Systolic Blood Pressure Variability in Acute Ischemic Stroke: A Predictor of Infarct Growth and Hemorrhagic Transformation

Background: Blood pressure variability (BPV) has emerged as an important clinical factor in acute ischemic stroke (AIS), with evidence linking excessive fluctuations in systolic blood pressure (SBP) to secondary brain injury. This study aimed to assess the association between SBP variability during the first week of hospitalization and the risk of early post-stroke complications, specifically hemorrhagic transformation and infarct growth. Methods: We conducted a prospective cohort study involving 138 AIS patients admitted to the Pius Brinzeu County Emergency Hospital, Timișoara, between November 2022 and December 2024. Systolic blood pressure (SBP) was assessed three times daily over a period of seven days, with variability determined as the standard deviation (SD) of the recorded values. Patients were categorized based on treatment modality (conservative versus intravenous thrombolysis), and complications were evaluated using repeated computed tomography (CT) imaging. Results: SBP variability was significantly higher in patients who developed hemorrhagic transformation (OR 3.64, 95% CI: 2.21–5.99, p < 0.001) or infarct growth (OR 1.80, 95% CI: 1.24–2.61, p = 0.001). A monotonic trend was observed across SBP variability categories, with complication rates increasing significantly with higher variability levels (p < 0.001 for hemorrhagic transformation; p = 0.001 for infarct growth). In multivariable models, SBP variability remained an independent predictor of hemorrhagic transformation in both the conservative group (OR 4.78, 95% CI: 2.07–37.14, p = 0.02) and thrombolysis group (OR 1.47, 95% CI: 1.13–2.08, p = 0.01), and was also associated with infarct growth in the thrombolysis group (OR 1.51, 95% CI: 1.13–2.25, p = 0.02). Conclusions: Medium-term SBP variability is an independent predictor of early ischemic and hemorrhagic complications following AIS, particularly in patients receiving thrombolysis. These findings support the need for targeted strategies to stabilize BP during the acute phase of stroke care.