Impact of Enterococci vs. Staphylococci Induced Infective Endocarditis after Transcatheter Aortic Valve Implantation

Background: The two most common organisms found in infective endocarditis following transcatheter aortic valve implantation (TAVI-IE) are enterococci (EC-IE) and staphylococci (SC-IE). We aimed to compare clinical characteristics and outcomes of patients with EC-IE and SC-IE.

Methods: TAVI-IE patients from 2007 to 2021 were included in this analysis. The 1-year mortality was the primary outcome measure of this retrospective multi-center analysis.

Results: Out of 163 patients, 53 (32.5%) EC-IE and 69 (42.3%) SC-IE patients were included. Subjects were comparable with regard to age, sex, and clinically relevant baseline comorbidities. Symptoms at admission were not significantly different between groups, except for a lower risk for presenting with septic shock in EC-IE than SC-IE. Treatment was performed in 78% by antibiotics alone and in 22% of patients by surgery and antibiotics, with no significant differences between groups. The rate of any complication, in particular heart failure, renal failure, and septic shock during treatment for IE, was lower in EC-IE compared with SC-IE (p < 0.05). In-hospital (EC-IE: 36% vs. SC-IE: 56%, p = 0.035) and 1-year mortality (EC-IE: 51% vs. SC-IE: 70%, p = 0.009) were significantly lower in EC-IE compared with SC-IE.

Conclusions: EC-IE, compared with SC-IE, was associated with a lower morbidity and mortality. However, absolute numbers are high, a finding that should trigger further research in appropriate perioperative antibiotic management and improvement of early IE diagnosis in the case of clinical suspicion.