Association between 24-hour blood pressure variability and mortality in acute ischemic stroke patients admitted in intensive care units: a MIMIC-IV study.

Introduction: Acute ischaemic stroke (AIS) patients in the intensive care unit (ICU) face high mortality. This study examined the association between systolic blood pressure variability (SBPV), specifically average real variability (SBP-ARV), and short-term mortality in critically ill AIS patients.

Methods: We conducted a retrospective cohort study using the MIMIC-IV database. The primary outcomes were 28-day and 90-day all-cause mortality. Cox regression, Kaplan-Meier curves, restricted cubic spline (RCS) models, and subgroup analyses were used to assess associations.

Results: A total of 861 AIS patients were included. The 28-day and 90-day mortality rates were 20.9% and 23.3%, respectively. Higher SBP-ARV was independently associated with increased mortality. Compared with the lowest tertile, the highest tertile of SBP-ARV had significantly increased 28-day mortality (HR: 1.53; 95% CI: 1.03-2.27; p = 0.035). SBP-ARV as a continuous variable was also significantly associated with 28-day and 90-day mortality. RCS analysis showed that mortality risk increased when SBP-ARV exceeded 11.63.

Conclusion: Our findings suggest that elevated systolic blood pressure variability, particularly higher SBP-ARV within the first 24 h of ICU admission, is significantly associated with increased 28-day and 90-day mortality in AIS patients. SBP-ARV may serve as a valuable prognostic marker for risk stratification and early clinical intervention in critically ill stroke patients.