TTR and amyloidosis: We may encounter false-negative results for ATTR-CA in the following circumstances: rib fractures or valvular calcifications, recent myocardial infarction, genetic variants with reduced sensitivity to bisphosphonate scintigraphy (Phe64Leu [23], Phe84Leu, Ser97Tyr [2]), a mild form of amyloidosis or noncompliance with acquisition types for scintigraphy [2].