Effect of Migalastat on cArdiac InvOlvement in FabRry DiseAse: MAIORA study.

BACKGROUND: A small but significant reduction in left ventricular (LV) mass after 18 months of migalastat treatment has been reported in Fabry disease (FD). This study aimed to assess the effect of migalastat on FD cardiac involvement, combining LV morphology and tissue characterisation by cardiac magnetic resonance (CMR) with cardiopulmonary exercise testing (CPET). METHODS: Sixteen treatment-naïve patients with FD (4 women, 46.4±16.2 years) with cardiac involvement (reduced T1 values on CMR and/or LV hypertrophy) underwent ECG, echocardiogram, troponin T and NT-proBNP (N-Terminal prohormone of Brain Natriuretic Peptide) assay, CMR with T1 mapping, and CPET before and after 18 months of migalastat. RESULTS: No change in LV mass was detected at 18 months compared to baseline (95.2 g/m2 (66.0-184.0) vs 99.0 g/m2 (69.0-121.0), p=0.55). Overall, there was an increase in septal T1 of borderline significance (870.0 ms (848-882) vs 860.0 ms (833.0-875.0), p=0.056). Functional capacity showed an increase in oxygen consumption (VO2) at anaerobic threshold (15.50 mL/kg/min (13.70-21.50) vs 14.50 mL/kg/min (11.70-18.95), p=0.02), and a trend towards an increase in percent predicted peak VO2 (72.0 (63.0-80.0) vs 69.0 (53.0-77.0), p=0.056) was observed. The subset of patients who showed an increase in T1 value and a reduction in LV mass (n=7, 1 female, age 40.5 (28.6-76.0)) was younger and at an earlier disease stage compared to the others, and also exhibited greater improvement in exercise tolerance. CONCLUSION: In treatment-naïve FD patients with cardiac involvement, 18-month treatment with migalastat stabilised LV mass and was associated with a trend towards an improvement in exercise tolerance. A tendency to T1 increase was detected by CMR. The subset of patients who had significant benefits from the treatment showed an earlier cardiac disease compared to the others. TRIAL REGISTRATION NUMBER: NCT03838237.

IN VIVO OBSERVATION OF RETINAL VASCULAR DEPOSITS USING ADAPTIVE OPTICS IMAGING IN FABRY DISEASE.

PURPOSE: To report a novel finding in patients with Fabry disease, that is, the observation by adaptive optics ophthalmoscopy of intracellular lipidic deposits in retinal vessels. METHODS: Observational two-center case series. Eighteen patients with genetically proven Fabry disease underwent flood-illumination adaptive optics ophthalmoscopy imaging (rtx1; Imagine Eyes, Orsay, France) of retinal vessels. RESULTS: Fourteen patients (78% of all patients; 7 of the 10 women and 7 of the 8 men) showed paravascular punctuate or linear opacities in both eyes. In the least-affected patients, these were seen only in the wall of precapillary arterioles as discrete spots of 5 µm to 10 µm large, whereas in those more severely affected, capillaries and first-order vessels were also involved with diffuse opacification of the wall. These deposits sometime showed a striated pattern, suggesting colocalization with vascular smooth muscle cells. CONCLUSION: Adaptive optics ophthalmoscopy of retinal vessels may be of interest for patients with Fabry disease, providing noninvasive, gradable evaluation of microvascular involvement.

International External Validation Study of the 2014 European Society of Cardiology Guidelines on Sudden Cardiac Death Prevention in Hypertrophic Cardiomyopathy (EVIDENCE-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.

Defining the diagnostic effectiveness of genes for inclusion in panels: the experience of two decades of genetic testing for hypertrophic cardiomyopathy at a single center.

PURPOSE: Genetic testing in hypertrophic cardiomyopathy (HCM) has long relied on Sanger sequencing of sarcomeric genes. The advent of next-generation sequencing (NGS) has catalyzed routine testing of additional genes of dubious HCM-causing potential. We used 19 years of genetic testing results to define a reliable set of genes implicated in Mendelian HCM and assess the value of expanded NGS panels. METHODS: We dissected genetic testing results from 1,198 single-center HCM probands and devised a widely applicable score to identify which genes yield effective results in the diagnostic setting. RESULTS: Compared with early panels targeting only fully validated sarcomeric HCM genes, expanded NGS panels allow the prompt recognition of probands with HCM-mimicking diseases. Scoring by "diagnostic effectiveness" highlighted that PLN should also be routinely screened besides historically validated genes for HCM and its mimics. CONCLUSION: The additive value of expanded panels in HCM genetic testing lies in the systematic screening of genes associated with HCM mimics, requiring different patient management. Only variants in a limited set of genes are highly actionable and interpretable in the clinic, suggesting that larger panels offer limited additional sensitivity. A score estimating the relative effectiveness of a given gene's inclusion in diagnostic panels is proposed.

A Finite Element Model of Cerebral Vascular Injury for Predicting Microbleeds Location.

Finite Element (FE) models of brain mechanics have improved our understanding of the brain response to rapid mechanical loads that produce traumatic brain injuries. However, these models have rarely incorporated vasculature, which limits their ability to predict the response of vessels to head impacts. To address this shortcoming, here we used high-resolution MRI scans to map the venous system anatomy at a submillimetre resolution. We then used this map to develop an FE model of veins and incorporated it in an anatomically detailed FE model of the brain. The model prediction of brain displacement at different locations was compared to controlled experiments on post-mortem human subject heads, yielding over 3,100 displacement curve comparisons, which showed fair to excellent correlation between them. We then used the model to predict the distribution of axial strains and strain rates in the veins of a rugby player who had small blood deposits in his white matter, known as microbleeds, after sustaining a head collision. We hypothesised that the distribution of axial strain and strain rate in veins can predict the pattern of microbleeds. We reconstructed the head collision using video footage and multi-body dynamics modelling and used the predicted head accelerations to load the FE model of vascular injury. The model predicted large axial strains in veins where microbleeds were detected. A region of interest analysis using white matter tracts showed that the tract group with microbleeds had 95th percentile peak axial strain and strain rate of 0.197 and 64.9 s-1 respectively, which were significantly larger than those of the group of tracts without microbleeds (0.163 and 57.0 s-1). This study does not derive a threshold for the onset of microbleeds as it investigated a single case, but it provides evidence for a link between strain and strain rate applied to veins during head impacts and structural damage and allows for future work to generate threshold values. Moreover, our results suggest that the FE model has the potential to be used to predict intracranial vascular injuries after TBI, providing a more objective tool for TBI assessment and improving protection against it.

Standard ECG for differential diagnosis between Anderson-Fabry disease and hypertrophic cardiomyopathy.

OBJECTIVES: To evaluate the role of the ECG in the differential diagnosis between Anderson-Fabry disease (AFD) and hypertrophic cardiomyopathy (HCM). METHODS: In this multicentre retrospective study, 111 AFD patients with left ventricular hypertrophy were compared with 111 patients with HCM, matched for sex, age and maximal wall thickness by propensity score. Independent ECG predictors of AFD were identified by multivariate analysis, and a multiparametric ECG score-based algorithm for differential diagnosis was developed. RESULTS: Short PR interval, prolonged QRS duration, right bundle branch block (RBBB), R in augmented vector left (aVL) ≥1.1 mV and inferior ST depression independently predicted AFD diagnosis. A point-by-point ECG score was then derived with the following diagnostic performances: c-statistic 0.80 (95% CI 0.74 to 0.86) for discrimination, the Hosmel-Lemeshow χ2 6.14 (p=0.189) for calibration, sensitivity 69%, specificity 84%, positive predictive value 82% and negative predictive value 72%. After bootstrap resampling, the mean optimism was 0.025, and the internal validated c-statistic for the score was 0.78. CONCLUSIONS: Standard ECG can help to differentiate AFD from HCM while investigating unexplained left ventricular hypertrophy. Short PR interval, prolonged QRS duration, RBBB, R in aVL ≥1.1 mV and inferior ST depression independently predicted AFD. Their systematic evaluation and the integration in a multiparametric ECG score can support AFD diagnosis.

Optical Coherence Tomography Angiography for the Evaluation of Retinal Vasculature in Fabry Disease: Our Experience and Review of Current Knowledge.

Purpose: Optical coherence tomography angiography (OCTA) is a non-invasive and objective tool for the evaluation of the retinal microvascular changes in Fabry disease (FD). We investigated changes in retinal vasculature in FD patients, and the possible correlation with systemic parameters, by using OCTA, and reviewed the current status of literature. Methods: Thirteen FD patients (eight females, five males, mean age 49.85 ± 14.7 years) were compared with 13 age- and sex-matched healthy controls. OCTA 3 × 3 mm macular scans were performed in all subjects. We evaluated the vessel density and vessel perfusion in distinct macular areas (whole, inner, and outer) of both the superficial capillary plexus (SCP VD and SCP VP) and of the deep capillary plexus (DCP VD and DCP VP). We also evaluated the foveal avascular zone (FAZ) metrics (area, perimeter, and circularity), and correlation between systemic and OCTA parameters. A literature review on the current understanding of OCTA in FD is then presented. Results: FD patients showed significantly lower SCP VD values in the whole area (17.37 ± 2.08 mm-1 vs. 18.54 ± 1.21 mm-1; p-value 0.022), as well as in the outer area (17.46 ± 2.10 mm-1 vs. 19.08 ± 1.14 mm-1; p-value 0.002), but not in the inner. Even the DCP VD was significantly lower in all the imaged areas: whole (17.75 ± 3.93 mm-1 vs. 19.71 ± 1.20 mm-1; p-value 0.024), outer (18.25 ± 4.17 mm-1 vs. 20.33 ± 1.20 mm-1; p-value 0.023), and inner (19.54 ± 4.17 mm-1 vs. 21.96 ± 1.55 mm-1; p-value 0.011). There were no significant differences in vessel perfusion parameters (both SCP VP and DCP VP ones) and FAZ. No significant correlations were found between the OCTA parameters and systemic parameters (maximal left ventricular wall thickness and glomerular filtration rate) in FD patients. Conclusions: OCTA can be considered as a promising non-invasive tool, which enables a quantitative evaluation of retinal vascular involvement in FD, despite the varying data reported in literature. Our results support the use of OCTA as an objective tool to evaluate retinal vascular abnormalities in FD. The utility of OCTA in FD needs to be validated by longitudinal studies taking into account the overall progression of the disease.

Erratum: New insights from the application of the FAbry STabilization indEX in a large population of Fabry cases.

[This corrects the article DOI: 10.1093/ckj/sfy108.].

New insights from the application of the FAbry STabilization indEX in a large population of Fabry cases.

BACKGROUND: The FAbry STabilization indEX (FASTEX) is an innovative index allowing the assessment of clinical stability over time in Fabry disease patients. This index was developed in a population of 28 male patients with the classical form of Fabry disease. OBJECTIVES: The aim of the study was to test the accuracy of the FASTEX in evaluating Fabry disease stability in 132 male and female patients with classical and non-classical Fabry disease from nine Italian centres and it also aimed to define the sensitivity and specificity of this new tool. In particular, we aimed to investigate the correlation between the FASTEX and clinical judgement in a large-scale cohort of the study population. METHODS: Statistical methods applied to this investigation included the calculation of accuracy, specificity and sensitivity, receiver operating characteristic (ROC) curves and Cohen's κ index related to the FASTEX and clinical judgement. RESULTS: The patient population included 58 males (43.9%). The mean age of the overall population was 46.3 ± 15. 1 years (range 31.2-61.4). The median interval between the two multidisciplinary evaluations used for FASTEX calculation was 398 days. Since no gold standard method is available to define the overall clinical condition of Fabry patients over time, the results of the FASTEX were compared with clinical judgements given by the physicians involved in this study. In this way, the FASTEX classified 121 of 132 (92%) patients correctly. In particular, the FASTEX correctly identified 93% (41/44) of clinically 'unstable' and 91% (80/88) of clinically 'stable' patients. The area under the curve of the ROC related to the FASTEX index cut-off (20) was equal to 0.967, very close to its theoretical maximum (1), which means that it is an excellent test for classifying patients as 'stable' or 'unstable' compared with clinical judgement. In addition, the FASTEX cut-off >20 provides the most acceptable balance between sensitivity and specificity. The Cohen's κ index value obtained in our study was 0.82, showing a highly statistically significant P-value < 0.01 related to the agreement between the FASTEX and clinical judgement. CONCLUSIONS: The FASTEX is demonstrated here to be a specific and sensitive tool. When applied to a large cohort of Fabry patients, it was shown to be a valid instrument in helping physicians to discriminate objectively the clinical stability of individual Fabry patients.

Quantitative Analysis of Conjunctival and Retinal Vessels in Fabry Disease.

Fabry Disease (FD) is a rare X-linked lysosomal storage disorder characterized by systemic and ocular involvement. It has been described an increasing in retinal and conjunctival vessel tortuosity and this feature represents an important marker for the disease. Currently, there is not an objective method to measure and quantify this parameter. We tested a new semi-automatic software measuring retinal and conjunctival vessel tortuosity from eye fundus and conjunctival digital images in a group of FD patients. We performed an observational case-control study evaluating three mathematical parameters describing tortuosity (sum of angle metric [SOAM], product of angle distance [PAD], triangular index [I2e]) obtained from fundus and conjunctival pictures of 11 FD patients and 11 age and sex-matched controls. Both eyes were considered. Mann-Whitney test was used to compare the FD group versus the control group and, within the FD group, male versus female patients. Linear regression analysis was performed to evaluate the possible association of retinal and conjunctival vessels tortuosity parameters with age and with specific markers of systemic disease's progression. The tortuosity parameters (SOAM, PAD and I2e) were significantly higher in retinal vessels and in conjunctival nasal vessels in FD patients in comparison with the controls (p=0.003, p=0.002, p=0.001 respectively for retina) (p=0.023, p=0.014, p=0.001 respectively for nasal conjunctiva). No significant association was found between retinal and conjunctival tortuosity parameters and increasing age or systemic involvement markers. Vessel tortuosity represents an important clinical manifestation in FD. A computer-assisted analysis of retinal and conjunctival vasculature demonstrated an increased vessels tortuosity in patients affected by Fabry disease. This non-invasive technique might be useful to help the diagnosis in early stages, to establish disease severity and monitor its progression.

Effectiveness of subcutaneous implantable cardioverter-defibrillator testing in patients with hypertrophic cardiomyopathy.

BACKGROUND: Subcutaneous ICD (S-ICD) is a promising option for Hypertrophic Cardiomyopathy (HCM) patients at risk of Sudden Cardiac Death (SCD). However, its effectiveness in terminating ventricular arrhythmias in HCM is yet unresolved. METHODS: Consecutive HCM patients referred for S-ICD implantation were prospectively enrolled. Patients underwent one or two attempts of VF induction by the programmer. Successful conversion was defined as any 65J shock that terminated VF (not requiring rescue shocks). Clinical and instrumental parameters were analyzed to study predictors of conversion failure. RESULTS: Fifty HCM patients (34 males, 40±16years) with a mean BMI of 25.2±4.4kg/m2 were evaluated. Mean ESC SCD risk of was 6.5±3.9% and maximal LV wall thickness (LVMWT) was 26±6mm. In 2/50 patients no arrhythmias were inducible, while in 7 (14%) only sustained ventricular tachycardia was induced and cardioverted. In the remaining 41 (82%) patients, 73 VF episodes were induced (1 episode in 14 and >1 in 27 patients). Of these, 4 (6%) spontaneously converted. In 68/69 (98%) the S-ICD successfully cardioverted, but failed in 1 (2%) patient, who needed rescue defibrillation. This patient was severely obese (BMI 36) and LVMWT of 25mm. VF was re-induced and successfully converted by the 80J reversed polarity S-ICD. CONCLUSIONS: Acute DT at 65J at the implant showed the effectiveness of S-ICD in the recognition and termination of VT/VF in all HCM patients except one. Extreme LVH did not affect the performance of the device, whereas severe obesity was likely responsible for the single 65J failure.

Unusual gastric and pancreatic metastatic renal cell carcinoma presentation 10 years after surgery and immunotherapy: A case report and a review of literature.

Renal cell carcinoma (RCC) is the most common renal tumor, accounting for 2%-3% of all malignancies. Though RCC is known to spread hematogenously, isolated RCC metastasis to the stomach is a rare event. In this article, we describe the clinical course of a patient who developed a pancreatic recurrence of RCC and 1 year later a gastric recurrence of RCC treated 10 years ago with a resection and interleukin-2 (IL-2). Accumulating evidence indicates that metastatic involvement of the pancreas and stomach should be suspected in any patient with a history of RCC who presents with gastrointestinal symptoms even 10 years after RCC resection and immunotherapy.