# Infective Endocarditis and Antimicrobial Timing: A Case for Delay?

## TL;DR

This study finds that delaying antibiotics in stable patients with suspected heart infection does not worsen outcomes.

## Contribution

Shows deferring antimicrobial treatment in stable infective endocarditis patients does not increase mortality.

## Key findings

- No difference in 30-day mortality between immediate and deferred treatment groups.
- Deferred treatment did not increase risk of embolic events or new infections in confirmed IE cases.

## Abstract

In patients with suspected infective endocarditis (IE), current guidelines recommend prompt initiation of empiric antimicrobial treatment after obtaining blood cultures. However, the clinical benefit of immediate treatment in hemodynamically stable patients remains uncertain. This study assessed the impact of deferring antimicrobial treatment in patients with suspected IE.

We conducted a multicenter cohort study of adult patients with bacteremia and clinical suspicion of IE from 2 university hospitals (2015–24). Patients presenting with sepsis, intensive care unit admission, neutropenia, or a clearly identifiably focus other than IE were excluded. All cases were adjudicated by a dedicated Endocarditis Team as either IE or not IE. The primary outcome for all episodes was 30-day mortality; for confirmed IE cases, the composite outcome included 30-day mortality, new embolic events, or new bone and joint infection.

Among 1230 episodes, empirical antimicrobial treatment was initiated immediately (Group I) after blood culture collection in 675 episodes (55%) and deferred until preliminary blood culture results (Group D) in 555 episodes (45%). Thirty-day mortality was 5% (59 episodes), with no difference between Groups I and D (5% vs 5%; P = .894). Of 597 confirmed IE episodes (49%) IE, 327 (55%) were in Group I and 270 (45%) in Group D. The composite primary endpoint occurred in 157 episodes (26%), with no difference between groups (28% vs 24%; P = .304).

In clinically stable patients with suspected IE, deferring antimicrobial treatment until available blood culture results was not associated with worse clinical outcomes.

In this retrospective cohort study of 1230 hemodynamically stable adults with suspected infective endocarditis, deferring antimicrobial treatment until blood culture results were available was not associated with 30-day mortality. The same was observed in 597 confirmed infective endocarditis episodes.

Graphical AbstractThis graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/infective-endocarditis-and-antimicrobial-timing-a-case-for-delay?utm_campaign=tidbitlinkshare&utm_source=IO

This graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/infective-endocarditis-and-antimicrobial-timing-a-case-for-delay?utm_campaign=tidbitlinkshare&utm_source=IO