As a superstar, I had a cold heart (4)

I believe the answer is:

idol

I'm a little stuck... Click here to teach me more about this clue!

'as a superstar' is the definition.
I can't tell whether this definition defines the answer.

'i had a cold heart' is the wordplay.
'i had' becomes 'i'd' (I'd).
'heart' indicates the central letters.
The central letters of 'cold' are 'ol'.
'id'+'ol'='IDOL'

Can you help me to learn more?

(Other definitions for idol that I've seen before include "Who's greatly respected" , "Superstar; graven image" , "Pop - - (TV)" , "Object of excessive adoration" , "Heathen god" .)

I've seen this clue in the Evening Standard.

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