Case report of isolated aortic valve AL-amyloidosis following aortic valve replacement.

Background: Light chain (AL)-amyloidosis is a haematologic malignancy where cardiac involvement confers a worse prognosis. There is a recognized association between aortic stenosis (AS) and transthyretin amyloidosis (ATTR) cardiomyopathy. However, there is no such reported association with AL amyloidosis.

Case summary: We present a case of degenerative AS where the pathology analysis post-surgical replacement demonstrated amyloid deposits subsequently identified as AL subtype by mass spectrometry. Subsequent investigations demonstrated no myocardial or systemic involvement. Following multidisciplinary discussion, cardiac biopsy and chemotherapy were deferred given the isolated nature of aortic valve involvement and clinical stability.

Discussion: Incidental detection of aortic valve AL-amyloidosis in this case demonstrates that such deposits cannot be assumed to be ATTR, and further work-up and amyloid typing is necessary.