P2728Prognostic impact of left atrial function in patients with cardiac amyloidosis: a cardiac magnetic resonance study

Abstract

Abstract Background Left atrial function (AEF) is a parameter of paramount importance that has a prognostic value in a number of heart conditions. Cardiac involvement in both light-chain and transthyretin amyloidosis is the main driver of prognosis and influences treatment strategies. Cardiac magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences. Purpose The aim of our study was to assess by CMR left atrial function and his correlation with prognosis in patients with cardiac amyloidosis. Method We enrolled 80 consecutive patients with diagnosis of cardiac amyloidosis: 38 patients (47%) with light-chain and 42 patients (53%) with transthyretin one. CMR was performed using a 1.5-T scanner. In all subjects, the study of atria was obtained by acquiring cine steady-state free precession (SSFP). Left Atrial function was evaluated by the ratio between the maximum and the minimum LA volume. A median follow up of 937 days was performed and 36 patients (44%) died of cardiac causes. We evaluated cardiac death as endpoint. We split out all the patient in 4 different quartiles depending on left atrial function: in the first quartile patients with AEF≤14% that reflects severe atrial dysfunction, in the second quartile patients with AEF between 14 and 19%, in the third quartile patients with AEF between 19 and 36% and in the last one patients with AEF≥36% that represent patients with normal value of left atrial function. Results We found that CMR assessed left atrial function allowed to individuate and stratify the prognosis in patients with cardiac amyloidosis. The most effective parameter to evaluate cardiac death was left atrial function with a cut off ≤14% that could predict cardiac related mortality with the same accuracy in both light-chain and transthyretin amyloidosis patients. Kaplan Meier analysis showed that patients with AEF≤14% had a worse prognosis as compared to patient with AEF≥14% (log rank p. 0001). Furthermore patients with AEF≤14% have a cardiac death risk of 32% at 1 year and 61% at 3 years. Kaplan Meier analysis Conclusion Cardiac magnetic resonance is an imaging modality that allows to individuate with great accuracy left atrial function in patients with various heart conditions and especially cardiac amyloidosis. CMR left atrial function assessment clearly identifies a subgroup of cardiac amyloid patients with an increased risk of death.