Investigation of left ventricular function and biomarkers following chemotherapy in patients with light-chain cardiac amyloidosis

Abstract

Objective To assess whether strain parameters derived from three-dimensional speckle tracking imaging (3D-STI) could identify improvement of cardiac function and predict response of patients with immunoglobulin light-chain cardiac amyloidosis (AL-CA) following chemotherapy. Methods Totally 13 patients with AL-CA [aged (58.5±8.9)years; 69% males] were treated with melphalan or bortezomib-based regimens and by regular chemotherapy for 6 months.The clinical data was collected. Maximal left ventricular wall thickness (MLVWT), left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), systolic mitral annular velocity (s′), early diastolic mitral annular velocity echocardiography (e′), 3D-STI global longitudinal, circumferential, radial and area strain (GLS, GCS, GRS, and GAS), the standard deviation of time to peak longitudinal strain among 16 left ventricular segments (TS-SD_GLS) were obtained by conventional echocardiography and 3D-STI. In addition, serologic biomarkers including N-terminal pro-brain natriuretic peptide (NT-proBNP) and free light chains (FLC) were acquired at baseline and 6 months after chemotherapy. These patients were divided into two groups according to difference of FLC: complete response (CR) group and Non-CR group. The clinical data, cardiac ultrasound parameters and serological parameters were compared between groups, each group parameters at baseline and 6 months after chemotherapy were compared within the group. Results ①There were no significant difference in conventional echocardiographic parameters, GCS, GRS and GAS, as well as TS-SD_GLS in either group between before and after chemotherapy. But GLS was improved only in CR group (P=0.036), and its improvement was correlated with the decrease in NT-proBNP (r=-0.738, P=0.037). ②In baseline evaluation, patients in Non-CR group had increased LVMI, deteriorated e′ and GLS, and longer Ts-SD as compared to those in CR group (all P 4.7 cm/s, absolute value of GLS>16.6%, and TS-SD_GLS<35.2 ms, which may have better hematologic response to chemotherapy. Conclusions GLS can identify early improvement of cardiac function in AL-CA patients after chemotherapy. Moreover, LVMI, e′, GLS and TS-SD_GLS are sensitive measurements of pre-treatment ventricular impairment, and may predict better response to chemotherapy. Key words: Echocardiography; Light-chain cardiac amyloidosis; Ventricular function, left; Three-dimensional speckle tracking imaging; Biomarker; Chemotherapy