Background and purpose: Elevations in blood pressure (BP) and blood glucose are common during stroke and may represent a stress response secondary to the acute neurological deficit. If so, they should settle more completely in recombinant tissue-type plasminogen activator (rtPA)-treated patients in association with improved neurological status.
Methods: We performed a controlled comparison of 24-hour declines in BP and glucose in rtPA-treated and control patients from the Virtual Stroke International Stroke Trial Archive (VISTA) database. Twenty-four-hour falls in BP and glucose were compared using multiple regression to account for baseline imbalances. The logarithmic transformation of glucose was used and 24-hour differences expressed as ratios of 24 hours to admission geometric means. Two-way analysis of variance was used to test for interaction between rtPA and early improvement for 24-hour falls in BP and blood glucose.
Results: BP analysis included 5406 patients (rtPA=41%) and glucose analysis 4288 (rtPA=37%). rtPA-treated patients were younger, less likely to have a history of hypertension or diabetes, and had more severe strokes on admission. BP and glucose were lower at baseline in rtPA-treated patients than control subjects. On regression, rtPA predicted significantly greater 24-hour falls in systolic BP (β=3.9; 95% CI, 2.8-5.0), diastolic BP (β=3.1; 95% CI, 2.4-3.9), and glucose (β=0.97; 95% CI, 0.95-0.99). rtPA did not interact with early neurological improvement for 24-hour falls in systolic BP (P=0.72), diastolic BP (P=0.79), or blood glucose (P=0.51).
Conclusions: A stress response does not appear to be the principal cause of elevations in BP and glucose during stroke.