Impact of the duration of antibiotic therapy on relapse and survival following surgery for active infective endocarditis.

Objectives: Surgery is often required for acute infective endocarditis (IE) to repair or replace damaged heart valves. Traditionally, long courses of antibiotic treatment have been prescribed after surgery for active IE for fear of infecting newly implanted/repaired valves, but the need for this, in the present era of enhanced antimicrobial stewardship, has been questioned. In our institution, the choice and duration of antimicrobial therapy is tailored to individual patients by a multidisciplinary team with an interest in IE. The influence of the duration of postoperative antibiotic therapy on outcomes was studied in patients requiring surgery prior to the completion of a planned course of antibiotic therapy.

Methods: This was a retrospective observational study on patients with acute IE requiring surgery between January 2004 and December 2015. The primary outcome was relapse. Secondary outcomes were early reoperation and 1-year mortality.

Results: In total, 182 IE episodes were included in the final analysis. The median duration of postoperative antibiotic therapy was 23.5 days (interquartile range 12-40 days) and decreased significantly during the period of study (P < 0.001). There were 2 relapses (1.1%) and 18 (9.9%) postoperative deaths within 1 year. Nine (5%) patients underwent early reoperation. The duration of postoperative antibiotic therapy did not affect either the primary or the secondary outcomes.

Conclusions: This work supports previous findings that selected patients who require surgery during active IE can be safely given shorter courses of postoperative antibiotics without an impact on relapse of infection or survival.