Hypertension in acute ischemic stroke: a compensatory mechanism or an additional damaging factor?

In acute ischemic stroke, a transient blood pressure (BP) elevation is common, but the best management is still unknown. Therefore, we investigated retrospectively the relationship between BP after ischemic stroke and neurological outcome (evaluated by means of the National Institutes of Health Stroke Scale score at day 7).

The medical records of 92 consecutive patients with acute ischemic stroke, aged 47 to 96 years, were examined. Blood pressure was measured on admission, 4 times during the first 24 hours, 3 times daily for the first 4 days, and twice daily on day 7 (or at discharge). Antihypertensive treatment was given according to American Heart Association guidelines.

The region damaged by the stroke was total anterior in 16 patients (17%), partial anterior in 30 (33%), lacunar in 34 (37%), and posterior circulation in 12 (13%). Stroke pathogenesis was cardioembolic in 28 (30%), atherothrombotic in 29 (32%), and lacunar in 34 (37%). The systolic BP range was 140 to 220 mm Hg; diastolic BP, 70 to 110 mm Hg. Initial BP was higher in the group with lacunar infarction than in the other groups (P<.05). The patients with the best outcome had the highest BP during the first 24 hours. The neurological outcome was strongly influenced by baseline stroke severity (NIH Scale score) and admission BP. Better initial neurological conditions and higher initial BP resulted in better neurological outcomes.

The outcome of stroke is influenced by the type of stroke and initial BP. Lacunar stroke and the highest BP on admission carry the best prognosis, whereas the reverse is true for posterior circulation infarction and low BP. We found no evidence that, within the present BP range, hypertension is harmful and that its lowering is beneficial.