[Object] A prophylactic or therapeutic agent for acardiovascular disease is provided.[Means for Resolution] An atropisomer of a compoundrepresented by the following general formula (I):(see formula I)(wherein R1 is a C1-C3 alkyl group or a hydroxy-C1-C3alkyl group; and R2 is a hydrogen atom or a C1-C3 alkoxygroup).