Erythema multiforme (EM) is a skin reaction that comes from an infection or another trigger. EM is a type of allergic reaction. In most cases, it occurs in response to an infection. In rare cases, it is caused by certain medicines or body-wide (systemic) illness. Infections that may lead to EM include:
1 Heart attack. A heart attack can damage the area of the heart muscle that supports the mitral valve, affecting the function of the valve. If the damage is extensive enough, a heart attack can cause sudden and severe mitral valve regurgitation.  Abnormality of the heart muscle (cardiomyopathy).
Mitral valve regurgitation cause anemia - Could mitral valve regurgitation cause anemia? Unlikely. If one has mixed mitral valve disease with a heavily calcified mitral valve that is both stenotic and regurgitant, one could imagine marked turbulance of the blood flow across the mitral valve with destruction of rbc's however, this is very unlikely.