Subclinical myocardial injury in ATTR-related familial amyloid polyneuropathy patients without clinical signs of cardiomyopathy

Abstract Background ATTR-related Familial Amyloid Polyneuropathy (FAP) is a hereditary disease that primarily affects peripheral nerve function. Few studies have investigated cardiac involvement and myocardial tissue remodeling in FAP. Aim To investigate subclinical FAP patients without cardiomyopathy using multiparametric CMR protocol. Results Thirty-one (46.9±16.1 years, 57% female, 60% Val30Met mutation) 33 healthy controls (41.3±13.7 58% female) were enrolled, undergoing protocol for assessment of ventricular morphology function, native T1, extracellular volume fraction (ECV) intracellular lifetime water). Cardiopulmonary exercise capacity was evaluated with cycle ergometer. Cardiac high-sensitive troponin T (cTnT) NT-proBNP measured to assess injury. The majority ATTR-PN stage 1 (70%) mild symptoms sensory, motor autonomic neuropathy. Adjusted maximum oxygen consumption reduced among compared (FAP: 22.2±8.2 mL/kg/min vs. controls: 30.3±10.2 mL/kg/min, p<0.001). Although none reported heart failure symptoms, 251.240±624.446 ng/dL, 34.3±29 p<0.005) cTnT 13.2 [3.0, 19.0] 3.6 6.0] elevated, both correlated ECV (cTnT: R=0.81, P<0.001; NT-proBNP: R=0.61, P=0.001, Fig. 1). While LVEF preserved 67.9±8.2% 65.4±4.3%, p=NS), LVmass index increased control subjects 58.5±18.8 42±9.2 g/m2, p<0.005). Both T1 1,303.924±120.152, 1,212.78±76.01 ms, p<0.05) 0.36±0.1, 0.26±0.02, p<0.001) markedly elevated patients. In contrast the water, validated marker cardiomyocyte size group 0.082±0.04 0.14±0.05, There trend increase linearly stage, trended higher 2 0. (R=0.89, (R=0.62, (Fig 2). Conclusion clinical signs involvement, significant matrix expansion present. LV mass these associated matrix, possibly as result diffuse replacement fibrosis, below-normal diameter. These findings from serum biomarkers phenotyping provide evidence sub-clinical through adverse presenting mostly Funding Acknowledgement Type funding sources: Private company. Main source(s): Pfizer