Diagnosis of Prosthetic Aortic Valve Endocarditis With Gallium-67 Citrate Single-Photon Emission Computed Tomography/Computed Tomography Hybrid Imaging Using Software Registration

Abstract

Prosthetic valve endocarditis can be challenging to diagnose and is associated with high mortality rates even if recognized and managed early. We present a case of staphylococcal sepsis soon after aortic valve surgery and permanent pacemaker implantation for which conventional investigation with echocardiography and computed tomography (CT) failed to identify an infective focus. Subsequent gallium–single-photon emission CT (67Ga-SPECT) imaging with software registration of the SPECT data helped to correctly identify the prosthetic aortic value as the source of sepsis, with resolution of changes on subsequent imaging. A 70-year-old woman underwent bioprosthetic aortic valve replacement and coronary artery bypass grafting for symptomatic severe aortic stenosis and significant 2-vessel coronary disease. Her postoperative course was complicated by significant bradycardia necessitating dual-chamber permanent pacemaker implantation. She presented 3 months after surgery in a confused state, with low-grade pyrexia. The examination identified a soft systolic aortic murmur but no diastolic component, normal breath sounds, absence of cutaneous markers of endocarditis, and no evidence of …