Endothelium-dependent vasodilatation in patients with familial amyloidotic polyneuropathy.

We examined endothelium-dependent vasodilatation in 15 familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin (ATTR) Valine30Methionine (Val30Met) patients and 12 healthy volunteers. Using ultrasonography, we measured the radial artery diameters under both baseline and hyperemic conditions. Endothelium-dependent vasodilatation was expressed as a percent increase in the diameters of the radial artery after induced hyperemia. Endothelium-dependent vasodilatation tended to decrease in the patients, compared with healthy volunteers. Responses were not elicited at all in patients with disease of more than 9 years' duration. Linear negative correlation was observed between endothelium-dependent vasodilatation and disease duration (P < 0.01). Correlation between endothelium-dependent vasodilatation and degree of autonomic dysfunction was significant (P = 0.0524) and for age was close to significance (P = 0.051). These results suggest that the peripheral vasomotor dysfunction in FAP patients may predominantly depend on the amount of amyloid deposition around the vessels through the course of illness.