Abstract 184: Blood Pressure Matters After Cardiac Arrest: Is Our Target Too Low?

Abstract

Introduction: Blood pressure is an important therapeutic target after cardiac arrest (CA), crucial for maintaining cerebral blood flow and preventing secondary brain injury. However, the optimal blood pressure during the post-resuscitation period remains unknown. Hypothesis: Proportion of time with mean arterial pressure (MAP) below a specific threshold will be associated with worse clinical outcomes. Methods: We assessed a retrospective cohort of CA patients admitted to an academic center between January 2014 - August 2022. Patients without a documented initial MAP, those who progressed to brain death, or who died within 96 hours were excluded. Multivariable logistic regression was used to test associations between proportion of time with MAP < 65mmHg or < 80mmHg and outcomes [survival and good neurologic outcome (Cerebral Performance Category 1-2) at hospital discharge]. We adjusted for age, sex, Charlson Comorbidity Score, CA location, initial rhythm, Pittsburgh Cardiac Arrest Category, and peak 24h norepinephrine equivalent. We evaluated the initial 96 hours from CA and the following sub-periods: 1) 0-24h, 2) 25-72h, and 3) 73-96h. Results: Of 817 patients with CA, 411 were included. Over the initial 96 hours, the proportion of time with MAP < 80 was inversely associated with survival and good neurologic outcome (adjusted OR [95% CI] per 10% time 0.83 [0.75 - 0.93] and 0.78 [0.69 - 0.89], respectively); no such association was found for MAP < 65. This inverse association held in period 2 (0.85 [0.78-0.93] and 0.79 [0.71-9.88], respectively) and period 3 (0.87 [0.80-0.94] and 0.85 [0.78-0.93], respectively), but not in period 1 (Figure 1). Conclusion: The proportion of time spent with MAP < 80mmHg was associated with worse outcomes, independent of disease severity. The neuroprotective effect of higher MAP appears to occur between 25-96h from CA. Future prospective studies are needed to further characterize the differential clinical impact of MAP across time.