Not all. There are various grades of heart failure and many with reversible causes. When the cause of heart failure is transient and reversible, the long term results are good. A classical example is peripartum cardiomyopathy, heart muscle disease which occurs in late pregnancy or in the few months after delivery. If the immediate crisis of heart failure can be tided over by appropriate treatment, they have a near normal life span, though there is a risk of recurrence in subsequent pregnancies. Only those cases of severe heart failure not responding to treatment have a poor outcome. Even in those situations, we have artificial devices and heart transplantation to bail out.