Sudden death possibly related to lenalidomide given for cardiac and muscle AL amyloidosis secondary to light chain deposition disease

Abstract

Objectives: Restrictive cardiomyopathy due to AL amyloidosis has not been reported as the cause of sudden death. The risk of sudden death in AL amyloidosis may be further increased by potentially cardiotoxic medication, as in the following case. Case report: In a 69-year-old female, AL amyloidosis from light-chain deposition disease manifested as gastrointestinal pseudo-obstruction, restrictive cardiomyopathy, and secondary myopathy. AL amyloidosis was histologically confirmed by endomyocardial biopsy and muscle biopsy. One month after initiation of steroids and lenalidomide the patient suddenly died during sleep. It is speculated that sudden death was due to restrictive cardiomyopathy, cardiotoxicity of lenalidomide, pulmonary embolism, sudden unexplained death in epilepsy syndrome or stroke. The possible causes of sudden death are discussed. Conclusions: This case shows that AL amyloidosis from light-chain deposition disease may predominantly affect the intestines, myocardium and the skeletal muscle and that lenalidomide may have a beneficial effect on the amyloidosis but should be given with caution for its potential arrhythmogenic and thrombogenic side-effects.