[Analysis of Clinical Features of Newly Diagnosed Multiple Myeloma Complicated with Light Chain Amyloidosis]

To analyze the clinical characteristics of patients with multiple myeloma (MM) complicated with light chain amyloidosis (AL), particularly those with cardiac amyloidosis (CA), in order to provide evidence for early identification.

Clinical data were retrospectively collected from 359 newly diagnosed MM patients at the First Affiliated Hospital of Soochow University from August 2017 to December 2023. Based on histopathological results, patients were grouped to compare the clinical characteristics between the multiple myeloma with amyloid light-chain (MM-AL) group and the multiple myeloma without amyloid light-chain (MM without AL) group, as well as between the cardiac involvement and non-cardiac involvement subgroups within the MM-AL cohort.

MM-AL patients accounted for 19.5% (70/359), of whom 30.0% had cardiac involvement. Compared with the MM without AL group, the MM-AL group had a higher proportion of λ light chain type (65.7% vs. 45.0%), a higher proportion of frail patients (45.7% vs. 29.1%), a lower proportion of DS stage III (84.3% vs. 93.4%), fewer patients presenting with bone pain as the initial symptom (45.7% vs. 69.2%), and higher proportions of patients with heart failure (12.8% vs. 4.2%) and non-hypoproteinemia polyserositis (27.2% vs. 5.9%) (all P < 0.05). Electrocardiogram abnormalities (low voltage, pseudo-infarction) were observed only in the MM-AL group. Compared with those without cardiac involvement, MM-CA patients had a higher proportion of light chain type (47.6% vs. 18.4%), a higher proportion of congestive heart-failure at onset (33.3% vs. 4.1%), a higher incidence of major adverse cardiovascular events during treatment (33.3% vs. 2.0%), and significantly elevated levels of NT-proBNP and hs-TnT, as well as a higher incidence of electrocardiogram abnormalities (all P < 0.05). Multivariate analysis showed that non-hypoproteinemia polyserositis (OR =7.66, P < 0.001) and λ light chain type (OR =2.40, P =0.017) were independent risk factors for MM complicated with AL. In terms of cytogenetics, the proportion of high-risk cytogenetic abnormalities was lower in MM-CA patients compared with those without cardiac involvement (14.3% vs. 36.7%, P =0.047).

Patients with MM complicated by AL present with distinct clinical and cytogenetic features. The presence of λ light chain type and non-hypoproteinemic polyserous effusions are independent risk factors. Electrocardiographic findings of low voltage and pseudoinfarction patterns are suggestive of early recognition of AL and cardiac involvement.