Reciprocal Interaction of 24-Hour Blood Pressure Variability and Systolic Blood Pressure on Outcome in Stroke Thrombolysis

Background and purpose: Significance and management of blood pressure (BP) changes in acute stroke care are unclear. Here we aimed to investigate the impact of 24h-BP-variability (BPV) on outcome in patients with acute ischemic stroke treated with intravenous thrombolysis.

Methods: From the SITS International Stroke Thrombolysis registry 28976 patients with documented pretreatment systolic BP (BPsys), at 2 hours and 24 hours were analyzed. The primary measure of BP variability was successive variability (BPVSV). Data were pre-processed using coarsened exact matching. We assessed early neurological improvement (ENI), symptomatic intracerebral hemorrhage (SICH) and long-term functional outcome [modified Rankin Scale (mRS) at 90 days] by binary and ordinal regression analysis.

Results: Attempts to explain BPVSV with patients’ characteristics at admission found BPsys (5.5% variance) to be most influential, yet 92% of BPV variance remained unexplained. Independently from BPsys, BPVSV was associated with poor functional outcome mRS 0—2 (OR 0.94, 95% CI 0.90-0.98), disadvantage across the shift of mRS (OR 1.04, 95% CI 1.01-1.08), mortality (OR 1.10, 95% CI 1.01-1.08), SICHSITS (OR 1.14, 95% CI 1.06-1.23), and SICHECASS (OR 1.24, 95% CI 1.10-1.40). Analyzing BPVSV as a function of pretreatment BPsys significantly improved the prediction of functional outcome (mRS 0—1, mRS 0–2, ENI, mRS-shift: all PInteraction<0.01). Excluding patients with atrial fibrillation in a sensitivity analysis gave consistent results overall.

Conclusions: This study suggests the need for a more individual blood pressure management accounting for pretreatment BP and the acute BP course (i.e. BPV) to achieve best possible outcome for the patient.