Blood pressure evolution after acute ischemic stroke in patients with and without sleep apnea.
OBJECTIVE
Sleep apnea (SA) is an independent risk factor for arterial hypertension and is present in 50% to 70% of patients with ischemic stroke. The effects of SA on blood pressure (BP) and stroke outcome in the acute stroke phase are essentially unknown.


METHODS
We studied 41 consecutive patients admitted within 96 hours after stroke onset. Stroke severity on admission (National Institutes of Health Stroke Scale [NIHSS]) and stroke outcome at discharge (modified Rankin Disability Scale [mRS]) were assessed. Nocturnal breathing was assessed with an ambulatory device the first night after admission. SA was defined by an apnea-hypopnea-index (AHI) > or =10/hour, and moderate-severe SA (MSSA) was defined by an AHI >30/hour. BP monitoring was performed during the first 36 hours after admission. A nondipping status (NDS) was defined by a ratio >0.9 of mean systolic BP during nights 1 to 2/mean systolic BP during day 2.


RESULTS
SA was found in 28 (68%) and MSSA in 11 (27%) of 41 patients. A correlation was found between AHI and both NIHSS (r=0.331; P=0.035) and mRS (r=0.341; P=0.031). Patients with MSSA had higher systolic and diastolic BP values during night 1 (P=0.003), day 2 (P=0.004), and night 2 (P=0.03). NDS was found in 26 (63%) patients. Nondippers had a similar AHI but higher NIHSS (P=0.004) and mRS (P=0.005) than dippers. AHI and NDS were confirmed to be independent predictors for both stroke severity and stroke outcome in a multiple stepwise linear regression model.


CONCLUSIONS
SA severity is associated with high 24-hour BP values but only weakly with stroke severity and outcome. Conversely, NDS is linked with a more severe stroke and a poorer evolution but not with SA severity. These data suggest different, although overlapping, pathophysiological and clinical implications of circadian and nocturnal BP values in acute stroke.
Selic
Claudia
C
Neurology Department, University Hospital of Zurich, Zurich, Switzerland.
Siccoli
Massimiliano M
MM
Hermann
Dirk M
DM
Bassetti
Claudio L
CL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000503:physiopathology*