Clinical Outcomes of Angiotensin II Therapy in Vasoplegic Shock: A Systematic Review and Meta-Analysis

Background: Angiotensin II is a peptide hormone vasopressor that activates angiotensin type 1 (AT1) receptors leading to vasoconstriction, the augmentation of arterial blood pressure (ABP), and organ perfusion. Angiotensin II was found to increase the ABP in catecholamine-refractory vasodilatory shock. Whether this effect improves the chances of survival or not remains inconclusive. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of angiotensin II in vasoplegic shock. Objectives: To evaluate the clinical significance of angiotensin II effects in vasoplegic shock concerning the hemodynamic impact, mortality outcomes, and side effects. Methods: Following PRISMA guidelines, we searched PubMed and EMBASE for experimental and observational studies published in English exploring the clinical outcomes of angiotensin II use in vasodilatory shock till 1 July 2024. Two independent authors assessed the quality and risk of bias of the included studies. A random effect model (Mantel-Haenszel) was used to combine data. The primary outcome was in-hospital mortality associated with angiotensin II use in comparison to standard therapy, while the secondary outcomes were mean arterial pressure (MAP) change, multi-organ failure (MOF), and the incidence of atrial fibrillation (AF). The Q test and I-2 were used to examine heterogeneity, with I-2 > 50% indicating marked heterogeneity. Results: A total of eight studies (n = 974) comparing angiotensin II to standard therapy in vasoplegic shock were included in the systematic review, with three studies comprising 461 patients included in the final analysis of the primary outcome. Only one study evaluated the use of angiotensin II as a primary vasopressor, while the rest reported angiotensin II use in catecholamine-refractory vasodilatory shock. Overall, angiotensin II use was associated with similar in-hospital mortality compared to standard therapy (risk ratio [RR] = 0.83; 95% CI, 0.68-1.02, I-2 = 0%). Likewise, there was no difference in MOF and AF (MOF: RR = 1.01; 95% CI, 0.61-1.65, I-2 = 0%; AF: RR = 1.27; 95% CI, 0.38-4.23, I-2 = 5%). However, angiotensin II use demonstrated a significant MAP increase (mean difference = -9.60; 95% CI, -9.71, -9.49, I-2 = 0%). Conclusions: In vasodilatory shock, angiotensin II use demonstrated comparable in-hospital mortality compared to standard therapy. Nevertheless, it resulted in significant MAP change, which may encourage clinicians to use it in cases of profound hypotension.