Prognostic significance of semiautomatic quantification of left ventricular long axis shortening in systemic light-chain amyloidosis

Abstract

Aims: To assess left ventricular long axis shortening (LAS) in patients with AL amyloidosis as a potential predictor for outcome.

Methods and results: We performed a de novo echocardiographic analysis of LAS in 120 patients with biopsy-proven AL amyloidosis evaluated at first presentation before specific treatment. Additionally, 47 control subjects were analyzed retrospectivly. LAS was measured using a semiautomatic tissue motion annular displacement software algorithm (TMAD). LAS was significantly better than ejection fraction (EF) (p < 0.0001) and M-mode-derived mitral annular plane systolic excursion (MAPSE) (p < 0.05) discriminating AL patients from control subjects, while being non-inferior compared to tissue Doppler-derived peak systolic mitral annular velocity. One year outcome analysis in patients with AL amyloidosis showed that LAS remained the only significant echocardiographic parameter (HR:0.76; p < 0.005) in a multivariable Cox regression model of echocardiographic values. In a comprehensive clinical model, LAS (HR:0.72, p < 0.0001), cardiac troponin-T (HR:2.86, p < 0.01) and free light chain difference (HR:1.00; p < 0.05) were independently associated with the outcome. Assessment of LAS led to a significant integrated discrimination improvement and offered incremental information compared to EF and biomarkers. The cut-off value for LAS discriminating the endpoint was 5.8%.

Conclusion: LAS was an independent predictor of survival within the first year and offers incremental information in patients with AL amyloidosis evaluated prior to specific treatment.

• Amyloidosis
• echocardiography
• long axis shortening
• longitudinal strain
• prognosis

Acknowlegements

We would like to thank our technicians Anita Hager, Christiane Selter and Arnold Siegmund for their excellent assistance.

Declaration of interest

Dr. Katus has developed the cTnT assay and holds a patent jointly with Roche Diagnostics. He has received grants and research support from several companies, and has received honoraria for lectures from Roche Diagnostics. The study was supported by a grant from the B. Braun Stiftung.