The phrase "as its heart" is correct and usable in written English.
It can be used to describe the central or most important part of something, often in a metaphorical sense.
Example: "The city is known for its vibrant arts scene, which serves as its heart, bringing together diverse communities and cultures."
Alternatives: "at its core" or "in its essence".
It's the first feature length film to tell the story of the Icelandic disappearances in detail, and like all good recent true crime thrillers – the Amanda Knox documentary, Making a Murderer, Serial – it takes as its heart a fascinating miscarriage of justice.
While the mercurial Westerberg has always been regarded as the public face and chief behind-the-scenes creative force for the band, it's Bob who emerges in the book as its heart and soul.
Yet that's not too surprising, as its heart isn't in this quest.
The Oakland Cannery is just the type of place that the city likes to promote as its heart and soul.
And, since camp is the denial of feeling, "The Woman in White" is a perfect camp object: all hysterical action, with artifice as its heart.
LETTER FROM LONDON discusses the South East Study, a report dealing with the country below a line drawn from the Wash to Dorset, with London as its heart.
It was explosive, in your face, no nonsense drama that is as dark at its heart as any story can get.
Jarvis was also however, mature and professional enough to know that at its heart, as it must be, endurance racing is a team sport.
As the title suggests, at its heart it's the tale of the substitution of reality with "reality," of factual truth with interpretive possibility.
It was a challenge to work Forest Pansy (Cercis canadensis) into my limited landscape, as its heart-shaped leaves and reddish-purple flowers did not fit in with my mixed tree border in the back.
The small, unconventional family at its heart is as committed to keeping itself whole as are the loved ones who risk their lives in coming to America.
