Effect of Induced Hypertension Therapy According to the Mechanism of Single Subcortical Infarction.

Background and purpose: Induced hypertension therapy (IHT) is effective for treating early neurological deterioration (END) in patients with single subcortical infarction (SSI). However, the underlying pathophysiology of SSI is diverse and may affect the efficacy of IHT.

Methods: We reviewed patients with SSI who experienced END and received IHT were enrolled. END was defined as ≥2-point increase in the National Institutes of Health Stroke Scale (NIHSS) score, ≥1 motor point increase. IHT was performed by using phenylephrine infusion to raise systolic blood pressure by 10%-20% over baseline. SSI was classified into three subtypes: distal (dSSI), proximal (pSSI), and SSI with parental artery disease (SSIPAD; with stenosis at parental artery disease <50%). Responders were defined as patients who showed neurological improvement (decrease of ≥2 points in NIHSS, ≥1 motor point decrease) within one day after IHT initiation. Multivariable analysis identified factors associated with responders.

Results: Characteristics were compared between responders and non-responders, and factors associated with response to IHT were investigated. Among 96 patients (mean age, 64.7±12.9 years; 61.5% male), 49 (51.0%) patients were categorized as responders. Multivariable analysis showed that pSSI (adjusted odds ratio [aOR]=18.10, 95% confidence interval [CI] 5.04-80.60, p<0.001) and SSIPAD (aOR=4.56, 95% CI 1.31-19.00, p=0.024) were associated with a positive response to IHT compared to dSSI. Additionally, less white matter changes (Fazekas scale 0-1) were associated with a better response to IHT (aOR=0.15, 95% CI 0.03-0.67, p=0.019).

Conclusions: Response to IHT varied according to SSI subtypes and the severity of small vessel changes.