Diagnosing pulmonic valve infective endocarditis with positron emission tomography-CT

A Rare Case of Blood Culture-Negative Isolated Pulmonic Valve Endocarditis Causing Empyema

Right-sided native valve infective endocarditis (IE) refers to IE involving the tricuspid or pulmonic valve. The most common factors causing right-sided IE include intravenous drug use, intracardiac device, and central venous catheters. Isolated pulmonic valve IE has only been reported in less than 2% of all IE cases. We present a unique case of a patient with a history of poor oral hygiene found to have isolated blood culture-negative pulmonic valve IE, who subsequently developed empyema positive for Streptococcus constellatus.

Pulmonary Valve Endocarditis: The Potential Utility of Multimodal Imaging Prior to Surgery

BACKGROUND

The presence of echocardiographic (echo) evidence is a major criterion for the diagnosis of infective endocarditis (IE) by modified Duke criteria. Pulmonary valve (PV) IE, however, can be challenging to identify by echo. We sought to evaluate the added utility of multimodal imaging in PV IE.

METHODS

This is a single-center case series. We retrospectively analyzed demographic, laboratory, imaging, clinical, and surgical data from patients diagnosed with PV IE from 2008 to 2018.

RESULTS

A total of 23 patients were identified with definite PV IE by Duke criteria (83% male and ages 2 months to 70 years). Twenty-two patients had congenital heart disease, with 21 involving the right ventricular outflow tract (including three with transcatheter PV implant). Overall, 20 (87%) of 23 had positive blood cultures. A total of 17 (74%) of 23 patients demonstrated echo evidence of PV IE. In three cases, echo was negative (did not show vegetations) but showed new PV obstruction. In four cases with negative transthoracic echocardiogram and transesophageal echocardiogram, evidence of PV IE was subsequently seen by positron emission tomography/computed tomography (n = 2) or cardiac magnetic resonance imaging (n = 2). Pulmonary valve IE was confirmed at surgery by evaluation of pathologic samples in 20 cases.

CONCLUSIONS

Multimodal imaging improves the ability to preoperatively identify endocardial involvement in PV IE in cases where echo is negative. Consideration should be given to revise Duke criteria to include new obstruction and endocardial involvement by multimodal imaging for PV IE.

Isolated pulmonary valve endocarditis: truth or myth?

Pulmonary valve (PV) infective endocarditis (IE) is an extremely rare disease that involves normal as well as abnormal valves. This condition mostly occurs in patients with underlying predisposing factors. It could be missed if patients do not present with typical features of right-sided endocarditis or in the absence of classic risk factors. The case presented here did not have any known risk factors for IE until surgery and presented mainly with fever, weight loss, and musculoskeletal symptoms.