Based on the kind of cardiac amyloid (protein), the extent of organ involvement, and the stage of diagnosis, the average life expectancy varies. In severe cases, based on these variables, it could be six months, while in some circumstances, the life expectancy can be eight to ten years after diagnosis. The Genetic and Rare Diseases Information Center estimates that individuals with familial ATTR-type amyloidosis live for seven to twelve years on average after diagnosis.