition of the impaired myocardium. However, the usefulness of obtaining an EMB from the right and left ventricles (RV and LV, respectively), and its associations with echocardiographic parameters, have not been explored. Methods and Results: Ninety-five consecutive patients with non-ischemic cardiomyopathy excluding myocarditis who underwent EMB between July 2017 and May 2019 were studied. Seventy-nine RV and 93 LV biopsy specimens were pathologically analyzed. The relationships among echocardiographic data before EMB and pathologically measured cardiomyocyte diameter (CMD) and interstitial fibrosis (IF) were evaluated. CMD in both LV and RV specimens correlated with echocardiographic LV morphology, but only CMD in the LV was significantly correlated with cardiac function evaluation, including LV ejection fraction, E' and E/E'. In contrast, there were no significant correlations between IF in either the LV or RV and any echocardiographic parameters measured. Furthermore, CMD of both ventricles was significantly correlated with B-type natriuretic peptide (BNP) concentration at EMB, whereas IF of the LV was barely related and IF of the RV was not significantly correlated with BNP concentrations. Conclusions: Pathologically evaluated CMD of EMB specimens of the LV may be more related to functional parameters for heart failure status and LV geometry on echocardiographic examination, than IF.

Association of Late-Gadolinium Enhancement in Cardiac Magnetic Resonance with Mortality, Ventricular Arrhythmias, and Heart Failure in Patients with Non-Ischemic Cardiomyopathy: A Systematic Review and Meta-Analysis

Background

Late gadolinium enhancement (LGE) on cardiac magnetic resonance is a predictor of adverse events in patients with nonischemic cardiomyopathy (NICM).

Objective

This meta-analysis evaluated the correlation between LGE and mortality, ventricular arrhythmias (VAs) and sudden cardiac death (SCD), and heart failure (HF) outcomes.

Methods

A literature search was conducted for studies reporting the association between LGE in NICM and the study endpoints. The primary endpoint was mortality. Secondary endpoints included VA and SCD, HF hospitalization, improvement in left ventricular ejection fraction (LVEF) to >35%, and heart transplantation referral. The search was not restricted to time or publication status. The minimum follow-up duration was 1 year.

Results

A total of 46 studies and 10,548 NICM patients (4610 with LGE, 5938 without LGE) were included; mean follow-up was 3 years (range 13-71 months). LGE was associated with increased mortality (odds ratio [OR] 2.9; 95% confidence interval [CI] 2.3-3.8; P < .01) and VA and SCD (OR 4.6; 95% CI 3.5-6.0; P < .01). LGE was associated with an increased risk of HF hospitalization (OR 3.4; 95% CI 2.3-5.0; P < .01), referral for transplantation (OR 5.1; 95% CI 2.5-10.4; P < .01), and decreased incidence of LVEF improvement to >35% (OR 0.2; 95% CI 0.03-0.85; P = .03).

Conclusion

LGE in NICM patients is associated with increased mortality, VA and SCD, and HF hospitalization and heart transplantation referral during long-term follow up. Given these competing risks of mortality and HF progression, prospective randomized controlled trials are required to determine if LGE is useful for guiding prophylactic implantable cardioverter-defibrillator placement in NICM patients.

Cardiac remodelling - Part 2: Clinical, imaging and laboratory findings. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes. The remodelling process ultimately involves all cardiac chambers, but has been traditionally evaluated in terms of left ventricular volumes and ejection fraction. This is the second part of a review paper by the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology dedicated to ventricular remodelling. This document examines the proposed criteria to diagnose RR and AR, their prevalence and prognostic value, and the variables predicting remodelling in patients managed according to current guidelines. Much attention will be devoted to RR in patients with heart failure with reduced ejection fraction because most studies on cardiac remodelling focused on this setting.

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.

Reverse Remodeling in Human Heart Failure after Cardiac Resynchronization Therapy Is Associated With Reduced RHO-Kinase Activation

Background: Reverse remodeling is a clinically relevant endpoint in heart failure with reduced ejection fraction (HFrEF). Rho-kinase (ROCK) signaling cascade activation correlates with cardiac remodeling and left ventricular (LV) systolic dysfunction in HFrEF patients. Cardiac resynchronization therapy (CRT) is effective in HFrEF, especially when there is a left bundle block, as this treatment may stimulate reverse remodeling, thereby improving quality of life and prolonging survival for patients with this severe condition. Here, we evaluate the hypothesis that ROCK activation is reduced after effective CRT in HFrEF. Methods: ROCK activation in circulating leukocytes was evaluated in 28 HFrHF patients, using Western blot (myosin light chain phosphatase subunit 1 phosphorylation, MYPT1p/t), before and three months after initiation of CRT. LV systolic function and remodeling were assessed by echocardiography. Results: Three months after CRT, LV ejection fraction increased an average of 14.5% (p < 0.001) in 13 patients (responders), while no change was observed in 15 patients (non-responders). End-systolic diameter decreased 16% (p < 0.001) in responders, with no change in non-responders. ROCK activation in PBMCs decreased 66% in responders (p < 0.05) but increased 10% in non-responders (NS). LV end-diastolic diameter was also 5.2 mm larger in non-responders vs. responders (p = 0.058). LV ejection fraction, systolic diameter, and ROCK activation levels were similar in both groups at baseline. Conclusion: In HFrEF patients, 3 months of effective CRT induced reverse myocardial remodeling, and ROCK activation was significantly decreased in circulating leukocytes. Thus, decreased ROCK activation in circulating leukocytes may reflect reverse cardiac remodeling in patients with heart failure.

Myocardial Fibrosis as a Pathway of Prediction of Ventricular Arrhythmias and Sudden Cardiac Death in Patients With Nonischemic Dilated Cardiomyopathy

The mechanism of sudden cardiac death (SCD) in patients with nonischemic dilated cardiomyopathy (NIDCM) is mostly due to sustained ventricular tachycardia and ventricular fibrillation. The clinical guidelines for the therapeutic management of this set of patients are mostly based on left ventricular ejection fraction value which has a low specificity to differentiate the risk of SCD from the risk of mortality associated with heart failure or other comorbidities. Moreover, since SCD can occur in patients with normal or mildly depressed ejection fraction, it is necessary to identify new markers to improve the prognostic stratification of SCD. Several studies that analyzed the ventricular arrhythmia substrate found that myocardial fibrosis plays an important role in the genesis of ventricular arrhythmias in patients with NIDCM. The surrounding zone of the area of fibrosis is a heterogeneous medium, where tissue with different levels of fibrosis coexists, resulting in both viable and nonviable myocardium. This myocardial fibrosis may constitute a substrate for ventricular arrhythmias, where slow and heterogeneous conduction may favor the genesis of reentry mechanism increasing the chance to develop sustained ventricular tachycardia or ventricular fibrillation. Therefore, the evaluation of ventricular fibrosis by late gadolinium enhancement (LGE) cardiac magnetic resonance imaging has been suggested as an indicator for SCD risk stratification. Indeed, LGE in patients with NIDCM is associated with increased risk of all-cause mortality, heart failure hospitalization, and SCD. Detection of myocardial fibrosis as LGE by cardiac magnetic resonance imaging can be considered as a useful pathway of prediction of malignant ventricular arrhythmias since it has excellent prognostic characteristics and may help guide risk stratification and management in patients with NIDCM.

Wisteria floribunda agglutinin staining for the quantitative assessment of cardiac fibrogenic activity in a mouse model of dilated cardiomyopathy

Cardiac fibrosis is a typical phenomenon in failing hearts for most cardiac diseases, including dilated cardiomyopathy (DCM), and its specific detection and quantification are crucial for the analysis of cardiac remodeling. Since cardiac fibrosis is characterized by extensive remodeling of the myocardial extracellular matrix (ECM), in which glycoproteins are the major components, we assumed that fibrosis-related alterations in the cardiac glycome and glycoproteome would be suitable targets for the detection of cardiac fibrosis. Here, we compared protein glycosylation between heart tissues of normal and DCM model mice by laser microdissection-assisted lectin microarray. Among 45 lectins, Wisteria floribunda agglutinin (WFA) was selected as the most suitable lectin for staining cardiac fibrotic tissues. Although the extent of WFA staining was highly correlated (r > 0.98) with that of picrosirius red staining, a common collagen staining method, WFA did not bind to collagen fibers. Further histochemical analysis with N-glycosidase revealed that WFA staining of fibrotic tissues was attributable to the binding of WFA to N-glycoproteins. Using a mass spectrometry-based approach, we identified WFA-binding N-glycoproteins expressed in DCM hearts, many of which were fibrogenesis-related ECM proteins, as expected. In addition, the identified glycoproteins carrying WFA-binding N-glycans were detected only in DCM hearts, suggesting their cooperative glycosylation alterations with disease progression. Among these WFA-binding ECM N-glycoproteins, co-localization of the collagen α6(VI) chain protein and WFA staining in cardiac tissue sections was confirmed with a double-staining analysis. Collectively, these results indicate that WFA staining is more suitable for the quantitative assessment of cardiac fibrogenic activity than current collagen staining methods. Furthermore, given that plasma WFA-binding glycoprotein levels were significantly correlated with the echocardiographic parameters for left ventricular remodeling, cardiac WFA-binding glycoproteins are candidate circulating glyco-biomarkers for the quantification and monitoring of cardiac fibrogenesis.

Imaging, Biomarker, and Clinical Predictors of Cardiac Remodeling in Heart Failure With Reduced Ejection Fraction

In response to injury, hemodynamic changes, or neurohormonal activation, the heart undergoes a series of structural and functional changes that have been termed cardiac remodeling. Remodeling is defined as changes in cardiac geometry and/or function over time and can be measured in terms of changes in cardiac chamber dimensions, wall thickness, volumes, mass, and ejection fraction at serial imaging examinations. As to cardiac chambers, left ventricular (LV) remodeling has been best studied in patients with heart failure with reduced ejection fraction. Although LV remodeling may compensate for abnormal hemodynamic parameters and function in the short term, left unchecked, it is associated with worsening cardiac function and poor prognosis. On the other hand, reversing LV geometry and/or function closer to that of a normal heart (also known as reverse remodeling) is associated with improved cardiac function and better prognosis. Because of its close relationship with clinical outcomes, remodeling may potentially be targeted in clinical management and used in trials as a surrogate endpoint. Standardized definition of remodeling and reliable tools to predict and monitor the presence, direction, and magnitude of cardiac remodeling are needed. Together with clinical and imaging findings, circulating biomarkers (most notably N-terminal pro-B-type natriuretic peptide, high-sensitivity troponin, and soluble suppression of tumorigenesis-2) may be helpful in this respect.

Sudden Cardiac Death Risk Prediction: The Role of Cardiac Magnetic Resonance Imaging

Sudden cardiac death (SCD) accounts for more than 4 million global deaths per year. While it is most commonly caused by coronary artery disease, a final common pathway of ventricular arrhythmias is shared by different etiologies. The most effective primary and secondary prevention strategy is an implantable cardioverter-defibrillator (ICD). The decision to implant an ICD for primary prevention is largely based on a left ventricular ejection fraction ≤ 35%, but this criterion in isolation is neither sensitive nor specific. Novel imaging parameters hold promise to improve ICD candidate selection. Cardiac magnetic resonance (CMR) imaging is a powerful and versatile technique, with the ability to comprehensively assess cardiac structure and function. A range of variables based on CMR techniques (late gadolinium enhancement, T₁ mapping, T₂* relaxometry, deformation imaging) have been associated with ventricular arrhythmias and SCD risk. The role of CMR in the estimation of ventricular arrhythmias and SCD risk in coronary artery disease, nonischemic cardiomyopathies, cardiac transplant, iron-overload cardiomyopathy and valvular heart disease is reviewed in this article. Prospective, randomized trials and standardization of CMR techniques are required before its routine use can be recommended for guiding SCD prevention strategies.

Dilated cardiomyopathy with re-worsening left ventricular ejection fraction

Re-worsening left ventricular ejection fraction (LVEF) is observed in some patients with dilated cardiomyopathy (DCM) despite initial improvements in LVEF. We analyzed cardiac outcomes and clinical variables associated with this re-worsening LVEF. A total of 180 newly diagnosed DCM patients who received only pharmacotherapy were enrolled. Echocardiography was performed after 6, 12, 24, and 36 months after initiation of pharmacotherapy. Patients were divided into three groups: (1) Improved: (n = 113, 63%), defined as those > 10% increase in LVEF after 12 months and no decrease (> 10%) between 12 and 36 months; (2) Re-worse: (n = 12, 7%), those with > 10% increase in LVEF after 12 months but with decrease (> 10%) between 12 and 36 months; and (3) Not-improved: (n = 55: 30%), those with no increase in LVEF (> 10%) after 12 months. Patients with re-worse group were older (P = 0.04) and had higher brain natriuretic peptide (BNP) levels after 12 months (P = 0.002) than those in the Improved group. Major cardiac events (sudden death, implantation of a ventricular assist device, and death due to heart failure,) were observed in 13 (7%) patients after 36 months of pharmacotherapy. Multivariate analysis revealed that the Re-worse group had a higher risk for cardiac events (hazard ratio 11.7, 95% confidence interval 1.9-90.7, P = 0.01) than the Improved group, but had a similar risk compared with the Not-improved group. Re-worsening LVEF was associated with poor cardiac outcomes in newly diagnosed DCM patients. Age and persistently high-BNP levels after improvement in LVEF were significantly associated with re-worsening LVEF.

The Prognostic Value of Late Gadolinium-Enhanced Cardiac Magnetic Resonance Imaging in Nonischemic Dilated Cardiomyopathy: A Review and Meta-Analysis

OBJECTIVES

This review and meta-analysis reviews the prognostic value of cardiac magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (DCM).

BACKGROUND

Late gadolinium-enhanced (LGE) CMR is a noninvasive method to determine the underlying cause of DCM and previous studies reported the prognostic value of the presence of LGE to identify patients at risk of major adverse cardiovascular events.

METHODS

PubMed was searched for studies describing the prognostic implication of LGE in patients with DCM for the specified endpoints cardiovascular mortality, major ventricular arrhythmic events including appropriate implantable cardioverter-defibrillator therapy, rehospitalization for heart failure, and left ventricular reverse remodeling.

RESULTS

Data from 34 studies were included, with a total of 4,554 patients. Contrast enhancement was present in 44.8% of DCM patients. Patients with LGE had increased cardiovascular mortality (odds ratio [OR]: 3.40; 95% confidence interval [CI]: 2.04 to 5.67), ventricular arrhythmic events (OR: 4.52; 95% CI: 3.41 to 5.99), and rehospitalization for heart failure (OR: 2.66; 95% CI: 1.67 to 4.24) compared with those without LGE. Moreover, the absence of LGE predicted left ventricular reverse remodeling (OR: 0.15; 95% CI: 0.06 to 0.36).

CONCLUSIONS

The presence of LGE on CMR substantially worsens prognosis for adverse cardiovascular events in DCM patients, and the absence indicates left ventricular reverse remodeling.

Prognostic value of fibrosis-related markers in dilated cardiomyopathy: A link between osteopontin and cardiovascular events

INTRODUCTION

Serum markers of fibrosis provide an insight into extracellular matrix (ECM) fibrosis in heart failure (HF) and dilated cardiomyopathy (DCM). However, their role as predictors of cardiovascular (CV) events in DCM is poorly understood.

METHODS

This is an observational, prospective cohort study. 70 DCM patients (48±12.1years, ejection fraction - EF 24.4±7.4) were recruited. Markers of collagen type I and III synthesis - procollagen type I and III carboxy- and amino-terminal peptides (PICP, PIIICP, PINP, PIIINP), fibrosis controlling factors - ostepontin (OPN), transforming growth factor (TGF1-β) and connective tissue growth factor (CTGF), and matrix metalloproteinases (MMP-2, MMP-9) and tissue inhibitor (TIMP-1), were measured in serum. All patients underwent endomyocardial biopsy. The end-point was combined with CV death and urgent HF hospitalization. Patients were divided into two groups: those who did (group 1, n=45) and did not reach (group 2, n=25) an end-point.

RESULTS

Over a 12-month period of observation, 6 CV deaths and 19 HF hospitalizations occurred. Qualitative and quantitative measures of ECM fibrosis were similar in both groups. The levels of all of the markers of collagen synthesis, TGF1-β, MMP-9 and TIMP-1 were similar, however, OPN, CTGF and MMP-2 were significantly lower in group 1.

CONCLUSIONS

Invasively-determined fibrosis levels were not related with CV outcomes in DCM. Out of the 11 markers of fibrosis under study, only OPN was found to be related to CV outcomes. OPN is not only the pivotal protein controlling fibrosis, but may also serve as a biomarker associated with prognosis.

Prognostic Impact of Segmental Wall Motion Abnormality in Patients With Idiopathic Dilated Cardiomyopathy

The clinical impact of left ventricular (LV) segmental wall motion abnormalities (SWMA) in patients with idiopathic dilated cardiomyopathy (IDCM) has not been well elucidated.Among 100 consecutive IDCM patients with follow-up visits, we enrolled 85 after excluding those with left bundle branch block and/or ventricular pacemaker implantation. LV wall motion was assessed using left ventriculography scored for 7 segments according to the American Heart Association classification as follows: 0, normokinesis; 1, hypokinesis; 2, akinesis; and 3, dyskinesis. SWMA were defined as a score dispersion of more than 1 degree among the segments.SWMA was exhibited by 26 patients. Kaplan-Meier curves demonstrated that the patients with SWMA (SWMA+) had a significantly higher cardiac event-free rate than the patients without SWMA (P < 0.001). Cox proportional hazards analysis showed that SWMA+ was an independent predictor of cardiac events (P = 0.03; hazard ratio = 3.38; 95% confidence interval [CI], 1.11-10.8). Furthermore, multiple regression analysis showed that SWMA+ was an independent predictor of decreased LV end-systolic dimension index after optimal pharmacotherapy (β = -0.24; 95%CI, -9.12 to -0.73; P = 0.02).SWMA is common in patients with IDCM and is independently associated with a poor prognosis and less morphometric and functional improvement of LV in response to pharmacotherapy.

Multimodality imaging assessment of mitral valve anatomy in planning for mitral valve repair in secondary mitral regurgitation

Secondary mitral regurgitation (MR) is frequent valvular heart disease and conveys worse prognostic. Therapeutic surgical or percutaneous options are available in the context of severe symptomatic secondary MR, but the best approach to treat these patients remains unclear, given the lack of clear clinical evidence of benefit. A comprehensive evaluation of the mitral valve apparatus and the left ventricle (LV) has the ability to clearly define and characterize the disease, and thus determine the best option for the patient to improve its clinical outcomes, as well as quality of life and symptoms. The current report reviews the mitral valve (MV) anatomy, the underlying mechanisms associated with secondary MR, the related therapeutic options available, and finally the usefulness of a multimodality imaging approach for the planning of surgical or percutaneous mitral valve intervention.

In-hospital management and outcomes in patients with peripartum cardiomyopathy: a descriptive study using a national inpatient database in Japan

Peripartum cardiomyopathy (PPCM) is a rare but life-threatening cardiac disorder characterized by maternal systolic heart failure. Although PPCM is a major cause of maternal mortality, little is known about the acute-phase management of PPCM in real-world clinical settings. We retrospectively identified patients hospitalized with PPCM from 2007 to 2014 using the Diagnosis Procedure Combination database in Japan. We investigated patient characteristics, in-hospital examinations and treatment, and in-hospital outcomes. The study patients were 283 patients hospitalized with PPCM at 177 hospitals. The mean age was 32.7 ± 5.5 years. Of the eligible patients, 134 (47.3%) patients had a hypertensive disorder, including 48 (17.0%) patients with pre-eclampsia, and 111 (39.2%) patients were admitted to the intensive care unit or emergency center. Coronary angiography, cardiac magnetic resonance imaging, and endomyocardial biopsy were performed during hospitalization in 69 (24.4%), 42 (14.8%), and 43 (15.2%) patients, respectively. Invasive pulmonary artery pressure monitoring was used in 14 (4.9%) patients. Mechanical circulatory support was used in 13 (4.6%) patients (intra-aortic balloon pumping, n = 12; extracorporeal membrane oxygenation, n = 5; ventricular assist device, n = 0). Catecholamine therapy and phosphodiesterase-III inhibitor therapy were used in 79 (27.9%) and 13 (4.6%) patients, respectively. Prolactin blockade therapy was used in 78 (27.6%) patients. During hospitalization, four (1.4%) patients died and nine (3.2%) patients developed ventricular tachycardia or fibrillation. Two (0.7%) patients received an implantable cardioverter defibrillator, but no patient received other permanent cardiac devices. This retrospective cohort study suggests that attending physicians should be ready to provide intensive care for patients with PPCM during the acute phase.

Late Gadolinium Enhancement and the Risk for Ventricular Arrhythmias or Sudden Death in Dilated Cardiomyopathy: Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this study was to evaluate the association between late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging and ventricular arrhythmias or sudden cardiac death (SCD) in patients with dilated cardiomyopathy (DCM).

BACKGROUND

Risk stratification for SCD in DCM needs to be improved.

METHODS

A systematic review and meta-analysis were conducted. A systematic search of PubMed and Ovid was performed, and observational studies that analyzed the arrhythmic endpoint (sustained ventricular arrhythmia, appropriate implantable cardioverter-defibrillator [ICD] therapy, or SCD) in patients with DCM, stratified by the presence or absence of LGE, were included.

RESULTS

Twenty-nine studies were included, accounting for 2,948 patients. The studies covered a wide spectrum of DCM, with a mean left ventricular ejection fraction between 20% and 43%. LGE was significantly associated with the arrhythmic endpoint both in the overall population (odds ratio: 4.3; p < 0.001) and when including only those studies that performed multivariate analysis (hazard ratio: 6.7; p < 0.001). The association between LGE and the arrhythmic endpoint remained significant among studies with mean left ventricular ejection fractions >35% (odds ratio: 5.2; p < 0.001) and was maximal in studies that included only patients with primary prevention ICDs (odds ratio: 7.8; p = 0.008).

CONCLUSIONS

Across a wide spectrum of patients with DCM, LGE is strongly and independently associated with ventricular arrhythmia or SCD. LGE could be a powerful tool to improve risk stratification for SCD in patients with DCM. These results raise 2 major questions to be addressed in future studies: whether patients with LGE could benefit from primary prevention ICDs irrespective of their left ventricular ejection fractions, while patients without LGE might not need preventive ICDs despite having severe left ventricular dysfunction.

Temporal change of myocardial tissue character is associated with left ventricular reverse remodeling in patients with dilated cardiomyopathy: A cardiovascular magnetic resonance study

BACKGROUND

Prognostic significance of temporal change in myocardial tissue characterization by cardiovascular magnetic resonance (CMR) has not been elucidated in patients with non-ischemic dilated cardiomyopathy (DCM).

METHODS AND RESULTS

Sixty-eight patients with newly-diagnosed DCM who underwent CMR including late gadolinium enhancement (LGE) both at baseline and during follow-up period were enrolled. LGE score was defined by a signal intensity of ≥5 standard deviations above the remote reference myocardium mean. Left ventricular reverse remodeling (LVRR) defined as a LV ejection fraction increase of ≥10% and a decrease in indexed LV end-diastolic diameter of ≥10% compared to those at baseline was detected in 38% of the patients. There was no significant difference in LGE score between baseline and follow-up (5.8% vs. 7.3%; p=0.38). The change in LGE area (delta-LGE) was significantly lower in patients with LVRR than those without (-0.5%±3.4% vs. 3.0±7.4%; p=0.02). On the other hand, T2 ratio during the follow-up significantly reduced (1.95±0.48 vs. 1.67±0.56; p<0.01); however, there was no significant difference in the change in T2 ratio between patients with LVRR and those without (-0.29±0.73 vs. -0.27±0.66; p=0.88). Multivariate logistic analysis indicated that baseline LGE score [odds ratio; 0.78; 95% confidence interval (CI) 0.66 to 0.90; p<0.01] together with delta-LGE (odds ratio; 0.77; 95% CI 0.61 to 0.92; p=0.01) were independently associated with subsequent LVRR (p<0.01).

CONCLUSIONS

The temporal change of LGE-CMR score during the clinical course was significantly correlated with following LVRR.

Myocardial triglyceride content in patients with left ventricular hypertrophy: comparison between hypertensive heart disease and hypertrophic cardiomyopathy

Proton magnetic resonance spectroscopy (¹H-MRS) enables the assessment of myocardial triglyceride (TG) content, which is reported to be associated with cardiac dysfunction and morphology accompanied by metabolic disorder and cardiac hemodynamic status. The clinical usefulness of myocardial TG content measurements in patients with left ventricular hypertrophy (LVH) has not been fully investigated. We examined whether myocardial TG content assessed by ¹H-MRS was useful for diagnosis in patients with LVH. To quantify myocardial TG content, we conducted ¹H-MRS in 35 subjects with LVH. Left ventricular function was measured by cardiac magnetic resonance imaging. Patients were assigned to a hypertensive heart disease (HHD, n = 10) or hypertrophic cardiomyopathy (HCM, n = 25) group based on the histology and/or late gadolinium enhancement pattern. The myocardial TG content was significantly higher in the HHD group than in the HCM group (2.14 ± 1.29 vs. 1.09 ± 0.72 %, P < 0.001). Myocardial TG content were significantly and negatively correlated with LV mass (r = -0.41, P < 0.04) and stroke volume (r = -0.64, P < 0.05) in the HCM group and HHD group, respectively. In a multivariate analysis, LV mass volume and diagnosis of HCM or HHD were independent factors of the myocardial TG content. The results suggest that myocardial metabolism may differ between HCM and HHD patients and that measurement of myocardial TG content by ¹H-MRS may be useful for evaluating the myocardial metabolic features of LVH.

Is cardiac and hepatic iron status assessed by MRI T2* associated with left ventricular function in patients with idiopathic cardiomyopathy?

Excess accumulation of iron in the heart is known to aggravate cardiac function in some cases of genetic and acquired iron overload. We investigated the possible association between cardiac function and iron content in the heart and liver, estimated non-invasively by T2 star (T2*)-weighted magnetic resonance (MR) imaging among patients with cardiomyopathy. MR images were acquired on a 3.0 T MR imaging system using an 8-channel phased-array cardiac coil. Average T2* values of the heart were estimated at regions of interest that were located on short axis mid-ventricular slices positioned at the cardiac septum. In total, 82 patients were enrolled: 48 patients with dilated cardiomyopathy (DCM), 16 patients with hypertrophic cardiomyopathy (HCM), and 18 patients without apparent cardiovascular abnormalities. Cardiac T2* values were lower in the DCM group (median 18.6 ms) than in the HCM (22.0 ms) and control (21.4 ms) groups, although hepatic T2* values did not differ significantly across the groups. Among the whole population, the highest cardiac T2* tertile (≥21.2 ms) was significantly negatively associated with a low left ventricular ejection fraction (LVEF) of <50 %, and this association retained statistical significance after adjustment for sex, age, renal function, hemoglobin and hepatic T2*. Among DCM patients, both hemoglobin and cardiac T2* were selected as parameters that were, respectively, negatively and positively, associated with LVEF (P < 0.05). DCM patients with lower cardiac T2*, and thus higher iron content, were found to have lower LVEF. The possibility that cardiac iron overload may have a role in reducing the systolic cardiac function in DCM patients who do not have systemic iron overload requires further investigation in the future.

Late gadolinium enhancement on cardiac magnetic resonance predicts coronary vasomotor abnormality and myocardial lactate production in patients with chronic heart failure

Myocardial fibrosis and microvascular dysfunction are key determinants of outcome in heart failure (HF); we examined their relationship in patients with HF. Our study included 61 consecutive patients with HF but without coronary stenosis. All underwent gadolinium-enhanced cardiac magnetic resonance to evaluate late gadolinium enhancement (LGE) and an acetylcholine (ACh) provocation test to evaluate microvascular dysfunction. During the ACh provocation test, we sampled blood simultaneously from the coronary sinus and aortic root to compare lactate concentrations. We quantified coronary blood flow volume using an intracoronary Doppler-tipped guidewire. We detected LGE in 34 patients (LGE-positive); 27 were LGE-negative. Coronary blood flow volume increased significantly after the ACh provocation test only in LGE-negative patients (before vs. after ACh, 47.5 ± 36.8 vs. 69.2 ± 48.0 ml/min, respectively; p = 0.004). The myocardial lactate extraction ratio (LER) significantly decreased after the ACh test in both groups (LGE-negative, p = 0.001; LGE-positive, p < 0.001), significantly more so in the LGE-positive group (p = 0.017). Multivariate logistic regression analysis showed that a post-ACh LER < 0 (indicating myocardial lactate production) was a significant predictor of LGE-positivity (odds ratio 4.54; 95 % confidence interval 1.38-14.93; p = 0.013). In the LGE-positive group, an LGE volume greater than the median significantly predicted a post-ACh LER of <0 (p = 0.042; odds ratio 6.02; 95 % confidence interval 1.07-33.86). ACh-provoked coronary vasomotor abnormality is closely correlated with myocardial fibrosis in patients with HF but without organic coronary stenosis. Coronary vasomotor abnormalities in fibrotic myocardium may worsen HF.

Focal myocardial fibrosis assessed by late gadolinium enhancement cardiovascular magnetic resonance in children and adolescents with dilated cardiomyopathy

BACKGROUND

Different patterns of late gadolinium enhancement (LGE) including mid-wall fibrosis using cardiovascular magnetic resonance (CMR) have been reported in adult patients presenting with non-ischemic dilated cardiomyopathy (DCM). In these studies, LGE was associated with pronounced LV remodelling and predicted adverse cardiac outcomes. Accordingly, the purpose of our study was to determine the presence and patterns of LGE in children and adolescents with DCM.

METHODS

Patients <18 years of age presenting with severe congestive heart failure who were admitted for evaluation of heart transplantation at our centre underwent CMR examination which consisted of ventricular functional analysis and assessment of LGE for detection of myocardial fibrosis. Ischemic DCM was excluded by coronary angiography, and right ventricular endomyocardial biopsies ruled out acute myocarditis.

RESULTS

Thirty-one patients (mean age 2.1 ± 4.2 years) with severe LV dilatation (mean indexed LVEDV 136 ± 48 ml/m(2)) and LV dysfunction (mean LV-EF 23 ± 8%) were examined. LGE was detected in 5 of the 31 patients (16%) appearing in various patterns characterized as mid-wall (n = 1), focal patchy (n = 1), RV insertion site (n = 1) and transmural (n = 2). Based on histopathological analysis, 4 of the 5 LGE positive patients had lymphocytic myocarditis, whereas one patient was diagnosed with idiopathic DCM.

CONCLUSIONS

In children and adolescents with DCM, focal histologically proven myocardial fibrosis is rarely detected by LGE CMR despite marked LV dilatation and severely depressed LV function. LGE occurred in various patterns and mostly in patients with inflammatory cardiomyopathy. It remains unclear whether myocardial fibrosis in childhood DCM reflects different endogenous repair mechanisms that enable favourable reverse remodelling. Larger trials are needed to assess the prognostic implications of LGE in childhood DCM.

Left ventricular systolic function and the pattern of late-gadolinium-enhancement independently and additively predict adverse cardiac events in muscular dystrophy patients

BACKGROUND

Cardiac involvement is a frequent finding in patients with Duchenne (DMD) and Becker (BMD) muscular dystrophies. With this study, we aimed at elucidating the relationship between the phenotypic expression of cardiac involvement and the occurrence of adverse cardiac events in DMD/BMD patients.

METHODS

Eighty-eight male DMD/BMD patients (age 29 ± 14 yrs) were prospectively enrolled. All patients underwent cardiovascular magnetic resonance (CMR) comprising cine- and late-gadolinium-enhancement (LGE)-CMR at study entry and were subsequently followed-up for adverse cardiac events. The primary endpoint was defined as all-cause/cardiac death or cardiac transplantation. Secondary endpoints were (1) hospitalization for heart failure and/or (2) occurrence of non-/sustained ventricular tachycardia (VT).

RESULTS

During a mean follow-up time of 47 ± 18 months, the primary endpoint was observed in three (3%) and the secondary endpoint in 21 (24%) patients. On multivariable analysis, LV-EF (HR, 95% CI: 0.94, 0.89-0.97, p = 0.001) and the presence of "transmural" LGE (HR, 95% CI: 2.89, 1.09-7.68, p = 0.033) were the only independent predictors for secondary endpoints. A cut-off for LV-EF of 45% was associated with the highest hazard ratio (HR, 95% CI: 11.50, 4.49-29.43, p < 0.0001) in a Cox regression survival analysis. In the group of patients with a LV-EF (>45%), those patients already showing "transmural" LGE had a significantly lower event-free-survival (HR, 95% CI: 13.48, 1.89-96.12, p = 0.009) compared to those without.

CONCLUSIONS

An impaired LV systolic function (LV-EF ≤45%) and a "transmural" pattern of myocardial fibrosis independently predict the occurrence of adverse cardiac events in DMD/BMD patients. Even in DMD/BMD patients with relatively preserved LV-EF (>45%), the simple and visually assessable parameter "transmural LGE" is of additive prognostic value.

A P2X7 receptor antagonist attenuates experimental autoimmune myocarditis via suppressed myocardial CD4+ T and macrophage infiltration and NADPH oxidase 2/4 expression in mice

Myocarditis is a clinically serious disease; however, no effective treatment has been elucidated. The P2X7 receptor is related to the pathophysiology of inflammation in many cardiovascular diseases. The P2X7 receptor antagonist is promising as an immunosuppressive treatment; however, its role in myocarditis is still to be established. To clarify the role of the P2X7 receptor, we used a murine experimental autoimmune myocarditis (EAM) model. Mice were immunized on day 0 and 7 with synthetic cardiac myosin peptide to establish EAM. The mice with induced EAM were treated with A740003, the P2X7 receptor antagonist (n = 10), or not treated (n = 11); hearts were harvested on day 21. The P2X7 receptor antagonist improved myocardial contraction of the EAM hearts via suppressed infiltration of CD4+ T cells and macrophages. Similarly, mRNA expression of interleukin 1 beta, the P2X7 receptor and NADPH oxidase 2/4 was lower in the heart of the P2X7 receptor antagonist-treated group compared to the non-treat group. The P2X7 receptor antagonist suppressed EAM development; thus, this inhibition is promising for treating clinical myocarditis.