Long-Term Follow-Up after Mycobacterium Chimaera Infection Following Cardiac Surgery: Single-Center Experience.

Background: Disseminated Mycobacterium chimaera ( M . chimaera ) infection following cardiac surgery has been associated with a high mortality. The long-term impact of surgery and the appropriate surgical approach are still matters of debate.
Methods: From 2015 to 2019, seven patients with M. chimaera infection following cardiac surgery were isolated.
Results: The median incubation time was 30 months (IQR 18-38). Echocardiography was unremarkable in three patients (43%). We decided to redo cardiac surgery in all patients and explanted all previously implanted prosthetic material. All explant cultures yielded M. chimaera. One patient (14%) died in-hospital seven months after the redo surgery. After a median follow-up of 59.6 months (IQR 39.1-69.6), we observed three infection relapses among the survivors (43%), presumably due to concomitant extracardiac infection and recurrent cardiac implant infection.
Conclusions: M. chimaera infection following cardiac surgery is associated with a delayed and unspecific clinical presentation. Echocardiogaphy has a limited sensitivity for prosthetic valve infection with M. chimaera , and negative findings should not preclude the surgical decision. The extraction of all previously implanted material is crucial to achieving the source control, as the re-implantation of prosthetic material as well as uncontrolled extracardiac infection at the time of the redo cardiac surgery appear to be key factors for persisting/relapsing infection.