Dr. Marianna Fontana, MD - Clinical Importance of Left Atrial Infiltration in Cardiac Transthyretin Amyloidosis @dr_m...

Dr. Marianna Fontana works as the Director at the Royal Free Hospital in the UCL CMR unit. She is a Honorary Consultant Cardiologist and Professor of Cardiology at the National Amyloidosis Centre at the University College London. In this video Dr. Fontana discusses

https://www.jacc.org/doi/10.1016/j.jcmg.2021.06.022

Abstract
The goal of this study was to characterize left atrial (LA) pathology in explanted hearts with transthyretin amyloid cardiomyopathy (ATTR-CM); LA mechanics using echocardiographic speckle-tracking in a large cohort of ATTR-CM patients; and investigate the relationship between LA pathology and mortality.

Background

The clinical importance of LA involvement in ATTR-CM is a hot topic in medicine.

Methods

In 5 explanted ATTR-CM atria, Congo red staining and immunohistochemistry were used to characterize the presence, type, and amount of amyloid and related alterations. In 906 individuals with ATTR-CM (551 wild-type (wt)-ATTR-CM; 93 T60A-ATTR-CM; 241 V122I-ATTR-CM; 21 other), echo speckle tracking was employed to measure LA reservoir, conduit, contractile function, and stiffness.

Results

The 5 atria had a lot of ATTR amyloid infiltration, which caused loss of normal architecture, vascular remodeling, capillary disruption, and subendocardial fibrosis. After controlling for established predictors, echo speckle tracking in 906 patients with ATTR-CM revealed higher atrial stiffness (median [25th-75th quartile] 1.83 [1.15-2.92]), which remained independently linked with prognosis (lnLA stiff: HR: 1.23; 95 percent CI: 1.03-1.49; P = 0.029). The three phasic functional atrial components were severely harmed (reservoir 8.86 percent [5.94 percent -12.97 percent ]; conduit 6.5 percent [4.53 percent -9.28 percent ]; contraction function 4.0 percent [2.29 percent -6.56 percent ]). Atrial contraction was missing in 22.1 percent of patients with sinus rhythm (SR) "atrial electromechanical dissociation" on electrocardiograms (AEMD). Patients with AEMD had a worse outcome than those with SR and efficient mechanical contraction (P = 0.0018). Patients with atrial fibrillation who received AEMD had a similar prognosis.

Conclusions

ATTR-CM has a phenotype that includes considerable atrial infiltration, gradual loss of atrial function, and increasing stiffness, all of which are strong independent predictors of death. AEMD has developed as a distinct trait that can be used to identify patients in SR who have a bad prognosis.