Histoplasma endocarditis in a prosthetic pulmonary valve: A case report

Abstract

Introduction

Infective endocarditis (IE) following transcatheter pulmonary valve placement is a significant concern. Fungal endocarditis, though rare, poses significant diagnostic and therapeutic challenges, particularly when caused by Histoplasma capsulatum.

Case report

We present a 24-year-old female with tetralogy of Fallot (ToF) and a history of transcatheter prosthetic pulmonary valve replacement, who developed IE secondary to active histoplasmosis. Initial symptoms included worsening fatigue and jaundice, leading to hospitalization. Echocardiography revealed new stenosis of the pulmonary valve, prompting further investigation. Despite negative blood cultures, serological and molecular tests for histoplasmosis were positive, confirming the diagnosis. Treatment commenced with amphotericin B, followed by surgical valve replacement two weeks later, revealing hyphal elements indicative of H. capsulatum. The patient subsequently received prolonged antifungal therapy with itraconazole with near complete resolution of symptoms and a mild residual gradient.

Conclusion

This case emphasizes the necessity for heightened awareness of fungal pathogens in patients with prosthetic devices, particularly in the context of culture-negative endocarditis. Early diagnosis and intervention, including surgical resection and appropriate antifungal treatment, are critical for improving patient outcomes.