Résumé
Light chain amyloidosis (AL) is a kind of rare disease. The misfolding of the light chain of monoclonal immunoglobulin forms amyloid substances and deposit in different tissues and organs, resulting in organ dysfunction. The heart involvement is represented as light chain cardiac amyloidosis (AL-CA), leading to heart failure, arrhythmia, myocardial infarction, valvular and pericardial diseases. Cardiac involvement is crucial for the risk stratification and prognosis prediction of patients with AL. The median survival time of AL-CA patients is 24 months and only 6 months for the heart failure patients. In recent years, the prognosis of patients with AL-CA has been significantly improved, thanks to the advancement in diagnosis & treatment strategies of cardiac amyloidosis, the milestone in the breakthroughs in targeted therapy of AL, and the improvement of coordinated multidisciplinary treatment. This paper focuses on the cardiovascular involvement of AL and briefly illustrates the pathogenesis, clinical manifestations, and the diagnosis and treatment of AL-CA.
Résumé
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 differencein 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) . ② In 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 < 0 .05 ) . ③ ROC analysis revealed that these parameters had discriminative ability to forecast those with better therapeutic effectiveness ,esecially for AL-CA patients with baseline LVMI<96 .55 g/m2 ,e′>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 .