Discordance between serum cardiac biomarker and immunoglobulin-free light-chain response in patients with immunoglobulin light-chain amyloidosis treated with immune modulatory drugs.

We evaluated the capability of soluble cardiac biomarkers to predict tolerability and outcomes of IMiD-containing treatments among 106 patients treated on clinical trials. Baseline elevations in troponin T (TnT) and N-terminal brain naturietic protein (NT-proBNP) predicted for an inability to tolerate IMiD-based regimens. The best predictors for early attrition during cycle 1 were TnT ≥ 0.07 μg/L and NT-proBNP ≥ 11,939 ng/L. NT-proBNP-response underperformed TnT-response as a predictor for overall survival (OS), but both predicted for early protocol attrition. Despite hematologic response, IMiD-treated patients were at higher risk for NT-proBNP rises and early drug discontinuation than a control population but not for early death. These observations prompt two questions: (1) does IMiD-based therapy lead to increased fluid retention and/or cardiac toxicity and (2) is an NT-proBNP-driven cardiac response system valid in IMiD-treated amyloidosis patients? Recognition of potential drug-induced cardiac toxicity is important so that increased cardiac surveillance and drug dose-adjustment or discontinuation may be implemented.