Twenty percent of patients with cardiomyopathy die one year after diagnosis, and 70 to 80 percent die eight years after diagnosis, according to American Family Physician. The prognosis varies greatly depending on the cause of the condition.
Cardiomyopathy represents a broad range of diseases that lead to heart failure, explains American Family Physician. Dilated cardiomyopathy, the most common form of the disease, is the third most frequent cause of heart disease. Thirty percent of patients suffering from cardiomyopathy survive five years from diagnosis according to Patient. Patients who also have mitral regurgitation or diastolic dysfunction have a lower chance of survival.