Circadian Blood Pressure Phenotyping Identifies Subtype-Specific Risk and Outcomes in Acute Ischemic Stroke: A Prospective Study

Circadian organization of blood pressure (BP) is increasingly recognized as a determinant of vascular risk, but its role in acute ischemic stroke (AIS) remains undefined. We investigated whether early circadian BP phenotypes derived from high-frequency monitoring predict short- and long-term outcomes after AIS. In a prospective cohort of 529 patients with AIS, BP was recorded-noninvasively or via arterial line-during the first 72 h. Circadian parameters were extracted using cosinor analysis, and exploratory clustering was applied to identify recurrent BP patterns. Associations with early neurological deterioration (END), symptomatic intracerebral hemorrhage (sICH), 90-day functional outcome, mortality, and 1-year major adverse cardiovascular events (MACE) were assessed using multivariable logistic and Cox regression. Three distinct circadian BP phenotypes emerged: Steady-High (sustained elevation with blunted nocturnal decline), Disrupted-Rhythmicity (loss of amplitude and irregular oscillation), and Partial-Recovery (initial disorganization with progressive re-entrainment). Subtype-specific vulnerabilities were observed. In embolic stroke of undetermined source (ESUS), disrupted rhythmicity was associated with higher risk of END (adjusted OR 2.8, 95% CI 1.2-6.4). In cardioembolic stroke, circadian disorganization was linked to greater risk of sICH after reperfusion (adjusted OR 3.1, 95% CI 1.1-8.7). In large-artery atherosclerosis, the Steady-High phenotype predicted poor 90-day outcome (adjusted OR 2.2, 95% CI 1.0-4.6). Lacunar stroke showed relative preservation of circadian organization, with the lowest prevalence of adverse phenotypes. Across the cohort, Partial-Recovery was associated with the most favorable outcomes. High-frequency 72-hour BP monitoring combined with exploratory, data-driven clustering revealed reproducible circadian BP patterns with subtype-specific prognostic relevance in AIS. These findings suggest that circadian BP profiling may help inform individualized hemodynamic management in acute stroke.