Preserving Life: How Systolic Blood Pressure Influences Mortality After Cardiac Arrest, finds study

Recent study examines the relationship between systolic blood pressure (SBP) levels attained after administering vasoactive drugs during prehospital post-resuscitation care by Helicopter Emergency Medical Services (HEMS) and subsequent survival rates. Conducted as a retrospective registry-based cohort study, it includes data from 1861 patients who received vasoactive medication following return of spontaneous circulation (ROSC) between January 2012 and August 2019.

Participant Categorization

Participants were categorized based on their SBP at the time of hospital handover into four groups: hypotensive (<100 mmHg), lower normotensive (100-119 mmHg), higher normotensive (120-140 mmHg), and hypertensive (>140 mmHg). Multivariate logistic regression analysis assessed both 30-day and 1-day mortality outcomes while controlling for variables such as age, sex, time to ROSC, presumed cardiac cause, whether the arrest was witnessed, initial rhythm, and presence of bystander cardiopulmonary resuscitation (CPR).

Mortality Rate Findings

Out of 3029 post-resuscitation cases, significant findings revealed that lower mortality rates were correlated with normotension compared to both hypo- and hypertensive patients. Specifically, compared to the hypotensive group, the odds ratios for 30-day mortality were 0.54 (100-119 mmHg), 0.58 (120-140 mmHg), and 0.78 (>140 mmHg), while the odds ratios for 1-day mortality were 0.42 in both the lower and higher normotensive groups and 0.36 for the hypertensive group. However, while the hypertensive group showed a lower mortality rate within the first day, their outcomes worsened significantly thereafter.

Implications of Hemodynamics

The investigation highlights the precarious nature of post-resuscitation hemodynamics, emphasizing that adequate blood pressure is crucial for organ perfusion and survival. Patients typically present with inadequate circulation post-cardiac arrest, leading to systemic complications such as hypoxic-ischemic brain injury. It suggests that individualized treatment targets, rather than strict adherence to current guidelines, might be warranted, as the effects of vasoactive medications appear inconsistent.

Study Strengths and Limitations

Strengths of the study include its extensive dataset from a national registry with low rates of missing data. However, limitations were noted, such as the inability to validate manually entered data and the variations in recorded variables potentially influencing results. Overall, the findings underscore that achieving normotension may help improve survival outcomes in patients post-cardiac arrest treated in the prehospital setting, advocating for future research tailored toward establishing evidence-based treatment protocols.

Key Points

- -Study Design and Population-: A retrospective registry-based cohort study analyzed data from 1861 patients who received vasoactive medications after achieving return of spontaneous circulation (ROSC) during prehospital post-resuscitation care by Helicopter Emergency Medical Services (HEMS) from January 2012 to August 2019.

- -Participant SBP Categorization-: Participants were divided into four groups based on systolic blood pressure (SBP) at hospital handover: hypotensive (<100 mmHg), lower normotensive (100-119 mmHg), higher normotensive (120-140 mmHg), and hypertensive (>140 mmHg). Multivariate logistic regression was employed to evaluate 1-day and 30-day mortality while adjusting for variables such as demographics, time to ROSC, cardiac arrest circumstances, and CPR presence.

- -Mortality Rate Correlations-: Analysis revealed that normotensive patients had significantly lower mortality rates compared to both hypotensive and hypertensive groups. Specifically, odds ratios for 30-day mortality were 0.54 for lower normotensive, 0.58 for higher normotensive, and 0.78 for hypertensive compared to the hypotensive group. The odds ratios for 1-day mortality were even lower at 0.42 for both normotensive groups and 0.36 for the hypertensive group.

- -Hemodynamic Considerations-: The study emphasizes the importance of maintaining adequate blood pressure for organ perfusion and survival in post-cardiac arrest patients. It highlights complications arising from inadequate circulation, such as hypoxic-ischemic brain injuries, and suggests the need for individualized treatment targets rather than strict guidelines.

- -Strengths of the Study-: Strengths include access to a comprehensive dataset from a national registry with minimal missing data, allowing for robust statistical analyses and reliable conclusions regarding post-resuscitation care.

- -Limitations and Future Directions-: Limitations involve the inability to validate manually entered data and variability in recorded variables, which may impact findings. The study advocates for further research focused on developing evidence-based treatment protocols aimed at improving survival outcomes for patients post-cardiac arrest.

Reference –

Arno Niiranen et al. (2025). What Is The Optimal Prehospital Blood Pressure Level After Cardiac Arrest? A Retrospective Cohort Study On The Association Of Blood Pressure And Mortality Among Patients Treated With Vasoactive Medication.. *Resuscitation*,110589 . https://doi.org/10.1016/j.resuscitation.2025.110589.