Elevated diastolic but not systolic blood pressure increases mortality risk in hypertensive but not normotensive patients with acute ischemic stroke

Abstract

Background: The relationship between blood pressure (BP) at admission for acute ischemic stroke and outcome is controversial. We aimed to assess whether only systolic BP (SBP), only diastolic BP (DBP), both or neither predict outcome and whether these associations differ between patients with and without a history of hypertension.

Methods: We prospectively studied all patients who were admitted with acute ischemic stroke (n = 415; 39.5% males, age 78.8 ± 6.6 years). The severity of stroke was assessed at admission with the National Institutes of Health Stroke Scale (NIHSS). The outcome was evaluated with dependency at discharge (modified Rankin scale between 2 and 5) and in-hospital mortality.

Results: In the total study population, independent predictors of dependency at discharge were age, history of prior ischemic stroke, and NIHSS score at admission. Independent predictors of in-hospital mortality were DBP at admission and NIHSS score at admission. In patients with a history of hypertension (n = 343), independent predictors of dependency at discharge were age and NIHSS score at admission whereas independent predictors of in-hospital mortality were DBP at admission and NIHSS score at admission. In patients without a history of hypertension (n = 72), the only independent predictor of dependency at discharge and in-hospital mortality was the NIHSS score at admission.

Conclusions: Higher DBP at admission predict in-hospital mortality in patients with acute ischemic stroke whereas SBP in the acute phase is not associated with short-term outcome. The relationship between DBP at admission and outcome appears to be more prominent in hypertensive patients.

Keywords: blood pressure; cerebral flow autoregulation; hypertension; ischemic stroke; outcome; severity..