BHF announced that it was searching for an ad agency in April and appointed the AAR to run the pitch.
Grey has been appointed to handle three briefs for the BHF, which has in the past appointed agencies on a project-by-project basis.
The agency will produce work for the next stage of BHF's chest pains work, a kids "food for thought" campaign and a corporate brand push early next year.
The charity has previously worked with Farm, which created the "30 a day" ad campaign featuring a semi-naked couple urging the over-50s to do 30 minutes of exercise a day.
It has also worked with Euro RSCG, Lowe and RKCR/Y&R in the past.
The BHF also called a review of its £4m media planning and buying account last month. The incumbent Manning Gottlieb OMD had held the business for longer than a decade, during which time the BHF called several creative pitches but remained loyal to its media agency.
Earlier this month the BHF appointed BEC for a direct campaign, which will involve it handling the development and branding of a new information and support service due to launch later this year.
The BHF will then recruit people to sign up to the service through on- and offline marketing campaigns, also created by BEC.