Role of (18)F-FDG PET in Patients with Infectious Endocarditis

It was our purpose to evaluate the clinical impact of systematic PET/CT for the diagnosis of infectious embolisms in patients with infectious endocarditis (IE) in comparison with a historic cohort of IE patients managed without this technique. Detection of extracardiac lesions is an essential component of the management and outcome of IE. Studies using PET/CT for the evaluation of patients with IE are scarce, lack a control group, evaluate a small number of patients, or consist of case reports.

We performed a prospective cohort study (47 patients with definite IE undergoing PET/CT) with matched controls (94 patients with definite IE not undergoing PET/CT) from January 2012 to July 2013 in a tertiary hospital. The results were compared with those of conventional diagnostic techniques and clinical follow-up.

PET/CT revealed at least 1 lesion in 35 patients (74.5%): 18 showed an embolic complication, 8 showed pathologic uptake on the valves or cardiac devices, 1 showed both, 5 had incidental noninfectious findings, and the findings for 3 were considered false-positive. The validity values for the efficacy of PET/CT in the diagnosis of septic lesions were as follows: sensitivity, 100%; specificity, 80%; positive predictive value, 90%; and negative predictive value, 100%. PET/CT was the only initially positive imaging technique in 15 true-positive cases (55.5%). The systematic use of PET/CT was associated with a 2-fold reduction in the number of relapses (9.6% vs. 4.2%, P = 0.25) and enabled significantly more infectious complications to be diagnosed (18% vs. 57.4%, P = 0.0001).

PET/CT enables the extent of IE to be assessed using a single test. It is fast (<2 h) and comfortable for the patient, gathers whole-body data, and detects significantly more infectious complications.