Left Atrial Mechanics Associates With Paroxysmal Atrial Fibrillation in Light-Chain Amyloidosis Following Stem Cell Transplantation

Abstract

BackgroundAtrial fibrillation (AF) during high-dose melphalan and autologous stem-cell transplantation (HDM/SCT) for light-chain (AL) amyloidosis confers significant morbidity. Traditional risk factors provide limited prediction for development of paroxysmal AF during this vulnerable period. ObjectivesWe sought to assess the association of clinical and echocardiographic parameters, including left atrial (LA) mechanics and development of AF in patients undergoing HDM/SCT therapy. MethodsBaseline echocardiograms, electrocardiograms, and electronic medical records were retrospectively assessed among patients with AL amyloidosis before HDM/SCT (n = 91). LA function analysis was performed using speckle-tracking echocardiography. ResultsIn this study, 42 patients (46%) had cardiac involvement; in the peri-transplant period, 12 (13%) developed AF (7 with cardiac involvement). No significant differences in age, sex, cardiac biomarkers, or cardiac risk factors were seen between patients with and without development of AF; one-third of patients with AF peri-transplant had previous AF. Although LA reservoir strain was reduced in patients with development of AF, time to peak strain rate indexed to R-R interval (TPSRI) (p = 0.001) was prolonged in patients with development of AF compared with sinus rhythm patients in the total cohort but also in subgroups with and without cardiac involvement. ConclusionsTPSRI, a parameter of mechanical dispersion in the early reservoir phase of LA function, is associated with development of AF among patients undergoing HDM/SCT for AL amyloidosis. These findings require validation in larger prospective cohorts.