The Time Course and Determinants of Blood Pressure within the First 48 h after Ischemic Stroke

Abstract

Background and Purpose: Previous research suggests that blood pressure falls acutely after ischemic stroke. We aimed to further characterize this fall with a statistical technique that allows the application of regression techniques to serial blood pressure outcome data. Methods: In a prospectively recruited ischemic stroke cohort, systolic (SBP) and diastolic (DBP) blood pressure was recorded every 4 h until 48 h after stroke. Potential determinants of blood pressure, including stroke severity and acute infection, were also recorded. Mixed effects models were used to model serial blood pressure measurements over time, adjusted for significant determinants. Results: In 156 patients, SBP and DBP fell by 14.9 mm Hg (95% CI 6.2–22.6 mm Hg) and 6.2 mm Hg (95% CI 1.4–10.6 mm Hg), respectively, over the first 48 h after stroke. SBP was higher in patients with premorbid hypertension, a previous history of stroke or TIA, current alcohol use, increasing age, stroke of mild to moderate severity (NIHSS 3–13) and in patients treated with antihypertensives. SBP was lower in smokers. There was a progressive rise in SBP in patients with acute infection. No factors other than time were associated with DBP. Conclusions: The use of mixed effects models has identified a linear SBP and DBP fall over the first 48 h after stroke. The timing and magnitude of this fall should be accounted for in the design of future prognostic and intervention studies.

Pulse Pressure – Independent Predictor of Poor Early Outcome and Mortality following Ischemic Stroke

“…Arterial stiffness resulting in elevated PP and isolated systolic hypertension seems to have more influence on mortality and dependency after ischemic stroke than do MAP and other BP indices [11, 15, 17]. Premorbid hypertension and treatment with antihypertensive drugs are important determinants of higher SBP in the first 48 h after ischemic stroke, which could also be associated with higher PP values [22]. …”

Early Blood Pressure Reduction in Acute Ischemic Stroke with Various Severities: A Subgroup Analysis of the CATIS Trial

“…Observational clinical studies reported that stroke severity measured by the NIH Stroke Scale (NIHSS) was associated with elevated BP during the acute phase, and predicted poor clinical outcomes of ischemic stroke [10][11][12] . In a subgroup analysis of the Scandinavian Candesartan Acute Stroke Trial, there was a significant trend toward a better effect of candesartan on the functional outcome in patients with larger infarcts (total anterior circulation or partial anterior circulation) than in patients with smaller infarcts (lacunar infarction) [13] .…”

Response to the Letter by Dr. Hanne Christensen: Blood Pressure in Acute Stroke

“…Dear Sir, We thank Dr. Christensen [1] for her letter and the opportunity to clarify our findings. Dr. Christensen's main concerns appear to be how we handled data from patients in whom the time of stroke onset was not certain and how data from patients in whom there was a significant delay between stroke onset and admission might have affected our findings.…”