Clinical Phenotypes and Prognosis of Dilated Cardiomyopathy Caused by Truncating Variants in the TTN Gene

BACKGROUND: Truncating variants in the TTN gene (TTNtv) are the commonest cause of heritable dilated cardiomyopathy. This study aimed to study the phenotypes and outcomes of TTNtv carriers. METHODS: Five hundred thirty-seven individuals (61% men; 317 probands) with TTNtv were recruited in 14 centers (372 [69%] with baseline left ventricular systolic dysfunction [LVSD]). Baseline and longitudinal clinical data were obtained. The primary end point was a composite of malignant ventricular arrhythmia and end-stage heart failure. The secondary end point was left ventricular reverse remodeling (left ventricular ejection fraction increase by ≥10% or normalization to ≥50%). RESULTS: Median follow-up was 49 (18-105) months. Men developed LVSD more frequently and earlier than women (45±14 versus 49±16 years, respectively; P=0.04). By final evaluation, 31%, 45%, and 56% had atrial fibrillation, frequent ventricular ectopy, and nonsustained ventricular tachycardia, respectively. Seventy-six (14.2%) individuals reached the primary end point (52 [68%] end-stage heart failure events, 24 [32%] malignant ventricular arrhythmia events). Malignant ventricular arrhythmia end points most commonly occurred in patients with severe LVSD. Male sex (hazard ratio, 1.89 [95% CI, 1.04-3.44]; P=0.04) and left ventricular ejection fraction (per 10% decrement from left ventricular ejection fraction, 50%; hazard ratio, 1.63 [95% CI, 1.30-2.04]; P<0.001) were independent predictors of the primary end point. Two hundred seven of 300 (69%) patients with LVSD had evidence of left ventricular reverse remodeling. In a subgroup of 29 of 74 (39%) patients with initial left ventricular reverse remodeling, there was a subsequent left ventricular ejection fraction decrement. TTNtv location was not associated with statistically significant differences in baseline clinical characteristics, left ventricular reverse remodeling, or outcomes on multivariable analysis (P=0.07). CONCLUSIONS: TTNtv is characterized by frequent arrhythmia, but malignant ventricular arrhythmias are most commonly associated with severe LVSD. Male sex and LVSD are independent predictors of outcomes. Mutation location does not impact clinical phenotype or outcomes

Emery-Dreifuss muscular dystrophy Type 1 is associated with a high risk of malignant ventricular arrhythmias and end-stage heart failure

BACKGROUND AND AIMS: Emery-Dreifuss muscular dystrophy (EDMD) is caused by variants in EMD (EDMD1) and LMNA (EDMD2). Cardiac conduction defects and atrial arrhythmia are common to both, but LMNA variants also cause end-stage heart failure (ESHF) and malignant ventricular arrhythmia (MVA). This study aimed to better characterise the cardiac complications of EMD variants. METHODS: Consecutively referred EMD variant-carriers were retrospectively recruited from 12 international cardiomyopathy units. MVA and ESHF incidence in male and female variant-carriers was determined. Male EMD variant-carriers with a cardiac phenotype at baseline (EMDCARDIAC) were compared to consecutively recruited male LMNA variant-carriers with a cardiac phenotype at baseline (LMNACARDIAC). RESULTS: Longitudinal follow-up data were available for 38 male and 21 female EMD variant-carriers (mean [SD] ages 33.4 [13.3] and 43.3 [16.8] years, respectively). Nine (23.6%) males developed MVA and five (13.2%) developed ESHF during a median [IQR] follow-up of 65.0 [24.3, 109.5] months. No female EMD variant-carrier had MVA or ESHF, but nine (42.8%) developed a cardiac phenotype at a median [IQR] age of 58.6 [53.2, 60.4] years. Incidence rates for MVA were similar for EMDCARDIAC and LMNACARDIAC (4.8 and 6.6 per 100 person-years, respectively; log-rank p = 0.49). Incidence rates for ESHF were 2.4 and 5.9 per 100 person-years for EMDCARDIAC and LMNACARDIAC, respectively (log-rank p = 0.09). CONCLUSIONS: Male EMD variant-carriers have a risk of progressive heart failure and ventricular arrhythmias similar to that of male LMNA variant-carriers. Early implantable cardioverter defibrillator implantation and heart failure drug therapy should be considered in male EMD variant-carriers with cardiac disease

Emery-Dreifuss Muscular Dystrophy 1 is associated with high risk of malignant ventricular arrhythmias and end-stage heart failure.

BACKGROUND AND AIMS Emery-Dreifuss muscular dystrophy (EDMD) is caused by variants in EMD (EDMD1) and LMNA (EDMD2). Cardiac conduction defects and atrial arrhythmia are common to both, but LMNA variants also cause end-stage heart failure (ESHF) and malignant ventricular arrhythmia (MVA). This study aimed to better characterise the cardiac complications of EMD variants. METHODS Consecutively referred EMD variant-carriers were retrospectively recruited from 12 international cardiomyopathy units. MVA and ESHF incidence in male and female variant-carriers was determined. Male EMD variant-carriers with a cardiac phenotype at baseline (EMDCARDIAC) were compared to consecutively recruited male LMNA variant-carriers with a cardiac phenotype at baseline (LMNACARDIAC). RESULTS Longitudinal follow-up data were available for 38 male and 21 female EMD variant-carriers (mean [SD] ages 33.4 [13.3] and 43.3 [16.8] years, respectively). Nine (23.6%) males developed MVA and five (13.2%) developed ESHF during a median [IQR] follow-up of 65.0 [24.3, 109.5] months. No female EMD variant-carrier had MVA or ESHF, but nine (42.8%) developed a cardiac phenotype at a median [IQR] age of 58.6 [53.2, 60.4] years. Incidence rates for MVA were similar for EMDCARDIAC and LMNACARDIAC (4.8 and 6.6 per 100 person-years, respectively; log-rank p = 0.49). Incidence rates for ESHF were 2.4 and 5.9 per 100 person-years for EMDCARDIAC and LMNACARDIAC, respectively (log-rank p = 0.09). CONCLUSIONS Male EMD variant-carriers have a risk of progressive heart failure and ventricular arrhythmias similar to that of male LMNA variant-carriers. Early implantable cardioverter defibrillator implantation and heart failure drug therapy should be considered in male EMD variant-carriers with cardiac disease.The work reported in this publication was funded by: a British Heart Foundation Clinical Research Training Fellowship to D.E.C. (FS/CRTF/ 20/24022); a British Heart Foundation Clinical Research Training fellowship to A.P. (FS/18/82/34024); The Ministry of Health, Italy, project RC-2022-2773270 to E.B.; the National Institutes of Health (NIH) (R01HL69071, R01HL116906, R01HL147064, NIH/NCATS UL1 TR002535, and UL1 TR001082) to L.M.; and support from the Rose Foundation for K.M.S

Natural History of MYH7-Related Dilated Cardiomyopathy

BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVE: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of ≤35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare

Short-term effects of dapagliflozin on maximal functional capacity in heart failure with reduced ejection fraction (DAPA-VO2): a randomized clinical trial

Aims This study aimed to evaluate the effect of dapagliflozin on 1 and 3-month maximal functional capacity in patients with stable heart failure with reduced ejection fraction (HFrEF). Methods and results In this multicentre, randomized, double-blind clinical trial, 90 stable patients with HFrEF were randomly assigned to receive either dapagliflozin (n = 45) or placebo (n = 45). The primary outcome was a change in peak oxygen consumption (peakVO2) at 1 and 3 months. Secondary endpoints were changes at 1 and 3 months in 6-min walk test (6MWT) distance, quality of life (Minnesota Living with Heart Failure Questionnaire [MLHFQ]), and echocardiographic parameters (diastolic function, left chamber volumes, and left ventricular ejection fraction). We used linear mixed regression analysis to compare endpoint changes. Estimates were adjusted for multiple comparisons. The mean age was 67.1 ± 10.7 years, 69 (76.7%) were men, 29 (32.2%) had type 2 diabetes, and 80 (88.9%) were in New York Heart Association class II. Baseline means of peakVO2, 6MWT and MLHFQ were 13.2 ± 3.5 ml/kg/min, 363 ± 110 m, and 23.1 ± 16.2, respectively. The median (25th–75th percentile) of N-terminal pro-brain natriuretic peptide was 1221 pg/ml (889–2100). Most patients were on treatment with sacubitril/valsartan (88.9%), beta-blockers (91.1%), and mineralocorticoid receptor antagonists (74.4%). PeakVO2 significantly increased in patients on treatment with dapagliflozin (1 month: +Δ 1.09 ml/kg/min, 95% confidence interval [CI] 0.14–2.04; p = 0.021, and 3 months: +Δ 1.06 ml/kg/min, 95% CI 0.07–2.04; p = 0.032). Similar positive findings were found when evaluating changes from baseline. No significant differences were observed in secondary endpoints. Conclusions Among patients with stable HFrEF, dapagliflozin resulted in a significant improvement in peakVO2 at 1 and 3 months

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\ua0<\ua00.01), had less severe disease phenotype at presentation (P\ua0<\ua00.02), more favourable baseline cardiovascular risk profiles (P\ua0 64\ua00.007), and less medication use (P\ua0 64\ua00.042). Outcome at 1\ua0year was similar and predicted by NYHA class (HR 0.45; 95% CI [0.25\u20130.81]) and LVEF per % decrease (HR 1.05; 95% CI [1.02\u20131.08]. Throughout Europe, patients with FDCM received more genetic testing (47% vs. 8%, P\ua0<\ua00.01) and had higher genetic yield (55% vs. 22%, P\ua0<\ua00.01). 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

Association of Left Ventricular Systolic Dysfunction Among Carriers of Truncating Variants in Filamin C With Frequent Ventricular Arrhythmia and End-stage Heart Failure

Importance: Truncating variants in the gene encoding filamin C (FLNCtv) are associated with arrhythmogenic and dilated cardiomyopathies with a reportedly high risk of ventricular arrhythmia. / Objective To determine the frequency of and risk factors associated with adverse events among FLNCtv carriers compared with individuals carrying TTN truncating variants (TTNtv). / Design, Setting, and Participants: This cohort study recruited 167 consecutive FLNCtv carriers and a control cohort of 244 patients with TTNtv matched for left ventricular ejection fraction (LVEF) from 19 European cardiomyopathy referral units between 1990 and 2018. Data analyses were conducted between June and October, 2020. / Main Outcomes and Measures: The primary end point was a composite of malignant ventricular arrhythmia (MVA) (sudden cardiac death, aborted sudden cardiac death, appropriate implantable cardioverter-defibrillator shock, and sustained ventricular tachycardia) and end-stage heart failure (heart transplant or mortality associated with end-stage heart failure). The secondary end point comprised MVA events only. / Results: In total, 167 patients with FLNCtv were studied (55 probands [33%]; 89 men [53%]; mean [SD] age at baseline evaluation, 43 [18] years). For a median follow-up of 20 months (interquartile range, 7-60 months), 29 patients (17.4%) reached the primary end point (19 patients with MVA and 10 patients with end-stage heart failure). Eight (44%) arrhythmic events occurred among individuals with baseline mild to moderate left ventricular systolic dysfunction (LVSD) (LVEF = 36%-49%). Univariable risk factors associated with the primary end point included proband status, LVEF decrement per 10%, ventricular ectopy (≥500 in 24 hours) and myocardial fibrosis detected on cardiac magnetic resonance imaging. The LVEF decrement (hazard ratio [HR] per 10%, 1.83 [95% CI, 1.30-2.57]; P < .001) and proband status (HR, 3.18 [95% CI, 1.12-9.04]; P = .03) remained independent risk factors on multivariable analysis (excluding myocardial fibrosis and ventricular ectopy owing to case censoring). There was no difference in freedom from MVA between FLNCtv carriers with mild to moderate or severe (LVEF ≤35%) LVSD (HR, 1.29 [95% CI, 0.45-3.72]; P = .64). Carriers of FLNCtv with impaired LVEF at baseline evaluation (n = 69) had reduced freedom from MVA compared with 244 TTNtv carriers with similar baseline LVEF (for mild to moderate LVSD: HR, 16.41 [95% CI, 3.45-78.11]; P < .001; for severe LVSD: HR, 2.47 [95% CI, 1.04-5.87]; P = .03). / Conclusions and Relevance: The high frequency of MVA among patients with FLNCtv with mild to moderate LVSD suggests that higher LVEF values than those currently recommended should be considered for prophylactic implantable cardioverter-defibrillator therapy in FLNCtv carriers

Clinical features and natural history of PRKAG2 Variant Cardiac Glycogenosis

BACKGROUND PRKAG2 gene variants cause a syndrome characterized by cardiomyopathy, conduction disease, and ventricular pre-excitation. Only a small number of cases have been reported to date, and the natural history of the disease is poorly understood. OBJECTIVES The aim of this study was to describe phenotype and natural history of PRKAG2 variants in a large multicenter European cohort. METHODS Clinical, electrocardiographic, and echocardiographic data from 90 subjects with PRKAG2 variants (53% men; median age 33 years; interquartile range [IQR]: 15 to 50 years) recruited from 27 centers were retrospectively studied. RESULTS At first evaluation, 93% of patients were in New York Heart Association functional class I or II. Maximum left ventricular wall thickness was 18 +/- 8 mm, and left ventricular ejection fraction was 61 +/- 12%. Left ventricular hypertrophy (LVH) was present in 60 subjects (67%) at baseline. Thirty patients (33%) had ventricular pre-excitation or had undergone accessory pathway ablation; 17 (19%) had pacemakers (median age at implantation 36 years; IQR: 27 to 46 years), and 16 (18%) had atrial fibrillation (median age 43 years; IQR: 31 to 54 years). After a median follow-up period of 6 years (IQR: 2.3 to 13.9 years), 71% of subjects had LVH, 29% had AF, 21% required de novo pacemakers (median age at implantation 37 years; IQR: 29 to 48 years), 14% required admission for heart failure, 8% experienced sudden cardiac death or equivalent, 4% required heart transplantation, and 13% died. CONCLUSIONS PRKAG2 syndrome is a progressive cardiomyopathy characterized by high rates of atrial fibrillation, conduction disease, advanced heart failure, and life-threatening arrhythmias. Classical features of pre-excitation and severe LVH are not uniformly present, and diagnosis should be considered in patients with LVH who develop atrial fibrillation or require permanent pacemakers at a young age. (c) 2020 the American College of Cardiology Foundation. Published by Elsevier. All rights reserved.Instituto de Salud Carlos IIIInstituto de Salud Carlos IIIEuropean Commission [PI17/01941, AC16/0014, PI17/01690, PI18/01582, PT17/0015/0043]ERA-CVD Joint Transnational Call 2016 (GENPROVIC)DETECTIN-HF project (ERA-CVD framework)Wellcome TrustWellcome TrustEuropean Commission [107469/Z/15/, HICF-R6-373]National Institute for Health Research (NIHR) Royal Brompton Cardiovascular Biomedical Research UnitNIHR Imperial Biomedical Research CentreDepartment of Health, United Kingdom [HICF-R6-373]British Heart FoundationBritish Heart Foundation [SP/10/10/28431]Obra Social La Caixa FoundationLa Caixa Foundation [100010434]Fundacio Privada Daniel Bravo AndreuInstituto de Salud Carlos III - Plan Estatal de I.D.I. 2013-2016, European Regional Development Fund ("A Way of Making Europe")Spanish Ministry of Economy and Competitiveness - Plan Estatal de I.D.I. 2013-2016, European Regional Development Fund ("A Way of Making Europe")Medical Research Council Clinical Academic Research Partnership AwardUCL Hospitals NIHR Biomedical Research CentreFondazione per la Ricerca Ospedale MaggioreNIHR Great Ormond Street Hospital Biomedical Research Centreinfo:eu-repo/semantics/publishedVersio