Contemporary comparison of infective endocarditis caused by Candida albicans and Candida parapsilosis: a cohort study

Abstract Background Although Candida albicans is the most frequent microorganism causing fungal endocarditis, its incidence has decreased during the last two decades, and that of non-albicans Candida species has risen. Among the last, Candida parapsilosis is of particular interest, representing the second most frequent Candida species causing IE1, 2. Purpose To compare the clinical course, imaging findings and outcomes among patients with IE caused by C. albicans (CAIE) and C. parapsilosis (CPIE) in order to identify organism-specific peculiarities. Methods From January 1998 to June 2020, all consecutive cases of CAIE and CPIE (n=16), admitted to a hospital network composed of 3 tertiary hospitals and prospectively recruited on a multipurpose database, were retrospectively analysed. All cases were evaluated by the Endocarditis Team (ET) and underwent a thorough diagnostic work-up, including blood cultures at admission, transoesophageal echocardiography (TEE) and culture of the valves extracted at surgery. Other imaging tests, such as PET/CT, were performed at the ET's discretion. Diagnosis of IE was made according to the modified Duke criteria until 20153, and the European Society of Cardiology (ESC) 2015 modified diagnostic criteria thereafter4. Results Eight patients were diagnosed with CAIE and 8 with CPIE. Regarding predisposing conditions, a higher prevalence of prosthetic valves was found among CPIE. Other population's baseline information is shown in Table 1. Compared to CAIE, CPIE presented a longer time from the beginning of symptoms to hospital admission (40 vs 7 days; p=0.062), but no differences regarding signs and symptoms were observed. Aortic location was the most frequent infection side in both groups, but prosthetic valve involvement was remarkably more frequent among patients with CPIE (75% vs 37.5%; p=0.315. Figure 1). CPIE also presented a higher rate of positive blood cultures at admission (100% vs 62.5%; p=0.200), persistently blood cultures 48–72 hours after antifungals initiation (100% vs 0%; p=0.021) and positive valve cultures (83.3% vs 57.1%; p=0.569). No differences regarding TEE and other imaging tests findings were observed. All patients but 4 underwent valve replacement surgery. No differences in in-hospital complications or in mortality were observed between CAIE and CPIE, even after adjusting for therapeutic management. Conclusions Compared to CAIE, CPIE presented a more frequent involvement of prosthetic valves, a longer course of symptoms before admission and a bigger proportion of persistently positive blood cultures. In-hospital complications and mortality were similar between the two groups. Funding Acknowledgement Type of funding sources: None. Table 1. Population characteristicsFigure 1. Valve involvement distribution