Does rheumatic fever cause mitral valve disease?

Yes. One of the features of rheumatic fever is pan-carditis, meaning that all layers of the heart are inflamed. Involvement of the mitral valve occurs 10x more often in women and aortic valve disease 4x more often in men. Quite frequently both the aortic and mitral valves are involved, with the tricuspid next in frequency and the pulmonic the least common. This can result in many complications.