J Thorac Cardiovasc Surg 2006;131:1181-1183
© 2006 The American Association for Thoracic Surgery
Fungal prosthetic mitral valve endocarditis caused by Scopulariopsis species: Case report and review of the literature
Alice May B. Isidro, MS
a
,
Valerianna Amorosa, MD
b
,
Gary A. Stopyra, MD
c
,
Harold L. Rutenberg, MD
d
,
William H. Pentz, MD
d
,
Charles R. Bridges, MD, ScD
a
,
*
a Department of Surgery, the University of Pennsylvania Health System, Pennsylvania Hospital, Philadelphia, Pa
b Department of Medicine, Division of Infectious Diseases, University of Pennsylvania Health System, Philadelphia, Pa
c Department of Pathology, Pennsylvania Hospital, Philadelphia, Pa
d Division of Cardiology, Pennsylvania Hospital, Philadelphia, Pa
Received for publication November 17, 2005; revisions received December 22, 2005; accepted for publication December 30, 2005.
* Address for reprints: Charles R. Bridges, MD, ScD, Department of Surgery, the University of Pennsylvania Health System, 4 Silverstein, Hospital of the University of Pennsylvania, Philadelphia, PA 19104 (Email: cbridges{at}pahosp.com).
Scopulariopsis species is a keratinolytic mold with a propensity to cause onychomycosis and rarely to cause deep tissue infection. Scopulariopsis brevicaulis is the most common Scopulariopsis species seen clinically. We review 3 cases of Scopulariopsis species–induced endocarditis in the literature and present a fourth case of Scopulariopsis species–induced prosthetic valve endocarditis.
Clinical Summary
A 67-year-old woman with a past medical history significant for rheumatic fever, gout, pulmonary hypertension, atrial fibrillation, congestive heart failure, and 3 prior valve operations presented with fever and right leg pain. One year before presentation she underwent replacement of her aortic and mitral valves with a 19-mm Carpentier-Edwards Magna pericardial valve and a 25-mm Carpentier-Edwards pericardial valve (Baxter Healthcare Corp, Edwards Lifesciences, Irvine, Calif), respectively. Her social history was significant for pet finches. Her temperature was 101°F, she had a systolic murmur at the left sternal border, and her right foot was cold with diminished pulses. She had no evidence of onychomycosis or peripheral emboli. Abdominal computed tomography demonstrated a nonocclusive clot in the right ileac artery. Hematologic parameters and chemistries were normal. Blood cultures, including fungal isolator blood cultures incubated over 4 weeks, were negative. After the patient's left leg became cold and pulseless, she urgently underwent thromboendarterectomy of an acutely occluded femoral artery. Pathology from the embolectomized specimen demonstrated septated hyphal elements. Subsequently on day 5, fungal cultures grew a mold morphologically identified as a Scopulariopsis species (Figure 1). She underwent a transesophageal echocardiogram revealing a larger than 12-mm vegetation on the mitral valve with moderate mitral regurgitation. Confirmatory identification and susceptibility testing performed at Focus Diagnostics (Cyprus, Calif) identified the organism as S brevicaulis and demonstrated mean inhibitory concentrations of 4 µg/mL to amphotericin B, 1 µg/mL to terbinafine, 8 µg/mL to voriconazole, and greater than 8 µg/mL to itraconazole. The patient underwent excision of the senescent infected mitral valve pericardial prosthesis, extensive debridement of the associated fungal vegetation, and a mitral valve replacement with a Carpentier-Edwards pericardial valve. She was treated preoperatively and postoperatively with amphotericin B and voriconazole. The amphotericin was continued for 3 weeks postoperatively, and the voriconazole was arbitrarily continued for 11 weeks until the patient could not tolerate it because of debilitating nausea. She had a complicated respiratory course postoperatively and was discharged to a rehabilitation facility. She was subsequently readmitted with dyspnea and died 5 months after initial presentation without signs of recurrent infection. Culture of her pet finch's feathers grew Aspergillus species and not Scopulariopsis species, despite the mold's propensity to grow in bird feathers.
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Figure 1.
Scopulariopsis species isolated from the patient's thrombectomy. (Original magnification 1000x; lactophenol cotton blue stain.)
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Discussion
Fungi are responsible for less than 10% of cases of infective endocarditis. Although the majority of these are caused by Candida species, infections with opportunistic mold are seen in patients with previous valve operations.
1
In the last 10 years, prosthetic valvular endocarditis caused by Scopulariopsis species has been reported in 3 cases in the literature (Table 1).
2–4
Major emboli, a common presentation of fungal endocarditis,
1
occurred in 3 of the 4 reported cases, including our case. Blood cultures did not grow in any of the cases, and the diagnoses were based on fungal cultures of embolectomy tissue and prosthetic heart valves. In the cases in which susceptibility patterns were reported, the organism demonstrated significant in vitro resistance to multiple antifungal agents, corroborating with other reports noting high-level resistance in clinical isolates of S brevicaulis.
5
Fungal valvular vegetations generally require surgical intervention for treatment because a long-term cure for fungal prosthetic endocarditis is unlikely. Subsequent antimicrobial therapy is typically continued for long durations. Although clinical correlation with in vitro susceptibility data is not fully established for Scopulariopsis species, the high level of in vitro resistance demonstrated for Scopulariopsis species to multiple antifungal agents,
5
taken together with several reports of emergency and progressive infection on broad antifungal therapy, suggests that successful treatment without surgical debridement might be even more unlikely for Scopulariopsis species than for other more treatment-responsive fungi.
2–4
The appropriate duration of antifungal therapy after surgical intervention is unclear, although it is reasonable to continue antifungal agents for several weeks to months through endothelialization of a prosthetic valve. When Scopulariopsis species is identified in a clinical specimen, before susceptibility results are known, initial empiric use of intravenous amphotericin B alone or in combination with voriconazole or itraconazole is reasonable. Additional experience is needed to optimize antifungal selection in this setting, particularly as relates to combination antifungal therapy and the role of newer azoles, such as posaconazole; the echinocandins, such as caspofungin; or the allylamine terbinafine in synergy. Given the intrinsic resistance demonstrated by Scopulariopsis species in vitro, early surgical debridement is the mainstay of therapy for Scopulariopsis species–induced endocarditis and should be strongly considered when Scopulariopsis species infection is diagnosed.
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