The tricuspid annulus in cardiac amyloidosis – a three-dimensional speckle-tracking echocardiographic study
Authors: Nemes A , Racz G , Kormanyos A , Foldeak D , Borbenyi Z 
Published: October 2021

Abstract

Introduction
Amyloidosis is a rare condition due to extracellular deposition of excessive amount of protein in parenchymal tissues including the heart. The present study aimed to test whether cardiac amyloidosis (CA) is associated with morphological and functional abnormalities of the tricuspid annulus (TA). For this aim, the results of patients having CA were compared to age- and gender-matched healthy controls by three-dimensional speckle-tracking echocardiography (3DSTE). Moreover, differences in TA parameters between light-chain CA (AL-CA) and transthyretin CA (TTR-CA) were studied as well.

Methods
The study comprised 27 CA patients (mean age: 62.7±9.1 years, 21 males), their results were compared to those of 20 age- and gender-matched healthy volunteers (59.3±3.8 years, 13 males). Current consensus criteria were used for the definition of CA. Biopsy was carried out in all patients to confirm the diagnosis of CA. The first positive biopsy site was the myocardium in 7 cases, bone marrow in 6 cases, duodenum and rectum in 5 cases, salivary gland in 1 case, skin and subcutaneous tissue in 2 cases and kidney in 10 cases in the CA patients. In 5 CA patients, biopsy samples were collected from more than one organ. CA proved to be AL-CA in 21 subjects and TTR-CA in 6 patients. Complete two-dimensional Doppler echocardiography and 3DSTE were performed in all CA patients and controls.

Results
CA patients had significantly higher left atrial diameter, left ventricular (LV) end-diastolic diameter, thicker interventricular septum and LV posterior wall and increased E/A ratio compared to the results of healthy controls. None of the 27 CA patients and their matched controls had atrial fibrillation in their medical history. Dilated 3DSTE-derived end-diastolic and end-systolic TA diameter (3.0±0.6 cm vs. 2.1±0.2 cm, p&lt;0.05 and 2.6±0.6 cm vs. 1.6±0.2 cm, p&lt;0.05, respectively), area (10.7±3.5 cm2 vs. 6.1±1.1 cm2, p&lt;0.05 and 8.0±3.2 cm2 vs. 4.1±1.0 cm2, p&lt;0.05, respectively) and perimeter (12.5±2.0 cm vs. 9.8±1.0 cm, p&lt;0.05 and 10.6±2.1 cm vs. 8.0±1.0 cm, p&lt;0.05, respectively) could be detected in all CA patients and in the AL-CA and TTR-CA subgroups, as well. Although only a few TTR-CA patients were involved, morphologic TA parameters proved to be tendentiously higher as compared to those of AL-CA patients. Functional parameters of TA represented by TA fractional area change (TAFAC, 26.1±11.2% vs. 32.0±11.1%, p=0.07) and TA fractional shortening (TAFS, 12.8±10.3% vs. 21.6±7.4%, p&lt;0.05) were found to be reduced in CA patients, which were more enhanced in TTR-CA patients (TAFAC for TTR-CA: 27.1±14.3% vs. TAFAC for AL-CA:25.7±10.5%, p=ns; TAFS for TTR-CA: 16.0±9.8% vs. TAFS for AL-CA: 11.9±10.4%, p=ns).

Conclusions
Dilated TA is associated with its functional deterioration in CA. Patients with TTR-CA have tendentiously more dilated TA with more enhanced TA functional parameters.

Funding Acknowledgement
Type of funding sources: None.