Echocardiographic and biohumoral characteristics in patients with AL and TTR amyloidosis at diagnosis

Abstract

Background: Few studies have analyzed the clinical and echocardiographic differences between light-chain (AL) and transthyretin (TTR) amyloidosis.

Hypothesis: The aim of the present research was to compare, in a real-world setting, the clinical and echocardiographic profiles of these kinds of amyloidosis, at the time of diagnosis, using new-generation echocardiography.

Methods: Seventy-nine patients with AL and 48 patients with TTR amyloidosis were studied.

Results: According to the criterion of mean left ventricular (LV) thickness >12 mm, 45 AL (C-AL) and all TTR patients had cardiac amyloidotic involvement, whereas 34 AL patients did not. TTR patients had increased right ventricular (RV) and LV chambers with increased RV and LV wall thickness and reduced LV ejection fraction and fractional shortening. Furthermore, TTR patients showed lower N-terminal pro Brain Natriuretic Peptide concentrations and New York Heart Association functional class when compared with C-AL.

Conclusions: Our data show that at time of first diagnosis, TTR patients have a more advanced amyloidotic involvement of the heart, despite less severe symptoms and biohumoral signs of heart failure. We can hypothesize that we observed different diseases at different stages. In fact, AL amyloidosis is a multiorgan disease with quick progression rate, that becomes rapidly symptomatic, whereas TTR amyloidosis might have a slow progression rate and might remain poorly symptomatic for a greater amount of time.