Diagnostic value of left ventricular layer strain and specific regional strain patterns in cardiac amyloidosis and Fabry disease.

Aims: Layer-specific left ventricular (LV) strain alterations have been suggested as a specific finding in Fabry disease (FD). Our study aimed to assess the diagnostic value of layer-specific radial strain (RS) indices compared to the established LV regional strain pattern in cardiac amyloidosis (CA) and FD, i.e. apical sparing and posterolateral strain deficiency (PLSD). Methods and results: We retrospectively analysed the global, subendocardial, subepicardial LV radial strain, the corresponding strain gradient, as well as the regional and global longitudinal strain. The diagnostic accuracy of the diverse LV strain analyses was comparatively assessed using receiver operating characteristic curve and multivariable regression analyses. In 40 FD and 76 CA patients, CA featured more reduced layer strain values [global RS -12.3 (-15.6 to -9.6) in CA vs. -16.7 (-20.0 to -13.6) in FD; P < 0.001; subendocardial RS -22.3 (-27.4 to -15.9) vs. -28.3 (-31.8 to -23.6), P < 0.001; subepicardial RS -6.6 (-8.6 to -4.7) in CA vs. -8.9 (-11.7 to - 6.5) in FD; P < 0.001]. Global radial and longitudinal strain held an area under the curve (AUC) of 0.75 (0.66-0.84) and AUC 0.73 (0.63-0.83). While the apical sparing and PLSD strain pattern showed the highest accuracy as single parameters [AUC 0.87 (0.79-0.95) and 0.81 (0.72-0.89), P < 0.001], the combination of subendocardial RS and the apical sparing pattern featured the highest diagnostic accuracy [AUC 0.92 (0.87-0.97)]. Conclusion: Combining radial strain-derived parameters to the established strain pattern apical sparing and PLSD improve the diagnostic accuracy in the echocardiographic assessment in suspected storage disease.

Right heart and left atrial strain to differentiate cardiac amyloidosis and Fabry disease.

Echocardiographic differentiation of cardiac amyloidosis (CA) and Fabry disease (FD) is often challenging using standard echocardiographic parameters. We retrospectively analyzed the diagnostic accuracy of right heart and left atrial strain parameters to discriminate CA from FD using receiver operating characteristic curve analyses and logistic regression models. A total of 47 FD and 88 CA patients with left ventricular wall thickening were analyzed. The comparison of both cardiomyopathies revealed significantly reduced global and free wall longitudinal right ventricular strain (RVS; global RVS: CA - 13 ± 4%, n = 67, vs. FD - 18 ± 4%, n = 39, p < 0.001) as well as right atrial strain (RAS; reservoir RAS: CA 12 ± 8%, n = 70, vs. FD 26 ± 9%, n = 40, p < 0.001) and left atrial strain (LAS) in CA patients. Individually, global RVS as well as phasic LAS and RAS showed the highest diagnostic accuracy to distinguish CA and FD. The best diagnostic accuracy was achieved by combining the age, basal RV diameter, global RVS, and reservoir and conduit RAS (area under the curve 0.96 [95% CI 0.90-1.00]). Differential echocardiographic diagnostic work-up of patients with suspected CA or FD can be improved by integrating structural and functional parameters of the right heart and the left atrium.Trial registration: DRKS00027403.

Diagnostic value of papillary muscle hypertrophy and mitral valve thickness to discriminate cardiac amyloidosis and Fabry disease.

BACKGROUND: Cardiac amyloidosis (CA) and Fabry disease (FD) cause myocardial damage but may also affect the valvular and subvalvular apparatus. We aimed to evaluate the diagnostic accuracy of new echocardiographic indices including mitral valve thickness and papillary muscle (PM) hypertrophy to differentiate CA and FD. METHODS: In patients with confirmed CA and FD, a detailed assessment of valvular function, mitral valve leaflet thickness and PM area as well as PM left ventricular area ratio (PM/LV-ratio) was performed in offline analyses. Receiver operating characteristic curve analyses were conducted to determine the diagnostic accuracy of mitral valve thickness, PM hypertrophy, and PM/LV-ratio to distinguish CA from FD. RESULTS: We retrospectively analyzed a cohort of 129 patients (FD n = 49, CA n = 80). CA patients showed significantly more thickened mitral valve leaflets (4.1 ± 1.3 mm vs. 2.9 ± 1.1 mm, p < 0.001) and a higher PM area [4.0 (3.1-4.6) mm2 vs. 2.8 (2.1-4.6) mm2, p = 0.009] with a comparable PM/LV-ratio in both groups. Mitral valve thickness showed the highest diagnostic accuracy to discriminate CA [AUC 0.77 (95% CI 0.67-0.87)]. The prevalence of aortic, tricuspid, and pulmonary valve regurgitation was significantly higher in CA (aortic regurgitation ≥ II° 13% vs. 4%, tricuspid regurgitation≥ II° 19% vs. 8%, p < 0.001). CONCLUSION: Our results suggest that the assessment of mitral valve thickness may be a new useful echocardiographic parameter to differentiate CA and FD, whereas papillary muscle hypertrophy and PM/LV-ratio showed a limited diagnostic performance to discriminate CA. German clinical trials registry: DRKS00027403.

Treatment of Fabry Disease management with migalastat-outcome from a prospective 24 months observational multicenter study (FAMOUS).

AIMS: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal enzyme α-galactosidase A (GLA/AGAL), resulting in the lysosomal accumulation of globotriaosylceramide (Gb3). Patients with amenable GLA mutations can be treated with migalastat, an oral pharmacological chaperone increasing endogenous AGAL activity. In this prospective observational multicentre study, safety as well as cardiovascular, renal, and patient-reported outcomes and disease biomarkers were assessed after 12 and 24 months of migalastat treatment under 'real-world' conditions. METHODS AND RESULTS: A total of 54 patients (26 females) (33 of these [61.1%] pre-treated with enzyme replacement therapy) with amenable mutations were analysed. Treatment was generally safe and well tolerated. A total of 153 events per 1000 patient-years were detected. Overall left ventricular mass index decreased after 24 months (all: -7.5 ± 17.4 g/m2, P = 0.0118; females: -4.6 ± 9.1 g/m2, P = 0.0554; males: -9.9 ± 22.2 g/m2, P = 0.0699). After 24 months, females and males presented with a moderate yearly loss of estimated glomerular filtration rate (-2.6 and -4.4 mL/min/1.73 m2 per year; P = 0.0317 and P = 0.0028, respectively). FD-specific manifestations/symptoms remained stable (all P > 0.05). A total of 76.9% of females and 50% of males suffered from pain, which has not improved under treatment. FD-specific disease scores (Disease Severity Scoring System and Mainz Severity Score Index) remained stable during treatment. AGAL activities and plasma lyso-Gb3 values remained stable, although some male patients presented with increasing lyso-Gb3 levels over time. CONCLUSIONS: Treatment with migalastat was generally safe and resulted in most patients in an amelioration of left ventricular mass. However, due to the heterogeneity of FD phenotypes, it is advisable that the treating physician monitors the clinical response regularly.

Comparative analysis of phasic left atrial strain and left ventricular posterolateral strain pattern to discriminate Fabry cardiomyopathy from other forms of left ventricular hypertrophy.

BACKGROUND: "Classical" echocardiographic signs of Fabry cardiomyopathy (FC), such as left ventricular hypertrophy (LVH), posterolateral strain impairment (PLSI), and papillary muscle hypertrophy may be of limited diagnostic accuracy in clinical practice. Our aim was to evaluate the diagnostic value of left atrial (LA) strain impairment compared to "classical" echocardiographic findings to discriminate FC. METHODS: In standard echocardiographic assessments, we retrospectively analyzed the diagnostic value of the "classical" red flags of FC as well as LA strain in 20 FC patients and in 20 subjects with other causes of LVH. Receiver operating characteristic (ROC) curve analysis was performed to assess the respective diagnostic accuracy. RESULTS: FC was confirmed in 20 patients by genetic testing. In the LVH group, 12 patients were classified by biopsy to have hypertrophic cardiomyopathy, two had hypertensive heart disease, and six LVH combined with borderline myocarditis. Global and regional left ventricular (LV) strain was not significantly different between groups while LA strain was significantly impaired in FC (Left atrial reservoir strain (LASr) 19.1%±8.4 in FC and 25.6%±8.9 in LVH, p = 0.009; left atrial conduction strain (LAScd) -8.4%±4.9 in FC and -15.9%±8.4 in LVH, p < 0.01). LAScd, with an area under the curve (AUC) of .81 (95% confidence interval [CI] .66-.96) showed the highest diagnostic accuracy to discriminate FC. The PLSI pattern showed an AUC of .49, quantification of papillary muscle hypertrophy an AUC of .47. CONCLUSION: Adding LA strain analysis to a comprehensive echocardiographic work-up of unclear LVH may be helpful to identify FC as a possible cause.

Treatment switch in Fabry disease- a matter of dose?

BACKGROUND: Patients with Fabry disease (FD) on reduced dose of agalsidase-beta or after switch to agalsidase-alfa show a decline in chronic kidney disease epidemiology collaboration-based estimated glomerular filtration rate (eGFR) and a worsened plasma lyso-Gb3 decrease. Hence, the most effective dose is still a matter of debate. METHODS: In this prospective observational study, we assessed end-organ damage and clinical symptoms in 78 patients who had received agalsidase-beta (1.0 mg/kg) for >1 year, which were assigned to continue this treatment (agalsidase-beta, regular-dose group, n=17); received a reduced dose of agalsidase-beta and subsequent switch to agalsidase-alfa (0.2 mg/kg) or a direct switch to 0.2 mg/kg agalsidase-alfa (switch group, n=22); or were re-switched to agalsidase-beta after receiving agalsidase-alfa for 12 months (re-switch group, n=39) with a follow-up of 88±25 months. RESULTS: No differences for clinical events were observed for all groups. Patients within the re-switch group started with the worst eGFR values at baseline (p=0.0217). Overall, eGFR values remained stable in the regular-dose group (p=0.1052) and decreased significantly in the re-switch and switch groups (p<0.0001 and p=0.0052, respectively). However, in all groups males presented with an annual loss of eGFR by -2.9, -2.5 and -3.9 mL/min/1.73 m² (regular-dose, re-switch, switch groups, all p<0.05). In females, eGFR decreased significantly only in the re-switch group by -2.9 mL/min/1.73 m² per year (p<0.01). Lyso-Gb3 decreased in the re-switch group after a change back to agalsidase-beta (p<0.05). CONCLUSIONS: Our data suggest that a re-switch to high dosage of agalsidase results in a better biochemical response, but not in a significant renal amelioration especially in classical males.

Assessment of Peripheral Nervous System Alterations in Patients with the Fabry Related GLA-Variant p.A143T.

Background The purpose of this study is to examine alterations of the peripheral nervous system (PNS) in oligo-symptomatic patients carrying the Fabry related GLA-gene variant p.A143T by Magnetic Resonance Neurography (MRN) and skin biopsy. This prospective study assessed dorsal root ganglia (DRG) volume L3 to S2, vascular permeability of the DRG L5, S1, and the spinal nerve L5 in five patients carrying p.A143T in comparison to patients with classical Fabry mutations and healthy controls. Moreover, skin punch biopsies above the lateral malleolus of the right foot were obtained in four patients and intraepidermal nerve fiber density (IENFD) was counted individually. Compared to controls, DRG volumes of p.A143T patients were enlarged by 30% (L3, p < 0.05), 35% (L4, p < 0.05), 29% (L5, p = 0.15), 36% (S1, p < 0.01), and 18% (S2, p < 0.05), but less pronounced compared to patients carrying a classical Fabry mutation. Compared to healthy controls, vascular permeability was decreased by 40% (L5 right), 49% (L5 left), 48% (S1 right), and 49% (S1) (p < 0.01-p < 0.001), but non-significant less than patients carrying a classical Fabry mutation. Compared to sex-matched 5% lower normative reference values per decade, IENFD was decreased in three of four patients. MRN and determination of IENFD is able to detect early alteration of the PNS segment in oligo-symptomatic patients with the disease-modifying GLA-variant p.A143T on an individual basis. This procedure might also help in further GLA-variants of uncertain significance for early identification of patients with single major organ manifestation.

Treatment of Fabry's Disease With Migalastat: Outcome From a Prospective Observational Multicenter Study (FAMOUS).

Fabry's disease (FD) is an X-linked lysosomal storage disorder caused by the deficient activity of the lysosomal enzyme α-galactosidase A (α-Gal A) leading to intracellular accumulation of globotriaosylceramide (Gb3). Patients with amenable mutations can be treated with migalastat, a recently approved oral pharmacologic chaperone to increase endogenous α-Gal A activity. We assessed safety along with cardiovascular, renal, and patient-reported outcomes and disease biomarkers in a prospective observational multicenter study after 12 months of migalastat treatment under "real-world" conditions. Fifty-nine (28 females) patients (34 (57.6%) pretreated with enzyme replacement therapy) with amenable mutations were recruited. Migalastat was generally safe and well tolerated. Females and males presented with a reduction of left ventricular mass index (primary end point) (-7.2 and -13.7 g/m2 , P = 0.0050 and P = 0.0061). FD-specific manifestations and symptoms remained stable (all P > 0.05). Both sexes presented with a reduction of estimated glomerular filtration rate (secondary end point) (-6.9 and -5.0 mL/minute/1.73 m2 ; P = 0.0020 and P = 0.0004, respectively), which was most prominent in patients with low blood pressure (P = 0.0271). α-Gal A activity increased in male patients by 15% from 29% to 44% of the normal wild-type activity (P = 0.0106) and plasma lyso-Gb3 levels were stable in females and males (P = 0.3490 and P = 0.2009). Reevaluation of mutations with poor biochemical response revealed no marked activity increase in a zero activity background. We conclude that therapy with migalastat was generally safe and resulted in an amelioration of left ventricular mass. In terms of impaired renal function, blood pressure control seems to be an unattended important goal.

Dose-Dependent Effect of Enzyme Replacement Therapy on Neutralizing Antidrug Antibody Titers and Clinical Outcome in Patients with Fabry Disease.

BACKGROUND: Use of enzyme replacement therapy (ERT) to treat Fabry disease, caused by deficient lysosomal α-galactosidase A activity, can lead to formation of neutralizing antidrug antibodies (ADAs). These antibodies are associated with increased accumulation of plasma globotriaosylceramide (Gb3) and disease progression. Because agalsidase ERT can saturate ADA-binding sites during infusions (achieving agalsidase/antibody equilibrium), we investigated in this open cohort study whether saturated patients (who have excess agalsidase after infusions) experience better clinical outcomes compared with not saturated patients (who have excess ADAs after infusions). METHODS: We isolated ADAs from sera of 26 men with Fabry disease receiving ERT (for a median of 94 months) and determined the amount of agalsidase necessary for antibody saturation. Clinical and biochemical outcomes included measurements of eGFR, interventricular septum thickness, and lyso-Gb3. RESULTS: ADA titers decreased significantly in all patients during infusion. Agalsidase-α and agalsidase-ß had similar ADA-binding capacity and comparable ADA saturation frequency. Fourteen patients with saturated ADAs presented with mild (but significant) loss of eGFR, stable septum thickness, and significantly decreased lyso-Gb3 levels. The 12 not saturated patients had a more pronounced and significant loss of eGFR, increased septum thickness, and a smaller, nonsignificant reduction in lyso-Gb3, over time. In three patients, dose escalation resulted in partially elevated ADA titers, but importantly, also in reduced lyso-Gb3 levels. CONCLUSIONS: A not saturated ADA status during infusion is associated with progressive loss of eGFR and ongoing cardiac hypertrophy. Dose escalation can result in saturation of ADAs and decreasing lyso-Gb3 levels, but may lead to increased ADA titers.

Long-term Outcomes of Kidney Transplantation in Fabry Disease.

BACKGROUND: Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene that obliterate or markedly reduce α-galactosidase A activity. This results in the systemic accumulation of its glycosphingolipid substrates in body fluids and organs, including the kidney. Fabry nephropathy can lead to end-stage renal disease requiring kidney transplantation. Little is known about its long-term outcomes and the overall patient survival after kidney transplantation. METHODS: Here, we report 17 Fabry patients (15 male and 2 female subjects) who received kidney transplants and their long-term treatment and follow-up at 4 specialized Fabry centers. RESULTS: The posttransplant follow-up ranged to 25 years, with a median of 11.5 (range, 0.8-25.5] years. Graft survival was similar, and death-censored graft survival was superior to matched controls. Fabry patients died with functioning kidneys, mostly from cardiac causes. In 2 male subjects 14 and 23 years posttransplant, the grafts had a few typical FD lamellar inclusions, presumably originating from invading host macrophages and vascular endothelial cells. CONCLUSIONS: We conclude that kidney transplantation has an excellent long-term outcome in FD.

Fabry disease under enzyme replacement therapy-new insights in efficacy of different dosages.

Background: Fabry patients on reduced dose of agalsidase-beta or after switch to agalsidase-alfa show a decline in estimated glomerular filtration rate (eGFR) and an increase of the Mainz Severity Score Index. Methods: In this prospective observational study, we assessed end-organ damage and clinical symptoms in 112 patients who had received agalsidase-beta (1.0 mg/kg) for >1 year, who were (i) non-randomly assigned to continue this treatment regime (regular-dose group, n = 37); (ii) received a reduced dose of agalsidase-beta and subsequent switch to agalsidase-alfa (0.2 mg/kg) or a direct switch to 0.2 mg/kg agalsidase-alfa (switch group, n = 38); or (iii) were re-switched to agalsidase-beta after receiving agalsidase-alfa for at least 12 months (re-switch group, n = 37) with a median follow-up of 53 (38-57) months. Results: eGFR of patients in the regular-dose group remained stable. Patients in the switch group showed an annual eGFR loss of - 4.6 ± 9.1 mL/min/1.73 m2 (P < 0.05). Patients in the re-switch group also had an eGFR loss of - 2.2 ± 4.4 mL/min/1.73 m2 after re-switch to agalsidase-beta, but to a lower degree compared with the switch group (P < 0.05). Patients in the re-switch group suffered less frequently from diarrhoea (relative risk 0.42; 95% confidence interval 0.19-0.93; P = 0.02). Lyso-Gb3 remained stable in the switch (P = 0.97) and the regular-dose (P = 0.48) groups, but decreased in the re-switch group after change of the therapy regimen (P < 0.05). Conclusions: After switch to agalsidase-alfa, Fabry patients experienced a continuous decline in eGFR, while this decline was attenuated in patients who were re-switched to agalsidase-beta. Decreasing lyso-Gb3 levels may indicate a better treatment response in the latter group.

Multicenter Female Fabry Study (MFFS) - clinical survey on current treatment of females with Fabry disease.

BACKGROUND: The aim of the present study was to assess manifestations of and applied treatment concepts for females with Fabry disease (FD) according to the current European Fabry Guidelines. METHODS: Between 10/2008 and 12/2014, data from the most recent visit of 261 adult female FD patients from six German Fabry centers were retrospectively analyzed. Clinical presentation and laboratory data, including plasma lyso-Gb3 levels were assessed. RESULTS: Fifty-five percent of females were on enzyme replacement therapy (ERT), according to recent European FD guidelines. Thirty-three percent of females were untreated although criteria for ERT initiation were fulfilled. In general, the presence of left ventricular hypertrophy (LVH) seemed to impact more on ERT initiation than impaired renal function. In ERT-naïve females RAAS blockers were more often prescribed if LVH was present rather than albuminuria. Affected females with missense mutations showed a similar disease burden compared to females with nonsense mutations. Elevated plasma lyso-Gb3 levels in ERT-naïve females seem to be a marker of disease burden, since patients showed comparable incidences of organ manifestations even if they were ~8 years younger than females with normal lyso-Gb3 levels. CONCLUSION: The treatment of the majority of females with FD in Germany is in line with the current European FD guidelines. However, a relevant number of females remain untreated despite organ involvement, necessitating a careful reevaluation of these females.

Alpha-Galactosidase A p.A143T, a non-Fabry disease-causing variant.

BACKGROUND: Fabry disease (FD) is an X-linked multisystemic disorder with a heterogeneous phenotype. Especially atypical or late-onset type 2 phenotypes present a therapeutical dilemma. METHODS: To determine the clinical impact of the alpha-Galactosidase A (GLA) p.A143T/ c.427G > A variation, we retrospectively analyzed 25 p.A143T patients in comparison to 58 FD patients with other missense mutations. RESULTS: p.A143T patients suffering from stroke/ transient ischemic attacks had slightly decreased residual GLA activities, and/or increased lyso-Gb3 levels, suspecting FD. However, most male p.A143T patients presented with significant residual GLA activity (~50 % of reference), which was associated with normal lyso-Gb3 levels. Additionally, p.A143T patients showed less severe FD-typical symptoms and absent FD-typical renal and cardiac involvement in comparison to FD patients with other missense mutations. Two tested female p.A143T patients with stroke/TIA did not show skewed X chromosome inactivation. No accumulation of neurologic events in family members of p.A143T patients with stroke/transient ischemic attacks was observed. CONCLUSIONS: We conclude that GLA p.A143T seems to be most likely a neutral variant or a possible modifier instead of a disease-causing mutation. Therefore, we suggest that p.A143T patients with stroke/transient ischemic attacks of unknown etiology should be further evaluated, since the diagnosis of FD is not probable and subsequent ERT or chaperone treatment should not be an unreflected option.

Patients with Fabry Disease after Enzyme Replacement Therapy Dose Reduction and Switch-2-Year Follow-Up.

Because of the shortage of agalsidase-ß supply between 2009 and 2012, patients with Fabry disease either were treated with reduced doses or were switched to agalsidase-α. In this observational study, we assessed end organ damage and clinical symptoms with special focus on renal outcome after 2 years of dose-reduction and/or switch to agalsidase-α. A total of 89 adult patients with Fabry disease who had received agalsidase-ß (1.0 mg/kg body wt) for >1 year were nonrandomly assigned to continue this treatment regimen (regular-dose group, n=24), to receive a reduced dose of 0.3-0.5 mg/kg and a subsequent switch to 0.2 mg/kg agalsidase-α (dose-reduction-switch group, n=28), or to directly switch to 0.2 mg/kg agalsidase-α (switch group, n=37) and were followed-up for 2 years. We assessed clinical events (death, myocardial infarction, severe arrhythmia, stroke, progression to ESRD), changes in cardiac and renal function, Fabry-related symptoms (pain, hypohidrosis, diarrhea), and disease severity scores. Determination of renal function by creatinine and cystatin C-based eGFR revealed decreasing eGFRs in the dose-reduction-switch group and the switch group. The Mainz Severity Score Index increased significantly in these two groups (P=0.02 and P<0.001, respectively), and higher frequencies of gastrointestinal pain occurred during follow-up. In conclusion, after 2 years of observation, all groups showed a stable clinical disease course with respect to serious clinical events. However, patients under agalsidase-ß dose-reduction and switch or a direct switch to agalsidase-α showed a decline of renal function independent of the eGFR formula used.

Global cardiac alterations detected by speckle-tracking echocardiography in Fabry disease: left ventricular, right ventricular, and left atrial dysfunction are common and linked to worse symptomatic status.

The aim of this study was to test the hypothesis that in patients with Fabry disease, 2D speckle-tracking echocardiography (2DSTE) could detect functional myocardial alterations such as left ventricular (LV), right ventricular (RV), and left atrial (LA) dysfunction, even when conventional cardiac measurements are normal. In addition, we hypothesized that these global cardiac alterations could be linked to worse symptomatic status in these patients. Fifty patients with Fabry disease and a control group of 118 healthy subjects of similar age and gender were included. The myocardial function and structural changes of the LV, RV, and LA were analyzed by 2DSTE and cardiac magnetic resonance imaging. Patients with Fabry disease had significantly lower functional myocardial values of the LV, RV, and LA than healthy subjects (LV, RV, and LA strain -18.1 ± 4.0, -21.4 ± 4.9, and 29.7 ± 9.9 % vs. -21.6 ± 2.2, -25.2 ± 4.0, and 44.8 ± 11.1 %, respectively, P < 0.001) and elevated rates of LV, RV, and LA myocardial dysfunction (24, 20, and 26 %, respectively), even when conventional cardiac measurements such as LVEF, TAPSE, and LAVI were normal. LV septal wall thickness ≥15 mm, RV free wall thickness ≥7 mm, and LV longitudinal dysfunction were the principal factors linked to reduced LV, RV, and LA strain, respectively. In addition, but to a lesser extent, LV and RV fibrosis were linked to reduced LV and RV strain. Patients with reduced LV, RV, and LA strain had worse functional class (dyspnea-NYHA classification) than those with normal cardiac function. In conclusion, in patients with Fabry disease, 2DSTE analyses detect LV, RV, and LA functional myocardial alterations, even when conventional cardiac measurements are normal. These functional myocardial alterations are common and significantly associated with worse symptomatic status in Fabry patients. Therefore, these findings provide important evidence to introduce global myocardial analyses using 2DSTE in the early detection of functional cardiac alterations in Fabry disease.

Patients with Fabry disease after enzyme replacement therapy dose reduction versus treatment switch.

Because of the shortage of agalsidase-beta in 2009, many patients with Fabry disease were treated with lower doses or were switched to agalsidase-alfa. This observational study assessed end-organ damage and clinical symptoms during dose reduction or switch to agalsidase-alfa. A total of 105 adult patients with Fabry disease who had received agalsidase-beta (1.0 mg/kg body weight) for ≥1 year were nonrandomly assigned to continue this treatment regimen (regular-dose group, n=38), receive a reduced dose of 0.3-0.5 mg/kg (dose-reduction group, n=29), or switch to 0.2 mg/kg agalsidase-alfa (switch group) and were followed prospectively for 1 year. We assessed clinical events (death, myocardial infarction, severe arrhythmia, stroke, progression to ESRD); changes in cardiac, renal, and neurologic function; and Fabry-related symptoms (neuropathic pain, hypohidrosis, diarrhea, and disease severity scores). Organ function and Fabry-related symptoms remained stable in the regular-dose group. In contrast, estimated GFR decreased by about 3 ml/min per 1.73 m(2) (P=0.01) in the dose-reduction group, and the median albumin-to-creatinine ratio increased from 114 (0-606) mg/g to 216 (0-2062) mg/g (P=0.03) in the switch group. Furthermore, mean Mainz Severity Score Index scores and frequencies of pain attacks, chronic pain, gastrointestinal pain, and diarrhea increased significantly in the dose-reduction and switch groups. In conclusion, patients receiving regular agalsidase-beta dose had a stable disease course, but dose reduction led to worsening of renal function and symptoms. Switching to agalsidase-alfa is safe, but microalbuminuria may progress and Fabry-related symptoms may deteriorate.