What is the usual prognosis for a severe coarctation of the aorta?

Depends on treatment: Untreated coarctation can lead to debilitating claudication, heart failure, renal failure and death. However, coarctation should be a completely curable condition with excellent long term outcomes.

Depends: The specific prognosis depends on age of diagnosis, other medical conditions, any problems prior to diagnosis, and the location of the lesion which affects the means of treatment (i.e. Surgery or cath). The prognosis can be excellent, even with "severe" cases, but depends on the factor above. Please discuss this with your cardiologist.