A Multicenter Observational Cohort Study of Angiotensin II in Shock

ANGIOTENSIN II IN THE TREATMENT OF DISTRIBUTIVE SHOCK: A SYSTEMATIC-REVIEW AND META-ANALYSIS

ABSTRACT

Objective: While nonnorepinephrine vasopressors are increasingly used as a rescue therapy in cases of norepinephrine-refractory shock, data on their efficacy are limited. This systematic review and meta-analysis aims to synthesize existing literature on the efficacy of angiotensin II (ATII) in distributive shock. Methods: We preregistered our meta-analysis with PROSPERO (CRD42023456136). We searched PubMed, Scopus, and gray literature for studies presenting outcomes on ATII use in distributive shock. The primary outcome of the meta-analysis was all-cause mortality. We used a random effects model to calculate pooled risk ratio (RR) and 95% confidence intervals (CIs). Results: By incorporating data from 1,555 patients included in 10 studies, we found that however, all-cause mortality was similar among patients receiving ATII and controls (RR = 1.02; 95% CI: 0.89 to 1.16, P = 0.81), the reduction in norepinephrine or norepinephrine-equivalent dose at 3 h after treatment initiation was greater among patients receiving ATII (MD = -0.06; 95% CI: -0.11 to -0.02, P = 0.008), while there were no higher rates of adverse events reported among ATII patients. Conclusions: While ATII did not reduce mortality among distributive shock patients, it allowed for significant adjunctive vasopressor reduction at 3 h without an increase in reported adverse events, deeming it a viable alternative for the increasingly adopted multimodal vasopressor for minimizing catecholamine exposure and its adverse events.

Proposal for the use of angiotensin II in distributive shock after extracorporeal circulation - position paper of the Section of Intensive Care Medicine and the Section of Cardiothoracic Anaesthesiology of the Polish Society of Anaesthesiology and Intensive Therapy

Angiotensin II (AT) is a potent vasoconstrictor and hypertensive drug that is registered for the treatment of severe hypotension in vasoplegic shock. Growing experience with the use of AT in cardiac surgery allows the first therapeutic algorithms to be created. This paper is a proposal for the use of AT in distributive shock after extracorporeal circulation.

Angiotensin ii therapy in refractory septic shock: which patient can benefit most? A narrative review

Patients with septic shock who experience refractory hypotension despite adequate fluid resuscitation and high-dose noradrenaline have high mortality rates. To improve outcomes, evidence-based guidelines recommend starting a second vasopressor, such as vasopressin, if noradrenaline doses exceed 0.5 µg/kg/min. Recently, promising results have been observed in treating refractory hypotension with angiotensin II, which has been shown to increase mean arterial pressure and has been associated with improved outcomes. This narrative review aims to provide an overview of the pathophysiology of the renin-angiotensin system and the role of endogenous angiotensin II in vasodilatory shock with a focus on how angiotensin II treatment impacts clinical outcomes and on identifying the population that may benefit most from its use.

Medical therapy of cardiogenic shock: Contemporary use of inotropes and vasopressors

Cardiogenic shock is a primary cardiac disorder that results in both clinical and biochemical evidence of tissue hypoperfusion and can lead to multi-organ failure and death depending on its severity. Inadequate cardiac contractility or cardiac power secondary to acute myocardial infarction remains the most frequent cause of cardiogenic shock, although its contribution has declined over the past two decades, compared with other causes. Despite some advances in cardiogenic shock management, this clinical syndrome is still burdened by an extremely high mortality. Its management is based on immediate stabilization of haemodynamic parameters so that further treatment, including mechanical circulatory support and transfer to specialized tertiary care centres, can be accomplished. With these aims, medical therapy, consisting mainly of inotropic drugs and vasopressors, still has a major role. The purpose of this article is to review current evidence on the use of these medications in patients with cardiogenic shock and discuss specific clinical settings with indications to their use.

Trajectory of PaO2/FiO2 Ratio in Shock After Angiotensin II

INTRODUCTION

High-dose catecholamines can impair hypoxic pulmonary vasoconstriction and increase shunt fraction. We aimed to determine if Angiotensin II (Ang-2) is associated with improved PaO2/FiO2 and SpO2/FiO2 in patients in shock.

METHODS

Adult patients at four tertiary care centers and one community hospital in the United States who received Ang-2 from July 2018-September 2020 were included in this retrospective, observational cohort study. PaO2, SpO2, and FiO2 were measured at 13 timepoints during the 48-h before and after Ang-2 initiation. Piecewise linear mixed models of PaO2/FiO2 and SpO2/FiO2 were created to evaluate hourly changes in oxygenation after Ang-2 initiation. The difference in the proportion of patients with PaO2/FiO2 ≤ 300 mm Hg at the time of Ang-2 initiation and 48 h after was also examined.

RESULTS

The study included 254 patients. In the 48 h prior to Ang-2 initiation, oxygenation was significantly declining (hourly PaO2/FiO2 change -4.7 mm Hg/hr, 95% CI - 6.0 to -3.5, p < .001; hourly SpO2/FiO2 change -3.1/hr, 95% CI-3.7 to -2.4, p < .001). Ang-2 treatment was associated with significant improvements in PaO2/FiO2 and SpO2/FiO2 in the 48-h after initiation (hourly PaO2/FiO2 change +1.5 mm Hg/hr, 95% CI 0.5-2.5, p  =  .003; hourly SpO2/FiO2 change +0.9/hr, 95% CI 0.5-1.2, p < .001). The difference in the hourly change in oxygenation before and after Ang-2 initiation was also significant (pinteraction < 0.001 for both PaO2/FiO2 and SpO2/FiO2). This improvement was associated with significantly fewer patients having a PaO2/FiO2 ≤ 300 mm Hg at 48 h compared to baseline (mean difference -14.9%, 95% CI -25.3% to -4.6%, p  =  .011). Subgroup analysis found that patients with either a baseline PaO2/FiO2 ≤ 300 mm Hg or a norepinephrine-equivalent dose requirement >0.2 µg/kg/min had the greatest associations with oxygenation improvement.

CONCLUSIONS

Ang-2 is associated with improved PaO2/FiO2 and SpO2/FiO2. The mechanisms for this improvement are not entirely clear but may be due to catecholamine-sparing effect or may also be related to improved ventilation-perfusion matching, intrapulmonary shunt, or oxygen delivery.

Management of Sepsis and Septic Shock: What Have We Learned in the Last Two Decades?

Sepsis is a clinical syndrome encompassing physiologic and biological abnormalities caused by a dysregulated host response to infection. Sepsis progression into septic shock is associated with a dramatic increase in mortality, hence the importance of early identification and treatment. Over the last two decades, the definition of sepsis has evolved to improve early sepsis recognition and screening, standardize the terms used to describe sepsis and highlight its association with organ dysfunction and higher mortality. The early 2000s witnessed the birth of early goal-directed therapy (EGDT), which showed a dramatic reduction in mortality leading to its wide adoption, and the surviving sepsis campaign (SSC), which has been instrumental in developing and updating sepsis guidelines over the last 20 years. Outside of early fluid resuscitation and antibiotic therapy, sepsis management has transitioned to a less aggressive approach over the last few years, shying away from routine mixed venous oxygen saturation and central venous pressure monitoring and excessive fluids resuscitation, inotropes use, and red blood cell transfusions. Peripheral vasopressor use was deemed safe and is rising, and resuscitation with balanced crystalloids and a restrictive fluid strategy was explored. This review will address some of sepsis management's most important yet controversial components and summarize the available evidence from the last two decades.

Utilization of Synthetic Human Angiotensin II for Catecholamine-Resistant Vasodilatory Shock in Critically Ill Children: A Single-Center Retrospective Case Series

OBJECTIVES

To describe our institutional experience utilizing adjunctive synthetic angiotensin II in critically ill children with catecholamine-resistant vasodilatory shock (CRVS).

DESIGN

Single-center, retrospective case series.

SETTING

PICU and cardiac ICU (CICU) at a large, quaternary children's hospital in the United States.

PATIENTS

Twenty-three pediatric patients with CRVS who were prescribed synthetic angiotensin II at the discretion of bedside clinicians from January 2018 to April 2023.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty-three patients (20 in PICU, 3 in CICU) with a median age of 10.4 years (interquartile range [IQR] 1.5-18.5) received angiotensin II over the study period, 70% of whom died. At the time of angiotensin II initiation, 17 patients (74%) were receiving one or more forms of extracorporeal therapy, and median Pediatric Logistic Organ Dysfunction-2 Score-2 in the prior 24 hours was 9 (IQR 7-11). The median time between initiation of the first vasoactive agent and angiotensin II was 127 hours (IQR 13-289), and the median total norepinephrine equivalent (NED) at initiation was 0.65 μg/kg/min (IQR 0.36-0.78). The median duration of therapy was 27 hours (IQR 4-68), and at each timepoint assessed, patients had median improvement in NED and mean arterial pressure (MAP) with treatment. Survivors initiated angiotensin II nearly 3 days earlier in vasoactive course (91.5 hr vs 161 hr, p = 0.23), and had both greater reduction in NED (-75% [IQR -96 to -50] vs +2.1% [IQR -55 to 33], p = 0.008) and greater increase in MAP (+15 mm Hg [IQR 10-27] vs -1.5 mm Hg [IQR -27 to 18], p = 0.052) at angiotensin II discontinuation.

CONCLUSIONS

We demonstrate reduction in NED and improved MAP following initiation of angiotensin II in critically ill children with CRVS. Further prospective work is needed to examine optimal timing of angiotensin II initiation, appropriate patient selection, and safety in this population.

Initiating angiotensin II at lower vasopressor doses in vasodilatory shock: an exploratory post-hoc analysis of the ATHOS-3 clinical trial

BACKGROUND

High dose vasopressors portend poor outcome in vasodilatory shock. We aimed to evaluate the impact of baseline vasopressor dose on outcomes in patients treated with angiotensin II (AT II).

METHODS

Exploratory post-hoc analysis of the Angiotensin II for the Treatment of High-Output Shock (ATHOS-3) trial data. The ATHOS-3 trial randomized 321 patients with vasodilatory shock, who remained hypotensive (mean arterial pressure of 55-70 mmHg) despite receiving standard of care vasopressor support at a norepinephrine-equivalent dose (NED) > 0.2 µg/kg/min, to receive AT II or placebo, both in addition to standard of care vasopressors. Patients were grouped into low (≤ 0.25 µg/kg/min; n = 104) or high (> 0.25 µg/kg/min; n = 217) NED at the time of study drug initiation. The primary outcome was the difference in 28-day survival between the AT II and placebo subgroups in those with a baseline NED ≤ 0.25 µg/kg/min at the time of study drug initiation.

RESULTS

Of 321 patients, the median baseline NED in the low-NED subgroup was similar in the AT II (n = 56) and placebo (n = 48) groups (median of each arm 0.21 µg/kg/min, p = 0.45). In the high-NED subgroup, the median baseline NEDs were also similar (0.47 µg/kg/min AT II group, n = 107 vs. 0.45 µg/kg/min placebo group, n = 110, p = 0.75). After adjusting for severity of illness, those randomized to AT II in the low-NED subgroup were half as likely to die at 28-days compared to placebo (HR 0.509; 95% CI 0.274-0.945, p = 0.03). No differences in 28-day survival between AT II and placebo groups were found in the high-NED subgroup (HR 0.933; 95% CI 0.644-1.350, p = 0.71). Serious adverse events were less frequent in the low-NED AT II subgroup compared to the placebo low-NED subgroup, though differences were not statistically significant, and were comparable in the high-NED subgroups.

CONCLUSIONS

This exploratory post-hoc analysis of phase 3 clinical trial data suggests a potential benefit of AT II introduction at lower doses of other vasopressor agents. These data may inform design of a prospective trial.

TRIAL REGISTRATION

The ATHOS-3 trial was registered in the clinicaltrials.gov repository (no. NCT02338843). Registered 14 January 2015.

How Effective is Angiotensin II in Decreasing Mortality of Vasodilatory Shock? A Systematic Review

Background

Patients with severe vasodilation accompanied by refractory hypotension despite high doses of vasopressors were associated with a high mortality rate. The Ang-2 for the Treatment of High-Output Shock (ATHOS) 3 trial demonstrated that angiotensin 2 (Ang-2) could effectively increase MAP and blood pressure in vasodilatory shock patients. This systematic review aims to summarize the impact of Ang-2 for the treatment of vasodilatory shock on clinical outcomes, including length of stay, MAP level (before and after), and mortality also Ang-2 dose needed.

Methods

A systematic search in PubMed, Sage, ScienceDirect, Scopus and Gray literature was conducted to obtain studies about the use of Ang-2 in vasodilatory shock patients.

Results

In all of the studies that we obtained, there were different results regarding mortality in patients with vasodilatory shock with Ang-2. Mortality was significantly lower when Ang-2 was administered to patients with elevated renin. The initial dose of Ang-2 can be started at 10-20 ng/kg/min, but there is no agreement on the maximum dose. Ang-2 may be considered a third-line vasopressor if the targeted MAP has not been achieved after administration of norepinephrine >200 ng/kg/min for more than 6 hours. Although not statistically significant, the use of Ang-2 can reduce the length of stay in the ICU and in the hospital when compared to patients without Ang-2 therapy, in addition to reducing the dose of vasopressor.

Conclusion

Overall, the use of Ang-2 has potential to be a regimen for patients with vasodilatory shock. Further study is needed to obtain more data.

Angiotensin II for Vasodilatory Hypotension in Patients Requiring Mechanical Circulatory Support

Background: Patients supported on mechanical circulatory support devices experience vasodilatory hypotension due to high surface area exposure to nonbiological and non-endothelialized surfaces. Angiotensin II has been studied in general settings of vasodilatory shock, however concerns exist regarding the use of this vasopressor in patients with pre-existing cardiac failure. The objective of this study was to assess the systemic and central hemodynamic effects of angiotensin II in patients with primary cardiac or respiratory failure requiring treatment with mechanical circulatory support devices. Methods: Multicenter retrospective observational study of adults supported on a mechanical circulatory support device who received angiotensin II for vasodilatory shock. The primary outcome was the intraindividual change from baseline in mean arterial pressure (MAP) and vasopressor dosage after angiotensin II. Results: Fifty patients were included with mechanical circulatory devices that were primarily used for cardiac failure (n = 41) or respiratory failure (n = 9). At angiotensin II initiation, the norepinephrine equivalent vasopressor dosage was 0.44 (0.34, 0.64) and 0.47 (0.33, 0.73) mcg/kg/min in the cardiac and respiratory groups, respectively. In the cardiac group, MAP increased from 60 to 70 mmHg (intraindividual P < .001) in the 1 h after angiotensin II initiation and the vasopressor dosage declined by 0.04 mcg/kg/min (intraindividual P < .001). By 12 h, the vasopressor dosage declined by 0.16 mcg/kg/min ( P = .001). There were no significant changes in cardiac index or mean pulmonary artery pressure throughout the 12 h following angiotensin II. In the respiratory group, similar but nonsignificant effects at 1 h on MAP (61-81 mmHg, P = .26) and vasopressor dosage (decline by 0.13 mcg/kg/min, P = .06) were observed. Conclusions: In patients requiring mechanical circulatory support for cardiac failure, angiotensin II produced beneficial systemic hemodynamic effects without negatively impacting cardiac function or pulmonary pressures. The systemic hemodynamic effects in those with respiratory failure were nonsignificant due to limited sample size.

Effects of Ziyin Qianyang Formula on Renal Fibrosis through the TGF-β1/Smads Signaling Pathway in Spontaneously Hypertensive Rats

OBJECTIVE

The aim of the study is to explore the effects and mechanisms of action of Ziyin Qianyang Formula (ZYQYF) on renal fibrosis in spontaneously hypertensive rats (SHRs).

METHODS

Forty SHRs were randomly divided into a model group, Ziyin Qianyang Formula regular-dose and high-dose groups (ZYQYF-R, 20 g/kg; ZYQYF-H, 40 g/kg), and a western medicine group (enalapril 10 mg/kg), and 10 Sprague-Dawley rats were selected as the normal group. The rats received continuous gavage administration for 6 weeks and systolic blood pressure (SBP) measurements were obtained every fortnight. The serum levels of urea, serum creatinine (sCr), and uric acid (UA) were measured; the pathological morphology and collagen content of the kidneys were observed by hematoxylin-eosin (HE) and Masson staining; and the serum Ang II level was measured by an enzyme-linked immunosorbent assay (ELISA). Transforming growth factor (TGF)-β1, Smad-2, Smad-3, and Smad-7 protein and mRNA expressions in kidney tissues was evaluated by western blotting and reverse transcription-polymerase chain reaction.

RESULTS

The ZYQYF-H group showed significantly a lower renal weight and renal weight/body weight than the model group. The enalapril and ZYQYF-H groups showed significantly lower SBP than other groups after 6 weeks of administration. The ZYQYF-H group showed better improvement than the ZYQYF-R and enalapril groups in glomerular and tubular morphology and better reductions in inflammatory cell infiltration and collagen volumetric fraction. The ZYQYF-H group also showed better reductions in serum UA and Ang II levels; collagen-I, collagen-III, and p-Smad2/Smad-2 protein expression; and Smad-2 mRNA expression and a better increase in Smad-7 protein and mRNA expression than the enalapril group. Besides, the degree of renal function and fibrosis improvement was positively correlated with the dose of ZYQYF.

CONCLUSION

ZYQYF can significantly reduce SHR blood pressure, protect renal function and structure, and improve renal fibrosis by regulating Smad proteins through TGF-β1.

The pharmacotherapeutic options in patients with catecholamine-resistant vasodilatory shock

INTRODUCTION

Septic and vasoplegic shock are common types of vasodilatory shock (VS) with high mortality. After fluid resuscitation and the use of catecholamine-mediated vasopressors (CMV), vasopressin, angiotensin II, methylene blue (MB) and hydroxocobalamin can be added to maintain blood pressure.

AREAS COVERED

VS treatment utilizes a phased approach with secondary vasopressors added to vasopressor agents to maintain an acceptable mean arterial pressure (MAP). This review covers additional vasopressors and adjunctive therapies used when fluid and catecholamine-mediated vasopressors fail to maintain target MAP.

EXPERT OPINION

Evidence supporting additional vasopressor agents in catecholamine resistant VS is limited to case reports, series, and a few randomized control trials (RCTs) to guide recommendations. Vasopressin is the most common agent added next when MAPs are not adequately supported with CMV. VS patients failing fluids and vasopressors with cardiomyopathy may have cardiotonic agents such as dobutamine or milrinone added before or after vasopressin. Angiotensin II, another class of vasopressor is used in VS to maintain adequate MAP. MB and/or hydoxocobalamin, vitamin C, thiamine and corticosteroids are adjunctive therapies used in refractory VS. More RCTs are needed to confirm the utility of these drugs, at what doses, which combinations and in what order they should be given.

Angiotensin II in Patients With Shock on Mechanical Circulatory Support: A Single-Center Retrospective Case Series

OBJECTIVES

To describe angiotensin II (ANGII) use in patients on mechanical circulatory support (MCS). To evaluate the efficacy and safety of ANGII in patients with shock on MCS.

DESIGN

Retrospective cohort study.

SETTING

A single-center, quaternary care academic medical center.

PARTICIPANTS

The study comprised critically ill patients on MCS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Fourteen patients were included in this retrospective analysis. The median age was 54 years (44.8, 68.3) and 78.6% were men. Six patients were receiving venoarterial extracorporeal membrane oxygenation support, 4 patients were receiving venovenous extracorporeal membrane oxygenation support, and 4 patients were on left ventricular assist devices. Five patients (36%) achieved hemodynamic response to ANGII at 3 hours, defined as a mean arterial pressure (MAP) of ≥65 mmHg or a 10-mmHg increase in MAP with a decrease or no change in total vasopressor dose. Overall, the median MAP increased from 61 mmHg (51, 73) at baseline to 66 mmHg (58, 71) at 3 hours, and the median norepinephrine dose decreased from 0.45 µg/kg/min (0.28, 0.6) at baseline to 0.2 µg/kg/min (0.18, 0.32) at 3 hours. The in-hospital mortality rate was 78.6%. Two patients experienced severe adverse drug events and 1 patient had a sentinel thrombotic event.

CONCLUSIONS

This study suggested that ANGII may provide a salvage treatment option in patients on MCS with refractory vasodilatory shock. There are several safety considerations with the use of ANGII in these patients. Prospective randomized controlled trials are needed to evaluate the safety and efficacy of ANGII in patients on MCS.

Timing of vasoactive agents and corticosteroid initiation in septic shock

Septic shock remains a health care concern associated with significant morbidity and mortality. The Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock recommend early fluid resuscitation and antimicrobials. Beyond initial management, the guidelines do not provide clear recommendations on appropriate time to initiate vasoactive therapies and corticosteroids in patients who develop shock. This review summarizes the literature regarding time of initiation of these interventions. Clinical data regarding time of initiation of these therapies in relation to shock onset, sequence of treatments with regard to each other, and clinical markers evaluated to guide initiation are summarized. Early-high vasopressor initiation within first 6 h of shock onset is associated with lower mortality. Following norepinephrine initiation, the exact dose and timing of escalation to adjunctive vasopressor agents are not well elucidated in the literature. However, recent data indicate that timing may be an important factor in initiating vasopressors and adjunctive therapies, such as corticosteroids. Norepinephrine-equivalent dose and lactate concentration can aid in determining when to initiate vasopressin and angiotensin II in patients with septic shock. Future guidelines with clear recommendations on the time of initiation of septic shock therapies are warranted.

Effectiveness of Angiotensin II for Catecholamine Refractory Septic or Distributive Shock on Mortality: A Propensity Score Weighted Analysis of Real-World Experience in the Medical ICU

Supplemental Digital Content is available in the text.

Angiotensin II (ATII) was approved for septic or other distributive shock due to its property of increasing blood pressure within 3 hours. Limited data exist regarding its effectiveness when used in real-world clinical practice.

Angiotensin II: A Review of Current Literature

Up to one-third of all patients admitted to intensive care units carry a diagnosis of shock. The use of angiotensin II is becoming widespread in all forms of shock, including cardiogenic, after the U.S. Food and Drug Administration's (FDA's) initial approval for vasoplegic shock in 2017. Here, the authors review the literature on angiotensin II's mechanism of action, benefits, and future therapeutic opportunities.