Efficacy of Low-Dose Continuous Infusion of .ALPHA.-Human Atrial Natriuretic Peptide (hANP) During Cardiac Surgery Possibility of Postoperative Left Ventricular Remodeling Effect

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 carperitide on the 1 year prognosis of patients with acute decompensated heart failure

Aims

Acute heart failure (AHF) is a clinical syndrome with a poor prognosis and a major public health concern worldwide. The aim of this study was to investigate whether carperitide administration improves the 1 year prognosis of patients with AHF and to check whether there is an optimal dose of the drug.

Methods and results

We analysed the data of COOPERATE‐HF‐J (the Consortium for Pooled Data Analysis regarding Hospitalized Patients with Heart Failure in Japan), combining two cohorts (NARA‐HF and REALITY‐AHF), which included 2435 patients with acute decompensated heart failure. The patients were divided into no carperitide (NO‐ANP, n = 1098); very low‐dose carperitide (VLD‐ANP, <0.02 μg/kg/min, n = 593); and low‐dose carperitide groups (LD‐ANP, ≥0.02 μg/kg/min, n = 744). The primary endpoint was cardiovascular mortality within 1 year after admission. The secondary endpoints were all‐cause mortality and rehospitalization due to worsening heart failure within 1 year after admission. The median carperitide doses in the VLD‐ANP and LD‐ANP groups were 0.013 and 0.025 μg/kg/min, respectively. Kaplan–Meier analysis showed that cardiovascular mortality and all‐cause mortality were significantly lower in the LD‐ANP group than in the NO‐ANP and VLD‐ANP groups (P < 0.001 and P = 0.002, respectively). Multivariable Cox regression analysis for cardiovascular and all‐cause mortality revealed that LD‐ANP was significantly associated with lower cardiovascular and all‐cause mortality within 1 year after admission, even after adjusting other covariates (hazard ratio: 0.696 and 0.791, 95% confidence interval: 0.513–0.944 and 0.628–0.997, P = 0.020 and 0.047, respectively).

Conclusions

Low‐dose carperitide was significantly associated with lower cardiovascular and all‐cause mortality within 1 year after admission. Our results suggest the necessity for well‐designed randomized controlled trials to determine the doses of carperitide that could improve clinical outcomes in patients with AHF.

Effect of low-dose atrial natriuretic peptide in critically ill patients with acute kidney injury: a retrospective, single-center study with propensity-score matching

Background

Acute kidney injury (AKI) is a major comorbidity in critically ill patients. Low-dose atrial natriuretic peptide (ANP) has been shown to effectively prevent acute kidney injury (AKI), especially in cardiovascular surgery patients. However, its treatment effects for AKI in critically ill patients are unclear.

Methods

This single-center, retrospective, observational study included patients with AKI diagnosed within 7 days after intensive care unit (ICU) admission during the period January 2010 to December 2017. We conducted a propensity-matched analysis to estimate the treatment effect of low-dose carperitide (a recombinant human ANP) on the clinical outcomes. The primary outcome was a composite of death, renal replacement therapy dependence, or no recovery from AKI (defined as an increase of the serum creatinine level to ≥200% of baseline) at hospital discharge.

Results

During the study period, 4479 adult patients were admitted to the ICU. We identified 1374 eligible patients with AKI diagnosed within 7 days after ICU admission. Among these patients, 346 (25.2%) were treated with low-dose carperitide, with an average dose of 0.019 μg kg^− 1 min^− 1. The primary outcome occurred more often in the treatment group than in the control group (29.7% versus 23.4%, respectively; p = 0.022). After propensity score matching, characteristics of 314 patients from each group were well- balanced. Significant difference of the primary outcome, as seen with the full cohort, was no longer obtained; no benefit of carperitide was detected in the matched cohort (29.0% versus 25.2%; p = 0.281).

Conclusions

Low-dose ANP showed no treatment effect in general critically ill patients who developed AKI.

Low-dose atrial natriuretic peptide for prevention or treatment of acute kidney injury: a systematic review and meta-analysis

Background

Theoretically, atrial natriuretic peptide (ANP), especially low-dose ANP, is beneficial in acute kidney injury (AKI). In this study, we examined whether low-dose ANP is effective in preventing or treating AKI by conducting an updated systematic review for randomized controlled trials (RCTs).

Method

We searched the Excerpta Medica database (EMBASE), PubMed, and Cochrane CENTRAL databases for RCTs that compare the effects of low-dose ANP (≤ 50 ng/kg/min) with a placebo or conventional therapy in at-risk patients or patients with AKI. The primary outcome was the incidence of new AKI (in prevention RCTs), while the secondary outcomes were in-hospital mortality rate, renal replacement therapy (RRT) requirement, length of hospital and intensive care unit (ICU) stay, incidence of hypotension, and peak serum creatinine levels. The risk-of-bias was evaluated using the Cochrane Collaboration risk-of-bias tool. Trial sequential analysis (TSA) was used for each outcome of interest.

Results

A total of 18 RCTs (16 prevention and two treatment trials) fulfilled our inclusion criteria. In prevention RCTs, the incidence of new AKI was significantly low in the low-dose ANP group (relative risk [RR] = 0.51; 95% confidence interval [CI] = 0.36–0.72; P = 0.0001) compared to the control group. In addition, the low-dose ANP group showed a significantly reduced RRT requirement in both prevention (RR = 0.17; 95% CI = 0.04–0.64; P = 0.009) and treatment (RR = 0.43; 95% CI = 0.20–0.93; P = 0.03) RCTs. Among secondary outcomes, in some cases, low-dose ANP was associated with a reduction in ICU and in-hospital stay. The risk-of-bias assessment and TSA results indicated that the sample sizes and qualities of the RCTs were insufficient to conclude the efficacy of low-dose ANP.

Conclusion

Low-dose ANP might be effective in preventing or treating AKI. However, the evidence accumulated so far is not strong enough to demonstrate ANP’s beneficial effects. The next step is to elucidate the effects of low-dose ANP by conducting multicenter, high-quality, large-sample RCTs.

Trial registration

PROSPERO registry CRD42017068568. Registered 20 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2330-z) contains supplementary material, which is available to authorized users.

Comparative Efficacy of Drugs for Preventing Acute Kidney Injury after Cardiac Surgery: A Network Meta-Analysis

BACKGROUND

Acute kidney injury (AKI) occurs frequently after cardiac surgery and has been associated with increased hospital length of stay, mortality, and costs.

OBJECTIVE

We aimed to evaluate the efficacy of pharmacologic strategies for preventing AKI after cardiac surgery.

METHODS

We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL) up to 6 May 2017 and the reference lists of relevant articles about trials. The outcome was the occurrence of AKI. This is the first network meta-analysis of the different prevention strategies using Bayesian methodology.

RESULTS

The study included 63 articles with 19,520 participants and evaluated the effect of ten pharmacologic strategies to prevent AKI in patients undergoing cardiac surgery. Compared with placebo, the odds ratio (OR) for the occurrence of AKI was 0.24 [95% confidence interval (CI) 0.16-0.34] with natriuretic peptide, 0.33 (95% CI 0.14-0.70) with fenoldopam, 0.54 (95% CI 0.31-0.84) with dexmedetomidine, 0.56 (95% CI 0.29-0.95) with low-dose erythropoietin, 0.63 (95% CI 0.43-0.88) with levosimendan, 0.76 (95% CI 0.52-1.10) with steroids, 0.83 (95% CI 0.48-1.40) with high-dose erythropoietin, 0.85 (95% CI 0.64-1.14) with N-acetylcysteine, 0.96 (95% CI 0.69-1.29) with sodium bicarbonate, and 1.05 (95% CI 0.70-1.41) with statins. The surface under the cumulative ranking curve probabilities indicated that natriuretic peptide was the best treatment therapy and that fenoldopam ranked second.

CONCLUSIONS

Natriuretic peptide is probably the preferred pharmacologic strategy to prevent AKI in adult patients undergoing cardiac surgery, especially in those at high risk of AKI.

Treatment of Patients with Cardiac Surgery Associated-Acute Kidney Injury

Members of the Acute Dialysis Quality Initiative (ADQI) participated in a 3-day conference in Vicenza in May 2007 to evaluate the available literature on this topic and draft consensus recommendations for research studies in this area. This report summarizes the available evidence and describes the key questions that will need to be addressed with the goal of standardizing the care of patients with cardiac surgery-associated acute kidney injury (CSA-AKI) and improving outcomes.

Protective roles of bioactive peptides during ischemia-reperfusion injury: From bench to bedside

Ischemia-reperfusion (I/R) is a well-known pathological condition which may lead to disability and mortality. I/R injury remains an unresolved and complicated situation in a number of clinical conditions, such as cardiac arrest with successful reanimation, as well as ischemic events in brain and heart. Peptides have many attractive advantages which make them suitable candidate drugs in treating I/R injury, such as low toxicity and immunogenicity, good solubility property, distinct tissue distribution pattern, and favorable pharmacokinetic profile. An increasing number of studies indicate that peptides could protect against I/R injury in many different organs and tissues. Peptides also face several therapeutic challenges that limit their clinical application. In this review, we present the mechanisms of action of peptides in reducing I/R injury, as well as further discuss modification strategies to improve the functional properties of bioactive peptides.

Low-dose carperitide (α-human A-type natriuretic peptide) alleviates hemoglobin concentration decrease during prolonged oral surgery: a randomized controlled study

PURPOSE

Surgical injury stimulates the renin-angiotensin-aldosterone system (RAAS) and causes antidiuresis, leading to postoperative oliguria. Carperitide (α-human A-type natriuretic peptide) is a cardiac peptide hormone secreted from the atrium. This peptide hormone enhances diuresis by suppressing the RAAS. In our experience, carperitide alleviates decreased hemoglobin (Hb) concentration during elective surgery. In the current study, we investigated the relationship between low-dose carperitide (0.01 µg/kg/min) and Hb concentration during oral surgery.

METHODS

Patients (ASA-PS: I-II, 40-80 years old) undergoing oral maxillofacial surgery (duration of operation >8 h) were enrolled in this study. Patients were divided into two groups: the carperitide group received carperitide at 0.01 µg/kg/min and the control group received normal saline. Body fluid water [including total body water (TBW), extracellular water (ECW), and intracellular water (ICW)], urine volume, and chemical parameters such as Hb concentration, PaO₂, and serum electrolytes were evaluated every 2 h.

RESULTS

In the carperitide group (n = 15), Hb decreased from 12.6 ± 1.1 to 10.8 ± 1.5 g/dl, while it decreased from 12.6 ± 1.4 to 9.5 ± 1.3 g/dl in the control group (n = 15) (p < 0.05). Urine volume (2557.3 ± 983.5 mL) in the carperitide group was significantly more than it was in the control group (1108.8 ± 586.4 mL; p < 0.001). There were no significant differences in clinical characteristics, body fluid water, PaO₂, and serum electrolytes between the two groups. In addition, there were no perioperative clinical respiratory and hemodynamic complications in the groups.

CONCLUSION

The Hb concentration in the group administered low-dose carperitide at 0.01 µg/kg/min remained higher than that in the control group during surgery. Administration of low-dose carperitide may therefore reduce the risk of blood transfusion during surgery.

Renin-Angiotensin System Control for Chronic Kidney Disease Patients Undergoing Coronary Surgery

PURPOSE

We investigated the effectiveness of active renin-angiotensin-aldosterone system (RAAS) control with human atrial natriuretic peptide (hANP) and an angiotensin II receptor blocker (ARB) in patients with chronic kidney disease (CKD) undergoing coronary artery bypass grafting (CABG).

METHODS

A total of 286 consecutive patients with CKD undergoing CABG were divided into three groups: Group C (n = 50) receiving placebo, the hANP group (n = 60) receiving hANP, and the active RAAS control therapy (ARC) group (n = 56) receiving hANP plus an ARB. Renal function, brain natriuretic peptide (BNP) and RAAS parameters were analyzed.

RESULTS

After 1 year, renal function parameters were better in the hANP and ARC groups compared with group C, and the dialysis rate was significantly lower (group C: 12%, hANP group: 1.7%, ARC group: 1.8%, p = 0.018) in the hANP and ARC groups. BNP levels were significantly lower in the hANP and ARC groups compared with group C (p = 0.001). There was also a significant difference of aldosterone among the groups (p = 0.023), as well as a significant difference between group C and the ARC group (p = 0.017).

CONCLUSIONS

The present study showed that active RAAS control preserved renal function in patients with CKD undergoing CABG. The improved early postoperative outcome with RAAS control may lead to long-term inhibition of cardiovascular events.

Effects of continuous infusion of low-dose human atrial natriuretic peptide (hANP) on the lungs during cardiac surgery

OBJECTIVE

The objective of this study was to determine the effects of a continuous infusion of low-dose hANP on the lungs during cardiac surgery in patients under cardiopulmonary bypass (CPB).

METHODS

We analyzed 30 consecutive cases of cardiac surgery performed at our hospital from 2007-2008. The patients were divided into a group that received hANP (hANP group) or a group that received saline and no hANP (N-hANP group). We measured various parameters before and after surgery using a PiCCO monitor.

RESULT

There were no differences in the preoperative characteristics between the groups, although urine volume during the operation was significantly greater in the hANP group. After surgery, there were no significant differences between the groups in cardiac output index (CI), global enddiastolic volume index (GEDVI), intrathoracic blood volume index (ITBI), pulmonary blood volume index (PBI), extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI), total protein, and creatine. In contrast, interleukin-6 (IL-6) and renin were significantly lower, and albumin was significantly higher in the hANP group.

CONCLUSION

We found that low-dose hANP during open cardiac surgery inhibited the secretion and plasma activity of IL-6 and renin. Although there were no differences in lung circulatory parameters such as the amount of fluid in the pulmonary blood vessels between the two groups, we believe that the strong diuretic effect of hANP reduced third-space fluid retention caused by CPB.

Low-dose atrial natriuretic peptide for chronic kidney disease in coronary surgery

PURPOSE

Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease. We investigated the effectiveness of human atrial natriuretic peptide (hANP) infusion in CKD patients undergoing coronary artery bypass grafting (CABG).

PATIENTS AND METHODS

We analyzed 134 consecutive cases in which CABG had been performed in our hospital from 2002 to 2005. They were divided into four groups: Group A (n = 19) was CKD + placebo, Group B (n = 30) was non-CKD + placebo, Group C (n = 22) was CKD + hANP, and Group D (n = 63) was non-CKD + hANP). The serum creatinine (mg/dl) and estimated glomerular filtration rate (ml/min/1.73 m²) were measured as evaluation values.

RESULTS

The value of sCr changed preoperatively and at 1 year postoperatively from 1.09 ± 0.09, 51.3 ± 4.4 to 1.26 ± 0.42, 49.4 ± 14.4 in Group A, from 0.77 ± 0.14, 75.5 ± 12.1 to 0.91 ± 0.40, 72.3 ± 19.5 in Group B, from 0.99 ± 0.12, 54.8 ± 3.0 to 0.93 ± 0.16, 64.2 ± 12.3 in Group C and from 0.77 ± 0.13, 77.7 ± 13.4 to 0.83 ± 0.17, 75.9 ± 16.2 in Group D, respectively. There was a significant difference between Group A and Group C regarding the change of creatinine (p =0.0022).

CONCLUSION

Our study has confirmed that an infusion of hANP during CABG in patients with CKD not only improves perioperative renal function, but also prevents the progression of CKD.

Pharmacological therapies for the prevention of acute kidney injury following cardiac surgery: a systematic review

Post-cardiac surgery acute kidney injury (AKI) is common and is associated with a significant increase in morbidity and mortality. We aimed to systematically review randomised trials that assessed the renoprotective utility of pharmacological agents in patients undergoing cardiac surgery. We searched PubMed, Embase and the Cochrane Central Register of Controlled Trials for randomised controlled trials comparing renoprotective pharmacological interventions with control in adult patients undergoing cardiac surgery with cardiopulmonary bypass. We extracted data for mortality, need for renal replacement therapy (RRT), incidence of AKI, and creatinine clearance at 24-48 h. About 49 randomised controlled trials involving 4605 patients were included. Pharmacological interventions included dopamine, fenoldopam, calcium channel antagonists, natriuretic peptides, diuretics, and N-acetylcysteine. Most trials were of poor quality, with small sample sizes, under-reporting of randomisation procedure, allocation concealment and method of blinding. No pharmacological intervention significantly reduced mortality. Fenoldopam and Atrial Natriuretic Peptide (ANP) reduced the need for renal replacement therapy by 5% (NNT 20, 95% CI 11.3, 83.0) and 3.5% (NNT 29, 95% CI 17.1, 84.4), respectively. Brain Natriuretic Peptide resulted in a 10% reduction in the incidence of AKI (NNT 11, 95% CI 6.2, 32.0). Dopamine caused a significant reduction in creatinine clearance (-4.26 ml/min, 95% CI -7.14, -1.39). The quality of studies that have assessed pharmacological renoprotective agents in cardiac surgery is generally poor. Fenoldopam, ANP and BNP show evidence of renoprotection. Randomised studies evaluating the effect of novel renoprotective agents that are powered to detect clinically relevant differences in outcomes are required.

Human atrial natriuretic peptide treatment for acute heart failure: a systematic review of efficacy and mortality

BACKGROUND

The objectives of this study were to assess the effect of human atrial natriuretic peptide (hANP) treatment on physiological parameters and mortality in acute heart failure.

METHODS

The MEDLINE (1966-2009), EMBASE (1980-2009), Cochrane Central Register of Controlled Trials (1991-2009), American College of Physicians Journal Club (1991), Ichushi (Japana Centra Revuo Medicina) (1983-2009), Cinni (NII Scholarly and Academic Information Navigator) (1959-2009), National Diet Library Online Public Access Catalog (1969-2009), Webcat Plus (Japanese National Institute of Informatics) (1986-2009), Medical Online (1947-2009), and JST China (1981-2009) databases were searched for studies that compared the efficacy of hANP and the mortality in patients with acute heart failure with placebo controls. Only randomized controlled trials (RCTs) were included in the study.

RESULTS

Out of 347 articles, a total of 4 studies involving 220 patients with acute heart failure fulfilled the predefined inclusion criteria. There were significant differences in the hemodynamic parameters between the hANP and placebo groups, especially in the pulmonary capillary wedge pressure (PCWP) reduction (standard mean difference [SMD] 2.07; 95% confidence interval [CI], 0.34-3.81) and the cardiac index (SMD 1.79; 95% CI, 0.12-3.47). No statistically significant differences in mortality rates were found (relative risk 1.03; 95% CI, 0.27-3.92).

CONCLUSIONS

In a limited number of studies, hANP appears to improve several hemodynamic parameters, including pulmonary capillary wedge pressure and cardiac index, but not mortality. Further high-quality studies are needed to corroborate these results.

Myocardial protective effect of human atrial natriuretic Peptide in cardiac surgery. -hANP Shot” in clinical safety trial-

BACKGROUND

We studied low-dose human atrial natriuretic peptide (hANP) infusion therapy during cardiac surgery and reported the cardiac and renal protective effects. The efficacy of a bolus injection of hANP (the "hANP shot") simultaneously with induction of cardioplegia has been proven in animal experiments. In the present study the clinical effects of this "hANP shot" were examined.

METHODS AND RESULTS

The subjects were 67 patients undergoing Coronary artery bypass grafting. At the time of inducing cardioplegia, 1 group received a simultaneous bolus injection of 100 μg of hANP (hANP group) and the other group received an injection of physiological saline (placebo group). The primary endpoints were (1) operative mortality and complications, and (2) the creatine kinase isoenzyme MB (CPK-MB), troponin-I, and human heart fatty acid binding protein (H-FABP) levels. The secondary endpoints were (1) the incidence of arrhythmia, and levels of (2) atrial and B-type natriuretic peptides, and cyclic guanosine monophosphate (cGMP), and (3) renin, angiotensin II, and aldosterone. Postoperative CPK-MB, troponin-I, and H-FABP levels were significantly lower in the hANP group than in the placebo group. Postoperative arrhythmia was significantly less frequent in the hANP group than in the placebo group.

CONCLUSIONS

It is possible to achieve cardioprotective effects based on the safety of the "hANP shot", as well as from biomarkers of ischemia and results related to arrhythmia. The "hANP shot" should also be evaluated as a safer and new cardioprotective method for cardiac surgery.

Long-term results (three-year) of emergency coronary artery bypass grafting for patients with unstable angina pectoris

Satisfactory results are achieved by elective coronary artery bypass grafting (CABG), but the results of emergency CABG are less than satisfactory and readmission for cardiac events is common. We examined long-term results of emergency CABG for unstable angina pectoris from the viewpoints of preoperative, intraoperative, and postoperative factors. Subjects were 154 patients who underwent emergency CABG for unstable angina pectoris. Operative mortality rate was 1.9%. Univariate analysis showed female gender, chronic renal failure, hemodialysis, nonuse of human atrial natriuretic peptide (hANP), nonuse of angiotensin II receptor blockers and aldosterone blockers, 3-month postoperative brain natriuretic peptide level > or =200 pg/ml, and 3-month postoperative aldosterone level > or =100 pg/ml as risk factors for late cardiac events. Multivariate analysis confirmed nonuse of hANP, nonuse of aldosterone blockers, 3-month brain natriuretic peptide level > or =200 pg/ml, and 3-month aldosterone level > or =100 pg/ml as risk factors. Intraoperative hANP infusion and postoperative treatment with aldosterone blockers and angiotensin II receptor blockers can control the renin-angiotensin-aldosterone system, inhibit left ventricular remodeling, decrease extent of infarction, and improve cardiac function, yielding a favorable long-term prognosis. The best results are obtained by combining good surgical technique and perioperative management with the long-term outcome in mind.

Experimental investigation of direct myocardial protective effect of atrial natriuretic peptide in cardiac surgery

OBJECTIVE

Human atrial natriuretic peptide has recently become known not only as a heart failure drug but also for myocardial protection. We investigated its direct myocardial protective effect on ischemia-reperfusion injury in cardiac surgery.

METHODS

Male pigs (35-45 kg) undergoing surgery with cardiopulmonary bypass, with 60-minute reperfusion after 30-minute cardioplegia, were grouped by timing of atrial natriuretic peptide administration: group C (n = 8), no atrial natriuretic peptide (cardioplegia only); group H1 (n = 8); 100-mug atrial natriuretic peptide administration after aortic crossclamping; group H2 (n = 8), administration before aortic declamping; and group H1 + H2 (n = 8), administration both after crossclamping and before declamping. Blood and myocardial cyclic guanosine monophosphate, calcium, and residual adenosine triphosphate levels were determined. Histologic investigation was conducted by electron and optical microscopy.

RESULTS

Atrial natriuretic peptide increased blood and myocardial cyclic guanosine monophosphate levels (P < .0001, P < .0001, P < .007 H1 + H2 vs C; P < .0014, P < .0007, P < .003 H1 vs C), decreased myocardial calcium (P < .0038 H1 + H2 vs C), and increased myocardial residual adenosine triphosphate. Electron microscopy revealed ischemic changes in mitochondria and nuclei in group C but not in treatment groups.

CONCLUSIONS

Ischemia-reperfusion injury was inhibited with equal effectiveness by atrial natriuretic peptide both during ischemia and immediately before reperfusion, acting directly on myocardium through cyclic guanosine monophosphate. Atrial natriuretic peptide may be useful as a supportive measure for patients with long aortic crossclamping time or difficulties in weaning from cardiopulmonary bypass.

Atrial natriuretic peptide for preventing and treating acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is common in hospitalised patients and is associated with significant morbidity and mortality. Despite recent advances, outcomes have not substantially changed in the last four decades. Atrial natriuretic peptide (ANP) has shown promise in animal studies, however randomised controlled trials (RCTs) have shown inconsistent clinical benefits.

OBJECTIVES

To assess the benefits and harms of ANP for preventing and treating AKI.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE and EMBASE and reference lists of retrieved articles.

SELECTION CRITERIA

RCTs that investigated all forms of ANP versus any other treatment in adult hospitalised patients with or "at risk" of AKI.

DATA COLLECTION AND ANALYSIS

Results were expressed as risk ratios (RR) with 95% confidence intervals (CI) or mean difference (MD). Outcomes were analysed separately for low and high dose ANP for preventing or treating AKI.

MAIN RESULTS

Nineteen studies (11 prevention, 8 treatment; 1,861 participants) were included. There was no difference in mortality between ANP and control in either the low or high dose prevention studies. Low (but not high) dose ANP was associated with a reduced need for RRT in the prevention studies (RR 0.32, 95% CI 0.14 to 0.71). Length of hospital and ICU stay were significantly shorter in the low dose ANP group. For established AKI, there was no difference in mortality with either low or high dose ANP. Low (but not high) dose ANP was associated with a reduction in the need for RRT (RR 0.54, 95% CI 0.30 to 0.98). High dose ANP was associated with more adverse events (hypotension, arrhythmias). After major surgery there was a significant reduction in RRT requirement with ANP in the prevention studies (RR 0.56, 95% CI 0.32 to 0.99), but not in the treatment studies. There was no difference in mortality between ANP and control in either the prevention or treatment studies. There was a reduced need for RRT with low dose ANP in patients undergoing cardiovascular surgery (RR 0.35, 95% CI 0.18 to 0.70). ANP was not associated with outcome improvement in either radiocontrast nephropathy or oliguric AKI.

AUTHORS' CONCLUSIONS

ANP may be associated with improved outcomes when used in low doses for preventing AKI and in managing postsurgery AKI and should be further explored in these two settings. There were no significant adverse events in the prevention studies, however in the high dose ANP treatment studies there were significant increases hypotension and arrhythmias.

Influence of continuous infusion of low-dose human atrial natriuretic peptide on renal function during cardiac surgery: a randomized controlled study

OBJECTIVES

The purpose of this study was to determine the effect of human atrial natriuretic peptide (hANP) in patients who underwent coronary artery bypass grafting (CABG) on renal function.

BACKGROUND

Acute renal failure after cardiac surgery is associated with high morbidity and mortality.

METHODS

A total of 504 patients who underwent CABG were divided into 2 groups: 1 group received hANP at 0.02 microg/kg/min from the start of cardiopulmonary bypass (hANP group), and 1 group did not receive hANP (placebo group). Various parameters were measured before and after surgery.

RESULTS

There was no difference in mortality between the 2 groups, but post-operative complications were less frequent in the hANP group (p = 0.0208). In the hANP group, serum creatinine (Cr) was significantly lower and urinary Cr and Cr clearance were significantly higher from post-operative day 1 to week 1. The maximum post-operative Cr level and percent increase of Cr were significantly lower in the hANP group (p < 0.0001). Patients with Cr exceeding 2.0 mg/dl included 1 in the hANP group and 8 in the placebo group, showing a significant difference (p = 0.0374). Four patients in the placebo group and none in the hANP group required hemodialysis, but the difference was not statistically significant.

CONCLUSIONS

Continuous infusion of low-dose hANP from the start of cardiopulmonary bypass effectively maintained post-operative renal function. Infusion of hANP prevents early post-operative acute renal failure and helps to achieve safer cardiac surgery. (

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000001440).

Atrial natriuretic peptide for management of acute kidney injury: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Randomized controlled trials (RCTs) with atrial natriuretic peptide (ANP) have shown inconsistent effects for renal end-points. The authors aimed to systematically review these trials to ascertain the benefit of ANP in prevention and treatment of acute kidney injury (AKI).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The authors searched MEDLINE, EMBASE, and Cochrane Renal Health Library that investigated ANP in adult patients considered with or at risk for AKI. Outcomes were analyzed separately for prevention and treatment of AKI.

RESULTS

Nineteen RCTs (11 prevention, 8 treatment) involving 1861 participants were included. Pooled analysis of prevention trials showed a trend toward reduction in renal replacement therapy in the ANP group (OR = 0.45, 95% CI, 0.21 to 0.99) and good safety profile, but no improvement in mortality. For the treatment of established AKI, ANP, particularly in high doses, was associated with a trend toward increased mortality and more adverse events. Subgroup analysis of AKI after a major surgery (14 RCTs, 817 participants) showed a significant reduction in renal replacement therapy requirement in the ANP group (OR = 0.49, 95% CI, 0.27 to 0.88). Included RCTs were mostly low- or moderate-quality, underpowered studies.

CONCLUSIONS

There are an insufficient number of high-quality studies to make any definite statement about the role of ANP in AKI. Analysis of the existing literature suggests ANP might be associated with beneficial clinical effects when administered in patients undergoing major surgery such as cardiovascular surgery. Its use, in low doses, should be explored further in this setting.

Effects of human atrial natriuretic peptide on renal function in patients undergoing abdominal aortic aneurysm repair

OBJECTIVE

Ischemia-reperfusion injury is an important cause of renal dysfunction after abdominal aortic aneurysm repair. Human atrial natriuretic peptide (hANP) is a potent endogenous natriuretic, diuretic, and vasorelaxant peptide. The objective of the present study was to evaluate the effects of hANP on renal function in patients undergoing abdominal aortic aneurysm repair.

DESIGN

A prospective, randomized, placebo-controlled study

SETTING

Intensive care unit of a university hospital.

PATIENTS

Forty patients undergoing elective abdominal aortic aneurysm repair.

INTERVENTIONS

The patients were randomized to receive a continuous infusion of either hANP (0.01-0.05 microg/kg/min) (n = 20) or placebo (n = 20) immediately before aortic cross-clamping. The infusion of hANP or placebo continued for 48 hrs.

MEASUREMENTS AND MAIN RESULTS

Blood and urine samples were taken before surgery, at admission to the intensive care unit, and on days 1, 2, and 3 postoperatively, for measurement of serum concentrations of sodium, creatinine, and blood urea nitrogen and plasma concentrations of ANP and brain natriuretic peptide (BNP). Urine volume and urinary concentrations of N-acetyl-beta-D-glucosaminidase (NAG), sodium, and creatinine were also measured. The mean plasma concentration of ANP was significantly higher in the hANP group than in the placebo group. The mean plasma BNP concentration was significantly lower in the hANP group than in the placebo group. The mean serum concentrations of creatinine and blood urea nitrogen were significantly (p < .05) lower in the hANP group than in the placebo group. The mean urine volume and mean creatinine clearance were significantly (p < .05) higher in the hANP group than in the placebo group. The mean urinary NAG/creatinine ratio was significantly (p < .05) lower in the hANP group than in the placebo group.

CONCLUSIONS

The intraoperative and postoperative infusion of low-dose hANP preserved renal function in patients undergoing abdominal aortic aneurysm repair. Further studies are needed to assess the efficacy of prophylactic hANP infusion on perioperative renal outcome.

Efficacy of continuous low-dose hANP administration in patients undergoing emergent coronary artery bypass grafting for acute coronary syndrome

BACKGROUND

Low-dose continuous human atrial natriuretic peptide (hANP) administration during cardiac surgery has been reported on previously. In the present study, the efficacy of the therapy during emergent coronary artery bypass grafting (CABG) for acute coronary syndrome (ACS) is investigated.

METHODS AND RESULTS

One hundred and twenty-four patients patients undergoing emergent CABG for ACS were divided into 2 groups; a group receiving administration of hANP (hANP group) and a group not receiving hANP infusion (non-hANP group). The postoperative peak levels of creatine kinase-MB were significantly lower in the hANP group as compared with those in the non-hANP group. The incidence of postoperative arrhythmias was also significantly lower in the hANP group as compared with that in the non-hANP group. The postoperative brain natriuretic peptide was significantly lower in the hANP group as compared with that in the non-hANP group until 1 year after the operation. The free-rate of cardiac events after the operation was also significantly higher in the hANP group as compared with that in the non-hANP group.

CONCLUSIONS

It is therefore considered that hANP might not only be effective for overcoming some major shortcomings of cardiopulmonary bypass, but also might be effective to attenuate ischemia-reperfusion injury, protect the myocardium, have an anti-arrhythmic effect, and suppress left ventricular remodeling.

Low dose nesiritide and the preservation of renal function in patients with renal dysfunction undergoing cardiopulmonary-bypass surgery: a double-blind placebo-controlled pilot study

BACKGROUND

Renal insufficiency is associated with increased morbidity and mortality after cardiopulmonary bypass cardiac surgery. B-type natriuretic peptide is a cardiac hormone that enhances glomerular filtration rate and inhibits aldosterone. Cystatin has been shown to be a better endogenous marker of renal function than creatinine.

METHODS AND RESULTS

We performed a double-blinded placebo-controlled proof of concept pilot study in patients (n=40) with renal insufficiency preoperatively (defined as an estimated creatinine clearance of <60 mL/min determined by the Cockroft-Gault formula), undergoing cardiopulmonary bypass cardiac surgery. Patients were randomized to placebo (n=20) or i.v. low dose nesiritide (n=20; 0.005 microg/Kg/min) for 24 hours started after the induction of anesthesia and before cardiopulmonary bypass. Patients in the nesiritide group had an increase of plasma B-type natriuretic peptide and its second messenger cGMP with a decrease in plasma cystatin levels at the end of the 24-hour infusion. These changes were not observed in the placebo group. There was a significant activation of aldosterone in the placebo group at the end of the 24-hour infusion, but not in the nesiritide group. At 48 and 72 hours, there was a decrease in estimated creatinine clearance and an increase in plasma cystatin as compared with end of the 24-hour infusion in the placebo group. In contrast, renal function was preserved in the nesiritide group with no significant change in estimated creatinine clearance and a trend for plasma cystatin to increase as compared with end of the 24-hour infusion.

CONCLUSION

This proof of concept pilot study supports the conclusion that perioperative administration of low dose nesiritide is biologically active and decreases plasma cystatin in patients with renal insufficiency undergoing cardiopulmonary bypass cardiac surgery. Further studies are warranted to determine whether these physiological observations can be translated into improved clinical outcomes.