(1512) Impact of Angiotensin II on Clinical Outcomes in Shock: A Systematic Review and Meta-Analysis

Introduction: Angiotensin II (Ang II) is a vasopressor hormone that activates angiotensin type 1 (AT1) and AT2 receptors, causing vasoconstriction and increased arterial blood pressure (ABP). While Ang II has shown promise in increasing ABP in catecholamine-refractory vasodilatory shock, its impact on mortality remains inconclusive. To address this, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of Ang II in vasoplegic shock.

Methods: Following PRISMA guidelines, we searched PubMed and EMBASE for English-language experimental and observational studies exploring clinical outcomes of Ang II in vasodilatory shock until 12/06/2023. Two independent reviewers assessed study quality and risk of bias. Data were combined using a random-effect model. The primary outcome was in-hospital mortality associated with Ang II use compared to standard therapy. Secondary outcomes included mean arterial pressure (MAP) change, multi-organ failure (MOF), and atrial fibrillation (AF). Heterogeneity was assessed using Q test and I2, with I2 > 50% indicating marked heterogeneity.

Results: Eight studies comparing Ang II to standard therapy in vasodilatory shock were included in the systematic review, with 3 studies (n=461) in the final analysis for the primary outcome. While one study evaluated Ang II as a primary vasopressor, others reported its use in catecholamine-refractory vasodilatory shock. Overall, Ang II use was associated with similar in-hospital mortality compared to standard therapy (Risk Ratio [RR]= 0.83; 95% CI, 0.68-1.02, I2= 0%). Likewise, there was no difference in MOF and AF (MOF: RR= 1.01; 95% CI, 0.61-1.65, I2= 0%; AF: RR= 1.27; 95% Cl, 0.38-4.23, I2= 5%). However, Ang II use demonstrated a significant increase in MAP (mean difference= -9.60; 95% CI, -9.71,-9.49, I2= 0%).

Conclusions: In vasodilatory shock, Ang II use resulted in significant hemodynamic changes, particularly boosting MAP, which may encourage its utilization in case of profound hypotension. However, Ang II use demonstrated similar in-hospital mortality compared to standard therapy.