Comparison of Angiotensin-Converting Enzyme Inhibitor and Angiotensin Receptor Blocker Management Strategies Before Cardiac Surgery: A Pilot Randomized Controlled Registry Trial

Diagnosis and Management of Vasoplegia in Temporary Mechanical Circulatory Support: A Narrative Review

Refractory vasodilatory shock, or vasoplegia, is a pathophysiologic state observed in the intensive care unit and operating room in patients with a variety of primary diagnoses. Definitions of vasoplegia vary by source but are qualitatively defined clinically as a normal or high cardiac index and low systemic vascular resistance causing hypotension despite high-dose vasopressors in the setting of euvolemia. This definition can be difficult to apply to patients undergoing mechanical circulatory support (MCS). A large body of mostly retrospective literature exists on vasoplegia in the non-MCS population, but the increased use of temporary MCS justifies an examination of vasoplegia in this population. MCS, particularly extracorporeal membrane oxygenation, adds complexity to the diagnosis and management of vasoplegia due to challenges in determining cardiac output (or total blood flow), lack of clarity on appropriate dosing of noncatecholamine interventions, increased thrombosis risk, the difficulty in determining the endpoints of adequate volume resuscitation, and the unclear effects of rescue agents (methylene blue, hydroxocobalamin, and angiotensin II) on MCS device monitoring and function. Care teams must combine data from invasive and noninvasive sources to diagnose vasoplegia in this population. In this narrative review, the available literature is surveyed to provide guidance on the diagnosis and management of vasoplegia in the temporary MCS population, with a focus on noncatecholamine treatments and special considerations for patients supported by extracorporeal membrane oxygenation, transvalvular heart pumps, and other ventricular assist devices.

Pre-operative maintenance of angiotensin-converting enzyme inhibitors is not associated with acute kidney injury in cardiac surgery patients with cardio-pulmonary bypass: a propensity-matched multicentric analysis

Objective: We investigated the effects of the maintenance of angiotensin-converting enzyme inhibitors (ACE inhibitors) the day of the surgery on the incidence of postoperative acute kidney injury (AKI) and cardiac events in patients undergoing cardiac surgery. Methods: We performed a multicentric observational study with propensity matching on 1,072 patients treated with ACE inhibitors. We collected their baseline demographic data, comorbidities, and operative and postoperative outcomes. AKI was defined by KDIGO (Kidney Disease: Improving Global Outcome). Results: Maintenance of an ACE inhibitor was not associated with an increased risk of AKI (OR: 1.215 (CI95%:0.657-2.24), p = 0.843, 71 patients (25.1%) vs. 68 patients (24%)). Multivariate logistic regression and sensitive analysis did not demonstrate any association between ACE inhibitor maintenance and AKI, following cardiac surgery (OR: 1.03 (CI95%:0.81-1.3)). No statistically significant difference occurs in terms of incidence of cardiogenic shock (OR: 1.315 (CI95%:0.620-2.786)), stroke (OR: 3.313 (CI95%:0.356-27.523)), vasoplegia (OR: 0.741 (CI95%:0.419-1.319)), postoperative atrial fibrillation (OR: 1.710 (CI95%:0.936-3.122)), or mortality (OR: 2.989 (CI95%:0.343-26.034)). ICU and hospital length of stays did not differ (3 [2; 5] vs. 3 [2; 5] days, p = 0.963 and 9.5 [8; 12] vs. 10 [8; 14] days, p = 0.638). Conclusion: Our study revealed that maintenance of ACE inhibitors on the day of the surgery was not associated with increased postoperative AKI. ACE inhibitor maintenance was also not associated with an increased rate of postoperative major cardiovascular events (arterial hypotension, cardiogenic shock, vasopressors use, stroke and death).

Effect of pre-transplantation use of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in kidney transplant recipients-propensity score-matched analysis

BACKGROUND

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEi/ARBs) can cause acute kidney injury under dehydratation or in hemodynamically unstable conditions. Regarding kidney transplantation (KT), the risk of using ACEi/ARBs before surgery is not well established. Therefore, we evaluated the clinical outcomes to determine the effect of preoperative use of ACEi/ARBs on KT.

METHODS

We retrospectively collected 1187 patients who received living-donor KT between January 2017 and December 2021. We conducted a propensity score-matched analysis between the ACEi/ARB(+) and ACEi/ARB(-) groups and evaluated the effects of ACEi/ARBs on delayed graft function, post-KT renal function, hyperkalemia events, rejection, and graft survival.

RESULTS

The ACEi/ARB(+) group showed a similar incidence of delayed graft function as the ACEi/ARB(-) group (1.8% vs. 1.0%, P = 0.362). The risk of delayed graft function was not upregulated in the ACEi/ARB(+) group after propensity score-matching (odds ratio: 0.50, 95% confidence interval (CI) 0.13-2.00). Postoperative creatinine levels and the slope of creatinine levels after KT also were not significantly different between the two groups (creatinine slope from POD#0 to POD#7: - 0.73 ± 0.35 vs. - 0.75 ± 0.32 mg/dL/day, P = 0.464). Hyperkalemia did not occur more often in the ACEi/ARB(+) group than in the ACEi/ARB(-) group during perioperative days. Rejection-free survival (P = 0.920) and graft survival (P = 0.621) were not significantly different between the two groups.

CONCLUSIONS

In KT, the preoperative use of ACEi/ARBs did not significantly affect clinical outcomes including delayed graft function, postoperative renal function, hyperkalemia events, incidence of rejection, and graft survival rates compared to the patients who did not receive ACEi/ARBs.

Association between Premorbid Renin-Angiotensin-Aldosterone System Blockade and the Risk of Acute Kidney Injury in Critically Ill Patients

Background

Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) are commonly used for hypertension and cardiovascular diseases. However, whether their use increases the risk of acute kidney injury (AKI) and should be discontinued during acute illness remains controversial.

Methods

This retrospective study enrolled 952 dialysis-free patients who were admitted to intensive care units (ICUs) between 2015 and 2017, including 476 premorbid long-term (> 1 month) ACEi/ARB users. Propensity score matching was performed to adjust for age, gender, comorbidities, and disease severity. The primary endpoint was the occurrence of AKI during hospitalization, and the secondary endpoint was mortality or dialysis within 1 year.

Results

Compared with non-users, the ACEi/ARB users were not associated with an increased AKI risk during hospitalization [66.8% vs. 70.4%; hazard ratio (HR): 1.13, 95% confidence interval (CI): 0.97-1.32, p = 0.126]. However, the ACEi/ARB users with sepsis (HR: 1.29, 95% CI: 1.04-1.60, p = 0.021) or hypotension (HR: 1.21, 95% CI: 1.02-1.14, p = 0.034) were found to have an increased AKI risk in subgroup analysis. Nevertheless, compared with the non-users, the ACEi/ARB users were associated with a lower incidence of mortality or dialysis within 1 year (log-rank p = 0.011).

Conclusions

Premorbid ACEi/ARB usage did not increase the incidence of AKI, and was associated with a lower 1-year mortality and dialysis rate in patients admitted to ICUs. Regarding the results of subgroup analysis, renin-angiotensin-aldosterone system blockade may still be safe and beneficial in the absence of sepsis or circulation failure. Further large-scale studies are needed to confirm our findings.

Adult Cardiac Surgery-Associated Acute Kidney Injury: Joint Consensus Report

OBJECTIVES

Acute kidney injury (AKI) is increasingly recognized as a source of poor patient outcomes after cardiac surgery. The purpose of the present report is to provide perioperative teams with expert recommendations specific to cardiac surgery-associated AKI (CSA-AKI).

METHODS

This report and consensus recommendations were developed during a joint, in-person, multidisciplinary conference with the Perioperative Quality Initiative and the Enhanced Recovery After Surgery Cardiac Society. Multinational practitioners with diverse expertise in all aspects of cardiac surgical perioperative care, including clinical backgrounds in anesthesiology, surgery and nursing, met from October 20 to 22, 2021, in Sacramento, California, and used a modified Delphi process and a comprehensive review of evidence to formulate recommendations. The quality of evidence and strength of each recommendation were established using the Grading of Recommendations Assessment, Development, and Evaluation methodology. A majority vote endorsed recommendations.

RESULTS

Based on available evidence and group consensus, a total of 13 recommendations were formulated (4 for the preoperative phase, 4 for the intraoperative phase, and 5 for the postoperative phase), and are reported here.

CONCLUSIONS

Because there are no reliable or effective treatment options for CSA-AKI, evidence-based practices that highlight prevention and early detection are paramount. Cardiac surgery-associated AKI incidence may be mitigated and postsurgical outcomes improved by focusing additional attention on presurgical kidney health status; implementing a specific cardiopulmonary bypass bundle; using strategies to maintain intravascular euvolemia; leveraging advanced tools such as the electronic medical record, point-of-care ultrasound, and biomarker testing; and using patient-specific, goal-directed therapy to prioritize oxygen delivery and end-organ perfusion over static physiologic metrics.

Perioperative Management of the Patient at High-Risk for Cardiac Surgery-Associated Acute Kidney Injury

Acute kidney injury (AKI) is one of the most common major complications of cardiac surgery, and is associated with increased morbidity and mortality. Cardiac surgery-associated AKI has a complex, multifactorial etiology, including numerous factors such as primary cardiac dysfunction, hemodynamic derangements of cardiac surgery and cardiopulmonary bypass, and the possibility of a large volume of blood transfusion. There are no truly effective pharmacologic therapies for the management of AKI, and, therefore, anesthesiologists, intensivists, and cardiac surgeons must remain vigilant and attempt to minimize the risk of developing renal dysfunction. This narrative review describes the current state of the scientific literature concerning the specific aspects of cardiac surgery-associated AKI, and presents it in a chronological fashion to aid the perioperative clinician in their approach to this high-risk patient group. The evidence was considered for risk prediction models, preoperative optimization, and the intraoperative and postoperative management of cardiac surgery patients to improve renal outcomes.

Strategies for post–cardiac surgery acute kidney injury prevention: A network meta-analysis of randomized controlled trials

Objects

Cardiac surgery is associated with acute kidney injury (AKI). However, the effects of various pharmacological and non-pharmacological strategies for AKI prevention have not been thoroughly investigated, and their effectiveness in preventing AKI-related adverse outcomes has not been systematically evaluated.

Methods

Studies from PubMed, Embase, and Medline and registered trials from published through December 2021 that evaluated strategies for preventing post–cardiac surgery AKI were identified. The effectiveness of these strategies was assessed through a network meta-analysis (NMA). The secondary outcomes were prevention of dialysis-requiring AKI, mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS. The interventions were ranked using the P-score method. Confidence in the results of the NMA was assessed using the Confidence in NMA (CINeMA) framework.

Results

A total of 161 trials (involving 46,619 participants) and 53 strategies were identified. Eight pharmacological strategies {natriuretic peptides [odds ratio (OR): 0.30, 95% confidence interval (CI): 0.19–0.47], nitroprusside [OR: 0.29, 95% CI: 0.12–0.68], fenoldopam [OR: 0.36, 95% CI: 0.17–0.76], tolvaptan [OR: 0.35, 95% CI: 0.14–0.90], N-acetyl cysteine with carvedilol [OR: 0.37, 95% CI: 0.16–0.85], dexmedetomidine [OR: 0.49, 95% CI: 0.32–0.76;], levosimendan [OR: 0.56, 95% CI: 0.37–0.84], and erythropoietin [OR: 0.62, 95% CI: 0.41–0.94]} and one non-pharmacological intervention (remote ischemic preconditioning, OR: 0.76, 95% CI: 0.63–0.92) were associated with a lower incidence of post–cardiac surgery AKI with moderate to low confidence. Among these nine strategies, five (fenoldopam, erythropoietin, natriuretic peptides, levosimendan, and remote ischemic preconditioning) were associated with a shorter ICU LOS, and two (natriuretic peptides [OR: 0.30, 95% CI: 0.15–0.60] and levosimendan [OR: 0.68, 95% CI: 0.49–0.95]) were associated with a lower incidence of dialysis-requiring AKI. Natriuretic peptides were also associated with a lower risk of mortality (OR: 0.50, 95% CI: 0.29–0.86). The results of a sensitivity analysis support the robustness and effectiveness of natriuretic peptides and dexmedetomidine.

Conclusion

Nine potentially effective strategies were identified. Natriuretic peptide therapy was the most effective pharmacological strategy, and remote ischemic preconditioning was the only effective non-pharmacological strategy. Preventive strategies might also help prevent AKI-related adverse outcomes. Additional studies are required to explore the optimal dosages and protocols for potentially effective AKI prevention strategies.

Effect of preoperative renin-angiotensin system blockade on vasoplegia after cardiac surgery: A systematic review with meta-analysis

BACKGROUND

Vasoplegia is a common complication of cardiac surgery but its causal relationship with preoperative use of renin angiotensin system (RAS) blockers [angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARB)] is still debated.

AIM

To update and summarize data on the effect of preoperative use of RAS blockers on incident vasoplegia.

METHODS

All published studies from MEDLINE, EMBASE, and Web of Science providing relevant data through January 13, 2021 were identified. A random-effects meta-analysis method was used to pool estimates, and post-cardiac surgery shock was differentiated from vasoplegia.

RESULTS

Ten studies reporting on a pooled population of 15672 patients (none looking at ARBs exclusively) were included in the meta-analysis. All were case-control studies. Use of ACEIs was associated with an increased risk of vasoplegia [pooled adjusted odds ratio (Aor) of 2.06, 95%CI: 1.45-2.93] and increased inotropic/vasopressor support requirement (pooled aOR 1.19, 95%CI: 1.10-1.29). Post-cardiac surgery shock was increased in the presence of left ventricular dysfunction (pooled aOR 2.32, 95%CI: 1.60-3.36; I² 49%) but not increased by the use of beta blockers (pooled aOR 0.78, 95%CI: 0.36-1.69; I² 77%). Two randomized control trials (RCTs), not eligible for the meta-analysis, did not show an association between continuation of RAS blockers and vasoplegia.

CONCLUSION

Preoperative continuation of ACEIs is associated with an increased need for inotropic support postoperatively and with an increased risk of vasoplegia in observational studies but not in RCTs. The absence of a consensus definition of vasoplegia should lead to the use of perioperative cardiovascular monitoring when designing RCTs to better understand this discrepancy.

Impact of Renin-Angiotensin System Blockers on Mortality in Veterans Undergoing Cardiac Surgery

Background

Renin‐angiotensin system blockers (RASBs) have well‐validated benefit in patients with hypertension, coronary artery disease, and left ventricular systolic dysfunction. Their use in the perioperative period, however, has been controversial, including in patients undergoing cardiac surgery, who often have a strong indication for their use. In the current study, we explore the impact of RASB use with 30‐day and 1‐year mortality after cardiac surgery.

Methods and Results

The Veterans Affairs Surgical Quality Improvement Program and Corporate Data Warehouse were data sources for this retrospective cohort study. A total of 37 197 veterans undergoing elective coronary artery bypass grafting and or valve repair or replacement over a 10‐year period met inclusion criteria and were stratified into 4 groups by preoperative exposure (preoperative exposure versus no preoperative exposure) and postoperative continuing exposure (current exposure versus no current exposure) to RASBs. After adjusting for all baseline covariates, the preoperative exposure/current exposure group had lower 30‐day and 1‐year mortality than the preoperative exposure/no current exposure (30‐day hazard ratio [HR], 0.25; 95% CI, 0.19–0.33 [P<0.001] and 1‐year HR, 0.40; 95% CI, 0.33–0.48 [P<0.001] or no preoperative exposure/no current exposure (30‐day HR, 0.44; 95% CI, 0.32–0.60 [P<0.001] and 1‐year HR, 0.72; 95% CI, 0.62–0.84 [P<0.001] groups. The no preoperative exposure/current exposure group had significantly lower 30‐day (HR, 0.31; 95% CI, 0.14–0.71 [P=0.006]) and 1‐year (HR, 0.64; 95% CI, 0.53–0.77 [P<0.001]) mortality than the no preoperative exposure/no current exposure group.

Conclusions

Continuation of preoperative RASBs and initiation before discharge is associated with decreased mortality in veterans undergoing cardiac surgery. Given these findings, continuation of preoperative RASBs or initiation in the early postoperative period should be considered in patients undergoing cardiac surgery.

Withholding vs. Continuing Angiotensin-Converting Enzyme Inhibitors or Angiotensin Receptor Blockers Before Non-cardiac Surgery in Older Patients: Study Protocol for a Multicenter Randomized Controlled Trial

Background: Older hypertensive adults are at increased risk for postoperative morbidity and mortality. As first line antihypertensive drug therapy, angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) have many beneficial effects. However, the use of ACEIs/ARBs in the perioperative period remains controversial. This study aims to determine the effects of withholding vs. continuing ACEIs/ARBs before non-cardiac surgery on perioperative hypotension and postoperative outcomes in older patients.

Methods: In this multicenter, randomized, double-blind, placebo-controlled trial, a total of 2036 patients aged 60–80 years undergoing non-cardiac surgical procedures will be randomly assigned, in a 1:1 ratio, to receive oral ACEIs/ARBs (the ACEIs/ARBs continued group) or inactive placebos (the ACEIs/ARBs withheld group) on the morning of surgery. For both groups, the ACEIs/ARBs will be continued from the first postoperative day. The primary outcome measure is the incidence of perioperative hypotensive events, defined as mean blood pressure (MBP) < 65 mmHg or ≥30% reduction in MBP from baseline during surgery and in a post-anesthesia care unit. The secondary outcomes include duration of perioperative hypotension, intraoperative use of fluids and vasopressors, hypotensive events within postoperative 3 days, and perioperative neurocognitive disorders, major adverse cardiocerebral events (a composite outcome of stroke, coma, myocardial infarction, heart block, and cardiac arrest), and mortality within 30 days after surgery.

Discussion: The results of this trial will offer an evidence-based perioperative ACEIs/ARBs therapy for older hypertensive adults undergoing non-cardiac surgery.

Study Registration: This study is approved by the Medical Ethics Committee of The First Affiliated Hospital of Soochow University (Approval No. 2020-077-1) and by the institutional ethics review board of each participating center. This protocol is registered at the Chinese Clinical Trials Registry (ChiCTR2000039376).

Comparison of Angiotensin-Converting Enzyme Inhibitor and Angiotensin Receptor Blocker Management Strategies Before Cardiac Surgery: A Pilot Randomized Controlled Registry Trial

Background

Postoperative clinical outcomes associated with the preoperative continuation or discontinuation of angiotensin‐converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) before cardiac surgery remain unclear.

Methods and Results

In a single‐center, open‐label, randomized, registry‐based clinical trial, patients undergoing nonemergent cardiac surgery were assigned to ACEI/ARB continuation or discontinuation 2 days before surgery. Among the 584 patients screened, 261 met study criteria and 126 (48.3%) patients were enrolled. In total,121 patients (96% adherence; 60 to continuation and 61 to ACEI/ARB discontinuation) underwent surgery and completed the study protocol, and follow‐up was 100% complete. Postoperative intravenous vasopressor use (78.3% versus 75.4%, P=0.703), vasodilator use (71.7% versus 80.3%, P=0.265), vasoplegic shock (31.7% versus 27.9%, P=0.648), median duration of vasopressor (10 versus 5 hours, P=0.494), and vasodilator requirements (10 versus 9 hours, P=0.469) were not significantly different between the continuation and discontinuation arms. No differences were observed in the incidence of acute kidney injury (1.7% versus 1.6%, P=0.991), stroke (no events, mortality (1.7% versus 1.6%, P=0.991), median duration of mechanical ventilation (6 versus 6 hours, P=0.680), and median intensive care unit length of stay (43 versus 27 hours, P=0.420) between the treatment arms.

Conclusions

A randomized study evaluating the routine continuation or discontinuation of ACEIs or ARBs before cardiac surgery was feasible, and treatment assignment was not associated with differences in postoperative physiological or clinical outcomes. These preliminary findings suggest that preoperative ACEI/ARB management strategies did not affect the postoperative course of patients undergoing cardiac surgery.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02096406.