Wake-up Stroke and Blood Pressure Variability

Study Questions:

What is the blood pressure variability (BPV) difference between wake-up stroke (WUS) and non-WUS patients?


The investigators identified consecutive ischemic stroke patients from a single-center prospective registry. BPV was calculated as the coefficient of variation of the mean arterial pressure during the first 24 hours after hospitalization. The authors assessed 24-hour BPV as a continuous measure and in quartiles in WUS versus non-WUS patients using univariable and multivariable statistics.


Among 369 patients (64.9 ± 16.5 years; 50.1% male; 64.7% white), 78 were WUS (21.1%). Clinical characteristics and medical history were not different between WUS and non-WUS patients except WUS patients were older (69.0 vs. 63.8 years; p = 0.015) and more frequently had previous ischemic stroke (29.5% vs. 17.2%; p = 0.012). Initial 24-hour BPV (11.77 vs. 10.76; p = 0.098) was similar between groups. However, WUS patients had greater nocturnal BPV (10.50 vs. 8.95; p = 0.030), whereas daytime BPV was similar between groups (10.96 vs. 10.47, p = 0.459). In multivariate analysis, the highest quartile (≥11.48 mm Hg) of nocturnal BPV was independently associated with WUS (adjusted odds ratio, 1.95; confidence interval, 1.13–3.39; p = 0.017).


The authors report that there is greater nocturnal BPV during the first 24 hours after hospitalization in WUS than non-WUS patients.


This study reports that in the first 24 hours after ischemic stroke admission, WUS patients have increased nocturnal but not daytime blood pressure variability when compared with non-WUS patients. These data suggest that autoregulation of blood pressure, with greater nocturnal variability, may play a possible role in onset of stroke during sleep. Nocturnal autonomic instability needs additional research as a potential mechanism of WUS and whether therapies that may ameliorate this phenomenon will reduce wake-up strokes need to be tested.

Clinical Topics: Prevention, Sleep Apnea

Keywords: Autonomic Nervous System, Blood Pressure, Blood Pressure Determination, Hemostasis, Ischemia, Primary Prevention, Sleep, Stroke, Vascular Diseases

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