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

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

Methods: Between 2010-2021, all patients undergoing left-sided valve surgery were identified using Danish nationwide registries. Incidence and type bacteremia within one-year post-surgery was analyzed. Secondary outcome of interest was infective endocarditis. Cumulative incidence curves were stratified for bacterial species and for subgroups of interest: type of valve surgery, age, and sex.

Results: 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 one-year cumulative incidence of bacteremia was 6.1% (95% CI 5.7-6.5%), and the most frequent bacteremia was coagulase-negative staphylococci (27%). More than half of the bacteremia with coagulase-negative staphylococci occurred within 30 days of follow-up. Patients developing bacteremia had a significantly higher Charlson comorbidity score at baseline, more often underwent CABG concomitant to valve surgery, and more often had surgery on both valves. The one-year cumulative incidence of infective endocarditis 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 infective endocarditis was 109 days.

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