Factors associated with persistent bacteraemia among patients with suspected infective endocarditis.

Purpose: To ascertain the predictors of persistent bacteraemia among patients with suspected infective endocarditis (IE) and those with IE.

Methods: Retrospective study.

Setting: This study conducted at a Swiss university hospital (2015-2023) included adult patients with bacteraemia and suspected IE. Persistent bacteraemia was defined as continued positive blood cultures with the same microorganism for at least 48 h from antibiotic treatment initiation. Endocarditis Team classified cases as IE or not IE.

Results: Among 2312 episodes of suspected IE, S. aureus was the most common pathogen (1045 episodes; 45%). IE (644; 28%) was the most prevalent infection type. Persistent bacteraemia was observed in 480 (21%) episodes and was independently associated with S. aureus, ≥ 2 positive sets of index blood cultures, resistant bacterium, sepsis, IE, central venous catheter-associated bacteraemia, and acute native bone and joint infections (BJIs), while, streptococcal bacteraemia, appropriate initial antimicrobial treatment and, performance of source control interventions within 48 h were associated with rapid blood culture clearance. Of the 644 IE episodes, persistent bacteraemia was observed in 196 (30%) and was associated with obesity, S. aureus, ≥ 2 positive sets of index blood cultures, resistant bacterium, acute native BJIs, immunologic phenomena, thoracic embolic events, while streptococcal bacteraemia and performance of source control interventions within 48 h were associated with rapid clearance of blood cultures.

Conclusions: Persistent bacteraemia was associated with S. aureus and BJI. Delaying source control interventions may increase the risk of persistent bacteraemia. No specific intracardiac lesion was associated with persistent bacteraemia in IE episodes.