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Purpose of Review: Fabry Disease (FD) is a rare lysosomal storage disorder characterised by multiorgan accumulation of glycosphingolipid due to deficiency in the enzyme α-galactosidase A. Cardiac sphingolipid accumulation triggers various types of arrhythmias, predominantly ventricular arrhythmia, bradyarrhythmia, and atrial fibrillation. Arrhythmia is likely the primary contributor to FD mortality with sudden cardiac death, the most frequent cardiac mode of death. Traditionally FD was seen as a storage cardiomyopathy triggering left ventricular hypertrophy, diastolic dysfunction, and ultimately, systolic dysfunction in advanced disease. The purpose of this review is to outline the current evidence exploring novel mechanisms underlying the arrhythmia substrate., Recent Findings: There is growing evidence that FD cardiomyopathy is a primary arrhythmic disease with each stage of cardiomyopathy (accumulation, hypertrophy, inflammation, and fibrosis) contributing to the arrhythmia substrate via various intracellular, extracellular, and environmental mechanisms. It is therefore important to understand how these mechanisms contribute to an individual's risk of arrhythmia in FD. In this review, we outline the epidemiology of arrhythmia, pathophysiology of arrhythmogenesis, risk stratification, and cardiac therapy in FD. We explore how advances in conventional cardiac investigations performed in FD patients including 12-lead electrocardiography, transthoracic echocardiography, and cardiac magnetic resonance imaging have enabled early detection of pro-arrhythmic substrate. This has allowed for appropriate risk stratification of FD patients. This paves the way for future work exploring the development of therapeutic initiatives and risk prediction models to reduce the burden of arrhythmia., (© 2024. The Author(s).)

Background: Pegunigalsidase alfa is a PEGylated α-galactosidase A enzyme replacement therapy. BALANCE (NCT02795676) assessed non-inferiority of pegunigalsidase alfa versus agalsidase beta in adults with Fabry disease with an annualised estimated glomerular filtration rate (eGFR) slope more negative than -2 mL/min/1.73 m 2 /year who had received agalsidase beta for ≥1 year., Methods: Patients were randomly assigned 2:1 to receive 1 mg/kg pegunigalsidase alfa or agalsidase beta every 2 weeks for 2 years. The primary efficacy analysis assessed non-inferiority based on median annualised eGFR slope differences between treatment arms., Results: Seventy-seven patients received either pegunigalsidase alfa (n=52) or agalsidase beta (n=25). At baseline, mean (range) age was 44 (18-60) years, 47 (61%) patients were male, median eGFR was 74.5 mL/min/1.73 m 2 and median (range) eGFR slope was -7.3 (-30.5, 6.3) mL/min/1.73 m 2 /year. At 2 years, the difference between median eGFR slopes was -0.36 mL/min/1.73 m 2 /year, meeting the prespecified non-inferiority margin. Minimal changes were observed in lyso-Gb3 concentrations in both treatment arms at 2 years. Proportions of patients experiencing treatment-related adverse events and mild or moderate infusion-related reactions were similar in both groups, yet exposure-adjusted rates were 3.6-fold and 7.8-fold higher, respectively, with agalsidase beta than pegunigalsidase alfa. At the end of the study, neutralising antibodies were detected in 7 out of 47 (15%) pegunigalsidase alfa-treated patients and 6 out of 23 (26%) agalsidase beta-treated patients. There were no deaths., Conclusions: Based on rate of eGFR decline over 2 years, pegunigalsidase alfa was non-inferior to agalsidase beta. Pegunigalsidase alfa had lower rates of treatment-emergent adverse events and mild or moderate infusion-related reactions., Trial Registration Number: NCT02795676., Competing Interests: Competing interests: ELW has consulting agreements and/or grants with Sanofi, Protalix, Chiesi, Idorsia, 4DMT, Amicus and Natera. OG-A has conducted contracted research, received consulting fees and/or served on advisory boards with Amicus, Freeline, Genentech, Protalix, Sangamo, Sanofi, Takeda, 4DMT and Avrobio. WRW has been or is currently involved in clinical trials and/or registries with Alexion, Amicus, BioMarin, Chiesi, Freeline, Idorsia, Orphazyme, Pfizer, Protalix, Sanofi, Sangamo, Takeda and 4DMT. He has received honoraria from Alexion, Amicus, BioMarin, Sanofi, Spark and Takeda, and research funding from Amicus and Takeda. MH received speaker-related fees from Protalix and has been, or is currently, involved in clinical trials with Sanofi, Sangamo, Avrobio, Protalix and Idorsia (no direct funding received for these trials because they are institution directed). JB receives research support from Avrobio, BioMarin Pharmaceutical, Chiesi Farmaceutici, Idorsia Pharmaceuticals, Pfizer, Protalix Biotherapeutics, Sangamo Therapeutics, Sanofi, Takeda, Travere Therapeutics; and has received a speaker honorarium from the Fabry Support and Information Group; and has participated in advisory boards for Chiesi USA, Sanofi and Takeda. NL receives research support from and has participated in advisory boards for Amicus, Astellas, Avrobio, BioMarin Pharmaceutical, Homology, Horizon, Moderna, Pfizer, Protalix Biotherapeutics, PTC Biotherapeutics, Reneo, Sanofi, Takeda and Ultragenyx (no direct funding is received because they are institution directed). DH has received honoraria for speaking and consulting fees for advisory boards from Protalix, Takeda, Sanofi, Freeline and Sangamo, administered through University College London consultants and used in part to support research in lysosomal storage diseases. PG has been involved in premarketing studies with Genzyme, Protalix and Idorsia, and has received grants from Sanofi-Genzyme and Takeda; monies received for these activities have been deposited into the Spanish Foundation for the Study and Treatment of Gaucher Disease (FEETEG) to contribute to the development of research in lysosomal storage disorders. MJM, DO, MM, BAB, JK, TG and KN have no disclosures. RJH has received consulting fees from Alexion, Amicus Therapeutics, Inc., Avrobio, Chiesi, Sangamo, Sanofi/Genzyme, and Takeda; advisory fees from Alexion, Amicus Therapeutics, Inc., and Sanofi/Genzyme; speakers' bureau fees from Alexion and Sanofi/Genzyme and grants/research funding from Alexion, Amicus Therapeutics, Inc., Idorsia, Protalix, Sangamo, Sanofi/Genzyme and Takeda. CT has received honoraria, travel support, and/or participated as an investigator in clinical studies supported by Protalix, Sanofi, Idorsia, Takeda, Amicus, Freeline and Acelink. All received honoraria went to her institution Haukeland University Hospital. AL has received consultancy and speaker's honoraria from Amicus Therapeutics, Sanofi, Takeda, 4DMT and Chiesi. PD has been a paid consultant with Sanofi; received speaker honoraria from Sanofi and Takeda and participated in an advisory board with Protalix. AJ has received a grant from Amicus and consultancy and speaker’s honoraria from Takeda, Sanofi and Amicus. VK is an advisory board member for the Sanofi-Genzyme North American Pompe Registry. She is the principal investigator for Sanofi-Genzyme Lysosomal Storage Disease registry at UC Irvine. She has received education grants, lecturing honoraria, and research support from Sanofi-Genzyme. She participates as an investigator in clinical studies supported by Protalix, Sanofi, Idorsia, Chiesi Farmaceutici and Sangamo. BV has received honoraria, travel and accommodation funding from Greenovation Biotech GmbH, Sanofi, Takeda, Amicus, Chiesi and Swixx, and is a member of the EU Advisory Board of Fabry Registry, sponsored by Sanofi. AN received lecturing honoraria and research support from Takeda, Amicus and Sanofi/Genzyme. AP received travel expenses and grants from Takeda, Sanofi, Amicus and Chiesi. DPG has received consulting honoraria from Chiesi, Idorsia Pharmaceuticals, Sanofi and Takeda, and speaker honoraria and travel support from Sanofi and Takeda. IK has received lecture, travel and consulting fees from Amicus, Chiesi, Bayer, Boehringer-Ingelheim, Sanofi-Genzyme and Takeda-Shire. AM has received non-financial support from Chiesi Pharmaceuticals, during the conduct of the study; personal fees from AstraZeneca, Bayer Pharmaceuticals and Janssen Pharmaceuticals, outside the submitted work. AK has received honoraria, travel support and/or participated as an investigator in clinical studies supported by Protalix, Sanofi and Idorsia and on advisory meetings for Protalix, Sanofi, Takeda, Amicus and Chiesi. SW has been a paid consultant to Protalix. ML is involved in premarketing studies with Sanofi-Genzyme, Protalix/Chiesi and Idorsia. Financial arrangements were made through AMC Research BV. No fees, travel support or grants were obtained from the pharmaceutical industry. EBA and RC were full-time employees of Protalix Biotherapeutics at the time of study conduct and analysis and are now consultants to Protalix Biotherapeutics. SA is a full-time employee of Protalix Biotherapeutics. RR is a full-time employee of Chiesi Farmaceutici S.p.A. AS was a paid consultant to Protalix at the time of study conduct and analysis and is currently a paid consultant to Chiesi USA, Inc. DGW is involved in clinical trials/registries/consulting with Amicus, Chiesi, Idorsia and Protalix., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Pegunigalsidase alfa is a novel, PEGylated α-galactosidase-A enzyme-replacement therapy approved in the EU and US to treat patients with Fabry disease (FD)., Objective/methods: BRIDGE is a phase 3 open-label, switch-over study designed to assess safety and efficacy of 12 months of pegunigalsidase alfa (1 mg/kg every 2 weeks) treatment in adults with FD who had been previously treated with agalsidase alfa (0.2 mg/kg every 2 weeks) for ≥ 2 years., Results: Twenty-seven patients were screened; 22 met eligibility criteria; and 20 (13 men, 7 women) completed the study. Pegunigalsidase alfa was well-tolerated, with 97% of treatment-emergent adverse events (TEAEs) being of mild or moderate severity. The incidence of treatment-related TEAEs was low, with 2 (9%) discontinuations due to TEAEs. Five patients (23%) reported infusion-related reactions. Overall mean (SD; n = 22) baseline estimated glomerular filtration rate (eGFR) was 82.5 (23.4) mL/min/1.73 m 2 and plasma lyso-Gb 3 level was 38.3 (41.2) nmol/L (men: 49.7 [45.8] nmol/L; women: 13.8 [6.1] nmol/L). Before switching to pegunigalsidase alfa, mean (standard error [SE]) annualized eGFR slope was - 5.90 (1.34) mL/min/1.73 m 2 /year; 12 months post-switch, the mean eGFR slope was - 1.19 (1.77) mL/min/1.73 m 2 /year; and mean plasma lyso-Gb 3 reduced by 31%. Seven (35%) out of 20 patients were positive for pegunigalsidase alfa antidrug antibodies (ADAs) at ≥ 1 study timepoint, two of whom had pre-existing ADAs at baseline. Mean (SE) changes in eGFR slope for ADA-positive and ADA-negative patients were + 5.47 (3.03) and + 4.29 (3.15) mL/min/1.73 m 2 /year, respectively, suggesting no negative impact of anti-pegunigalsidase alfa ADAs on eGFR slope., Conclusion: Pegunigalsidase alfa may offer a safe and effective treatment option for patients with FD, including those previously treated with agalsidase alfa. TRN: NCT03018730. Date of registration: January 2017., (© 2023. Institut National de la Santé et de la Recherche Médicale (INSERM).)

Introduction: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by enzyme deficiency, leading to glycosphingolipid accumulation. Cardiac accumulation triggers local tissue injury, electrical instability and arrhythmia. Bradyarrhythmia and atrial fibrillation (AF) incidence are reported in up to 16% and 13%, respectively., Objective: We conducted a systematic review evaluating AF burden and bradycardia requiring permanent pacemaker (PPM) implantation and report any predictive risk factors identified., Methods: We conducted a literature search on studies in adults with FD published from inception to July 2019. Study outcomes included AF or bradycardia requiring therapy. Databases included Embase, Medline, PubMed, Web of Science, CINAHL and Cochrane. The Risk of Bias Agreement tool for Non-Randomised Studies (RoBANS) was utilised to assess bias across key areas., Results: 11 studies were included, eight providing data on AF incidence or PPM implantation. Weighted estimate of event rates for AF were 12.2% and 10% for PPM. Age was associated with AF (OR 1.05-1.20 per 1-year increase in age) and a risk factor for PPM implantation (composite OR 1.03). Left ventricular hypertrophy (LVH) was associated with AF and PPM implantation., Conclusion: Evidence supporting AF and bradycardia requiring pacemaker implantation is limited to single-centre studies. Incidence is variable and choice of diagnostic modality plays a role in detection rate. Predictors for AF (age, LVH and atrial dilatation) and PPM (age, LVH and PR/QRS interval) were identified but strength of association was low. Incidence of AF and PPM implantation in FD are variably reported with arrhythmia burden likely much higher than previously thought., Prospero Database: CRD42019132045., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Venglustat inhibits the enzymatic conversion of ceramide to glucosylceramide, reducing available substrate for the synthesis of more complex glycosphingolipids. It offers a potential new approach to the treatment of patients with Fabry disease (α-Gal A deficiency), in whom progressive accumulation of such glycosphingolipids, including globotriaosylceramide (GL-3), in the lysosomes of a wide range of cell types often leads to vital organ complications in adulthood. An international, open-label, single-arm, Phase 2a uncontrolled 26-week clinical study (NCT02228460) and a 130-week extension study (NCT02489344) were conducted to assess the safety, pharmacodynamics, pharmacokinetics, and exploratory efficacy of 15 mg once daily oral venglustat in treatment-naïve adult male patients with classic Fabry disease. Of 11 patients (18-37 years old) who initially enrolled, nine completed the 26-week study and seven completed the extension study. A total of 169 treatment-emergent adverse events (TEAEs) were reported by nine patients, the majority being mild (73%) and unrelated to the study drug (70%). Nine serious TEAEs (serious adverse events) and 11 severe TEAEs, including a self-harm event, were reported. No deaths or treatment-related life-threatening adverse events were reported. Skin GL-3 scores in superficial skin capillary endothelium (SSCE), estimated by light microscopy, were unchanged from baseline at Week 26 in five patients, decreased in three patients, and increased in one patient. There was no significant change in GL-3 scores or significant shift in grouped GL-3 scores. Five of six patients had reductions from baseline in GL-3 score at the end of the extension study. At Weeks 26 and 156 the mean (standard deviation) changes from baseline in the fraction of the volume of SSCE cytoplasm occupied by GL-3 inclusions, measured by electron microscopy unbiased stereology, were - 0.06 (0.03) (p = 0.0010) and - 0.12 (0.04) (p = 0.0008), respectively. Venglustat treatment reduced markers in the synthetic and degradative pathway of major glycosphingolipids; proximal markers reduced rapidly and more distal markers (plasma GL-3 and globotriaosylsphingosine) reduced progressively. There were no biochemical or histological indications of progression of Fabry disease over 3 years of follow-up. These findings confirm target engagement and the pharmacodynamic effects of venglustat in adult males with classic Fabry disease. However, further clinical evaluation in larger studies is needed to determine efficacy and safety., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Fabry disease (FD) is a treatable X-linked condition leading to progressive cardiac disease, arrhythmia and premature death. We aimed to increase awareness of the arrhythmogenicity of Fabry cardiomyopathy, by comparing device usage in patients with Fabry cardiomyopathy and sarcomeric HCM. All Fabry patients with an implantable cardioverter defibrillator (ICD) implanted in the UK over a 17 year period were included. A comparator group of HCM patients, with primary prevention ICD implantation, were captured from a regional registry database., Results: Indications for ICD in FD varied with 72% implanted for primary prevention based on multiple potential risk factors. In FD and HCM primary prevention devices, arrhythmia occurred more frequently in FD over shorter follow-up (HR 4.2, p < 0.001). VT requiring therapy was more common in FD (HR 4.5, p = 0.002). Immediate shock therapy for sustained VT was also more common (HR 2.5, p < 0.001). There was a greater burden of AF needing anticoagulation and NSVT in FD (AF: HR 6.2, p = 0.004, NSVT: HR 3.1, p < 0.001)., Conclusion: This study demonstrates arrhythmia burden and ICD usage in FD is high, suggesting that Fabry cardiomyopathy may be more 'arrhythmogenic' than previously thought. Existing risk models cannot be mutually applicable and further research is needed to provide clarity in managing Fabry patients with cardiac involvement., (© 2022. The Author(s).)

Aims: Cardiac involvement in Fabry disease (FD) occurs prior to left ventricular hypertrophy (LVH) and is characterized by low myocardial native T1 with sphingolipid storage reflected by cardiovascular magnetic resonance (CMR) and electrocardiogram (ECG) changes. We hypothesize that a pre-storage myocardial phenotype might occur even earlier, prior to T1 lowering., Methods and Results: FD patients and age-, sex-, and heart rate-matched healthy controls underwent same-day ECG with advanced analysis and multiparametric CMR [cines, global longitudinal strain (GLS), T1 and T2 mapping, stress perfusion (myocardial blood flow, MBF), and late gadolinium enhancement (LGE)]. One hundred and fourteen Fabry patients (46 ± 13 years, 61% female) and 76 controls (49 ± 15 years, 50% female) were included. In pre-LVH FD (n = 72, 63%), a low T1 (n = 32/72, 44%) was associated with a constellation of ECG and functional abnormalities compared to normal T1 FD patients and controls. However, pre-LVH FD with normal T1 (n = 40/72, 56%) also had abnormalities compared to controls: reduced GLS (-18 ± 2 vs. -20 ± 2%, P < 0.001), microvascular changes (lower MBF 2.5 ± 0.7 vs. 3.0 ± 0.8 mL/g/min, P = 0.028), subtle T2 elevation (50 ± 4 vs. 48 ± 2 ms, P = 0.027), and limited LGE (%LGE 0.3 ± 1.1 vs. 0%, P = 0.004). ECG abnormalities included shorter P-wave duration (88 ± 12 vs. 94 ± 15 ms, P = 0.010) and T-wave peak time (Tonset - Tpeak; 104 ± 28 vs. 115 ± 20 ms, P = 0.015), resulting in a more symmetric T wave with lower T-wave time ratio (Tonset - Tpeak)/(Tpeak - Tend) (1.5 ± 0.4 vs. 1.8 ± 0.4, P < 0.001) compared to controls., Conclusion: FD has a measurable myocardial phenotype pre-LVH and pre-detectable myocyte storage with microvascular dysfunction, subtly impaired GLS and altered atrial depolarization and ventricular repolarization intervals., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background Cardiovascular magnetic resonance can demonstrate myocardial processes in Fabry disease (FD), such as low native T1 (sphingolipid storage) and late gadolinium enhancement (LGE, scar). Recently, high T2 (edema) has been observed in the basal inferolateral wall along with troponin elevation. We hypothesized that edema and myocyte injury would be chronically associated and have electrical, mechanical, and disease associations in FD. Methods A prospective international multicenter study was conducted on 186 consecutive FD patients (45.2±1.1 years, 58% females). Additionally, 28 patients with hypertrophic cardiomyopathy, 30 with chronic myocardial infarction and 59 healthy volunteers were included. All study participants underwent comprehensive cardiovascular magnetic resonance with T1 and T2 mapping, cines, and LGE imaging. Results LGE in the basal inferolateral wall in FD had T2 elevation (FD 58.2±5.0 ms versus hypertrophic cardiomyopathy 55.6±4.3 ms, chronic myocardial infarction 53.7±3.4 ms and healthy volunteers 48.9±2.5 ms, P <0.001), but when LGE was present there was also global T2 elevation (53.1±2.9 versus 50.6±2.2 ms, P <0.001). Thirty-eight percent of FD patients had high troponin. The strongest predictor of increased troponin was high basal inferolateral wall T2 (odds ratio, 18.2 [95% CI, 3.7-90.9], P <0.0001). Both T2 and troponin elevations were chronic over 1 year. High basal inferolateral wall T2 was associated with baseline global longitudinal strain impairment ( P =0.005) and electrocardiographic abnormalities (long PR, complete bundle branch block, left ventricular hypertrophy voltage criteria, long QTc, and T-wave inversion, all P <0.05) and predicted clinical worsening after 1 year (Fabry stabilization index >20%, P =0.034). Conclusions LGE in Fabry has chronic local T2 elevation that is strongly associated with chronic troponin elevation. In addition, there is slight global T2 elevation. Both are associated with ECG and mechanical changes and clinical worsening over 1 year.

Background: Fabry disease (FD) is a genetic disorder caused by defective α-galactosidase-A enzyme due to mutations in the GLA gene. A reliable diagnosis in classical FD males can be made by measuring the enzyme activity while diagnosing classical FD females and non-classical FD patients requires mutation analysis. Plasma globotriaosylsphingosine (Lyso-Gb 3 ) has progressively gained more importance as a diagnostic biomarker for FD in recent years. Having another biomarker to complement plasma Lyso-Gb 3 will increase the diagnostic accuracy in the era of mass screening, and also precision medicine. This study aims to highlight the clinical utility of the total concentration of urinary Lyso-Gb 3 plus its analogues in diagnosing FD., Method: Random urine samples collected from 42 FD patients and 48 healthy individuals. Lyso-Gb 3 and its analogues were enriched by solid phase extraction and analysed by liquid chromatography tandem mass spectrometry., Results: The total concentration of Lyso-Gb 3 plus its analogues in classical FD male and female patients were 1124.4 ± 181.2 and 308.6 ± 78.6 pmol/mmol creat., respectively. The levels in non-classical FD male and female patients were 229.2 ± 169.4 and 314.4 ± 156.4 pmol/mmol creat., respectively. Urinary Lyso-Gb 3 and its analogues were virtually undetectable in healthy volunteers making it 100% specific for FD diagnosis. For FD male and female patients, total concentration of urinary Lyso-Gb 3 plus its analogue levels ≥0.25 pmol/mmol creat. yielded a diagnostic sensitivity and specificity of 100% (AUC = 1, p < 0.00001)., Conclusions: Our study findings support that the total concentration of Lyso-Gb 3 plus its analogues in urine is specific to FD and may provide extra diagnostic utility for both classical and non-classical FD patients., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Fabry disease is a treatable X-linked condition leading to progressive cardiomyopathy, arrhythmia and premature death. Atrial and ventricular arrhythmias contribute significantly to adverse prognosis; however, guidance to determine which patients require cardiovascular implantable electronic devices (CIEDs) is sparse. We aimed to evaluate indications for implantation practice in the UK and quantify device utilisation., Methods: In this retrospective study, we included demographic, clinical and imaging data from patients in four of the largest UK Fabry centres. Ninety patients with Fabry disease were identified with CIEDs implanted between June 2001 and February 2018 (FD-CIED group). To investigate differences in clinical and imaging markers between those with and without devices, these patients were compared with 276 patients without a CIED (FD-control)., Results: In the FD-CIED group, 92% of patients with permanent pacemakers but only 28% with implantable cardioverter-defibrillators had a class 1 indication for implantation. A further 44% of patients had defibrillators inserted for primary prevention outside of current guidance. The burden of arrhythmia requiring treatment in the FD-CIED group was high (asymptomatic atrial fibrillation:29%; non-sustained ventricular tachycardia requiring medical therapy alone: 26%; sustained ventricular tachycardia needing anti-tachycardia pacing/defibrillation: 28%). Those with devices were older, had greater LV mass, more scar tissue and larger atrial size., Conclusions: Arrhythmias are common in Fabry patients. Those with cardiac devices had high rates of atrial fibrillation requiring anticoagulation and ventricular arrhythmia needing device treatment. These are as high as those in hypertrophic cardiomyopathy, supporting the need for Fabry-specific indications for device implantation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by BMJ.)

Background: Cardiac response to enzyme replacement therapy (ERT) in Fabry disease is typically assessed by measuring left ventricular mass index using echocardiography or cardiovascular magnetic resonance, but neither quantifies myocardial biology. Low native T1 in Fabry disease represents sphingolipid accumulation; late gadolinium enhancement with high T2 and troponin elevation reflects inflammation. We evaluated the effect of ERT on myocardial storage, inflammation, and hypertrophy., Methods: Twenty patients starting ERT (60% left ventricular hypertrophy-positive) were compared with 18 patients with early disease and 18 with advanced disease over 1 year at 3 centers. Cardiovascular magnetic resonance (left ventricular mass index, T1, T2, global longitudinal strain, and late gadolinium enhancement) and biomarkers (high-sensitive troponin-T and NT-proBNP [N-terminal Pro-B-type natriuretic peptide]) at baseline (pre-ERT) and 12 months were performed. Early disease controls were stable, treatment-naïve patients (mainly left ventricular hypertrophy-negative); advanced disease controls were stable, established ERT patients (mainly left ventricular hypertrophy-positive)., Results: Over 1 year, early disease controls increased maximum wall thickness and left ventricular mass index (9.8±2.7 versus 10.2±2.6 mm; P =0.010; 65±15 versus 67±16 g/m 2 ; P =0.005) and native T1 fell (981±58 versus 959±61 ms; P =0.002). Advanced disease controls increased T2 in the late gadolinium enhancement area (57±6 versus 60±7 ms; P =0.023) with worsening global longitudinal strain (-13.2±3.4 versus -12.1±4.8; P =0.039). Newly treated patients had a small reduction in maximum wall thickness (14.8±5.9 versus 14.4±5.7 mm; P =0.028), stable left ventricular mass index (93±42 versus 92±40 g/m 2 ; P =0.186) and a reduction in T1 lowering (917±49 versus 931±54 ms; P =0.017)., Conclusions: Fabry myocardial phenotype development is different at different disease stages. After 1 year of ERT initiation, left ventricular hypertrophy-positive patients have a detectable, small reduction in left ventricular mass and storage.

Background: Fabry disease (FD) is a genetic disorder caused by a deficiency in the enzyme alpha-galactosidase A, leading to an accumulation of glycosphingolipids in tissues across the body. Cardiac disease is the leading cause of morbidity and mortality. Advanced disease, characterised by extensive left ventricular hypertrophy, ventricular dysfunction and fibrosis, is known to be associated with an increase in arrhythmia. Data identifying risk factors for arrhythmia are limited, and no Fabry-specific risk stratification tool is available to select those who may benefit from initiation of medical or device therapy (implantable cardiac defibrillators). Current monitoring strategies have a limited diagnostic yield, and implantable loop recorders (ILRs) have the potential to change treatment and clinical outcomes., Aim: The aim of this study is to determine whether ILRs can (1) improve arrhythmia detection in FD and (2) identify risk predictors of arrhythmia., Methods: A prospective, 5-year, open-label, international, multi-centre randomised controlled trial of a minimum of 164 participants with genetically or enzymatically confirmed FD (or both) who have evidence of cardiac disease will be recruited from five centres: Queen Elizabeth Hospital, Birmingham, UK; Salford Royal Hospital, Salford, UK; Royal Free Hospital, London, UK; Addenbrookes Hospital, Cambridge, UK; and Westmead Hospital, Sydney, Australia. Participants will be block-randomised (1:1) to two study arms for cardiac monitoring (i) control arm: standard of care with annual 24 h or 5-day Holter monitor or (ii) treatment arm: continuous cardiac monitoring with ILR implantation plus standard of care. Participants will undergo multiple investigations-blood/urine biomarkers, 12-lead and advanced electrocardiogram (ECG) recording, echocardiography and cardiovascular magnetic resonance (CMR) imaging-at baseline and 6-12 monthly follow-up visits. The primary endpoint is identification of arrhythmia requiring initiation or alteration in therapy. Secondary outcome measures include characterising the risk factors associated with arrhythmia and outcome data in the form of imaging, ECG and blood biomarkers., Discussion: This is the first study evaluating arrhythmia burden and the use of ILR across the spectrum of risk profiles in Fabry cardiomyopathy. This will enable detailed characterisation of arrhythmic risk predictors in FD and ultimately support formulation of Fabry-specific guidance in this high-risk population., Trial Registration: ClinicalTrials.gov ( NCT03305250 ). Registered on 9 October 2017.

Introduction: Detecting early cardiac involvement in Fabry disease (FD) is important because therapy may alter disease progression. Cardiovascular magnetic resonance (CMR) can detect T1 lowering, representing myocardial sphingolipid storage. In many diseases, early mechanical dysfunction may be detected by abnormal global longitudinal strain (GLS). We explored the relationship of early mechanical dysfunction and sphingolipid deposition in FD., Methods: An observational study of 221 FD and 77 healthy volunteers (HVs) who underwent CMR (LV volumes, mass, native T1, GLS, late gadolinium enhancement), ECG and blood biomarkers, as part of the prospective multicentre Fabry400 study., Results: All FD had normal LV ejection fraction (EF 73%±8%). Mean indexed LV mass (LVMi) was 89±39 g/m 2 in FD and 55.6±10 g/m 2 in HV. 102 (46%) FD participants had left ventricular hypertrophy (LVH). There was a negative correlation between GLS and native T1 in FD patients (r=-0.515, p<0.001). In FD patients without LVH (early disease), as native T1 reduced there was impairment in GLS (r=-0.285, p<0.002). In the total FD cohort, ECG abnormalities were associated with a significant impairment in GLS compared with those without ECG abnormalities (abnormal: -16.7±3.5 vs normal: -20.2±2.4, p<0.001)., Conclusions: GLS in FD correlates with an increase in LVMi, storage and the presence of ECG abnormalities. In LVH-negative FD (early disease), impairment in GLS is associated with a reduction in native T1, suggesting that mechanical dysfunction occurs before evidence of sphingolipid deposition (low T1)., Trial Registration Number: NCT03199001; Results., Competing Interests: Competing interests: RK has received honoraria from Sanofi-Genzyme., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A enzyme. Cardiovascular (CV) disease is a common cause of mortality in FD, in particular as a result of heart failure and arrhythmia, with a significant proportion of events categorized as sudden. There are no clear models for risk prediction in FD. This systematic review aims to identify the risk factors for ventricular arrhythmia (VA) and sudden cardiac deaths (SCD) in FD. A systematic search was performed following PRISMA guidelines of EMBASE, Medline, PubMed, Web of Science, and Cochrane from inception to August 2016, focusing on identification of risk factors for the development of VA or SCD. Thirteen studies were included in the review (n = 4185 patients) from 1189 articles, with follow-up of 1.2-10 years. Weighted average age was 37.6 years, and 50% were male. Death from any cause was reported in 8.3%. Of these, 75% was due to CV problems, with the majority being SCD events (62% of reported deaths). Ventricular tachycardia was reported in 7 studies, with an average prevalence of 15.3%. Risk factors associated with SCD events were age, male gender, left ventricular hypertrophy, late gadolinium enhancement on CV magnetic resonance imaging, and non-sustained ventricular tachycardia. Although a multi-system disease, FD is a predominantly cardiac disease from a mortality perspective, with death mainly from SCD events. Limited evidence highlights the importance of clinical and imaging risk factors that could contribute to improved decision-making in the management of FD.

Background: Fabry disease (FD) is a rare and treatable X-linked lysosomal storage disorder. Cardiac involvement determines outcomes; therefore, detecting early changes is important. Native T1 by cardiovascular magnetic resonance is low, reflecting sphingolipid storage. Early phenotype development is familiar in hypertrophic cardiomyopathy but unexplored in FD. We explored the prehypertrophic cardiac phenotype of FD and the role of storage., Methods and Results: A prospective, international multicenter observational study of 100 left ventricular hypertrophy-negative FD patients (mean age: 39±15 years; 19% male) and 35 age- and sex-matched healthy volunteers (mean age: 40±14 years; 25% male) who underwent cardiovascular magnetic resonance, including native T1 and late gadolinium enhancement, and 12-lead ECG. In FD, 41% had a low native T1 using a single septal region of interest, but this increased to 59% using a second slice because early native T1 lowering was patchy. ECG abnormalities were present in 41% and twice as common with low native T1 (53% versus 24%; P =0.005). When native T1 was low, left ventricular maximum wall thickness, indexed mass, and ejection fraction were higher (maximum wall thickness 9±1.5 versus 8±1.4 mm, P <0.005; indexed left ventricular mass 63±10 versus 58±9 g/m 2 , P <0.05; and left ventricular ejection fraction 73±8% versus 69±7%, P <0.01). Late gadolinium enhancement was more likely when native T1 was low (27% versus 6%; P =0.01). FD had higher maximal apical fractal dimensions compared with healthy volunteers (1.27±0.06 versus 1.24±0.04; P <0.005) and longer anterior mitral valve leaflets (23±2 mm versus 21±3 mm; P <0.005)., Conclusions: There is a detectable prehypertrophic phenotype in FD consisting of storage (low native T1), structural, functional, and ECG changes., (© 2018 The Authors.)

Fabry disease (FD) is a multi-systemic X-linked lysosomal disorder caused by the deficient activity of α-galactosidase-A enzyme, which leads to accumulation of glycosphingolipids in various body tissues. The N215S mutation is a known variant of FD, with a late onset cardiac phenotype. Consensus guidelines acknowledged the use of globotriaosylsphingosine (Lyso-Gb 3 ) as a diagnostic marker for classical FD but its utility for cardiac variant FD is not clear. We aim to characterize the clinical features and evaluate the diagnostic accuracy of plasma and urinary Lyso-Gb 3 levels in N215S cardiac variant FD patients. Thirty-four FD patients with the late-onset N215S cardiac variant mutation were enrolled along with 62 classical FD patients and 109 healthy controls. Plasma and urinary Lyso-Gb 3 and its analogues were analyzed by LC-MS/MS. Both FD males and females with N215S mutation showed Lyso-Gb 3 levels of (mean ± SEM) 9.7 ± 1.0 and 5.4 ± 0.8 nM, respectively. These levels were significantly higher than healthy control and lower than classical FD patients (p < 0.0001). Plasma Lyso-Gb 3 levels equal to or higher than 2.7 nM yielded a diagnostic sensitivity and specificity of 100% (AUC = 1, p < 0.0001). Cardiac involvement was frequent with 16/34 (47%) developing left ventricular hypertrophy. Three patients who underwent renal biopsy had the characteristic sphingolipid deposition in the podocytes while 6/19 (32%) had evidence of white matter changes or infarct on brain MRI. Taken together, cardiac variant N215S mutation is rather an attenuated form of classical FD. Plasma Lyso-Gb 3 is a diagnostic hallmark to differentiate N215S variant phenotype from subjects with no FD.

Fabry disease is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A, resulting in the accumulation of glycosphingolipids in various organs. Globotriaosylceramide (Gb3) and its isoforms and analogues have been identified and quantified as biomarkers of disease severity and treatment efficacy. The current study aimed to establish rapid methods for urinary Gb3 extraction and quantitation. Urine samples from 15 Fabry patients and 21 healthy control subjects were processed to extract Gb3 by mixing equal volumes of urine, methanol containing an internal standard, and chloroform followed by sonication and centrifugation. Thereafter, the lower phase was analyzed by MALDI-TOF MS and the relative peak areas of the internal standard and four major species of Gb3 determined. The results showed high reproducibility with intra- and inter-assay coefficients variation of 9.9% and 13.7%, respectively. The limit of detection was 0.15 ng/μL and the limit of quantitation was 0.30 ng/μL. Total urinary Gb3 levels in both genders of classic Fabry patients were significantly higher than in healthy controls (p < 0.0001). Gb3 levels in Fabry males were higher than in Fabry females (p = 0.08). We have established a novel assay for urinary total Gb3 that takes less than 15 min from start to finish. Graphical Abstract ᅟ.

Introduction: Fabry disease (FD) is a lysosomal storage disorder resulting in progressive nervous system, kidney and heart disease. Enzyme replacement therapy (ERT) may halt or attenuate disease progression. Since administration is burdensome and expensive, appropriate use is mandatory. We aimed to define European consensus recommendations for the initiation and cessation of ERT in patients with FD., Methods: A Delphi procedure was conducted with an online survey (n = 28) and a meeting (n = 15). Patient organization representatives were present at the meeting to give their views. Recommendations were accepted with ≥75% agreement and no disagreement., Results: For classically affected males, consensus was achieved that ERT is recommended as soon as there are early clinical signs of kidney, heart or brain involvement, but may be considered in patients of ≥16 years in the absence of clinical signs or symptoms of organ involvement. Classically affected females and males with non-classical FD should be treated as soon as there are early clinical signs of kidney, heart or brain involvement, while treatment may be considered in females with non-classical FD with early clinical signs that are considered to be due to FD. Consensus was achieved that treatment should not be withheld from patients with severe renal insufficiency (GFR < 45 ml/min/1.73 m(2)) and from those on dialysis or with cognitive decline, but carefully considered on an individual basis. Stopping ERT may be considered in patients with end stage FD or other co-morbidities, leading to a life expectancy of <1 year. In those with cognitive decline of any cause, or lack of response for 1 year when the sole indication for ERT is neuropathic pain, stopping ERT may be considered. Also, in patients with end stage renal disease, without an option for renal transplantation, in combination with advanced heart failure (NYHA class IV), cessation of ERT should be considered. ERT in patients who are non-compliant or fail to attend regularly at visits should be stopped., Conclusion: The recommendations can be used as a benchmark for initiation and cessation of ERT, although final decisions should be made on an individual basis. Future collaborative efforts are needed for optimization of these recommendations.

Fabry disease (FD) is a rare X-linked lysosomal storage disorder manifesting as progressive multi-organ accumulation of sphingolipids due to deficiency in the enzyme α-Galactosidase A. Sphingolipid accumulation can take place in all cardiac cell types which manifests as left ventricular hypertrophy, microvascular ischaemia, conduction abnormalities, arrhythmia, heart failure, and valvular disease. The use of advanced cardiovascular imaging techniques have enabled clinicians to stage and prognosticate the disease and guide therapy. Transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) in conjunction are the hallmark imaging modalities to allow for this assessment. Traditionally, the assessment of cardiac involvement in FD was based on the assessment of maximal wall thickness (MWT) and the development of left ventricular hypertrophy (LVH). It is now understood that sphingolipid accumulation takes place before the development of LVH. Advances in techniques within TTE and CMR, particularly that of strain assessment and T1/T2 mapping, have meant that Fabry cardiomyopathy (FCM) can be diagnosed earlier in the disease process. This potentially provides a window for initiation of enzyme replacement therapy (ERT) at a stage where it is likely to have the most beneficial effect in reducing the high mortality associated with FCM. This review outlines the advances in multimodality imaging in staging and prognosticating FCM, as well as the applications of cardiac imaging in assessing symptoms and complications of FCM. [ABSTRACT FROM AUTHOR]

Aims Cardiac involvement in Fabry disease (FD) occurs prior to left ventricular hypertrophy (LVH) and is characterized by low myocardial native T1 with sphingolipid storage reflected by cardiovascular magnetic resonance (CMR) and electrocardiogram (ECG) changes. We hypothesize that a pre-storage myocardial phenotype might occur even earlier, prior to T1 lowering. Methods and results FD patients and age-, sex-, and heart rate-matched healthy controls underwent same-day ECG with advanced analysis and multiparametric CMR [cines, global longitudinal strain (GLS), T1 and T2 mapping, stress perfusion (myocardial blood flow, MBF), and late gadolinium enhancement (LGE)]. One hundred and fourteen Fabry patients (46 ± 13 years, 61% female) and 76 controls (49 ± 15 years, 50% female) were included. In pre-LVH FD (n  = 72, 63%), a low T1 (n  = 32/72, 44%) was associated with a constellation of ECG and functional abnormalities compared to normal T1 FD patients and controls. However, pre-LVH FD with normal T1 (n  = 40/72, 56%) also had abnormalities compared to controls: reduced GLS (−18 ± 2 vs. −20 ± 2%, P  < 0.001), microvascular changes (lower MBF 2.5 ± 0.7 vs. 3.0 ± 0.8 mL/g/min, P  = 0.028), subtle T2 elevation (50 ± 4 vs. 48 ± 2 ms, P  = 0.027), and limited LGE (%LGE 0.3 ± 1.1 vs. 0%, P  = 0.004). ECG abnormalities included shorter P-wave duration (88 ± 12 vs. 94 ± 15 ms, P  = 0.010) and T-wave peak time (T onset – T peak; 104 ± 28 vs. 115 ± 20 ms, P  = 0.015), resulting in a more symmetric T wave with lower T-wave time ratio (T onset – T peak)/(T peak – T end) (1.5 ± 0.4 vs. 1.8 ± 0.4, P  < 0.001) compared to controls. Conclusion FD has a measurable myocardial phenotype pre-LVH and pre-detectable myocyte storage with microvascular dysfunction, subtly impaired GLS and altered atrial depolarization and ventricular repolarization intervals. [ABSTRACT FROM AUTHOR]

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A enzyme. Cardiovascular (CV) disease is a common cause of mortality in FD, in particular as a result of heart failure and arrhythmia, with a significant proportion of events categorized as sudden. There are no clear models for risk prediction in FD. This systematic review aims to identify the risk factors for ventricular arrhythmia (VA) and sudden cardiac deaths (SCD) in FD. A systematic search was performed following PRISMA guidelines of EMBASE, Medline, PubMed, Web of Science, and Cochrane from inception to August 2016, focusing on identification of risk factors for the development of VA or SCD. Thirteen studies were included in the review (n = 4185 patients) from 1189 articles, with follow-up of 1.2-10 years. Weighted average age was 37.6 years, and 50% were male. Death from any cause was reported in 8.3%. Of these, 75% was due to CV problems, with the majority being SCD events (62% of reported deaths). Ventricular tachycardia was reported in 7 studies, with an average prevalence of 15.3%. Risk factors associated with SCD events were age, male gender, left ventricular hypertrophy, late gadolinium enhancement on CV magnetic resonance imaging, and non-sustained ventricular tachycardia. Although a multi-system disease, FD is a predominantly cardiac disease from a mortality perspective, with death mainly from SCD events. Limited evidence highlights the importance of clinical and imaging risk factors that could contribute to improved decision-making in the management of FD. [ABSTRACT FROM AUTHOR]