Fernando Dominguez

Truncating FLNC Mutations Are Associated With High-Risk Dilated and Arrhythmogenic Cardiomyopathies

BACKGROUND Filamin C (encoded by the FLNC gene) is essential for sarcomere attachment to the plasmatic membrane. FLNC mutations have been associated with myofibrillar myopathies, and cardiac involvement has been reported in some carriers. Accordingly, since 2012, the authors have included FLNC in the genetic screening of patients with inherited cardiomyopathies and sudden death. OBJECTIVES The aim of this study was to demonstrate the association between truncating mutations in FLNC and the development of high-risk dilated and arrhythmogenic cardiomyopathies. METHODS FLNC was studied using next-generation sequencing in 2,877 patients with inherited cardiovascular diseases. A characteristic phenotype was identified in probands with truncating mutations in FLNC. Clinical and genetic evaluation of 28 affected families was performed. Localization of filamin C in cardiac tissue was analyzed in patients with truncating FLNC mutations using immunohistochemistry. RESULTS Twenty-three truncating mutations were identified in 28 probands previously diagnosed with dilated, arrhythmogenic, or restrictive cardiomyopathies. Truncating FLNC mutations were absent in patients with other phenotypes, including 1,078 patients with hypertrophic cardiomyopathy. Fifty-four mutation carriers were identified among 121 screened relatives. The phenotype consisted of left ventricular dilation (68%), systolic dysfunction (46%), and myocardial fibrosis (67%); inferolateral negative T waves and low QRS voltages on electrocardiography (33%); ventricular arrhythmias (82%); and frequent sudden cardiac death (40 cases in 21 of 28 families). Clinical skeletal myopathy was not observed. Penetrance was >97% in carriers older than 40 years. Truncating mutations in FLNC cosegregated with this phenotype with a dominant inheritance pattern (combined logarithm of the odds score: 9.5). Immunohistochemical staining of myocardial tissue showed no abnormal filamin C aggregates in patients with truncating FLNC mutations. CONCLUSIONS Truncating mutations in FLNC caused an overlapping phenotype of dilated and left-dominant arrhythmogenic cardiomyopathies complicated by frequent premature sudden death. Prompt implantation of a cardiac defibrillator should be considered in affected patients harboring truncating mutations in FLNC.

A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li–Fraumeni-like families

Cardiac angiosarcoma (CAS) is a rare malignant tumour whose genetic basis is unknown. Here we show, by whole-exome sequencing of a TP53-negative Li–Fraumeni-like (LFL) family including CAS cases, that a missense variant (p.R117C) in POT1 (protection of telomeres 1) gene is responsible for CAS. The same gene alteration is found in two other LFL families with CAS, supporting the causal effect of the identified mutation. We extend the analysis to TP53-negative LFL families with no CAS and find the same mutation in a breast AS family. The mutation is recently found once in 121,324 studied alleles in ExAC server but it is not described in any other database or found in 1,520 Spanish controls. In silico structural analysis suggests how the mutation disrupts POT1 structure. Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility.

Natural History and Prognostic Factors in Alcoholic Cardiomyopathy

OBJECTIVES This study sought to determine the natural history of contemporary alcoholic cardiomyopathy (ACM), to compare it with that of idiopathic dilated cardiomyopathy (IDCM), and to identify risk factors for poor outcome. BACKGROUND ACM is a common cause of dilated cardiomyopathy (DCM), but little is known about its natural history or the effect of reducing alcohol intake on disease progression. METHODS We studied the clinical characteristics and outcomes of 94 consecutive patients with ACM and 188 with IDCM, evaluated over the period between 1993 and 2011. RESULTS After a median follow-up of 59 months (interquartile range: 25 to 107 months), 14 ACM patients (15%) had died from cardiovascular causes (6 from heart failure and 8 from sudden cardiac death), 14 (15%) underwent heart transplantation, 35 (37%) experienced recovery in left ventricular function, and 31 (33%) remained clinically stable without improvement in systolic function. Transplantation-free survival was higher in ACM patients than in IDCM patients (p = 0.002), and ACM was associated with a favorable outcome on multiple analysis of the entire cohort (odds ratio [OR]: 0.4; 95% confidence interval [CI]: 0.2 to 0.8; p = 0.01). Independent predictors of death or heart transplantation in ACM identified by multiple logistic regression analysis were atrial fibrillation (OR: 9.7; 95% CI: 2.56 to 36.79; p = 0.001); QRS duration >120 ms (OR: 7.2; 95% CI: 2.02 to 26; p = 0.002), and lack of beta-blocker therapy (OR: 4.4; 95% CI: 1.35 to 14.49; p = 0.014). ACM patients who reduced their alcohol intake to moderate levels exhibited similar survival (p = 0.22) and cardiac function recovery (p = 0.8) as abstainers. CONCLUSIONS ACM has a better prognosis than IDCM. Atrial fibrillation, QRS width >120 ms, and the absence of beta-blocker therapy identify patients with a poor outcome. Alcohol abstainers and those who reduce intake to a moderate degree show similar clinical outcomes.

Update on Myocarditis and Inflammatory Cardiomyopathy: Reemergence of Endomyocardial Biopsy.

Myocarditis is defined as an inflammatory disease of the heart muscle and is an important cause of acute heart failure, sudden death, and dilated cardiomyopathy. Viruses account for most cases of myocarditis or inflammatory cardiomyopathy, which could induce an immune response causing inflammation even when the pathogen has been cleared. Other etiologic agents responsible for myocarditis include drugs, toxic substances, or autoimmune conditions. In the last few years, advances in noninvasive techniques such as cardiac magnetic resonance have been very useful in supporting diagnosis of myocarditis, but toxic, infectious-inflammatory, infiltrative, or autoimmune processes occur at a cellular level and only endomyocardial biopsy can establish the nature of the etiological agent. Furthermore, after the generalization of immunohistochemical and viral genome detection techniques, endomyocardial biopsy provides a definitive etiological diagnosis that can lead to specific treatments such as antiviral or immunosuppressive therapy. Endomyocardial biopsy is not commonly performed for the diagnosis of myocarditis due to safety reasons, but both right- and left endomyocardial biopsies have very low complication rates when performed by experienced operators. This document provides a state-of-the-art review of myocarditis and inflammatory cardiomyopathy, with special focus on the role of endomyocardial biopsy to establish specific treatments.

Clinical characteristics of wild-type transthyretin cardiac amyloidosis: disproving myths

Aims Wild-type transthyretin amyloidosis (ATTRwt) is mostly considered a disease predominantly of elderly male, characterized by concentric LV hypertrophy, preserved LVEF, and low QRS voltages. We sought to describe the characteristics of a large cohort of ATTRwt patients to better define the disease. Methods and results Clinical findings of consecutive ATTRwt patients diagnosed at 2 centres were reviewed. ATTRwt was diagnosed histologically or non-invasively (LV hypertrophy ≥12 mm, intense cardiac uptake at 99mTc-DPD scintigraphy and AL exclusion). Mutations in TTR were excluded in all cases. The study cohort comprised 108 patients (78.6 ± 8 years); 67 (62%) diagnosed invasively and 41 (38%) non-invasively. Twenty patients (19%) were females. An asymmetric hypertrophy pattern was observed in 25 (23%) patients. Mean LVEF was 52 ± 14%, with 39 patients (37%) showing a LVEF < 50%. Atrial fibrillation (56%) and a pseudo-infarct pattern (63%) were the commonest ECG findings. Only 22 patients fulfilled QRS low-voltage criteria while 10 showed LV hypertrophy on ECG. Although heart failure was the most frequent profile leading to diagnosis (68%), 7% of individuals presented with atrioventricular block and 11% were diagnosed incidentally. Almost one third (35; 32%) were previously misdiagnosed. Conclusion The clinical spectrum of ATTRwt is heterogeneous and differs from the classic phenotype: women are affected in a significant proportion; asymmetric LV hypertrophy and impaired LVEF are not rare and only a minority have low QRS voltages. Clinicians should be aware of the broad clinical spectrum of ATTRwt to correctly identify an entity for which a number of disease-modifying treatments are under investigation.

Malignant ventricular arrhythmias in alcoholic cardiomyopathy

BACKGROUND Excessive alcohol consumption is a well-known aetiology of atrial arrhythmias but there is little information concerning the prevalence or incidence of malignant ventricular arrhythmias in alcoholic cardiomyopathy (ACM). This study sought to investigate incidence and predictive factors of ventricular arrhythmias in ACM. METHODS Retrospective observational study of the clinical characteristics and long-term arrhythmic events in 282 consecutive patients with ACM (94 individuals) and idiopathic dilated cardiomyopathy (IDCM) (188 individuals) evaluated between 1993 and 2011. RESULTS During a median follow-up of 38months (IQR:12-77), 42 patients died and 79 underwent heart transplantation [31 (33%) with ACM vs 90 (48%) with IDCM; p=0.017]. A total of 37 (13%) patients [18 (19%) ACM vs 20 (11%) IDCM; p=0.048] suffered malignant ventricular arrhythmias. On multivariate analysis, left bundle branch block (LBBB) (OR 2.4; CI95%: 1.2-5; p=0.015) and alcoholic aetiology (OR 2.3; CI95%: 1.1-4.5; p=0.026) were the only independent predictors of malignant ventricular arrhythmic events. A total of 18 (19%) ACM patients experienced 20 malignant ventricular arrhythmic events (4 aborted SCD, 8 SCD and 8 appropriate ICD therapies). At baseline evaluation, the only independent predictor of malignant ventricular arrhythmias in ACM patients was LBBB (OR 11.2; CI95%: 2.6-50; p=0.001). No malignant ventricular arrhythmias were recorded during follow-up in ACM patients if left ventricular ejection fraction (LVEF) had increased or remained ≥40%. CONCLUSIONS Malignant ventricular arrhythmias are more frequent in ACM than in IDCM. LBBB identifies ACM patients with increased risk of SCD. No malignant ventricular arrhythmias were found during follow-up in ACM patients when LVEF was ≥40%.

An International External Validation Study of the 2014 European Society of Cardiology Guideline on Sudden Cardiac Death Prevention in Hypertrophic Cardiomyopathy (Evidence from HCM)

Background: Identification of people with hypertrophic cardiomyopathy (HCM) who are at risk of sudden cardiac death (SCD) and require a prophylactic implantable cardioverter defibrillator is challenging. In 2014, the European Society of Cardiology proposed a new risk stratification method based on a risk prediction model (HCM Risk-SCD) that estimates the 5-year risk of SCD. The aim was to externally validate the 2014 European Society of Cardiology recommendations in a geographically diverse cohort of patients recruited from the United States, Europe, the Middle East, and Asia. Methods: This was an observational, retrospective, longitudinal cohort study. Results: The cohort consisted of 3703 patients. Seventy three (2%) patients reached the SCD end point within 5 years of follow-up (5-year incidence, 2.4% [95% confidence interval {CI}, 1.9–3.0]). The validation study revealed a calibration slope of 1.02 (95% CI, 0.93–1.12), C-index of 0.70 (95% CI, 0.68–0.72), and D-statistic of 1.17 (95% CI, 1.05–1.29). In a complete case analysis (n= 2147; 44 SCD end points at 5 years), patients with a predicted 5-year risk of <4% (n=1524; 71%) had an observed 5-year SCD incidence of 1.4% (95% CI, 0.8–2.2); patients with a predicted risk of ≥6% (n=297; 14%) had an observed SCD incidence of 8.9% (95% CI, 5.96–13.1) at 5 years. For every 13 (297/23) implantable cardioverter defibrillator implantations in patients with an estimated 5-year SCD risk ≥6%, 1 patient can potentially be saved from SCD. Conclusions: This study confirms that the HCM Risk-SCD model provides accurate prognostic information that can be used to target implantable cardioverter defibrillator therapy in patients at the highest risk of SCD.

Infective endocarditis in hypertrophic cardiomyopathy A multicenter, prospective, cohort study

AbstractInfective endocarditis (IE) complicating hypertrophic cardiomyopathy (HCM) is a poorly known entity. Although current guidelines do not recommend IE antibiotic prophylaxis (IEAP) in HCM, controversy remains.This study sought to describe the clinical course of a large series of IE HCM and to compare IE in HCM patients with IE patients with and without an indication for IEAP.Data from the GAMES IE registry involving 27 Spanish hospitals were analyzed. From January 2008 to December 2013, 2000 consecutive IE patients were prospectively included in the registry. Eleven IE HCM additional cases from before 2008 were also studied. Clinical, microbiological, and echocardiographic characteristics were analyzed in IE HCM patients (n = 34) and in IE HCM reported in literature (n = 84). Patients with nondevice IE (n = 1807) were classified into 3 groups: group 1, HCM with native-valve IE (n = 26); group 2, patients with IEAP indication (n = 696); group 3, patients with no IEAP indication (n = 1085). IE episode and 1-year follow-up data were gathered.One-year mortality in IE HCM was 42% in our study and 22% in the literature. IE was more frequent, although not exclusive, in obstructive HCM (59% and 74%, respectively). Group 1 exhibited more IE predisposing factors than groups 2 and 3 (62% vs 40% vs 50%, P < 0.01), and more previous dental procedures (23% vs 6% vs 8%, P < 0.01). Furthermore, Group 1 experienced a higher incidence of Streptococcus infections than Group 2 (39% vs 22%, P < 0.01) and similar to Group 3 (39% vs 30%, P = 0.34). Overall mortality was similar among groups (42% vs 36% vs 35%, P = 0.64).IE occurs in HCM patients with and without obstruction. Mortality of IE HCM is high but similar to patients with and without IEAP indication. Predisposing factors, previous dental procedures, and streptococcal infection are higher in IE HCM, suggesting that HCM patients could benefit from IEAP.

Direct oral anticoagulants in patients with hypertrophic cardiomyopathy and atrial fibrillation

BACKGROUND Chronic anticoagulation with vitamin K antagonists (VKAs) is recommended in patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF). Direct oral anticoagulants (NOACs) are an alternative to VKAs but there are limited data to support their use in HCM. We sought to describe the pattern of use, thromboembolic events, bleeding and quality of life in patients with HCM and AF treated with NOACs. METHODS Data from patients treated with NOACs (n=99) and VKA (n=433) at 9 inherited cardiac diseases units were retrospectively collected. Annual rates of embolic events, serious bleeding and death were analysed and compared. Quality of life and treatment satisfaction were evaluated with SF-36 and SAFUCA questionnaires in 80 NOAC-treated and 57 VKA-treated patients. RESULTS After median follow-up of 63 months (IQR: 26-109), thromboembolic events (TIA/stroke and peripheral embolism) occurred in 10% of patients on oral anticoagulation. Major/clinically relevant bleeding occurred in 3.8% and the global mortality rate was 23.3%. Thromboembolic event rate was 0.62 per 100patient-years in the NOAC group vs. 1.59 in the VKA group [subhazard ratio (SHR) 0.32;95%CI:0.04-2.45; p=0.27]. Major/clinically relevant bleeding occurred in 0.62 per 100person-years in the NOAC group vs. 0.60 in the VKA group (SHR 1.28;95%CI 0.18-9.30; p=0.85). Quality of life scores were similar in both groups; however, NOAC-treated patients achieved higher scores in the SAFUCA. CONCLUSIONS HCM patients with AF on NOACs showed similar embolic and bleeding rates to those on VKA. Although quality of life was similar in both groups, the NOAC group reported higher treatment satisfaction.

Endomyocardial biopsy in Anderson–Fabry disease: The key in uncertain cases

a Dept. of Cardiology, Charite, Campus Virchow Klinikum (CVK), Berlin, Germany b Dept. of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain c Dept. of Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany d Dept. of Nephrology, Charite, Campus Virchow Klinikum (CVK), Berlin, Germany e Berliner Zentrum fur Regenerative Therapien (BCRT), Campus Virchow Klinikum (CVK), Berlin, Germany f Deutsches Zentrum fur Herz Kreislaufforschung (DZHK) — Standort Berlin/Charite, Germany