Association of early mean arterial pressure trajectory subtypes with mortality in critically ill patients with ischemic stroke: A multicenter retrospective cohort study

Mean arterial pressure (MAP) management is crucial for cerebral perfusion in critically ill patients with ischemic stroke. However, prior studies have predominantly focused on static blood pressure measurements, and the prognostic relevance of early dynamic MAP patterns after intensive care unit (ICU) admission remains insufficiently characterized. This study aimed to identify distinct MAP trajectory subtypes during the first 24 hours after ICU admission and evaluate their associations with mortality in critically ill patients with ischemic stroke. This multicenter retrospective cohort study used data from Medical Information Mart for Intensive Care IV (MIMIC-IV) v3.1 (development cohort) and eICU v2.0 (external validation cohort). Adult patients with ischemic stroke and complete hourly MAP data during the first 24 hours of ICU admission were included. Group-based trajectory modeling identified distinct MAP trajectory subtypes. Cox proportional hazards regression was used to assess associations with in-hospital mortality in both cohorts and with 28-day and 1-year mortality in MIMIC-IV. Exploratory effect-modification analyses included continuous interaction models for major continuous covariates, complemented by categorized subgroup displays for descriptive presentation. A total of 4734 patients were analyzed (MIMIC-IV: 1934; eICU: 2800). Three trajectory subtypes were identified: High-Stable (approximately 103-108 mm Hg), Moderate-Declining (93-87 mm Hg), and Low-Persistent (80-73 mm Hg). In MIMIC-IV, in-hospital mortality rates were 11.9%, 18.9%, and 23.6% for the High-Stable, Moderate-Declining, and Low-Persistent subtypes, respectively. Compared with the High-Stable subtype, the Low-Persistent subtype was associated with increased in-hospital mortality (HR: 2.03, 95% CI: 1.47-2.79), as was the moderate-declining subtype (HR: 1.62, 95% CI: 1.17-2.23). Similar associations were observed in the eICU cohort (low-persistent HR: 2.01, 95% CI: 1.51-2.69; moderate-declining HR: 1.61, 95% CI: 1.21-2.14) and across 28-day and 1-year mortality in MIMIC-IV. Continuous interaction analyses showed broadly similar associations across the observed range of major continuous covariates, and categorized subgroup displays yielded consistent descriptive patterns. Early MAP trajectory subtypes were associated with mortality in critically ill patients with ischemic stroke, with the low-persistent pattern showing the highest risk. These findings suggest that early MAP trajectories may reflect clinically relevant hemodynamic phenotypes; however, their incremental value beyond conventional static MAP measures was not directly assessed in this study.