The present invention provides a medicament for preventing or treating heart failure. More specifically, the present invention provides a medicament for preventing or treating heart failure, comprising a compound selected from the group consisting of (5R)-N-[1-ethyl-1-(4-ethylphenyl)propyl]-2,7,7-trimethyl-5-phenyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-3-carboxamide, (5R)-N-[1-ethyl-1-(4-methoxyphenyl)propyl]-2,7,7-trimethyl-5-phenyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-3-carboxamide, (5R)-N-[1-ethyl-1-(4-ethylphenyl)propyl]-5-(2-fluorophenyl)-2,7,7-trimethyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-3-carboxamide and salts thereof.
