Apocryphal story (true) of a chap who had just passed his Class 1 CAA medical who collapsed and died, suffering a heart attack as he left the examiner's office. So much for his ECG. So much for the medical. And yet what more could be done? Of greatest importance is to run 6-monthly sim checks from Day One on FO's, allowing them to demonstrate their abilities to deal with an incapacitated captain. And vice versa.