Bacteraemia and infective endocarditis following left-sided heart valve surgery.

Background and aims: In patients undergoing heart valve surgery, subsequent bacteraemia and infective endocarditis (IE) are feared events. Data on the incidence and bacterial microbiological etiology following left-sided heart valve surgery are sparse.

Methods and results: Between 2010 and 2021, all patients undergoing left-sided valve surgery were identified using Danish nationwide registries. Incidence and type bacteraemia within 1-year post-surgery was analysed. Secondary outcome of interest was IE. Cumulative incidence curves were stratified for bacterial species and for subgroups of interest: type of valve surgery, age, and sex. A total of 14 935 patients were included, of which 69% were male and the median age was 70.4 years (25th-75th percentile 62.4-76.2 years). The 1-year cumulative incidence of bacteraemia was 6.1% (95% CI 5.7-6.5%), and the most frequent bacteraemia was coagulase-negative staphylococci (CoNS) (27%). More than half of the bacteraemia with CoNS occurred within 30 days of follow-up. Patients developing bacteraemia had a significantly higher Charlson comorbidity score at baseline, more often underwent coronary artery bypass grafting concomitant to valve surgery, and more often had surgery on both valves. The 1-year cumulative incidence of IE was 1.5% (95% CI 1.3-1.7), of which 23% were caused by Enterococci, and 22% were blood culture negative. The median time from surgery to IE was 109 days.

Conclusion: Bacteraemia and infective endocarditis following left-sided heart valve surgery occurred in 6.1% and 1.5% of patients, respectively. The most frequent bacteraemia was coagulase-negative staphylococci, and more than half of these occurred within 30 days of surgery. Optimization of prophylactic strategies are warranted.