Manage to come through cardiac operation (4)
I believe the answer is:
cope
'manage' is the definition.
(manage can mean to cope or do well)
'to come through cardiac operation' is the wordplay.
'to come through' says the answer is hidden in the clue.
'COPE' is hidden in the letters of 'cardiac operation'.
(Other definitions for cope that I've seen before include "Deal effectively (with a difficulty)" , "Deal well with difficulties" , "Deal with, manage successfully" , "Handle a situation" , "Manage, subsist" .)