Role of radiolabelled leucocyte scintigraphy in patients with a suspicion of prosthetic valve endocarditis and inconclusive echocardiography

In patients with a suspicion of prosthetic valve endocarditis (PVE), detection of perivalvular infection can be difficult based only on echocardiography. The aim of this retrospective study was to test the interest of radiolabelled leucocyte scintigraphy (LS) for the detection of perivalvular infection in patients with a suspicion of PVE and inconclusive transoesophageal echocardiography (TEE). LS was performed in 42 patients. The results of LS were classified as positive in the cardiac area (intense or mild), or negative. Macroscopical aspects and bacteriology were obtained from patients who underwent cardiac surgery (n 10). Clinical outcome was collected in patients treated medically (n 32). Among patients with intense signal with LS who underwent surgery (n 6), five had an abscess confirmed during intervention and one, post-operatively. Patients with intense accumulation of radiolabelled leucocytes with scintigraphy and treated medically (n 3) had a poor outcome: death (n 1); prosthetic valve dehiscence (n 1); and recurrent endocarditis (n 1). Among patients with mild activity with LS (n 5), one patient developed a large prosthetic valve dehiscence during the follow-up. The remaining four patients were treated medically and did not present any recurrent endocarditis after a median follow-up of 14 months. No abscess was detected in patients with negative LS who underwent surgery (n 4). Among the patients with negative LS treated medically (n 24), none presented recurrent endocarditis after a mean follow-up of 15 16 months. Patient management was influenced by the results of LS in 12 out of 42 patients (29). This study suggests that LS is useful for the identification of perivalvular infection in patients with a suspicion of PVE and inconclusive TEE.