The older they become, the worse it gets.
Narcissist have a good chance to get cured when they are getting help by psychologists. In reality most of them won't seek professional help. Instead they will suffer from becoming old.
Especially their self-esteem gets more and more damaged by not looking young and "perfect" anymore. They are lacking of efficiency as well.
When they realise that their lifetime will end without them being able to fill the emptyness inside their heart they become badly cold-hearted.