Impact of surgical timing in left-sided infective endocarditis with persistently positive blood cultures

Guidelines define persistent infection in infective endocarditis (IE) as positive blood cultures after 7 days of adequate antibiotic therapy. However, persistently positive blood cultures (PPBC) at 48 to 72 hours are already associated with a worse prognosis. We aimed to assess the clinical profile, temporal trends, and impact of surgical timing on outcomes in patients with left-sided IE and PPBC at 48 to 72 hours.

We performed a retrospective analysis of prospectively collected data from 3 Spanish tertiary centers (1998-2024). We compared patients with PPBC with those with blood culture clearance and assessed the effect of surgical timing using a time-dependent Cox model, inverse-probability-of-treatment weighting, and a day-7 landmark analysis to minimize immortal time bias and confounding by indication.

Among 1265 patients with positive baseline cultures, 283 (22.4%) had PPBC at 48 to 72 hours. These patients exhibited a more severe clinical and microbiological profile and higher in-hospital mortality (36.0% vs 22.3%; P < .001). In the day-7 landmark analysis, surgery within the first 7 days was associated with lower in-hospital mortality (HR, 0.53; 95%CI, 0.30-0.95), with consistent trends across the time-dependent Cox and inverse-probability-of-treatment weighting models.

PPBC at 48 to 72 hours identifies a high-risk subgroup of patients with left-sided IE. In these patients, early surgery within the first 7 days was associated with a potential survival benefit in adjusted models, supporting earlier reassessment of infection control to optimize surgical timing.