Progression of familial and non-familial dilated cardiomyopathy: long term follow up

The Prognostic Value of Left Ventricular Mechanical Dyssynchrony Derived from Cardiac MRI in Patients with Idiopathic Dilated Cardiomyopathy

Purpose

To investigate the prognostic value of mechanical dyssynchrony evaluated by deformable registration algorithm (DRA) analysis of cardiac MRI (CMR) in patients with idiopathic dilated cardiomyopathy (DCM).

Materials and Methods

This secondary analysis of a prospective study (clinical trial no. ChiCTR1800017058) enrolled 409 patients (mean age, 48 years ± 14:300 men) with idiopathic DCM who underwent CMR between June 2012 and September 2018. Mechanical dyssynchrony was measured as standard deviation of time-to-peak (sdTTP) and uniformity ratio estimate (URE) indexes by DRA strain analysis. The primary endpoint included all-cause mortality and heart transplantation. The secondary endpoint included primary endpoint, aborted sudden cardiac death, and heart failure readmission. Cox regression analyses and Kaplan-Meier survival analysis were performed to identify the association between variables and outcomes.

Results

During a median follow-up of 25.1 months, 57 and 132 patients reached primary and secondary endpoints, respectively. Most URE indexes were significantly lower in patients reaching primary endpoint. In multivariable analysis, circumferential URE (CURE) at apical level was independently associated with primary endpoints (hazard ratio, 0.307 [95% CI: 0.106, 0.883]; P = .03) and secondary endpoints (hazard ratio, 0.452 [95% CI: 0.209, 0.979]; P = .04), whereas most sdTTP measures were not. Furthermore, among patients with left ventricular ejection fraction of less than 35% or presence of late gadolinium enhancement, those with CURE at apical level of less than 0.917 had a significantly higher rate of adverse outcomes.

Conclusion

URE indexes were more predictive of prognostic outcomes compared with sdTTP measurements; the CURE at apical level was an independent predictor of adverse cardiac events in patients with DCM.Keywords: Heart, Outcomes Analysis, MR-ImagingClinical trial registration no. ChiCTR1800017058 Supplemental material is available for this article. See also commentary by Rajiah and François in this issue.© RSNA, 2021.

Differences between familial and sporadic dilated cardiomyopathy: ESC EORP Cardiomyopathy & Myocarditis registry

AIMS

Dilated cardiomyopathy (DCM) is a complex disease where genetics interplay with extrinsic factors. This study aims to compare the phenotype, management, and outcome of familial DCM (FDCM) and non-familial (sporadic) DCM (SDCM) across Europe.

METHODS AND RESULTS

Patients with DCM that were enrolled in the prospective ESC EORP Cardiomyopathy & Myocarditis Registry were included. Baseline characteristics, genetic testing, genetic yield, and outcome were analysed comparing FDCM and SDCM; 1260 adult patients were studied (238 FDCM, 707 SDCM, and 315 not disclosed). Patients with FDCM were younger (P < 0.01), had less severe disease phenotype at presentation (P < 0.02), more favourable baseline cardiovascular risk profiles (P ≤ 0.007), and less medication use (P ≤ 0.042). Outcome at 1 year was similar and predicted by NYHA class (HR 0.45; 95% CI [0.25-0.81]) and LVEF per % decrease (HR 1.05; 95% CI [1.02-1.08]. Throughout Europe, patients with FDCM received more genetic testing (47% vs. 8%, P < 0.01) and had higher genetic yield (55% vs. 22%, P < 0.01).

CONCLUSIONS

We observed that FDCM and SDCM have significant differences at baseline but similar short-term prognosis. Whether modification of associated cardiovascular risk factors provide opportunities for treatment remains to be investigated. Our results also show a prevalent role of genetics in FDCM and a non-marginal yield in SDCM although genetic testing is largely neglected in SDCM. Limited genetic testing and heterogeneity in panels provides a scaffold for improvement of guideline adherence.

Prognosis and Clinical Characteristics of Dilated Cardiomyopathy With Family History via Pedigree Analysis

BACKGROUND

The clinical characteristics and prognostic outcomes of dilated cardiomyopathy (DCM) with a familial history (FHx) via pedigree analysis are unclear.Methods and Results:We conducted a prospective observational study of 514 consecutive Japanese patients with DCM. FHx was defined as the presence of DCM in ≥1 family member within 2-degrees relative based on pedigree analysis. The primary endpoint was a composite of major cardiac events (sudden cardiac death and pump failure death). The prevalence of FHx was 7.4% (n=38). During a median follow-up of 3.6 years, 77 (15%) patients experienced a major cardiac event. Multivariable Cox regression analysis identified FHx as independently associated with major cardiac events (hazard ratio [HR] 4.32; 95% confidence interval [CI], 2.04-9.19; P<0.001) compared with conventional risk factors such as age, QRS duration, and left ventricular volume. In the propensity score-matched cohort (n=38 each), the FHx group had a significantly higher incidence of major cardiac events (HR, 4.48; 95% CI, 1.25-16.13; P=0.022). In addition, the FHx group had a higher prevalence of a diffuse late gadolinium enhancement (LGE) pattern than the no-FHx group (32% vs. 17%, P=0.022).

CONCLUSIONS

DCM patients with FHx had a worse prognosis, which was associated with a higher prevalence of a diffuse LGE pattern, than patients without FHx.

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.

Contemporary characteristics and outcomes of adults with familial dilated cardiomyopathy listed for heart transplantation

BACKGROUND

Familial dilated cardiomyopathy (FDCM) account for 20%-30% of non-ischemic cardiomyopathies (NICM). Previous published data showed that some patients with FDCM tend to have rapidly progressive disease; however, five-year mortality was not significantly different in the familial and non-familial forms of NICM with optimal medical therapy.

AIM

To better define the characteristics and clinical outcomes of FDCM patients listed for heart transplantation (HT).

METHODS

We queried the United Network for Organ Sharing Registry to identify FDCM patients listed for HT between January 2008 and September 2015 and compared them to NICM and ischemic cardiomyopathy (ICM) patients. We included all patients ≥ 18 years old and we separated patients to three groups: FDCM, NICM and ICM. Chi-square test was used to compare between categorical variables, the t-test was used to compare between continues variables, and Cox-proportional hazards model was used to perform time-dependent survival analyses.

RESULTS

Of the 24809 adults listed for HT, we identified 677 patients (2.7%) with the diagnosis of FDCM. Compared to patients with NICM and ICM, FDCM patients were younger (FDCM 43.9 ± 13.5 vs NICM 50.9 ± 12.3, P < 0.001, vs ICM 58.5 ± 8.1, P < 0.001), more frequently listed as status 2 (FDCM 35.2% vs NICM 26.5%, P < 0.001), with significantly lower left ventricular assist device (LVAD) utilization (FDCM 18.4% vs NICM 25.1%, P < 0.001; vs ICM 25.6%, P < 0.001), but higher use of total artificial heart (FDCM 1.3% vs NICM 0.6%, P = 0.039; vs ICM 0.4%, P = 0.002). Additionally, patients with FDCM were less frequently delisted for clinical deterioration or death and more likely to be transplanted compared to those with NICM [hazard ratio (HR): 0.617, 95% confidence interval (CI): 0.47-0.81; HR: 1.25, 95%CI: 1.14-1.37, respectively], and ICM (HR: 0.5, 95%CI: 0.38-0.66; HR: 1.18, 95%CI: 1.08-1.3, respectively). There was more frequent rejection among patients with FDCM (FDCM 11.4% vs NICM 9.8%, P = 0.28; vs ICM 8.4%, P = 0.034). One, three, and five post-transplant survival of patients with FDCM (91%, 88% and 80%) was similar to those with NICM (91%, 84%, 79%, P = 0.225), but superior to those with ICM (89%, 82%, 75%, P = 0.008), respectively.

CONCLUSION

End-stage FDCM patients are more likely to be transplanted, more likely to have early rejection, and have similar or higher survival than patients with other cardiomyopathies.

Characteristic adaptations of the extracellular matrix in dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a relatively common heart muscle disease characterized by the dilation and thinning of the left ventricle accompanied with left ventricular systolic dysfunction. Myocardial fibrosis is a major feature in DCM and therefore it is inevitable that corresponding extracellular matrix (ECM) changes are involved in DCM onset and progression. Increasing our understanding of how ECM adaptations are involved in DCM could be important for the development of future interventions. This review article discusses the molecular adaptations in ECM composition and structure that have been reported in both animal and human studies of DCM. Furthermore, we provide a transcriptome-based catalogue of ECM genes that are associated with DCM, generated by using NCBI Gene Expression Omnibus database sets for DCM. Based on this in silico analysis, many novel ECM components involved in DCM are identified and discussed in this review. With the information gathered, we propose putative pathways of ECM adaptations in onset and progression of DCM.

Left ventricular long axis strain: a new prognosticator in non-ischemic dilated cardiomyopathy?

BACKGROUND

Long axis strain (LAS) has been shown to be a fast assessable parameter representing global left ventricular (LV) longitudinal function in cardiovascular magnetic resonance (CMR). However, the prognostic value of LAS in cardiomyopathies with reduced left ventricular ejection fraction (LVEF) has not been evaluated yet.

METHODS AND RESULTS

In 146 subjects with non-ischemic dilated cardiomyopathy (NIDCM, LVEF ≤45 %) LAS was assessed retrospectively from standard non-contrast SSFP cine sequences by measuring the distance between the epicardial border of the left ventricular apex and the midpoint of a line connecting the origins of the mitral valve leaflets in end-systole and end-diastole. The final values were calculated according to the strain formula. The primary endpoint of the study was defined as a combination of cardiac death, heart transplantation or aborted sudden cardiac death and occurred in 24 subjects during follow-up. Patients with LAS values > -5 % showed a significant higher rate of cardiac events independent of the presence of late gadolinium enhancement (LGE). The multivariate Cox regression analysis revealed that LVEDV/BSA (HR: 1.01, p < 0.05), presence of LGE (HR: 2.51, p < 0.05) and LAS (HR: 1.28, p < 0.05) were independent predictors for cardiac events. In a sequential cox regression analysis LAS offered significant incremental information (p < 0.05) for the prediction of outcome in addition to LGE and LVEDV/BSA. Using a dichotomous three point scoring model for risk stratification, including LVEF <35 %, LAS > -10 % and the presence of LGE, patients with 3 points had a significantly higher risk for cardiac events than those with 2 or less points.

CONCLUSION

Assessment of long axis function with LAS offers significant incremental information for the prediction of cardiac events in NIDCM and improves risk stratification beyond established CMR parameters.

Heart failure from heart muscle disease in childhood: a 5-10 year follow-up study in the UK and Ireland

Aims

Our original study, the first national prospective study of new‐onset heart failure from heart muscle disease in children, showed overall 1‐year survival of 82%, and event (death or transplantation)‐free survival of 66%. This study aimed to evaluate 5 + year outcomes of this important cohort.

Methods and results

All centres in the UK and Ireland with 1‐year event‐free survivors participated (n = 14). Anonymised data based on last hospital attendance and echocardiograms were reviewed. The investigator was blinded to outcome at the time of echo review. Of sixty‐nine 1‐year event‐free survivors, data were obtained on 64, with three lost to follow‐up and two moved abroad. There were three deaths at 2.2, 3.3 and 9.0 years after presentation and one transplant, at 5.2 years. Overall/event‐free survival was 77%/62% at 5 years and 73%/59% at 10 years, respectively. Overall and event‐free survival conditional on 1‐year survival was 94% at 5 years, and 89% at 10 years. For the 60 event‐free survivors, median (range) follow‐up duration was 9.04 (5.0–10.33) years for those still under review (n = 45), or time to discharge 5.25 (0.67–10.0) years (n = 15). Fifty‐eight were in New York Heart Association (NYHA) Class 1, and two in Class 2. Forty‐one out of sixty had normal echocardiograms at last follow‐up. Predictors of better longer‐term outcome were the same as for the original 1‐year follow‐up study, namely, younger age and higher fractional shortening measurement at presentation.

Conclusions

Children who survive the first year following their first presentation with significant heart failure from heart muscle disease have a good longer‐term outcome although there remains a small attrition rate.

Familial dilated cardiomyopathy diagnosis is commonly overlooked at the time of transplant listing

BACKGROUND

The prevalence and clinical characteristics of familial dilated cardiomyopathy (FDCM) among patients with end stage heart failure (ESHF) has yet to be elucidated. We sought to determine the prevalence of FDCM in ESHF in the United Network for Organ Sharing (UNOS) registry and compare this with center specific data from a large tertiary teaching hospital. Patients with a banked UNOS diagnosis of dilated cardiomyopathy (DCM) whose care originated at our center then underwent detailed pedigree analysis in order to determine the true prevalence of FDCM.

METHODS AND RESULTS

A total of 16,091 patients with DCM from all centers were identified in the UNOS registry of whom 492 carried the diagnosis of FDCM (3.1%). Patients with the diagnosis of FDCM tended to be younger (42 versus 49 years old in idiopathic dilated cardiomyopathy (IDCM), p=0.001), were less likely to have diabetes (7.8% versus 16.5% in IDCM, p<0.0001), had slightly lower creatinine (1.2 versus 1.4 in IDCM, p=0.0001) and were more likely to have a panel reactive antibody level ≥ 20% (62.1% versus 44.7% in IDCM, p<0.0001). Consecutive living adult patients with ESHF were identified from the UNOS registry that had been treated at the Yale Center for Advanced Heart Failure (YCAHF). After excluding all diagnoses that did not include any form of non-ischemic DCM, 73 patients met the inclusion criteria. Center-specific UNOS data showed pre-pedigree analysis diagnosis of FDCM in 4.12% of patients (3 out of 73), consistent with that found in the UNOS database for all centers. However, after detailed family history and pedigree analysis, 19 (26%) of 73 patients were found to have FDCM, while the remaining 54 were found to have IDCM. Echocardiographic findings including mitral regurgitation, mitral valve annulus and left ventricular end diastolic dimension were not significantly different between groups when adjusting for multiple testing.

CONCLUSIONS

The diagnosis of FDCM was missed in the majority of patients with end stage heart failure enrolled in the UNOS database, as sampled from a large, tertiary care teaching hospital in the United States. Echocardiographic findings are unlikely to aid in the differentiation between DCM and FDCM. Detailed pedigree analysis can successfully identify undiagnosed FDCM and should be encouraged prior to transplant listing as it has important implications for early detection and treatment of disease in family members.

Principles of transthoracic echocardiographic evaluation

Transthoracic echocardiography is the most widely used imaging test in cardiology. Although completely noninvasive, transthoracic echocardiography has a well-established role in the diagnosis of numerous cardiovascular diseases, and also provides critical qualitative and quantitative information on their prognosis and pathophysiological processes. The aim of this Review is to outline the broad principles of transthoracic echocardiography, including the traditional techniques of two-dimensional, colour, and spectral Doppler echocardiography, and newly developed advances including tissue Doppler, myocardial deformation imaging, torsion, stress echocardiography, contrast and three-dimensional echocardiography. The advantages and disadvantages, clinical application, prognostic value, and salient research findings of each modality are described. Advances in complex imaging techniques are expected to continue unabated, and this Review highlights technical improvements that will influence the diagnosis and improve our understanding of cardiovascular function and disease.

A systematic analysis of genetic dilated cardiomyopathy reveals numerous ubiquitously expressed and muscle-specific genes

AIMS

Despite considerable progress being made in genetic diagnostics for dilated cardiomyopathy (DCM) using panels of the most prevalent genes, the cause remains unsolved in a substantial percentage of patients. We hypothesize that several previously described DCM genes with low or unknown prevalence have been neglected, which, if catalogued, could increase the yield of diagnostic DCM testing. The aim of this study is to catalogue all genetic evidence on DCM comprehensively.

METHODS AND RESULTS

We have conducted a systematic literature search on PubMed, Embase, and OMIM to find genes implicated in syndromic and non-syndromic DCM and peripartum cardiomyopathy (PPCM). Our search yielded 110 nuclear protein-coding genes and 24 mitochondrial DNA genes. For nuclear genes, in addition to 42 genes sufficiently reviewed previously (group A), we provide a comprehensive annotation of the level of genetic evidence for the remaining 68 genes (group B). Next, we investigated the tissue specificity of the collected genes using public RNA sequencing data. We show that genes primarily expressed in heart and skeletal muscle are more likely to result in DCM with possible skeletal myopathies, while genes expressed ubiquitously cause DCM with extramuscular manifestations.

CONCLUSION

This comprehensive analysis of DCM-associated genes revealed a much higher number of genes than currently screened in diagnostics. Since most genes in group B have only been found mutated in single DCM patients or families, their importance for DCM genetic diagnostics needs to be validated in large cohorts. Targeted sequencing of validated DCM-implicated protein-coding genes and mitochondrial DNA, together with consideration of the tissue specificity of mutated genes, may facilitate further genotype-phenotype studies in DCM.

Assessment of myocardial deformation with cardiac magnetic resonance strain imaging improves risk stratification in patients with dilated cardiomyopathy

AIMS

To investigate the prognostic impact of left-ventricular (LV) cardiac magnetic resonance (CMR) deformation imaging in patients with non-ischaemic dilated cardiomyopathy (DCM) compared with late-gadolinium enhancement (LGE) quantification and LV ejection fraction (EF).

METHODS AND RESULTS

A total of 210 subjects with DCM were examined prospectively with standard CMR including measurement of LGE for quantification of myocardial fibrosis and feature tracking strain imaging for assessment of LV deformation. The predefined primary endpoint, a combination of cardiac death, heart transplantation, and aborted sudden cardiac death, occurred in 26 subjects during the median follow-up period of 5.3 years. LV radial, circumferential, and longitudinal strains were significantly associated with outcome. Using separate multivariate analysis models, global longitudinal strain (average of peak negative strain values) and mean longitudinal strain (negative peak of the mean curve of all segments) were independent prognostic parameters surpassing the value of global and mean LV radial and circumferential strain, as well as NT-proBNP, EF, and LGE mass. A global longitudinal strain greater than -12.5% predicted outcome even in patients with EF < 35% (P < 0.01) and in those with presence of LGE (P < 0.001). Mean longitudinal strain was further investigated using a clinical model with predefined cut-offs (EF < 35%, presence of LGE, NYHA class, mean longitudinal strain greater than -10%). Mean longitudinal strain exhibited an independent prognostic value surpassing that provided by NYHA, EF, and LGE (HR = 5.4, P < 0.01).

CONCLUSION

LV longitudinal strain assessed with CMR is an independent predictor of survival in DCM and offers incremental information for risk stratification beyond clinical parameters, biomarker, and standard CMR.

Long-Term Outcomes of Dilated Cardiomyopathy Diagnosed During Childhood

Background—

Existing studies of childhood dilated cardiomyopathy deal mainly with early survival. This population-based study examines long-term outcomes for children with dilated cardiomyopathy.

Methods and Results—

The diagnosis of dilated cardiomyopathy was based on clinical, echocardiographic, and pathological findings. The primary study end point included time to the combined outcome of death or cardiac transplantation. There were 175 patients 0 to <10 years of age at the time of diagnosis. Survival free from death or transplantation was 74% (95% confidence interval, 67–80) 1 year after diagnosis, 62% (95% confidence interval, 55–69) at 10 years, and 56% (95% confidence interval, 46–65) at 20 years. In multivariable analysis, age at diagnosis <4 weeks or >5 years, familial cardiomyopathy, and lower baseline left ventricular fractional shortening Z score were associated with increased risk of death or transplantation, as was lower left ventricular fractional shortening Z score during follow-up. At 15 years after diagnosis, echocardiographic normalization had occurred in 69% of surviving study subjects. Normalization was related to higher baseline left ventricular fractional shortening Z score, higher left ventricular fractional shortening Z score during follow-up, and greater improvement in left ventricular fractional shortening Z score. Children with lymphocytic myocarditis had better survival and a higher rate of echocardiographic normalization. At the latest follow-up, 100 of 104 of survivors (96%) were free of cardiac symptoms, and 83 (80%) were no longer receiving pharmacotherapy.

Conclusions—

Death or transplantation occurred in 26% of patients with childhood dilated cardiomyopathy within 1 year of diagnosis and ~1% per year thereafter. Risk factors for death or transplantation include age at diagnosis, familial cardiomyopathy, and severity of left ventricular dysfunction. The majority of surviving subjects are well and free of cardiac medication.

Prognostic value of contrast-enhanced cardiac magnetic resonance imaging in patients with newly diagnosed non-ischemic cardiomyopathy: cohort study

Background

Owing to its variable course from asymptomatic cases to sudden death risk stratification is of paramount importance in newly diagnosed non-ischemic cardiomyopathy. We tested whether late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance (CMR) imaging is a prognostic marker in consecutive patients with newly diagnosed non-ischemic cardiomyopathy.

Methods

We enrolled 185 patients who presented for evaluation of newly diagnosed non-ischemic cardiomyopathy. Coronary artery disease was excluded by coronary angiography. Following risk markers were additionally assessed: NYHA functional class (≥II), brain natriuretic peptide (>100 ng/l), troponin I (TnI, ≥0.03 µg/l), left ventricular ejection fraction (LVEF, ≤40%), left ventricular enddiastolic diameter (>55 mm) and QRS duration (>98 ms). Endpoint of the study was the composite of all-cause mortality, heart transplantation, aborted sudden death, sustained ventricular tachycardia or hospitalization due to decompensated heart failure within three years of follow-up.

Results

During median follow-up of 21 months, 54 patients (29.2%) reached the composite endpoint. Ninety-four of the 185 patients (50.8%) were judged LGE-positive. Prognosis of LGE-positive patients was significantly worse than that of LGE-negative patients (cumulative 3-year event rates of 67.4% in LGE-positive and 27.2% in LGE-negative patients, respectively; p = 0.021). However, in multivariable analysis, presence of LGE was not an independent predictor of outcome. Only LVEF ≤40% and TnI ≥0.03 µg/l were independent risk predictors of the composite endpoint yielding relative risks of 3.9 (95% CI 1.9–8.1; p<0.0001) and 2.2 (95% CI 1.2–4.0; p = 0.014), respectively.

Conclusions

In consecutive patients presenting with newly diagnosed non-ischemic cardiomyopathy, LGE-positive patients had worse prognosis. However, only traditional risk parameters like left ventricular performance and cardiac biomarkers but not presence of LGE were independent risk predictors.

Cyclophilin A predicts clinical outcome in patients with congestive heart failure undergoing endomyocardial biopsy

AIMS

Cyclophilin A (CyPA) represents a ubiquitous intracellular protein, which is secreted by inflammatory and by dying/necrotic cells. The aim of this study was to evaluate the prognostic relevance of CyPA expression in endomyocardial biopsies of consecutive patients with congestive heart failure.

METHODS AND RESULTS

A total of 227 unselected patients (age 53.9 ± 15 years) with congestive heart failure undergoing endomyocardial biopsy for diagnostic reasons were enrolled. Biopsies were analysed using established histopathological and immunohistological criteria together with CyPA staining. Virus genome was studied by polymerase chain reaction. CyPA was significantly enhanced in patients with inflammatory cardiomyopathy (n = 127) as compared with patients with non-inflammatory cardiomyopathy (n = 100, P < 0.0001). During a mean follow-up of 16.3 months, 60 patients (26.4%) reached the primary endpoint, a composite of all-cause death, heart transplantation, malignant arrhythmia, and heart failure-related rehospitalization. Of all clinical (ejection fraction, New York Heart Association functional class), laboratory (brain natriuretic peptide), and immunohistological parameters (CyPA, extracellular matrix metalloproteinase inducer, CD68, CD3, major hisocompatibility complex II, and virus genome) tested, only CyPA was identified as an independent predictor for the composite endpoint [hazard ratio (HR) 2.4; 95% confidence interval (CI) 1.2-5.2; P = 0.019] as well as for all-cause death and heart transplantation alone (HR 4.7; 95% CI 1.1-19.8; P = 0.036). Subgroup analysis revealed CyPA as a predictor in patients with non-inflammatory cardiomyopathy for the composite endpoint (HR 3.0; 95% CI 1.3-6.6; P = 0.007) as well as all-cause death or heart transplantation alone (HR 6.4; 95% CI 1.4-28.1; P = 0.014).

CONCLUSIONS

CyPA is an independent predictor of clinical outcome in patients with congestive heart failure undergoing endomyocardial biopsy.

Genetic variation in the alternative splicing regulator RBM20 is associated with dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is a leading cause of heart failure and death. The etiology of DCM is genetically heterogeneous.

OBJECTIVES

We sought to define the prevalence of mutations in the RNA splicing protein RBM20 in a large cohort with DCM and to determine whether genetic variation in RBM20 is associated with clinical outcomes.

METHODS

Subjects included in the Genetic Risk Assessment of Defibrillator Events (GRADE) study were aged at least 18 years, had an ejection fraction of ≤30%, and an implantable cardioverter-defibrillator (ICD). The coding region and splice junctions of RBM20 were screened in subjects with DCM; 2 common polymorphisms in RBM20, rs942077 and rs35141404, were genotyped in all GRADE subjects.

RESULTS

A total of 1465 subjects were enrolled in the GRADE study, and 283 with DCM were screened for RBM20 mutations. The mean age of subjects with DCM was 58 ± 13 years, 64% were males, and the mean follow-up time was 24.2 ± 17.1 months after ICD placement. RBM20 mutations were identified in 8 subjects with DCM (2.8%). Mutation carriers had a similar survival, transplantation rate, and frequency of ICD therapy compared with nonmutation carriers. Three of 8 subjects with RBM20 mutations (37.5%) had atrial fibrillation (AF), whereas 19 subjects without mutations (7.4%) had AF (P = .02). Among all GRADE subjects, rs35141404 was associated with AF (minor allele odds ratio = 0.62; 95% confidence interval = 0.44-0.86; P = .006). In the subset of GRADE subjects with DCM, rs35141404 was associated with AF (minor allele odds ratio = 0.58; P = .047).

CONCLUSIONS

Mutations in RBM20 were observed in approximately 3% of subjects with DCM. There were no differences in survival, transplantation rate, and frequency of ICD therapy in mutation carriers.

Review and metaanalysis of the frequency of familial dilated cardiomyopathy

Several studies have investigated the frequency of familial dilated cardiomyopathy (FDC). However, no systematic review and meta-analysis on this topic are available. Therefore, using the PubMed, MEDLINE, Cochrane, and the ISI Web of Science databases, relevant reports published through December 2010 were identified. For the summation of prevalence findings, prevalence point estimates and 95% confidence intervals were computed using the logit transformation formula. An aggregate estimate of clinically confirmed FDC of 23% (95% confidence interval 0.17 to 0.31) was found. However, the prevalence rates reported across these studies varied widely, ranging from 2% to 65%, and the analysis showed very high heterogeneity (Q = 295, p <0.001, I(2) = 93%). Meta-regression analysis between logit event rate and year of publication explained 23% of between-study variance (p <0.05). Cumulative meta-analysis confirmed the influence of year of publication on the reported prevalence of FDC among the different studies. However, most of the observed heterogeneity may be explained by the fact that the various studies used different preselected criteria for the diagnosis of FDC. In conclusion, data obtained from trials performed using standardized criteria are needed to better define the true prevalence of FDC.

Celecoxib and 2,5-dimethyl-celecoxib prevent cardiac remodeling inhibiting Akt-mediated signal transduction in an inherited dilated cardiomyopathy mouse model

Celecoxib, a cyclooxygenase-2 (COX-2)-selective nonsteroidal anti-inflammatory drug, has been shown to inhibit Akt and prevent cardiac remodeling in aortic banding-induced failing heart in mice. However, it may be difficult to use celecoxib for the treatment of heart failure because of thromboembolic adverse reactions. Since 2,5-dimethyl (DM)-celecoxib, a derivative unable to inhibit COX-2, has been also reported to inhibit Akt, we attempted to examine whether DM-celecoxib retains the ability to prevent cardiac remodeling and improve cardiac functions using a mouse model of inherited dilated cardiomyopathy (DCM). DM-celecoxib as well as celecoxib administered daily for 4 weeks inhibited Akt and subsequent phosphorylation of glycogen synthase kinase-3β and mammalian target of rapamycin. Furthermore, both celecoxib and DM-celecoxib inhibited the activities of nuclear factor of activated T cell and β-catenin and the expression of TCF7L2 (T-cell-specific transcriptional factor-7L2) and c-Myc, downstream mediators related to cardiac hypertrophy. Functional and morphological measurements showed that these compounds improved left ventricular systolic functions (ejection fraction: vehicle, 34.7 ± 3.9%; 100 mg/kg celecoxib, 50.3 ± 1.1%, p < 0.01; 100 mg/kg DM-celecoxib, 49.8 ± 0.8%, p < 0.01), which was also evidenced by the decrease in β-myosin heavy chain and B-type natriuretic peptide, and prevented hypertrophic cardiac remodeling (heart/body weight ratio: vehicle, 10.4 ± 0.7 mg/g; 100 mg/kg celecoxib, 8.0 ± 0.3 mg/g, p < 0.01; 100 mg/kg DM-celecoxib, 8.2 ± 0.1 mg/g, p < 0.05). As a consequence, both compounds improved the survival rate (vehicle, 45%; 100 mg/kg celecoxib, 75%, p < 0.05; 100 mg/kg DM-celecoxib, 70%, p < 0.05). These results suggested that not only celecoxib but also DM-celecoxib prevents cardiac remodeling and reduces mortality in DCM through a COX-2-independent mechanism involving Akt and its downstream mediators.

Clinical and genetic issues in dilated cardiomyopathy: a review for genetics professionals

Dilated cardiomyopathy (DCM), usually diagnosed as idiopathic dilated cardiomyopathy (IDC), has been shown to have a familial basis in 20-35% of cases. Genetic studies in familial dilated cardiomyopathy (FDC) have shown dramatic locus heterogeneity with mutations identified in >30 mostly autosomal genes showing primarily dominant transmission. Most mutations are private missense, nonsense or short insertion/deletions. Marked allelic heterogeneity is the rule. Although to date most DCM genetics fits into a Mendelian rare variant disease paradigm, this paradigm may be incomplete with only 30-35% of FDC genetic cause identified. Despite this incomplete knowledge, we predict that DCM genetics will become increasingly relevant for genetics and cardiovascular professionals. This is because DCM causes heart failure, a national epidemic, with considerable morbidity and mortality. The fact that early, even pre-symptomatic intervention can prevent or ameliorate DCM, coupled with more cost-effective genetic testing, will drive further progress in the field. Ongoing questions include: whether sporadic (IDC) disease has a genetic basis, and if so, how it differs from familial disease; which gene-specific or genetic pathways are most relevant; and whether other genetic mechanisms (e.g., DNA structural variants, epigenetics, mitochondrial mutations and others) are operative in DCM. We suggest that such new knowledge will lead to novel approaches to the prevention and treatment of DCM.

What causes a broken heart--molecular insights into heart failure

Our understanding of the molecular processes which regulate cardiac function has grown immeasurably in recent years. Even with the advent of β-blockers, angiotensin inhibitors and calcium modulating agents, heart failure (HF) still remains a seriously debilitating and life-threatening condition. Here, we review the molecular changes which occur in the heart in response to increased load and the pathways which control cardiac hypertrophy, calcium homeostasis, and immune activation during HF. These can occur as a result of genetic mutation in the case of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) or as a result of ischemic or hypertensive heart disease. In the majority of cases, calcineurin and CaMK respond to dysregulated calcium signaling and adrenergic drive is increased, each of which has a role to play in controlling blood pressure, heart rate, and left ventricular function. Many major pathways for pathological remodeling converge on a set of transcriptional regulators such as myocyte enhancer factor 2 (MEF2), nuclear factors of activated T cells (NFAT), and GATA4 and these are opposed by the action of the natriuretic peptides ANP and BNP. Epigenetic modification has emerged in recent years as a major influence cardiac physiology and histone acetyl transferases (HATs) and histone deacetylases (HDACs) are now known to both induce and antagonize hypertrophic growth. The newly emerging roles of microRNAs in regulating left ventricular dysfunction and fibrosis also has great potential for novel therapeutic intervention. Finally, we discuss the role of the immune system in mediating left ventricular dysfunction and fibrosis and ways this can be targeted in the setting of viral myocarditis.

Identification of novel mutations in RBM20 in patients with dilated cardiomyopathy

The genetic basis of most of dilated cardiomyopathy (DCM) cases remains unknown. A recent study indicated that mutations in a highly localized five amino acid hotspot in exon 9 of RBM20, a gene encoding a ribonucleic acid-binding protein, caused aggressive DCM. We undertook this study to confi rm and extend the nature of RBM20 mutations in another DCM cohort. Clinical cardiovascular data, family histories, and blood samples were collected from patients with idiopathic DCM. DNA from 312 DCM probands was sequenced for nucleotide alterations in exons 6 through 9 of RBM20, and additional family members as possible. We found six unique RBM20 rare variants in six unrelated probands (1.9%). Four mutations, two of which were novel (R634W and R636C) and two previously identified (R634Q and R636H), were identified in a five amino acid hotspot in exon 6. Two other novel variants (V535I in exon 6 and R716Q in exon 9) were outside of this hotspot. Age of onset and severity of heart failure were variable, as were arrhythmias and conduction system defects, but many subjects suffered severe heart failure resulting in early death or cardiac transplantation. This article concludes that DCM in patients with RBM20 mutations is associated with advanced disease.

Viral myocarditis: diagnosis, aetiology and management

Myocarditis is an inflammatory disease of the cardiac muscle caused by myocardial infiltration of immunocompetent cells following any kind of cardiac injury. Classic myocarditis mainly occurs as a result of the host's immune response against organisms that cause common infectious illnesses, as a manifestation of hypersensitivity or as a toxic reaction to drug therapy. Chronic inflammatory events may survive successful clearance of initial cardiotoxic agents, be triggered or amplified by autoimmunological processes, or develop in the context of systemic diseases. If the underlying infectious or immune-mediated causes of the disease are carefully defined by clinical and biopsy-based tools, specific immunosuppressive and antiviral treatment options may improve the prognosis of patients with acute and chronic disease.

Potential strategies for myocardial regeneration in pediatric patients

Owing to the heart’s limited ability for self-repair, heart failure is a leading cause of death among all patient populations. Thus, a cell-based regenerative strategy for cardiac repair would be highly attractive. A variety of cell sources have been identified as candidates for myocardial repair, including skeletal myoblasts, various bone marrow stem cells, resident cardiac progenitors and embryonic stem cells. However, nearly all studies geared towards myocardial regeneration, both in animal models and in clinical trials, have focused on adult ischemic disease with regional muscle injury. Pediatric patients suffer from more diverse forms of heart disease, including congenital and acquired cardiomyopathies with global muscle dysfunction, as well as disorders of cardiac development, for example, left ventricular hypoplasia, atrial or ventricular septal defects. In this article, a broad range of cell-based therapies are discussed, emphasizing the rapidly evolving science surrounding these strategies and the outstanding questions before application to pediatric patients. It is probable that many of the cell types and delivery strategies capable of repairing adult myocardial diseases will require additional investigations to take advantage of the unique opportunities and challenges of pediatric patients.

Severe Myocardial Fibrosis Caused by a Deletion of the 5’ End of the Lamin A/C Gene

OBJECTIVES

The goal of this study was to identify the underlying gene defect in a family with inherited myocardial fibrosis.

BACKGROUND

A large family with an autosomal dominantly inherited form of myocardial fibrosis with a highly malignant clinical outcome has been investigated. Because myocardial fibrosis preceded the clinical and echocardiographic signs, we consider the disease to be a hereditary form of cardiac fibrosis.

METHODS

Twenty-five family members were clinically evaluated, and 5 unaffected and 8 affected family members were included in a genome-wide linkage study.

RESULTS

The highest logarithm of the odds (LOD) score (LOD = 2.6) was found in the region of the lamin AC (LMNA) gene. The LMNA mutation analysis, both by denaturing gradient gel electrophoresis and sequencing, failed to show a mutation. Subsequent Southern blotting, complementary deoxyribonucleic acid sequencing, and multiplex ligation-dependent probe amplification analysis, however, revealed a deletion of the start codon-containing exon and an adjacent noncoding exon. In vitro studies demonstrated that the deletion results in the formation of nuclear aggregates of lamin, suggesting that the mutant allele is being transcribed.

CONCLUSIONS

This novel LMNA deletion causes a distinct, highly malignant cardiomyopathy with early-onset primary cardiac fibrosis likely due to an effect of the shortened mutant protein, which secondarily leads to arrhythmias and end-stage cardiac failure.

Clinical characteristics of 304 kindreds evaluated for familial dilated cardiomyopathy

BACKGROUND

Familial dilated cardiomyopathy (FDC) is dilated cardiomyopathy of unknown cause occurring in 2 or more closely related family members.

METHODS AND RESULTS

Members of 304 families suspected to have FDC were evaluated by family history (FH) and medical record review and were categorized as affected with idiopathic dilated cardiomyopathy (IDC), unaffected, unknown, or no data. Pedigrees were categorized with confirmed FDC, probable FDC, possible FDC or IDC based on strength of evidence. Of the 304 pedigrees, 125 were categorized as confirmed FDC, 48 were probable FDC, 72 were possible FDC, and 59 had sporadic, nonfamilial IDC. Numbers of living first- and second-degree family members, and median number of relatives available for FH was greatest with confirmed FDC, and diminished for probable and possible FDC, and IDC categories. LV dimensions increased and LV function worsened in index patients along the spectrum from confirmed FDC, probable FDC, possible FDC and IDC, and a greater proportion of IDC patients underwent heart transplant. However, the age of onset, duration of disease, the time to death or heart transplant, and most other findings were similar among the 4 categories.

CONCLUSION

Clinical characteristics of IDC and FDC are similar, precluding an FDC diagnosis from clinical features only.

Immunomodulatory treatment strategies in inflammatory cardiomyopathy: current status and future perspectives

Chronic autoimmunity and viral persistence constitute prognostic factors for adverse outcome in dilated cardiomyopathy patients. Inflammatory cardiomyopathy is a specific cardiomyopathy entity diagnosed in approximately 50% of dilated cardiopmyopathy patients by immunohistological quantification of immunocompetent infiltrates and cell adhesion molecule abundance. Patients with autoimmune inflammatory cardiomyopathy benefit from immunosuppressive treatment and immunoadsorption by improvement of left ventricular ejection fraction and heart failure symptoms, paralleled by a significant suppression of intramyocardial inflammation. However, dilated cardiomyopathy patients with viral persistence do not respond favorably to immunosuppression.