Prognostic Value Of Left Atrial Strain Derived From CMR Fast Semi-automated Long-axis Strain Analysis In Cardiac Light-chain Amyloidosis

ObjectiveCardiac light-chain amyloidosis(AL-CA)is a rare and life-threatening disease characterized by deposition of amyloid fibrils in the heart.The evaluation of left atrial(LA)function is important for predicting the prognosis of AL-CA patients.This study aimed to investigate whether fast semi-automated long-axis strain(FLAS)technique can evaluate the LA function changes in AL-CA patients and whether it has additional prognostic value.MethodsForty-one AL-CA patients and 19 healthy volunteers were retrospectively enrolled,and LA strain parameters were analyzed using FLAS based on cardiac magnetic resonance imaging(CMR).The endpoint was defined as all-cause mortality,and survival time was from the CMR examination date to the last follow-up or death.The prognostic value of LA strain was evaluated using Kaplan-Meier method and COX regression model.The intraclass correlation coefficient(ICC)was used to assess the repeatability of LA strain.ResultsLA strain parameters showed good reproducibility both within and between observers(ICC range,0.945-0.991).Compared to the control group,AL-CA patients had significant left heart remodeling and dysfunction,including increased LVMI,decreased LVEF and LVLAS(all P<0.001),enlarged LA,decreased ejection fraction(both P<0.05),and significantly lower LA total strain(εs),active strain(εa),and passive strain(εe)(all P<0.001).During a median follow-up of 16 months,16 patients died.In Kaplan-Meier analysis,εs≤8.29%,εa≤2.05%,and εe≤2.78% all increased the risk of death.In the multivariate model,εs and εa were independent predictors of patient prognosis and significantly improved the predictive ability of the model after adding them to models constructed with NYHA class,Mayo 2004 stage,and LVEF(P=0.002 and P=0.005,respectively).ConclusionFLAS has good repeatability in evaluating LA strain.LA enlargement and dysfunction are common in AL-CA patients.LA strain is correlated with the prognosis of AL-CA patients,and εs and εa are independent predictors of all-cause mortality and provide additional prognostic value on the basis of common clinical staging and CMR parameters.