The most common and most likely answer to this crossword clue is the 8 letter word KINGPINS
I've seen this crossword clue in The Sunday Telegraph
K
I
N
G
P
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S
More clues leading to the result KINGPINS
Buddy explains!

The straight part
We know that "most important people" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case most important people = kingpins.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does KINGPINS mean?
KINGPINS noun- (motorized vehicles) The axis around which steered wheels pivot; a bolt that holds the axis in placeāa kingbolt.
- The pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex.
- The most important person in an undertaking or organization.
- The bolt holding together the truck of a roller skate or skateboard.