MRI feature tracking strain is prognostic for all-cause mortality in AL amyloidosis

Objectives: Cardiac involvement is a major determinate of mortality in light chain (AL) amyloidosis. Cardiac magnetic resonance imaging (MRI) feature tracking (FT) strain is a new method for measuring myocardial strain. This study retrospectively evaluated the association of MRI FT strain with all-cause mortality in AL amyloidosis. Materials and methods: Seventy-six patients with newly diagnosed AL amyloidosis underwent cardiac MRI. 75 had images suitable for MRI FT strain analysis. MRI delayed enhancement, morphologic and functional evaluation, cardiac biomarker staging and transthoracic echocardiography were also performed. Subjects’ charts were reviewed for all-cause mortality. Cox proportional hazards analysis was used to evaluate survival in univariate and multivariate analysis. Results: There were 52 deaths. Median follow-up of surviving patients was 1.7 years. In univariate analysis, global radial (Hazard Ratio (HR) = 0.95, p <.01), circumferential (HR = 1.09, p <.01) and longitudinal (HR = 1.08, p <.01) strain were associated with all-cause mortality. In separate multivariate models, radial (HR = 0.96, p =.02), circumferential (HR = 1.09, p =.03) and longitudinal strain (HR = 1.07, p =.04) remained prognostic when combined with presence of biomarker stage 3. Conclusions: MRI FT strain is associated with all-cause mortality in patients with AL amyloidosis.