[The clinical importance of scintigraphy with the murine monoclonal antigranulocyte antibody BW 250/183 for the diagnosis of prosthesis-related endocarditis].

Thirty-eight patients (16 men, 22 women; median age 62.5, range 7 to 80 years) were enrolled in a prospective study to assess the clinical utility of radioimaging using the antigranulocyte antibody BW 250/183 in suspected valve endocarditis. Eighteen patients had prosthetic valve endocarditis according to clinical criteria (surgical confirmation in 8 patients), the remaining 20 patients served as controls. All patients underwent transthoracic and transesophageal echocardiography. Eight to 10 MBq of technetium-99m-labeled antibody were intravenously injected and single-photon emission computed tomography (SPECT) of the thorax was performed after 20 to 24 h. Echocardiography revealed pathological findings in 16 of 18 patients with endocarditis (sensitivity 89%) and was false positive in one of 20 control subjects (specificity 95%). Scintigraphy was true positive in 14 of 18 patients with endocarditis (sensitivity 78%) and false positive in three of 20 control subjects (specificity 85%). Scintigraphy was true positive in the patients with false negative echocardiography and vice versa (sensitivity for both methods combined 100%, specificity 80%). In all five follow-up patients, scintigraphy became negative parallel to clinical improvement. This suggests that scintigraphy indicates the floridity of the inflammatory process. In clinically suspected prosthetic valve endocarditis with equivocal echocardiographic findings, SPECT using the antigranulocyte antibody BW 250/183 may provide valuable additional diagnostic information.