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

Clinical Response to Third-Line Angiotensin-II vs Epinephrine in Septic Shock: A Propensity-Matched Cohort Study

BACKGROUND

The appropriate third-line vasopressor in septic shock patients receiving norepinephrine and vasopressin is unknown. Angiotensin-II (AT-II) offers a unique mechanism of action to traditionally used vasopressors in septic shock.

OBJECTIVE

The objective of this study was to compare the clinical efficacy and safety of third-line AT-II to epinephrine in patients with septic shock.

METHODS

A single-center, retrospective cohort study of critically ill patients was performed between April 1, 2019 and July 31, 2022. Propensity-matched (2:1) analysis compared adults with septic shock who received third-line AT-II to controls who received epinephrine following norepinephrine and vasopressin. The primary outcome was clinical response 24 hours after third-line vasopressor initiation. Additional efficacy and safety outcomes were investigated.

RESULTS

Twenty-three AT-II patients were compared with 46 epinephrine patients. 47.8% of AT-II patients observed a clinical response at hour 24 compared with 28.3% of epinephrine patients (P = 0.12). In-hospital mortality (65.2% vs 73.9%, P = 0.45), cardiac arrhythmias (26.1% vs 26.1%, P = 0.21), and thromboembolism (4.3% vs 2.2%, P = 0.61) were not observed to be statistically different between groups.

CONCLUSIONS AND RELEVANCE

Administration of AT-II as a third-line vasopressor agent in septic shock patients was not associated with significantly improved clinical response at hour 24 compared with epinephrine. Although underpowered to detect meaningful differences, the clinical observations of this study warrant consideration and further investigation of AT-II as a third-line vasopressor in septic shock.

The use of angiotensin II for the management of distributive shock: expert consensus statements

BACKGROUND

Despite the growing body of evidence supporting the use of angiotensin II (ATII) in distributive shock, its integration into existing treatment algorithms requires careful consideration of factors related to patient comorbidities, hemodynamic parameters, cost-effectiveness, and risk-benefit balance. Moreover, several questions regarding its use in clinical practice warrant further investigations. To address these challenges, a group of Italian intensive care specialists (the panel) developed a consensus process using a modified Delphi technique.

METHODS

The panel defined five clinical questions during an online scoping workshop and then provided a short list of statements related to each clinical question based on literature review and clinical experience. A total of 20 statements were collected. Two coordinators screened and selected the final list of statements to be included in the online survey, which consisted of 17 statements. The consensus was reached when ≥ 75% of respondents assigned a score within the 3-point range of 1-3 (disagreement) or 7-9 (agreement).

RESULTS

Overall, a consensus on agreement was reached on 13 statements defining the existing gaps in scientific evidence, the possibility of evaluating the addition of drugs with different mechanisms of action for the treatment of refractory shock, the utility of ATII in reducing the catecholamine requirements in the treatment of vasopressor-resistant septic shock, and the effectiveness of ATII in treating patients in whom angiotensin-converting enzyme activity is reduced or pharmacologically blocked. It was widely shared that renin concentration can be used to identify patients who most likely benefit from ATII to restore vascular tone. Thus, the patients who might benefit most from using ATII were defined. Lastly, some potential barriers to the use of ATII were described.

CONCLUSIONS

ATII was recognized as a useful treatment to reduce catecholamine requirements in treating vasopressor-resistant septic shock. At the same time, the need for additional clinical trials to further elucidate the efficacy and safety of ATII, as well as investigations into potential mechanisms of action and optimization of treatment protocols in patients with refractory distributive shock, emerged.

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.

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.

Angiotensin II for the Treatment of Refractory Shock: A Matched Analysis

OBJECTIVES

To determine if angiotensin II is associated with improved outcomes as measured by 30- and 90-day mortality as well as other secondary outcomes such as organ dysfunction and adverse events.

DESIGN

Retrospective, matched analysis of patients receiving angiotensin II compared with both historical and concurrent controls receiving equivalent doses of nonangiotensin II vasopressors.

SETTING

Multiple ICUs in a large, university-based hospital.

PATIENTS

Eight hundred thirteen adult patients with shock admitted to an ICU and requiring vasopressor support.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Angiotensin II use had no association with the primary outcome of 30-day mortality (60% vs 56%; p = 0.292). The secondary outcome of 90-day mortality was also similar (65% vs 63%; p = 0.440) as were changes in Sequential Organ Failure Assessment scores over a 5-day monitoring period after enrollment. Angiotensin II was not associated with increased rates of kidney replacement therapy (odds ratio [OR], 1.39; 95% CI, 0.88-2.19; p = 0.158) or receipt of mechanical ventilation (OR, 1.50; 95% CI, 0.41-5.51; p = 0.539) after enrollment, and the rate of thrombotic events was similar between angiotensin II and control patients (OR, 1.02; 95% CI, 0.71-1.48; p = 0.912).

CONCLUSIONS

In patients with severe shock, angiotensin II was not associated with improved mortality or organ dysfunction and was not associated with an increased rate of adverse events.

Intravenous infusion of angiotensin II for treatment of cardiopulmonary bypass-induced vasoplegic shock after implantation of left ventricular assist device: a case report

We report on the first successful treatment of severe pharmacoresistant vasoplegic syndrome with angiotensin II acetate (ATII) in Croatia. ATII is a novel drug used to treat severe vasoplegic shock resistant to the administration of catecholamines or alternative vasopressors such as vasopressin or methylene blue. A 44-year-old patient with secondary toxic cardiomyopathy developed severe cardiopulmonary bypass-induced vasoplegic shock after scheduled implantation of a left-ventricular assist device. The cardiac output was maintained, but systemic vascular resistance (SVR) was extremely low. The patient had an inadequate reaction to the administration of high doses of norepinephrine (up to 0.7 µg/kg/min) and vasopressin (0.03 IU/min). At postoperative intensive care unit (ICU) admission, serum renin levels were unmeasurably high (>330 ng/L), and infusion of ATII 20 ng/kg/min was initiated. Soon after the start of the infusion, blood pressure increased. Vasopressin infusion was stopped, while the norepinephrine dose was decreased from 0.7 to 0.15 µg/kg/min. Serum lactate, mixed venous saturation, and glomerular filtration rate markedly improved. The patient was extubated 16 h after the ICU admission. Twenty-four hours after the start of the ATII infusion, serum renin dropped to 255 ng/L, and laboratory findings further improved. On postoperative day 3, the norepinephrine infusion was stopped. On day 6, renin further dropped to 136 ng/L, and the patient was hemodynamically stable and discharged from the ICU. In conclusion, ATII favorably affected the patient’s vascular tone, enabling rapid hemodynamic stabilization and shortening the ICU and hospital stay.

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.

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.