# Impact of white matter lesions on associations between prehospital blood pressure and outcomes in spontaneous intracerebral hemorrhage

## TL;DR

This study shows that white matter lesions affect how blood pressure changes before hospital impact outcomes in patients with brain hemorrhage.

## Contribution

The study reveals that white matter lesion severity modifies the relationship between prehospital blood pressure and clinical outcomes in ICH patients.

## Key findings

- Patients with moderate-to-severe WML had stronger associations between higher prehospital MAP and in-hospital mortality.
- WML modified the relationship between blood pressure change and worse clinical outcomes like mortality and disability scores.
- Greater blood pressure decrease was linked to worse outcomes in patients with severe WML compared to those with mild WML.

## Abstract

There are concerns about the safety of intensive blood pressure (BP) lowering in intracerebral hemorrhage (ICH) patients with white matter lesions (WML). We explored the impact of WML on associations between i) prehospital BP, and ii) BP change, and outcomes in acute, spontaneous ICH.

This retrospective study included consecutive patients with acute spontaneous ICH, admitted 2011–2020. WML on non-contrast computed tomography were categorized as none-to-mild (0–1) or moderate-to-severe (2–3) on the Fazekas scale. The first systolic BP (SBP) and mean arterial pressure (MAP) from the ambulance and admission, and absolute BP change between these time points, were collected. The outcomes were in-hospital mortality, mortality at 180 days, modified Rankin Scale (mRS) scores at 3 months, and hematoma expansion.

Of 548 patients, 260 (47%) had moderate-to-severe WML. Compared to patients with none-to-mild WML, these patients had a stronger association between higher prehospital MAP and in-hospital mortality (p interaction 0.017). WML did not modify associations between prehospital BP and other outcomes. WML modified associations between MAP change and in-hospital mortality (p interaction 0.049), MAP change and mRS score 3–6 at 3 months (p interaction 0.032), and SBP change and mRS score 3–6 at 3 months (p interaction 0.022). These outcomes were poorer with greater BP decrease in patients with moderate-to-severe compared to none-to-mild WML.

In acute ICH, WML modified the influence of prehospital BP and BP change on clinical outcomes, with a trend toward worse outcomes associated with higher prehospital BP and greater spontaneous BP decrease.

Graphical abstract