Relationship between outcome and baseline blood pressure and other haemodynamic measures in acute ischaemic stroke: data from the TAIST trial

BACKGROUND: A poor outcome after stroke is associated independently with high blood pressure during the acute phase; however, relationships with other haemodynamic measures [heart rate (HR), pulse pressure (PP), rate-pressure product (RPP)] remain less clear. METHODS: The Tinzaparin in Acute Ischaemic Stroke Trial is a randomised, controlled trial assessing the safety and efficacy of tinzaparin versus aspirin in 1484 patients with acute ischaemic stroke. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR measurements taken immediately prior to randomization were averaged, and the mid-blood pressure (MBP), PP, mean arterial pressure (MAP), pulse pressure index, and RPP were calculated. The relationship between these haemodynamic measures and functional outcome (death or dependency, modified Rankin Scale > 2) and early recurrent stroke, were studied with adjustment for baseline prognostic factors and treatment group. Odds ratios (OR) and 95% confidence intervals (CI) refer to a change in haemodynamic measure by 10 points. RESULTS: A poor functional outcome was associated with SBP (adjusted OR; 1.11; 95% CI, 1.03-1.21), HR (adjusted OR; 1.15; 95% CI, 1.00-1.31), MBP (adjusted OR; 1.15, 95% CI, 1.03-1.29), PP (adjusted OR; 1.14; 95% CI, 1.02-1.26), MAP (adjusted OR; 1.15; 95% CI, 1.02-1.31) and RPP (adjusted OR; 1.01; 95% CI, 1.00-1.02). Early recurrent stroke was associated with SBP, DBP, MBP and MAP. CONCLUSIONS: A poor outcome is independently associated with elevations in blood pressure, HR and their derived haemodynamic variables, including PP and the RPP. Agents that modify these measures may improve functional outcome after stroke.