The long-term outlook of pediatric cardiomyopathy continues to be unpredictable because it occurs with such a wide spectrum of severity and outcome. Even if a child has a family history of the disease, the degree to which he or she is affected can vary considerably from his/her parents or siblings. The overall prognosis for a child also depends on the type of cardiomyopathy and the stage the disease is first diagnosed.

Past prognosis on pediatric cardiomyopathy has been disappointing with very high projected mortality rates. Often children without obvious symptoms or a family history of the disease were either not diagnosed or not diagnosed early enough to prevent sudden cardiac death or progressive heart failure. Fortunately, in the past decade there have been diagnostics improvements, earlier recognition and more appropriate treatments. Currently, the annual mortality rate for children with hypertrophic cardiomyopathy is 3-6% while children diagnosed with dilated cardiomyopathy face a mortality rate close to 20% within the first year of diagnosis. On a more positive note, the five year survival rate for children diagnosed with hypertrophic cardiomyopathy is roughly 85%, and for children diagnosed with dilated cardiomyopathy, it is close to 60%. Children with restrictive cardiomyopathy have a 50% change for 2 year survival following presentation.

Although presently there is no cure for cardiomyopathy, some symptoms and complications can be managed and controlled with medication and implantable devices. Some children will stabilize with proper treatment and are able to lead normal or nearly normal lives with some restrictions on exercise capacity. For children with more complex forms of cardiomyopathy, there may be more limitations, specialized care, or developmental delays. A heart transplant may solve the problem but at the expense of other possible medical complications. Each year 80% of diagnosed children listed for a heart transplant receive a heart in time. Of the more than 100 children per year that undergo a heart transplant, the average three year survival rate is 77%.

Until researchers can identify the exact gene causing cardiomyopathy, there is no known way to prevent the disease from recurring. Families with a history of cardiomyopathy who are considering having more children should speak to a genetic counselor to understand the risks involved. The possibility of gene therapy is still a debatable point and not enough is known about the genetic origins of pediatric cardiomyopathy to completely rule out the possibility. Some believe that it is not a practical or reasonable solution since it would involve removing a defective protein as opposed to inserting a missing protein, which has proven successful in curing genetic disorders such as cystic fibrosis. With cardiomyopathy, it would be extremely difficult to introduce enough "good genes" to make all the muted genes normal. Also, there is no reassurance that gene therapy would work to reduce or reverse any wall thickening that has already occurred. At this point, researchers continue to investigate the feasibility of more innovative treatments.