Changes in Left Ventricular Ejection Fraction and Clinical Trajectories of Transthyretin Cardiac Amyloidosis with Systolic Dysfunction

Background: Transthyretin cardiac amyloidosis (ATTR-CM) is classically thought of as a progressive disease with preserved systolic function. The longitudinal clinical trajectories of ATTR-CM with impaired left ventricular ejection fraction (LVEF) remain unclear. Methods: This is a single-center retrospective cohort study of consecutive patients with ATTR-CM who underwent two or more echocardiograms with baseline LVEF < 50%. Patients were stratified according to the presence of >= 5% change in LVEF. A Cox proportional hazard model examined hazard of a composite outcome of death, transplant, or LVAD insertion over the two years following diagnosis. Results: In our study cohort of 179 patients, 62 patients (34.6%) experienced an increase in LVEF while 33 (18.4%) experienced a decrease in LVEF. After adjusting for covariates, patients with a decrease in EF experienced increased hazard of death (HR 2.15, 95% CI 1.05-4.40, p = 0.038) compared to those with stable or an increase in LVEF. Changes in LVEF corresponded with significant differences in NT proBNP trajectories, but initial biomarker levels or clinical staging were not predictive of LVEF trajectory. Conclusions: in ATTR-CM patients with impaired LVEF, over a third demonstrated improved LVEF over time, while those with a decrease in LVEF had worse long-term outcomes.