Prognostic Value of Left Ventricular Myocardial Strain Parameters Derived from Cardiac Magnetic Resonance Feature Tracking Technique in Light-Chain Cardiac Amyloidosis Patients: A Pilot Study

Background: Previous research on the prognostic implications of left ventricular myocardial strain using cardiac magnetic resonance feature tracking (CMR-FT) in light-chain cardiac amyloidosis (AL-CA) has shown promising potential. This study aimed to evaluate the prognostic significance of global and segmental left ventricular myocardial strain in AL-CA patients, specifically analyzing the American Heart Association's 16 segments. Methods: A total of 75 consecutive patients (50 men, mean age: 55.6 +/- 10.0 years) who underwent CMR examination with histologically confirmed systemic AL-CA were retrospectively enrolled between January 2014 and November 2022. Both global and segmental myocardial strain and the American Heart Association's 16 segments were quantified using CMR-FT on the steady-state free precession (SSFP) cine sequence. A comparative analysis was conducted between survivors and non-survivors based on the defined endpoint. Student t-test or Mann-Whitney U, receiver operating characteristic curve, Kaplan-Meier event-free survival curve, and Cox proportional hazards regression were used. Significance was set at p < 0.05. Results: Following a median follow-up of 34 months, 16 out of 75 patients experienced mortality events. B-type natriuretic peptides (BNP) (p < 0.001), global radial strain (RSglobal) (p = 0.033), and RS in the basal inferior segment (RSbas-inferior) (p = 0.025) remained significant as independent predictors of all-cause mortality. The cut-off values were identified as 24.97% for RSglobal, and 20.97% for RSbas-inferior. Kaplan-Meier survival curves revealed significantly reduced event-free survival for individuals in the lower cut-off groups for RSglobal and RSbas-inferior (p = 0.013, p < 0.001, respectively). Conclusions: Radial strain for the global and the basal inferior segment may prove valuable for risk stratification in patients with AL-CA.