The incumbent, Abbott Mead Vickers BBDO, which had held the account for four years, did not repitch.
The pitch process involved the shortlisted agencies organising interactive workshops for BHF departmental heads.
Betty McBride, the director of marketing and communications at the BHF, said: "The pitch workshops were designed to assess the strategic strength of the agencies, their understanding of the voluntary sector and, crucially, whether they could click with staff from every discipline in the charity."
Partners' first major project for the charity is a campaign around Valentine's Day to encourage women to make lifestyle changes that could improve the health of their heart. According to research, heart disease kills four times as many women as breast cancer. The campaign is designed to increase knowledge of the disease and raise awareness of the risks.
In June, AMV created a press campaign using graphic imagery of the symptoms of heart disease. One of the images showed a woman with a polythene bag over her head and the line: "I've got heart failure. And this is what it feels like every morning." The ad received hundreds of complaints and was censored by the Advertising Standards Authority, which agreed that children could copy it.
McBride added: "We have a complex, highly specialised marketing community here at the British Heart Foundation - our new agency will be expected to be part of the team."