247 Cardiac phenotype of familial amyloid polyneuropthy according to genotype

Abstract

Familial amyloid polyneuropathy (FAP) is an autosomic dominant disease due to the mutation in the transthyretin gene. The abnormal protein produced by the liver is responsible for polyneuropathy, autonomic dysfunction and cardiac involvement. Myocardial hypertrophy and conduction disturbances are the two major cardiac consequences in FAP. More than 100 mutations have been described: the substitution of methionine for valine at position 30 (Val30Met mutation) is the most common. The aim of our study was to compare cardiac data of the Val30Met population to other FAP population. One hundred ninety four consecutive patients (pts) were referred to our department to have a cardiac evaluation after FAP diagnosis, 168 pts out of them were genotyped. Standard ECG, echocardiography and electrophysiological study were performed for each patient. Main results are shown in table 1. In patients carrying other mutations than Val30Met, cardiac hypertrophy was associated with a longer HV interval (71±2ms in case of hypertrophy vs. 58±4ms ;P=0.0008). Such association wasn’t found considering Val30Met patients. Table 1: Main results Mean age (years) Gender % of male Abnormal ECG % Cardiac hypertrophy % LW point (bpm) HV interval (ms) Val30Met n=13 42.5 53 47 40 128±3 59 Other mutations n=55 55.7 71 46 72 151±3 66 p 0.0001 0.04 NS 0.0002 <0.0001 0.002 Abnormal ECG: RBB, LBB, abnormal axis or nodal AV block. Cardiac hypertrophy: interventricular septum thickness >12 mm. LW: lucianni Wenckebach anterior point. Demographic data and cardiac phenotype are significantly different according to the genotype between the val30met and other mutations population. In pts carrying other mutation than Val30Met, cardiac hypertrophy and infra nodal block were more common and seemed to be related. Follow up and treatment must take into a count the genotype.