ReviewAspergillus Endocarditis After Cardiac Surgery
Section snippets
Historical Perspective
The Aspergillus species was initially described by Micheli in 1729. The first case of Aspergillus disease in humans was reported in the mid 1800s. Hadorn described a case of Aspergillus aortitis in 1960. In 1964, Newman and Cordell reported the first case of Aspergillus endocarditis (AE) after mitral valvulectomy, which ended with the death of the patient soon after disease presentation and establishment of the diagnosis of AE postmortem. Amphotericin B has been the mainstay of therapy for the
Material and Methods
We conducted a literature search using the Pubmed-Medline database. We reviewed all articles in French or English from 1970 to today. Search terms used were “Aspergillus,” “Aspergillus endocarditis,” “cardiac surgery,” and “fungal endocarditis.” All articles, including isolated case reports, were reviewed.
Epidemiology
Aspergillus endocarditis is increasingly prevalent among hospitalized patients nowadays due, in part, to the increasing use of intracardiac devices [2]. Fungal endocarditis affects approximately 0.1% of all prosthetic valves [3] and the Aspergillus species contributes to approximately 25% of all cases of fungal endocarditis [1], second only to the Candida species with an Aspergillus to Candida ratio of 1:3 to 1:2 [1, 4]. Men are more commonly affected than women with a peak incidence during the
Microbiology
Numerous strands of Aspergillus have been identified, and the most commonly responsible for AE include Aspergillus fumigatus (60% to 90%), Aspergillus terreus (5% to 20%), Aspergillus flavus, Aspergillus niger, and Aspergillus nidus [7]. The predominance of one of these species owes to several intrinsic characteristics that vary from one strand to the other including mass doubling time, viability at body temperature as most species do not survive at 37°C [9], production of proteases, and
Sources and Risk Factors
Aspergillus infection may be community-acquired or may occur as a nosocomial event. The primary ecologic niche for Aspergillus species is vegetable material and soil [16, 17], but it may reside anywhere from water to food (tea, fruits, peppers, and spices) to potted plants and flowers as well as ice-making machines and air humidifiers. Air remains the principal means of transmission to patients, especially in cases of AE. Molds release an extremely high number of small-sized conidia (3 μm to 5
Clinical Presentation
Typically, AE presents with a relative paucity of peripheral signs of endocarditis (ie, Osler’s nodes, Janeway lesions, Roth spots) [30]. No consistent or pathognomonic features characterize AE. The most common clinical features are fever, major peripheral emboli, and a changing heart murmur [5]. Less commonly, patients present with focal or generalized neurologic deficits, heart failure, or dyspnea [1].
The interval between valve replacement and onset of infection is extremely variable, ranging
Complications
As already mentioned, major peripheral emboli are one of the most common presenting features of AE and occur in as many as 83% of patients with AE, averaging 68% of patients [31]. Peripheral emboli may lodge in the brain, skin, eyes, upper and lower limbs, mesenteric arteries, kidneys, and coronary artery beds, hence mimicking other pathologic conditions and contributing to delaying the diagnosis in some cases. The occurrence of emboli in a culture-negative environment should raise the
Diagnosis
The most critical step in the treatment of AE is establishing the diagnosis in a timely fashion, a difficult task that hampers therapeutic success. Several complementary methods can be used to establish the diagnosis of AE.
Treatment
Another stumbling area of modern medicine in the management of AE pertains to the therapeutic strategy to adopt in the face of such a complication. Therapeutic management conventionally consists of combined medical and surgical approaches whenever possible. However, despite years of wrestling with the disease with dismal results, very few advances have been introduced in the management of AE, and mortality rates remain extremely high.
Conclusion
Aspergillus endocarditis is an ominous complication after cardiac surgery with a dismal prognosis despite better understanding of the etiology of the disease. Its detection and eradication from the hospital environment, its diagnosis in patients, and the therapeutic arsenal available remain major limiting factors for obtaining better short- and long-term results. A multidisciplinary approach is therefore warranted when outbreaks of AE are encountered to act swiftly on the primary prevention of
References (59)
- et al.
Trends in the postmortem epidemiology of invasive fungal infections at a university hospital
J Infect
(1996) - et al.
Surgical and long-term antifungal therapy for fungal prosthetic valve endocarditis
Ann Thorac Surg
(1995) Fungal endocarditis
J Infect
(1997)- et al.
Aspergillus species endocarditisthe new face of a not so rare disease
Am J Med
(1974) - et al.
Interaction between Aspergillus fumigatus and basement membrane lamininbinding and substrate degradation
Biol Cell
(1993) - et al.
Cardiac aspergillosis
J Thorac Cardiovasc Surg
(2000) - et al.
Recovery of filamentous fungi from water in a pediatric bone marrow transplantation unit
J Hosp Infect
(2001) Aspergillus aortitis
J Thorac Cardiovasc Surg
(1990)- et al.
Aortic pseudo-aneurysm with aspergillus aortitis
Chest
(1986) - et al.
Aspergillus aortitis following replacement of aortic valve
J Thorac Cardiovasc Surg
(1967)