Clinical and Genotype Characteristics and Symptom Migration in Patients With Mixed Phenotype Transthyretin Amyloidosis from the Transthyretin Amyloidosis Outcomes Survey

Introduction: Transthyretin amyloidosis (ATTR amyloidosis) is primarily associated with a cardiac or neurologic phenotype, but a mixed phenotype is increasingly described. Methods: This study describes the mixed phenotype cohort in the Transthyretin Amyloidosis Outcomes Survey (THAOS). THAOS is an ongoing, longitudinal, observational survey of patients with ATTR amyloidosis, including both hereditary (ATTRv) and wild-type disease, and asymptomatic carriers of pathogenic transthyretin variants. Baseline characteristics of patients with a mixed phenotype (at enrollment or reclassified during follow-up) are described (data cutoff: January 4, 2022). Results: Approximately one-third of symptomatic patients (n = 1185/3542; 33.5%) were classified at enrollment or follow-up as mixed phenotype (median age, 66.5 years). Of those, 344 (29.0%) were reclassified to mixed phenotype within a median 1–2 years of follow-up. Most patients with mixed phenotype had ATTRv amyloidosis (75.7%). The most frequent genotypes were V30M (38.9%) and wild type (24.3%). Conclusions: These THAOS data represent the largest analysis of a real-world mixed phenotype ATTR amyloidosis population to date and suggest that a mixed phenotype may be more prevalent than previously thought. Patients may also migrate from a primarily neurologic or cardiologic presentation to a mixed phenotype over time. These data reinforce the need for multidisciplinary evaluation at initial assessment and follow-up of all patients with ATTR amyloidosis. Trial Registration: ClinicalTrials.gov: NCT00628745

Lafora Disease Is an Inherited Metabolic Cardiomyopathy

This work was supported by grants from the Spanish Ministry of Economy and Competitiveness (SAF2015-65722-R to Dr. Lara-Pezzi and SAF2014-59594-R to Dr. Serratosa), Autonomous Community of Madrid (2010-BMD2321, FIBROTEAM Consortium), European Union's FP7 (CardioNeT-ITN-289600, CardioNext-ITN-608027), the Spanish Carlos III Institute of Health (CPII14/00027 to Dr. Lara-Pezzi, PI13/00865 to Dr. Sanchez and RD12/0042/066 to Drs. Garcia-Pavia and Lara-Pezzi), and the National Institute of Neurological Disorders And Stroke of the National Institutes of Health (P01NS097197 to Dr. Sanchez). This work was also supported by the Plan Estatal de I+D+I 2013-2016-European Regional Development Fund (FEDER) "A way of making Europe," Spain. The Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (MINECO award SEV-2015-0505).S

Activation of Serine One-Carbon Metabolism by Calcineurin A beta 1 Reduces Myocardial Hypertrophy and Improves Ventricular Function

Background In response to pressure overload, the heart develops ventricular hypertrophy that progressively decompensates and leads to heart failure. This pathological hypertrophy is mediated, among others, by the phosphatase calcineurin and is characterized by metabolic changes that impair energy production by mitochondria. Objectives The authors aimed to determine the role of the calcineurin splicing variant CnAβ1 in the context of cardiac hypertrophy and its mechanism of action. Methods Transgenic mice overexpressing CnAβ1 specifically in cardiomyocytes and mice lacking the unique C-terminal domain in CnAβ1 (CnAβ1Δi12 mice) were used. Pressure overload hypertrophy was induced by transaortic constriction. Cardiac function was measured by echocardiography. Mice were characterized using various molecular analyses. Results In contrast to other calcineurin isoforms, the authors show here that cardiac-specific overexpression of CnAβ1 in transgenic mice reduces cardiac hypertrophy and improves cardiac function. This effect is mediated by activation of serine and one-carbon metabolism, and the production of antioxidant mediators that prevent mitochondrial protein oxidation and preserve ATP production. The induction of enzymes involved in this metabolic pathway by CnAβ1 is dependent on mTOR activity. Inhibition of serine and one-carbon metabolism blocks the beneficial effects of CnAβ1. CnAβ1Δi12 mice show increased cardiac hypertrophy and declined contractility. Conclusions The metabolic reprogramming induced by CnAβ1 redefines the role of calcineurin in the heart and shows for the first time that activation of the serine and one-carbon pathway has beneficial effects on cardiac hypertrophy and function, paving the way for new therapeutic approaches

Alternative Splicing of NOX4 in the Failing Human Heart

Increased oxidative stress is a major contributor to the development and progression of heart failure, however, our knowledge on the role of the distinct NADPH oxidase (NOX) isoenzymes, especially on NOX4 is controversial. Therefore, we aimed to characterize NOX4 expression in human samples from healthy and failing hearts. Explanted human heart samples (left and right ventricular, and septal regions) were obtained from patients suffering from heart failure of ischemic or dilated origin. Control samples were obtained from donor hearts that were not used for transplantation. Deep RNA sequencing of the cardiac transcriptome indicated extensive alternative splicing of the NOX4 gene in heart failure as compared to samples from healthy donor hearts. Long distance PCR analysis with a universal 5'-3' end primer pair, allowing amplification of different splice variants, confirmed the presence of the splice variants. To assess translation of the alternatively spliced transcripts we determined protein expression of NOX4 by using a specific antibody recognizing a conserved region in all variants. Western blot analysis showed up-regulation of the full-length NOX4 in ischemic cardiomyopathy samples and confirmed presence of shorter isoforms both in control and failing samples with disease-associated expression pattern. We describe here for the first time that NOX4 undergoes extensive alternative splicing in human hearts which gives rise to the expression of different enzyme isoforms. The full length NOX4 is significantly upregulated in ischemic cardiomyopathy suggesting a role for NOX4 in ROS production during heart failure

Insulin-like growth factor II prevents oxidative and neuronal damage in cellular and mice models of Parkinson's disease

Oxidative distress and mitochondrial dysfunction, are key factors involved in the pathophysiology of Parkinson's disease (PD). The pleiotropic hormone insulin-like growth factor II (IGF-II) has shown neuroprotective and antioxidant effects in some neurodegenerative diseases. In this work, we demonstrate the protective effect of IGF-II against the damage induced by 1-methyl-4-phenylpyridinium (MPP+) in neuronal dopaminergic cell cultures and a mouse model of progressive PD. In the neuronal model, IGF-II counteracts the oxidative distress produced by MPP + protecting dopaminergic neurons. Improved mitochondrial function, increased nuclear factor (erythroid-derived 2)-like2 (NRF2) nuclear translocation along with NRF2-dependent upregulation of antioxidative enzymes, and modulation of mammalian target of rapamycin (mTOR) signalling pathway were identified as mechanisms leading to neuroprotection and the survival of dopaminergic cells. The neuroprotective effect of IGF-II against MPP + -neurotoxicity on dopaminergic neurons depends on the specific IGF-II receptor (IGF-IIr). In the mouse model, IGF-II prevents behavioural dysfunction and dopaminergic nigrostriatal pathway degeneration and mitigates neuroinflammation induced by MPP+. Our work demonstrates that hampering oxidative stress and normalising mitochondrial function through the interaction of IGF-II with its specific IGF-IIr are neuroprotective in both neuronal and mouse models. Thus, the modulation of the IGF-II/IGF-IIr signalling pathway may be a useful therapeutic approach for the prevention and treatment of PD

Prediction of thrombo-embolic risk in patients with hypertrophic cardiomyopathy (HCM Risk-CVA)

Aims Atrial fibrillation (AF) and thrombo-embolism (TE) are associated with reduced survival in hypertrophic cardiomyopathy (HCM), but the absolute risk of TE in patients with and without AF is unclear. The primary aim of this study was to derive and validate a model for estimating the risk of TE in HCM. Exploratory analyses were performed to determine predictors of TE, the performance of the CHA2DS2-VASc score, and outcome with vitamin K antagonists (VKAs). Methods and results A retrospective, longitudinal cohort of seven institutions was used to develop multivariable Cox regression models fitted with pre-selected predictors. Bootstrapping was used for validation. Of 4821 HCM patients recruited between 1986 and 2008, 172 (3.6%) reached the primary endpoint of cerebrovascular accident (CVA), transient ischaemic attack (TIA), or systemic peripheral embolus within 10 years. A total of 27.5% of patients had a CHA2DS2-VASc score of 0, of whom 9.8% developed TE during follow-up. Cox regression revealed an association between TE and age, AF, the interaction between age and AF, TE prior to first evaluation, NYHA class, left atrial (LA) diameter, vascular disease, and maximal LV wall thickness. There was a curvilinear relationship between LA size and TE risk. The model predicted TE with a C-index of 0.75 [95% confidence interval (CI) 0.70-0.80] and the D-statistic was 1.30 (95% CI 1.05-1.56). VKA treatment was associated with a 54.8% (95% CI 31-97%, P = 0.037) relative risk reduction in HCM patients with AF. Conclusions The study shows that the risk of TE in HCM patients can be identified using a small number of simple clinical features. LA size, in particular, should be monitored closely, and the assessment and treatment of conventional vascular risk factors should be routine practice in older patients. Exploratory analyses show for the first time evidence for a reduction of TE with VKA treatment. The CHA2DS2-VASc score does not appear to correlate well with the clinical outcome in patients with HCM and should not be used to assess TE risk in this population

International Consensus on Differential Diagnosis and Management of Patients With Danon Disease: JACC State-of-the-Art Review

Danon disease is a rare X-linked autophagic vacuolar cardioskeletal myopathy associated with severe heart failure that can be accompanied with extracardiac neurologic, skeletal, and ophthalmologic manifestations. It is caused by loss of function variants in the LAMP2 gene and is among the most severe and penetrant of the genetic cardiomyopathies. Most patients with Danon disease will experience symptomatic heart failure. Male individuals generally present earlier than women and die of either heart failure or arrhythmia or receive a heart transplant by the third decade of life. Herein, the authors review the differential diagnosis of Danon disease, diagnostic criteria, natural history, management recommendations, and recent advances in treatment of this increasingly recognized and extremely morbid cardiomyopathy

Clinical Profile of Cardiac Involvement in Danon Disease: A Multicenter European Registry

Background: The X-linked Danon disease manifests by severe cardiomyopathy, myopathy, and neuropsychiatric problems. We designed this registry to generate a comprehensive picture of clinical presentations and outcome of patients with Danon disease in cardiomyopathy centers throughout Europe. Methods: Clinical and genetic data were collected in 16 cardiology centers from 8 European countries. Results: The cohort comprised 30 male and 27 female patients. The age at diagnosis was birth to 42 years in men and 2 to 65 in women. Cardiac involvement was observed in 96%. Extracardiac manifestations were prominent in men but not in women. Left ventricular (LV) hypertrophy was reported in 73% of male and 74% of female patients. LV systolic dysfunction was reported in 40% of men (who had LV ejection fraction, 34±11%) and 59% of women (LV ejection fraction, 28±13%). The risk of arrhythmia and heart failure was comparable among sexes. The age of first heart failure hospitalization was lower in men (18±6 versus 28±17 years; P<0.003). Heart failure was the leading cause of death (10 of 17; 59%), and LV systolic dysfunction predicted an adverse outcome. Eight men and 8 women (28%) underwent heart transplantation or received an LV assist device. Our cohort suggests better prognosis of female compared with male heart transplant recipients. Conclusions: Danon disease presents earlier in men than in women and runs a malignant course in both sexes, due to cardiac complications. Cardiomyopathy features, heart failure and arrhythmia, are similar among the sexes. Clinical diagnosis and management is extremely challenging in women due to phenotypic diversity and the absence of extracardiac manifestations

Mavacamten Treatment for Symptomatic Obstructive Hypertrophic Cardiomyopathy: Interim Results From the MAVA-LTE Study, EXPLORER-LTE Cohort.

This study was funded by Bristol Myers Squibb, Princeton, New Jersey, USA. Bristol Myers Squibb’s policy on data sharing is available online at https://www.bms.com/researchers-and-partners/clinicaltrials-and-research/disclosure-commitment.html. Dr Rader has received consulting fees from Medtronic, Bristol Myers Squibb, and ReCor Medical. Dr Ore˛ziak has received personal fees from Bristol Myers Squibb. Dr Saberi has received personal fees from Bristol Myers Squibb. Dr Fermin has received consulting fees from Alnylam, Eidos Therapeutics, Bristol Myers Squibb, and Pfizer. Dr Wheeler has received personal fees and research support from Bristol Myers Squibb. Dr Garcia-Pavia has received consulting and speaking fees from Bristol Myers Squibb, Rocket Pharmaceuticals, and Cytokinetics and speaking fees from Bristol Myers Squibb and Cytokinetics. Dr Zwas has received personal fees from Bristol Myers Squibb. Dr Masri has received grants from Akcea, Pfizer, and Ultromics and consulting fees from Alnylam, Cytokinetics, Eidos Therapeutics, Ionis, and Pfizer. Dr Owens has received consulting fees from Bristol Myers Squibb, Cytokinetics, and Pfizer. Dr Hegde serves on the faculty of the Cardiovascular Imaging Core Laboratory at Brigham and Women’s Hospital, and her institution has received payments for her consulting work from Bristol Myers Squibb. Dr Seidler has received consulting fees or honoraria for lectures from Bristol Myers Squibb and Cytokinetics. Dr Balaratnam and Dr Sehnert are employees of Bristol Myers Squibb and own stock of Bristol Myers Squibb. Shawna Fox is an employee of IQVIA, a partner providing statistics services to Bristol Myers Squibb. Dr Olivotto has received grants from Amicus, Boston Scientific, Bristol Myers Squibb, Cytokinetics, Genzyme, and Menarini International and consulting fees from Amicus, Cytokinetics, Genzyme, MS Pharma, Rocket Pharmaceuticals, and Tenaya Therapeutics.BACKGROUND Data assessing the long-term safety and efficacy of mavacamten treatment for symptomatic obstructive hypertrophic cardiomyopathy are needed. OBJECTIVES The authors sought to evaluate interim results from the EXPLORER-Long Term Extension (LTE) cohort of MAVA-LTE (A Long-Term Safety Extension Study of Mavacamten in Adults Who Have Completed EXPLORER-HCM; NCT03723655). METHODS After mavacamten or placebo withdrawal at the end of the parent EXPLORER-HCM (Clinical Study to Evaluate Mavacamten [MYK-461] in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy; NCT03470545), patients could enroll in MAVA-LTE. Patients received mavacamten 5 mg once daily; adjustments were made based on site-read echocardiograms. RESULTS Between April 9, 2019, and March 5, 2021, 231 of 244 eligible patients (94.7%) enrolled in MAVA-LTE (mean age: 60 years; 39% female). At data cutoff (August 31, 2021) 217 (93.9%) remained on treatment (median time in study: 62.3 weeks; range: 0.3-123.9 weeks). At 48 weeks, patients showed improvements in left ventricular outflow tract (LVOT) gradients (mean change ± SD from baseline: resting: -35.6 ± 32.6 mm Hg; Valsalva: -45.3 ± 35.9 mm Hg), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels (median: -480 ng/L; Q1-Q3: -1,104 to -179 ng/L), and NYHA functional class (67.5% improved by ≥1 class). LVOT gradients and NT-proBNP reductions were sustained through 84 weeks in patients who reached this timepoint. Over 315 patient-years of exposure, 8 patients experienced an adverse event of cardiac failure, and 21 patients had an adverse event of atrial fibrillation, including 11 with no prior history of atrial fibrillation. Twelve patients (5.2%) developed transient reductions in site-read echocardiogram left ventricular ejection fraction of <50%, resulting in temporary treatment interruption; all recovered. Ten patients discontinued treatment due to treatment-emergent adverse events. CONCLUSIONS Mavacamten treatment showed clinically important and durable improvements in LVOT gradients, NT-proBNP levels, and NYHA functional class, consistent with EXPLORER-HCM. Mavacamten treatment was well tolerated over a median 62-week follow-up.S