Background: Staphylococcus aureus (SA) has been extensively studied as causative microorganism of surgical prosthetic-valve infective endocarditis (IE). However, scarce evidence exists on SA IE after transcatheter aortic valve replacement (TAVR).
Methods: Data were obtained from the Infectious Endocarditis After TAVR International Registry, including patients with definite IE after TAVR from 59 centres in 11 countries. Patients were divided into 2 groups according to microbiologic etiology: non-SA IE vs SA IE.
Results: SA IE was identified in 141 patients out of 573 (24.6%), methicillin-sensitive SA in most cases (115/141, 81.6%). Self-expanding valves were more common than balloon-expandable valves in patients presenting with early SA IE. Major bleeding and sepsis complicating TAVR, neurologic symptoms or systemic embolism at admission, and IE with cardiac device involvement (other than the TAVR prosthesis) were associated with SA IE (P < 0.05 for all). Among patients with IE after TAVR, the likelihood of SA IE increased from 19% in the absence of those risk factors to 84.6% if ≥ 3 risk factors were present. In-hospital (47.8% vs 26.9%; P < 0.001) and 2-year (71.5% vs 49.6%; P < 0.001) mortality rates were higher among patients with SA IE vs non-SA IE. Surgery at the time of index SA IE episode was associated with lower mortality at follow-up compared with medical therapy alone (adjusted hazard ratio 0.46, 95% CI 0.22-0.96; P = 0.038).
Conclusions: SA IE represented approximately 25% of IE cases after TAVR and was associated with very high in-hospital and late mortality. The presence of some features determined a higher likelihood of SA IE and could help to orientate early antibiotic regimen selection. Surgery at index SA IE was associated with improved outcomes, and its role should be evaluated in future studies.
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