# Prognostic Implications of Vancomycin Therapeutic Drug Monitoring for Critically Ill Stroke Patients: Evidence From a Subtype‐Oriented Analysis

## TL;DR

Vancomycin therapeutic drug monitoring improves survival in critically ill hemorrhagic stroke patients but not ischemic stroke patients.

## Contribution

Demonstrates the prognostic value of vancomycin TDM specifically in hemorrhagic stroke patients using a large critical care database.

## Key findings

- Vancomycin TDM was associated with lower 28-day mortality in hemorrhagic stroke patients.
- The survival benefit of TDM persisted after propensity score matching and multivariable analysis.
- No significant survival benefit of TDM was observed in ischemic stroke patients.

## Abstract

Post‐stroke infections, particularly those caused by Gram‐positive pathogens, are frequent in neurocritical care and worsen outcomes. Vancomycin is widely used against severe Gram‐positive infections, and therapeutic drug monitoring (TDM) is recommended to optimize efficacy and minimize toxicity. However, its prognostic value in critically ill stroke patients remains unclear.

Clinical data were obtained from the MIMIC‐IV (v3.1) database. Adult patients with ischemic or hemorrhagic stroke receiving intravenous vancomycin were included. Patients were stratified by stroke subtype and TDM status. Propensity score matching (PSM) was performed to balance baseline characteristics. The primary outcome was 28‐day mortality; secondary outcomes included ICU, hospital, 60‐, 90‐, and 365‐day mortality.

A total of 1266 patients were analyzed (543 hemorrhagic, 723 ischemic). In hemorrhagic stroke, 28‐day mortality was lower in the TDM group (24.6% vs. 48.2%, p < 0.001), and the association persisted after PSM (23.3% vs. 40.8%, p = 0.007). Multivariable Cox analysis confirmed TDM as an independent predictor of reduced 28‐day mortality (adjusted HR = 0.29, 95% CI 0.15–0.56, p < 0.001). No significant association was observed in ischemic stroke.

Vancomycin TDM was independently linked to improved survival in hemorrhagic but not ischemic stroke, supporting individualized antimicrobial optimization in neurocritical care.

Using the MIMIC‐IV critical care database, vancomycin therapeutic drug monitoring was independently associated with improved short‐ and long‐term survival in patients with hemorrhagic stroke, but not ischemic stroke. These findings highlight the value of individualized antimicrobial optimization in neurocritical care.