Abstract 15734: Left Atrial Reservoir Strain as a Novel Prognostic Marker in Biopsy-proven Light-chain Amyloidosis

Abstract

Introduction: Light chain cardiac amyloidosis (AL) has a variable but usually poor prognosis. Left ventricular (LV) function measures including LV strain imaging for global longitudinal strain (GLS) have shown clinically prognostic value in AL. However, the utility of novel left atrial (LA) strain imaging and its associations with LV disease remains unclear. Hypothesis: LA strain is of additive prognostic value to GLS in AL. Methods: We included 99 consecutive patients with AL. Cardiac amyloidosis either confirmed by endocardial biopsy (25%) or by non-cardiac tissue biopsy and imaging data supportive of cardiac amyloidosis. Peak LA reservoir strain was calculated as an average of peak longitudinal strain from apical 2- and 4-chamber views. GLS and apical sparing ratio were assessed using the 3 standard apical views. All-cause mortality was tracked over a median of 5 years. Results: Echocardiographic GLS and peak longitudinal LA strain were feasible in 96 (97%) and 86 (87%) of patients, respectively. There were 48 AL patients who died during follow-up. Patients with low GLS (GLS < median; 10.3% absolute values) had worse prognosis than patients with high GLS group (p<0.001). Although peak longitudinal LA strain was correlated with GLS (R=0.65 p<0.001), peak longitudinal LA strain had additive prognostic value. AL patients with low GLS and low Peak LA strain (<13.4%) had a 8.3-fold increase in mortality risk in comparison to patients with high GLS (95% confidence interval: 3.84-18.03; p<0.001). Multivariable analysis showed peak longitudinal LA strain was significantly and independently associated with survival after adjusting for clinical and echocardiographic covariates (p<0.01). Conclusions: Peak longitudinal LA strain was additive to LV GLS in predicting prognosis in patients with biopsy confirmed AL amyloidosis. LA strain imaging has potential clinical utility in patients with AL cardiac amyloidosis.