Introduction
Right-sided infective endocarditis accounts for only 5–10% of all endocarditis cases, and isolated pulmonary valve involvement represents only 1–2%. Paediatric fungal infective endocarditis is rare but severe, with Candida spp. responsible for roughly half of fungal cases. Pulmonary artery banding can predispose to endovascular infection and unusual complications, including pseudoaneurysm and thrombus at the band site. Reference Jamil, Al-Kadri, Kheiri and Emara5
The 2023 European Society of Cardiology endocarditis guideline emphasises multimodality imaging, early involvement of an endocarditis team, and timely surgery for heart failure, uncontrolled infection, or prevention of emboli. Paediatric-focused guidance from the American Heart Association and antifungal recommendations from the Infectious Diseases Society of America (IDSA) inform species-directed therapy in children with Candida IE. Reference Delgado, Ajmone Marsan and de Waha1,Reference Baltimore, Gewitz and Baddour2,Reference Pappas, Kauffman and Andes3
The aim of this report is to present two rare cases of Candida endocarditis involving the pulmonary valve and main pulmonary artery after pulmonary artery banding, emphasising diagnostic challenges, management strategies, and outcomes.
Case presentation
Case 1
A female infant was diagnosed at 1 month of age in another centre with complete atrioventricular septal defect and underwent pulmonary artery banding for palliation. At 18 months of age, she was admitted to our clinic for definitive repair. On admission, her body weight was 6.8 kg, below the 3rd percentile for age. Transthoracic echocardiography demonstrated an 11 mm primum atrial septal defect and a 10 mm inlet ventricular septal defect with mild regurgitation of both right and left atrioventricular (AV) valves. The pressure gradient across the pulmonary artery band measured 44 mmHg, and the left pulmonary artery was 5 mm (Z-score –0.7). The patient had prolonged hospitalisation and had received intermittent broad-spectrum antibiotics prior to admission, which may have contributed to fungal overgrowth. However, she had not received total parenteral nutrition.
During hospitalisation, the patient developed a high fever, and blood cultures grew Candida albicans. Antifungal therapy was initiated intravenously with fluconazole (60 mg once daily). Follow-up echocardiography revealed a 5.8 × 4.1 mm mobile vegetation (Figure 1( a )) located on the pulmonary artery just proximal to the bifurcation. Surgery was performed 7 days after the first positive fungal culture, once persistent candidemia and a vegetation were confirmed. The patient subsequently underwent surgery, which included pulmonary debanding, complete atrioventricular septal defect repair, excision of the vegetation, closure of a pulmonary pseudoaneurysm (Figure 1( b )), and pulmonary artery reconstruction using bovine pericardium.
(a) Mobile mass at the pulmonary bifurcation producing flow acceleration. (b) Contrast-filled pseudoaneurysm contiguous with the main pulmonary artery adjacent to the prior band (arrow).
The postoperative course was notable for complete atrioventricular block, and the patient was supported with temporary pacing. In the intensive care unit, she received linezolid (71 mg twice daily), fluconazole (60 mg once daily), sulfamethoxazole-trimethoprim (200/40 mg twice daily), and meropenem (105 mg three times daily). Multiple antibacterial agents were administered to control concomitant bacterial infections and to cover possible nosocomial pathogens during prolonged ICU stays. These agents were not intended as antifungal therapy but were part of broad-spectrum coverage given the severity of the patient’s condition. She was extubated uneventfully on postoperative day 7. Because of persistent AV block, an epicardial permanent pacemaker was implanted. Although the early postoperative course was complicated by complete heart block requiring permanent pacemaker implantation, she recovered steadily and was ultimately discharged in good clinical condition. Reference Pappas, Kauffman and Andes3,Reference Talvard, Paranon, Dulac, Mansir, Kreitmann and Acar4
Case 2
A 2-month-old female infant weighing 3.5 kg (below the 3rd percentile for age) was admitted to our clinic with a diagnosis of a large subpulmonic ventricular septal defect. Preoperative transthoracic echocardiography revealed a 6 mm ventricular septal defect, transverse aortic arch hypoplasia measuring 3.9 mm (Z-score –4.5), and an isthmus diameter of 4.3 mm (Z-score –2.4). The patient underwent pulmonary artery banding and aortic arch reconstruction.
Case 2 had a prolonged postoperative intensive care stay with multiple courses of antibiotics for recurrent bronchopneumonia, representing an additional predisposing factor for candidaemia. Three months after discharge, she was readmitted to our institution with a high fever and signs of systemic infection. Blood cultures grew Candida parapsilosis, and antifungal therapy with amphotericin B (15 mg once daily) was initiated intravenously along with vancomycin (50 mg four times daily) and meropenem (100 mg three times daily). Subsequent cultures revealed Staphylococcus aureus bacteraemia, prompting discontinuation of vancomycin and initiation of teicoplanin (60 mg twice daily).
Follow-up echocardiography (Figure 2( a )) demonstrated a pressure gradient of 87 mmHg across the pulmonary band and a 13 × 7 mm mobile vegetation at the distal main pulmonary artery (Figure 2( b )). In Case 2, surgical intervention took place approximately 5 days after Candida parapsilosis was isolated, due to persistent fever and a rapidly enlarging vegetation. The patient underwent pulmonary debanding, ventricular septal defect closure, and pulmonary artery reconstruction using bovine pericardium.
(a) Distal main pulmonary artery vegetation (arrow) without valve destruction. (b) Endoluminal filling defect in the distal MPA consistent with vegetation; no peripheral septic emboli.
Postoperatively, she was managed in the intensive care unit with teicoplanin, meropenem, and amphotericin B. The patient was extubated uneventfully on postoperative day 1 and transferred to the ward. Control blood cultures were sterile, and she was discharged in good clinical condition without complications. Reference Pappas, Kauffman and Andes3,Reference Jamil, Al-Kadri, Kheiri and Emara5
Discussion
These two infants illustrate a rare but important cause of right-sided infective endocarditis—Candida involving the pulmonary valve/main pulmonary artery after pulmonary artery banding. The index of suspicion should be high in any infant with prior pulmonary artery banding who develops persistent candidemia or respiratory symptoms. Echocardiography remains first-line for diagnosis, while CT angiography can delineate pseudoaneurysm, thrombus, or distal embolic disease. In Case 1, CTPA demonstrated a main pulmonary artery pseudoaneurysm contiguous with the band site; such mycotic aneurysms have been reported in the context of right-sided infective endocarditis and may rupture if not treated promptly. We postulate that turbulent flow distal to the pulmonary artery band likely caused endothelial injury, which subsequently contributed to the development of the pulmonary pseudoaneurysm and infective endocarditis. Although the infection involves the endovascular surface of the pulmonary artery and may be termed “endarteritis,” we used the term ‘endocarditis’ in line with prevailing literature for right-sided Candida infections involving valve-adjacent structures. It is important to note that the indications for pulmonary artery banding differed between the two infants. Case 1 had already undergone pulmonary artery banding at an outside institution prior to referral, and the decision for palliation rather than complete repair had been made before our involvement. In Case 2, the patient presented to our centre weighing less than 3 kg, and complete repair of the ventricular septal defect and aortic arch reconstruction was considered extremely high-risk at that time. Therefore, arch reconstruction and pulmonary artery banding were selected as the safest initial palliative strategy. In contemporary centres where early complete repair is feasible in even smaller infants, some of these complications might potentially be avoided; however, the clinical circumstances in our cases necessitated a staged approach.
Guideline-concordant management of Candida infective endocarditis includes prompt antifungal therapy and early surgical consultation. The 2023 European Society of Cardiology guideline prioritises surgery for heart failure, uncontrolled infection, or embolic risk; in fungal infective endocarditis, many experts favour early surgery due to high relapse with medical therapy alone. IDSA recommends lipid amphotericin B ± flucytosine or an echinocandin for initial therapy, with step-down to fluconazole for fluconazole-susceptible isolates, for at least 6 weeks after valve surgery when feasible. Reference Delgado, Ajmone Marsan and de Waha1,Reference Pappas, Kauffman and Andes3,Reference Jamil, Al-Kadri, Kheiri and Emara5
In both infants, the clinical course was protracted, with persistent candidemia preceding diagnosis by several weeks. Case 1 developed a pulmonary bifurcation mass and pseudoaneurysm requiring debanding and reconstruction, followed by permanent pacemaker implantation. Case 2 had a distal main pulmonary artery vegetation managed by surgical debridement. Candida albicans was cleared after eight weeks of fluconazole, while Candida parapsilosis required amphotericin B induction and fluconazole step-down for eleven weeks. Both infants have now remained relapse-free for more than 30 months after surgery and completion of antifungal therapy, with no evidence of recurrent infection or haemodynamic deterioration on follow-up.
Species identification is crucial. Candida parapsilosis exhibits intrinsically higher echinocandin MICs; breakthrough infections on echinocandins are reported. When C. parapsilosis is identified or strongly suspected, amphotericin B-based induction or early step-down to high-dose fluconazole (if susceptible) should be considered with close mycologic and clinical monitoring.
Pulmonic valve infective endocarditis is rare in paediatrics, but contemporary series and case reports underscore substantial early mortality and frequent need for surgery. Our experience aligns with these observations and highlights the value of an endocarditis team, species-directed therapy, and multimodality imaging to guide the timing and extent of surgery. Although no cardiologist or infectious disease specialist is listed among the authors, both were actively involved in diagnosis and management as members of our institutional endocarditis team.
Limitations
This is a two-case experience from a single centre. Antifungal dosing and durations were tailored to each infant based on susceptibility, imaging, and clinical response; these may not generalise to other settings.
Conclusion
Candida endocarditis after pulmonary artery banding is rare but life-threatening. Early echocardiography, confirmatory CT angiography, species-directed antifungal therapy, and timely surgery can be lifesaving.
Ethical statement
Ethics committee approval was not required for this case report in accordance with institutional and national regulations. Written informed consent for participation and publication of clinical data and images was obtained from the legal guardians of both patients.
