Natural history of vegetations during successful medical treatment of endocarditis.

Although initial morphologic features of vegetations have been related to the risk of early complications, there is little information about the natural history of the vegetations during medical treatment or the relation of morphologic changes in vegetation to late complications. To assess the evolution of valvular vegetations by echocardiography during treatment of infective endocarditis and to relate the morphologic changes in vegetation to late prognosis, serial echocardiograms of patients with successful medical treatment for native valve infective endocarditis were reviewed to assess the presence and morphologic features of valvular vegetations at the onset and at the end of therapy. The evolution of vegetation size, mobility, consistency, the extent of the disease, and the severity of valvular regurgitation were related to late complications such as embolism, valve replacement, or death occurring after the end of therapy. Forty-one vegetations were identified in 32 patients on initial echocardiograms. At the end of treatment, 29 vegetations were still present; 59% had no significant change in size and 52% appeared to be denser in consistency. Morphologic changes did not relate to late complications, but the presence of severe valvular regurgitations was associated with late valve replacement. The echocardiographic persistence of vegetations is common after successful medical treatment of infective endocarditis. In the absence of severe valvular dysfunction, however, persistent vegetations are not independently associated with late complications.