Characteristics and outcomes of patients with postoperative Candida versus bacterial mediastinitis: a case-matched comparative study

Abstract

Objectives: Postoperative mediastinitis, a feared complication after cardiac surgery, is associated with high mortality, especially of critically ill patients. Candida species infections are rare and severe, with poorly known outcomes. We conducted a case-control study to describe the characteristics, management and outcomes of patients with postoperative Candida mediastinitis.

Methods: This French, monocentre, retrospective study included all patients with postoperative Candida mediastinitis (January 2003-February 2020) requiring intensive care unit admission. Candida mediastinitis patients (henceforth cases) were matched 1:1 with postoperative bacterial mediastinitis (henceforth control), based on 3 factors during mediastinitis management: age >40 years, cardiac transplantation and invasive circulatory device used. The primary end point was the probability of survival within 1 year after intensive care unit (ICU) admission.

Results: Forty cases were matched to 40 controls. The global male/female ratio was 2.1, with mean age at admission 47.9 ± 13.8 years. Candida species were: 67.5% albicans, 17.5% glabrata, 15% parapsilosis, 5.0% tropicalis, 2.5% krusei and 2.5% lusitaniae. The median duration of mechanical ventilation was 23, 68.8% of patients received renal replacement therapy and 62.5% extracorporeal membrane oxygenation support. The probability of survival within the first year after ICU admission was 40 ± 5.5% and was significantly lower for cases than for controls (43 ± 8% vs 80 ± 6.3%, respectively; Log-rank test: P < 0.0001). The multivariable Cox proportional hazards model retained only renal replacement therapy [hazard ratio (HR) 3.7, 95% confidence interval (CI) 1.1-13.1; P = 0.04] and Candida mediastinitis (HR 2.4, 95% CI 1.1-5.6; P = 0.04) as independently associated with 1-year mortality.

Conclusions: Candida mediastinitis is a serious event after cardiac surgery and independently associated with 1-year mortality. Further studies are needed to determine whether deaths are directly attributable to Candida mediastinitis.

Keywords: Candida; Deep sternal wound infection; Extracorporeal membrane oxygenation; Fungus; Mediastinitis; Transplantation.