Clinical and genetic profiles of patients with hereditary and wild type transthyretin amyloidosis: the transthyretin cardiac amyloidosis registry in the state of Sao Paulo, Brazil REACT-SP

INTRODUCTION: Transthyretin amyloidosis (ATTR) is a multisystem disease caused by the deposition of fibrillar protein in organs and tissues. ATTR genotypes and phenotypes are highly heterogeneous. PURPOSE: We designed the Transthyretin Cardiac Amyloidosis Registry in the state of São Paulo (REACT-SP), aiming to describe the demographic, genetic, clinical, and diagnostic test results and treatment of patients with ATTR. METHODS: We present data on physical signs and symptoms, cardiac and neurological assessments, and genetics in patients enrolled in the Transthyretin Cardiac Amyloidosis Registry in the state of São Paulo, Brazil. RESULTS: Six hundred-forty-four patients were enrolled, 505 with the variant form (ATTRv) and 139 with wild-type (ATTRwt). Sixteen different mutations were detected, the most common being Val50Met (48.3%) and V142Ile (40.8%). Overall, more than half of the patients presented cardiological involvement, and the difference in this proportion between the ATTRv and ATTRwt groups was significant (43.9 vs. 89.9%; p<0.001). The neurological phenotype also differed between ATTRv and ATTRwt (56.8 vs. 31.7%; p<0.001). The mixed phenotype was found in 25.6% of the population, without a significant difference between the forms of amyloidosis. A group of patients remained asymptomatic (10.4%), with a lower proportion of asymptomatic ATTRwt patients. The median time between the onset of symptoms and diagnosis was 1,853 (IQR 1277­2997) days, which was longer in ATTRv patients than in ATTRwt patients (p<0.001). Sinus rhythm was reported in 74.2%, atrial fibrillation in 17.0%, low voltage in 28.6%, repolarization abnormalities in 39.8%, and pseudo infarction in 27.4%. Echocardiography showed median Left Ventricular Ejection Fraction (LVEF) was 60%, Interventricular Septum (IVS) 14 mm, Posterior Wall Thickness (PWT) 13 mm, Left Atrium (LA) 41 mm, Left Ventricular Diastolic Diameter (LVDD) 45 mm, Left Ventricular Systolic Diameter (LVSD) 30 mm, basal Right Ventricular Diastolic Diameter (RVDD) 35 mm and Left Ventricle (LV) longitudinal strain 9.1%. There was some degree of LV diastolic dysfunction in 38.4%, apical sparing in 31.3%, and thrombus or masses in 1.0%. Late Gadolinium Enhancement (LGE) was absent in 29% and was subendocardial in 35.5%, transmural in 13.7%, mesocardial in 13.7%, and epicardial in 8.2%. CONCLUSIONS: This study details the clinical and genetic spectrum of patients with ATTR in São Paulo, Brazil. This preliminary analysis highlights the considerable phenotypic heterogeneity of neurological and cardiac manifestations in patients with variant and wild-type ATTR.

Clinical and laboratorial profile of patients with ATTR cardiomyopathy: comparison between wild type and pVal142Ile forms in the Brazilian population

BACKGROUND: In Brazil, besides the wild type (wt) form, transthyretin amyloid cardiomyopathy (ATTR-CM) is predominantly caused by hereditary form with Val142Ile mutation. Considering that both forms occur in elderly people, the clinical presentation may be similar. We sought to compare the clinical presentation of patients with wt and Val142Ile mutation in a Brazilian cohort of ATTR-CM patients. METHODS: Among the 642 patients enrolled in REACT/SP, 283 presented ATTR-CM, being 85 wt and 90 Val142Ile patients. We compared the main clinical characteristics between groups. RESULTS: The wt in comparison to Val142Ile patients, respectively, presented: older age (78.4+/-8.5 vs 74.2+/-8.1 y.o., p = 0.0009); similar proportion of males (82% vs 81%, p=0.85); lower proportion of blacks (11% vs 39%, p=0.0001); similar prevalence of heart failure (HF) symptoms (85% vs 79%, p=0.33); higher prevalence of syncope (13% vs 2%, p=0.008) and Pacemakers (PM) implantation (8% vs 1%, p=0.027); similar prevalence of neuropathy manifestations (38% vs 51%, p=0.17); lower creatinine (1.5+/-0.8 vs 2.1+/-2.1 mg/dL, p=0.02) and NT-ProBNP levels (2860.0+/-2843.3 vs. 5488.3+/-5455.6 pg/ml, p=0.0001); reduced interventricular septal thickness (15.6+/-3.3 vs 17.0+/-3.3 mm, p= 0.006), posterior left ventricular (LV) posterior wall thickness (14.2+/-2.4 vs 16.2+/-4.4 mm, p=0.0003), higher LV ejection fraction (52.0 +/-10.1 vs 48.2+/-13.6%, p=0.038), higher global LV longitudinal strain (8.6+/-8.7 vs 3.4+/-9.8, p=0.0003), smaller LV diastolic diameter (45.9 +/-6.1 vs 43.0+/-7.3 mm, p=0.005) at 2D-Echocardiogram. CONCLUSIONS: In the Brazilian population wt and Val142Ile patients had similar clinical presentation regarding HF and neuropathy symptoms, but higher prevalence of syncope and PM in wt patients. Conversely, Val142Ile patients presented more severe amyloid cardiac infiltration.