# SDNN predicts 90-day disability after intravenous thrombolysis: autonomic dysfunction as a novel predictors in acute ischemic stroke

## TL;DR

This study shows that autonomic dysfunction, measured by heart rate variability, can predict long-term disability in stroke patients treated with thrombolysis.

## Contribution

The study identifies autonomic dysfunction as a novel predictor of 90-day disability after intravenous thrombolysis in acute ischemic stroke.

## Key findings

- Lower standard deviation of normal-to-normal intervals is an independent risk factor for poor outcomes in stroke patients.
- Heart rate variability parameters reflecting sympathetic and parasympathetic activity are associated with better functional recovery.
- Autonomic dysfunction in the acute phase of stroke influences recovery up to 90 days later.

## Abstract

Recent studies have clarified the relationship between autonomic dysfunction and ischemic stroke location, etiology, and neurological outcomes. However, few studies have evaluated autonomic nervous system (ANS) function via heart rate variability (HRV) in patients undergoing intravenous thrombolysis. Moreover no HRV parameter has been conclusively established as an independent predictor of unfavorable prognosis in this clinical population.

We retrospectively analyzed data from acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT) between January 2021 and December 2023. HRV measurements were obtained within 7 days post-stroke to evaluate ANS function. Of the 150 patients included, a unfavorable outcome was defined as a modified Rankin Scale score >2 at 90-days. Multivariate logistic regression adjusted for potential confounders, was used to evaluate associations between HRV parameters and functional outcomes.

Linear regression analyses revealed consistent associations between favorable functional outcomes and HRV parameters reflectiving both sympathetic and parasympathetic activity, assessed at 7- and 90-days post-stroke (all p < 0.05). In multivariable logistic regression model, a lower standard deviation of normal-to-normal intervals was identified as an independent Influencing factor of worse modified Rankin Scale scores after adjustment for potential confounders.

Impaired autonomic nervous system function in the acute phase of ischemic stroke may exert a sustained influence on recovery, extending to 90 days post-onset. Standard deviation of normal-to-normal intervals emerged as an independent risk factor for unfavorable prognosis in acute ischemic stroke patients treated with intravenous thrombolysis.