Clinical implications of atrial natriuretic peptide amyloidosis.

A 74-year-old woman with a history of diastolic heart failure and refractory atrial fibrillation (AF) presented with unstable angina for coronary artery bypass grafting. Routine pathological analysis of tissue specimens obtained from the left atrial appendage revealed subendocardial and interstitial fibrosis and patchy amyloid deposits with Congo red staining demonstrating filamentous deposits. Mass spectrometry was consistent with isolated atrial amyloidosis (IAA). IAA in this patient was found incidentally on routine postoperative pathology, but likely contributed to significant morbidity. The established relationship between IAA with AF and diastolic heart failure underscores the relevance. Further delineating the pathogenesis has potentially immense implications for the future management of associated conditions. To bridge the gaps in the understanding, a standardised approach to diagnosis is needed to open the door to a large-scale study and further work toward establishing evidence-based management pathways.