People who run key enterprises losing heart (8)
I believe the answer is:
escapees
'people who run' is the definition.
'escapees' can be an answer for 'people' (escapee is a kind of person). I'm unsure of the remainder of the definition.
'key enterprises losing heart' is the wordplay.
'key' becomes 'escape' (key on a keyboard).
'enterprises' becomes 'els' (el is a kind of enterprise).
'losing heart' suggests removing the centre.
'els' with its middle removed is 'es'.
'escape'+'es'='ESCAPEES'
Can you help me to learn more?
(Other definitions for escapees that I've seen before include "They got away" , "They've run away from confinement" , "Those getting free (E, not R)" , "They get away from confinement" , "Gaol-breakers" .)