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

Angiotensin Receptor-Neprilysin Inhibitor Suppresses Renin-Angiotensin-Aldosterone System Activation After Cardiac Surgery Using Cardiopulmonary Bypass

BACKGROUND

Sacubitril/valsartan, being both a neprilysin inhibitor and angiotensin receptor blocker, exhibits a renin-angiotensin-aldosterone system (RAAS) inhibitory effect. However, no study has investigated the administration of sacubitril/valsartan in patients early after surgery using cardiopulmonary bypass.

METHODS AND RESULTS

This was a prospective observational study of 63 patients who underwent open heart surgery and were treated with sacubitril/valsartan. No serious adverse events occurred. Among the 63 patients, sacubitril/valsartan was discontinued in 13 due to hypotension (n=10), renal dysfunction (n=2), and dizziness (n=1). Atrial natriuretic peptide concentrations increased significantly from Day 3 of treatment (P=0.0142 vs. Postoperative Day 1) and remained high thereafter. In contrast, plasma renin activity was significantly suppressed from Day 3 onwards (P=0.00206 vs. Postoperative Day 1). A decrease in creatinine concentrations and an increase in the estimated glomerular filtration rate were observed on Day 3; this improvement in renal function was not observed in the historical control group, in which patients did not receive sacubitril/valsartan. New postoperative atrial fibrillation was less frequent in the study group compared with the historical control (12.7% vs. 38.0%; P=0.0034).

CONCLUSIONS

Sacubitril/valsartan administration was safe immediately after open heart surgery in patients without postoperative hypotension. It enhanced serum atrial natriuretic peptide concentrations and suppressed RAAS activation.

Advancing drug development for atrial fibrillation by prioritising findings from human genetic association studies

BACKGROUND

Drug development for atrial fibrillation (AF) has failed to yield new approved compounds. We sought to identify and prioritise potential druggable targets with support from human genetics, by integrating the available evidence with bioinformatics sources relevant for AF drug development.

METHODS

Genetic hits for AF and related traits were identified through structured search of MEDLINE. Genes derived from each paper were cross-referenced with the OpenTargets platform for drug interactions. Confirmation/validation was demonstrated through structured searches and review of evidence on MEDLINE and ClinialTrials.gov for each drug and its association with AF.

FINDINGS

613 unique drugs were identified, with 21 already included in AF Guidelines. Cardiovascular drugs from classes not currently used for AF (e.g. ranolazine and carperitide) and anti-inflammatory drugs (e.g. dexamethasone and mehylprednisolone) had evidence of potential benefit. Further targets were considered druggable but remain open for drug development.

INTERPRETATION

Our systematic approach, combining evidence from different bioinformatics platforms, identified drug repurposing opportunities and druggable targets for AF.

FUNDING

KK is supported by Barts Charity grant G-002089 and is mentored on the AFGen 2023-24 Fellowship funded by the AFGen NIH/NHLBI grant R01HL092577. RP is supported by the UCL BHF Research Accelerator AA/18/6/34223 and NIHR grant NIHR129463. AFS is supported by the BHF grants PG/18/5033837, PG/22/10989 and UCL BHF Accelerator AA/18/6/34223 as well as the UK Research and Innovation (UKRI) under the UK government's Horizon Europe funding guarantee EP/Z000211/1 and by the UKRI-NIHR grant MR/V033867/1 for the Multimorbidity Mechanism and Therapeutics Research Collaboration. AF is supported by UCL BHF Accelerator AA/18/6/34223. CF is supported by UCL BHF Accelerator AA/18/6/34223.

Effects of Recombinant Human Brain Natriuretic Peptide on Atrial Fibrillation After Coronary Artery Bypass Grafting

ABSTRACT

Previous studies reported that the use of natriuretic peptides (NPs) can effectively decrease arrhythmias. However, there is a lack of clinical evidence that recombinant human brain natriuretic peptide (rh-BNP) inhibits postoperative atrial fibrillation (POAF). This cohort aims to assess the effect of rh-BNP on POAF. This study retrospectively reviewed patients who underwent isolated coronary artery bypass grafting from January 2018 to January 2021. Patients were divided into 2 groups according to whether they received rh-BNP therapy within 5 days after surgery. A total of 1153 patients met the inclusion and exclusion criteria, of which 54 received rh-BNP therapy within 5 days. After propensity score matching, 53 patients were treated with rh-BNP, and 148 patients were not treated with rh-BNP. The incidence of POAF was lower in rh-BNP group than non-rh-BNP group (18.9% vs. 37.2%, odds ratio = 0.393, 95% confidence interval, 0.183-0.845, P = 0.017). There was no significant difference in the occurrence of ventricular arrhythmia ( P = 0.4), hypotension ( P = 0.763), and the risk of death ( P = 0.14). rh-BNP could significantly reduce the occurrence of POAF after coronary artery bypass grafting, and rh-BNP did not increase the risk of ventricular arrhythmia, hypotension, and death. Accordingly, rh-BNP could be a potential safe medicine for preventing POAF.

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 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.

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.

Protective effect of active perfusion in porcine models of acute myocardial ischemia

Mortality rates associated with off-pump coronary artery bypass (CAB) are relatively high, as the majority of patients requiring CAB are at a high risk for cardiac events. The present study aimed to establish porcine models of acute myocardial ischemia, and evaluate the protective role of shunt and active perfusion. A total of 30 pigs were randomly assigned to five groups, as follows: i) Sham (control); ii) A1 (shunt; stenosis rate, 55%); iii) A2 (shunt; stenosis rate, 75%); iv) B1 (active perfusion; stenosis rate, 55%); and v) B2 (active perfusion; stenosis rate, 75%) groups. Aortic pressure (P₀), left anterior descending coronary pressure (P₁), and coronary effective perfusion pressure (P₁/P₀) were measured. The expression levels of tumor necrosis factor-α (TNF-α), cardiac troponin (cTnI), creatine kinase-myocardial band (CK-MB), interleukin (IL)-6, IL-10, B-cell lymphoma 2 (Bcl-2), and caspase-3 were detected using enzyme-linked immunosorbent assay or western blotting. The myocardial apoptosis rate was determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Ischemia models with stenosis rates of 55 and 75% were successfully constructed following suturing of the descending artery. Compared with the control, the 55 and 75% stenosis groups demonstrated significantly decreased P₁/P₀, increased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, an increased rate of myocardial apoptosis, and a decreased expression level of anti-apoptotic protein, Bcl-2. At 30 min following successful establishment of the model (ST segment elevation to 1 mm), group B demonstrated significantly increased P₁/P₀, decreased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, a decreased rate of myocardial apoptosis, and an increased expression level of anti-apoptotic protein, Bcl-2. Furthermore, the current study indicated that active perfusion was more efficacious in maintaining myocardial perfusion and alleviating ischemic injury when compared with traditional shunt perfusion.

Effects of Wild-Type and Mutant Forms of Atrial Natriuretic Peptide on Atrial Electrophysiology and Arrhythmogenesis

Background—

Atrial natriuretic peptide (ANP) is a hormone with numerous beneficial cardiovascular effects. Recently, a mutation in the ANP gene, which results in the generation of a mutant form of ANP (mANP), was identified and shown to cause atrial fibrillation in people. The mechanism(s) through which mANP causes atrial fibrillation is unknown. Our objective was to compare the effects of wild-type ANP and mANP on atrial electrophysiology in mice and humans.

Methods and Results—

Action potentials (APs), L-type Ca 2+ currents ( I Ca,L ), and Na + current were recorded in atrial myocytes from wild-type or natriuretic peptide receptor C knockout (NPR-C −/− ) mice. In mice, ANP and mANP (10–100 nmol/L) had opposing effects on atrial myocyte AP morphology and I Ca,L . ANP increased AP upstroke velocity ( V max ), AP duration, and I Ca,L similarly in wild-type and NPR-C −/− myocytes. In contrast, mANP decreased V max , AP duration, and I Ca,L , and these effects were completely absent in NPR-C −/− myocytes. ANP and mANP also had opposing effects on I Ca,L in human atrial myocytes. In contrast, neither ANP nor mANP had any effect on Na + current in mouse atrial myocytes. Optical mapping studies in mice demonstrate that ANP sped electric conduction in the atria, whereas mANP did the opposite and slowed atrial conduction. Atrial pacing in the presence of mANP induced arrhythmias in 62.5% of hearts, whereas treatment with ANP completely prevented the occurrence of arrhythmias.

Conclusions—

These findings provide mechanistic insight into how mANP causes atrial fibrillation and demonstrate that wild-type ANP is antiarrhythmic.

Carperitide and atrial fibrillation after coronary bypass grafting: the Nihon University working group study of low-dose HANP infusion therapy during cardiac surgery trial for postoperative atrial fibrillation

BACKGROUND

Occurrence of atrial fibrillation after cardiac surgery is associated with long-term mortality. We investigated whether infusion of human atrial natriuretic peptide (carperitide) could prevent postoperative atrial fibrillation.

METHODS AND RESULTS

A total of 668 patients who underwent isolated coronary artery bypass grafting were randomized to receive infusion of carperitide or physiological saline from the initiation of cardiopulmonary bypass. Patients were monitored continuously for 1 week after surgery to detect atrial fibrillation. The risk factors were investigated by Cox proportional hazard model. Postoperative atrial fibrillation occurred in 41 of 335 patients (12.2%) from the carperitide group versus 110 of 333 patients (32.7%) from the placebo group (P<0.0001). Postoperative levels of angiotensin-II, aldosterone, creatine kinase MB isoenzyme, human heart fatty acid-binding protein, and brain natriuretic peptide were all significantly lower in the carperitide group. The risk factors for postoperative atrial fibrillation by the Cox proportional hazard model were an age ≥70 years, emergency surgery, preoperative aldosterone level >150 ng/mL, preoperative nonuse of angiotensin receptor antagonists, preoperative use of calcium antagonists, postoperative nonuse of β-blockers, postoperative nonuse of aldosterone blockers, and nonuse of carperitide.

CONCLUSIONS

-Perioperative carperitide infusion reduced the occurrence of postoperative atrial fibrillation. Accordingly, carperitide could be a useful option for preventing postoperative atrial fibrillation.

CLINICAL TRIAL REGISTRATION

-URL: http://www.umin.ac.jp. Unique Identifier: UMIN000003958.

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.

Reduction in the incidence of acute kidney injury after aortic arch surgery with low-dose atrial natriuretic peptide: a randomised controlled trial

BACKGROUND

Acute kidney injury (AKI) after surgery is associated with an increased risk of adverse events and death. Atrial natriuretic peptide (ANP) dilates the preglomerular renal arteries and inhibits the renin-angiotensin axis. A low-dose ANP infusion increases glomerular filtration rate after cardiovascular surgery, but it is not known whether it reduces the incidence of AKI or the mortality rate.

OBJECTIVE

To evaluate whether an intravenous ANP infusion prevents AKI in patients undergoing aortic arch surgery requiring hypothermic circulatory arrest.

DESIGN

A randomised controlled study.

SETTING

Operating room and intensive care unit at Kawasaki Saiwai Hospital, Kanagawa, Japan.

PATIENTS

Forty-two patients with normal preoperative renal function undergoing elective repair of an aortic arch aneurysm.

INTERVENTION

Patients were assigned randomly to receive a fixed dose of ANP (0.0125 μg (-1) kg(-1)  min) or placebo. The infusion was started after induction of anaesthesia and continued for 24  h postoperatively.

MAIN OUTCOME MEASURES

The primary end-point was the incidence of AKI within 48 h after surgery.

RESULTS

AKI developed in 30% of patients who received ANP compared with 73% of patients who received placebo (P = 0.014). Intraoperative urine output was almost 1 l greater in patients who received ANP (1865 ± 1299 versus 991 ± 480  ml in the control group, P = 0.005). However, there were no differences in mean arterial pressure or number of episodes of hypotension between the groups. Length of hospital and intensive care stays were not significantly different, nor was there a difference in 30-day mortality. No patients required haemodialysis or continuous renal replacement therapy.

CONCLUSION

We found that an intravenous infusion of ANP at 0.0125  μg  kg(-1)  min(-1) is an effective intervention for reducing the incidence of postoperative AKI, and appears to afford a degree of renal protection during and after cardiovascular surgery.

TRIAL REGISTRATION

Kawasaki ANP trial, UMIN Clinical Trials Registry ID: UMIN000011650.

Results of low-dose carperitide infusion in high-risk patients undergoing coronary artery bypass grafting

BACKGROUND

This study investigated the efficacy of human atrial natriuretic peptide (hANP, carperitide) for high-risk patients undergoing coronary artery bypass grafting (CABG).

METHODS

This was a randomized controlled trial of 367 high-risk patients (European System for Cardiac Operative Risk Evaluation above 6) undergoing CABG. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE). Secondary endpoints were (1) postoperative death, (2) MACCE + hemodialysis, and (3) serum creatinine and brain natriuretic peptide (BNP) levels. Logistic regression analysis was conducted to identify preoperative and perioperative factors related to early death and MACCE.

RESULTS

There was no significant difference of survival between the hANP and placebo groups (p = 0.1651), but the MACCE-free rate was significantly higher in the hANP group than in the placebo group (p < 0.0001). No patient from the hANP group started hemodialysis after operation, but 7 patients did in the placebo group, and the dialysis rate was significantly lower in the hANP group (p = 0.0147). Serum creatinine and BNP were also significantly lower in the hANP group at 1 year postoperatively. MACCE were strongly associated with age 75 years or older, chronic kidney disease, hemodialysis, left ventricular dysfunction, and nonuse of carperitide.

CONCLUSIONS

In the early postoperative period, carperitide has a cardiorenal protective effect that prevents postoperative MACCE and hemodialysis. Perioperative low-dose carperitide infusion may be useful in high-risk patients undergoing on-pump CABG.

Results of emergency coronary artery bypass grafting for acute myocardial infarction: importance of intraoperative and postoperative cardiac medical therapy

BACKGROUND

The results of emergency coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) are less than satisfactory, and readmission for cardiac events is common.

METHODS AND RESULTS

105 patients underwent emergency CABG for AMI. We examined the long-term results of emergency CABG for AMI from the viewpoints of preoperative, intraoperative, and postoperative factors. The operative mortality rate was 11.4%. Risk factors for early death were age ≥80 years, shock, veno-arterial bypass, creatine kinase isoenzyme Mb ≥100 U/L, non-use of a left internal thoracic artery graft and an extracorporeal circulation time ≥120 min. Risk factors for late cardiac events were ejection fraction <40%, non-use of human atrial natriuretic peptide (hANP) therapy, angiotensin II receptor blockers (ARB) and aldosterone blockers, and a 3-month postoperative brain natriuretic peptide level ≥200 pg/ml.

CONCLUSIONS

Early results of this study are similar to those seen in previous reports, whereas late phase results yield some new and interesting findings. We suggest that intraoperative hANP, and postoperative aldosterone blocker and ARB, following CABG for AMI, will, through control of the renin-angiotensin-aldsterone system, inhibit left ventricular remodelling, reduce the extent of infarction, and improve cardiac function, yielding a favourable long-term prognosis.

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.

Cardiovascular and renal effects of carperitide and nesiritide in cardiovascular surgery patients: a systematic review and meta-analysis

INTRODUCTION

Acute kidney injury (AKI) following cardiovascular surgery is a common disease process and is associated with both morbidity and mortality. The aim of our study was to evaluate the cardiovascular and renal effects of an atrial natriuretic peptide (ANP, carperitide) and a B-type (or brain) natriuretic peptide (BNP, nesiritide) for preventing and treating AKI in cardiovascular surgery patients.

METHODS

Electronic databases, including PubMed, EMBASE and references from identified articles were used for a literature search.

RESULTS

Data on the infusion of ANP or BNP in cardiovascular surgery patients was collected from fifteen randomized controlled trials and combined. The infusion of ANP or BNP increased the urine output and creatinine clearance or glomerular filtration rate, and reduced the use of diuretics and the serum creatinine levels. A meta-analysis showed that ANP infusion significantly decreased peak serum creatinine levels, incidence of arrhythmia and renal replacement therapy. The meta-analysis also showed that ANP or BNP infusion significantly decreased the length of ICU stay and hospital stay compared with controls. However, the combined data were insufficient to determine how ANP or BNP infusion during the perioperative period influences long-term outcome in cardiovascular surgery patients.

CONCLUSIONS

The infusion of ANP or BNP may preserve postoperative renal function in cardiovascular surgery patients. A large, multicenter, prospective, randomized controlled trial will have to be performed to assess the therapeutic potential of ANP or BNP in preventing and treating AKI in the cardiovascular surgical setting.

Molecular mechanisms underlying cardiac antihypertrophic and antifibrotic effects of natriuretic peptides

Natriuretic peptides (NPs) exert well-characterized protective effects on the cardiovascular system, such as vasorelaxation, natri- and diuresis, increase of endothelial permeability, and inhibition of renin-angiotensin-aldosterone system. It has been reported that they also possess antihypertrophic and antifibrotic properties and contribute actively to cardiac remodeling. As a consequence, they are involved in several aspects of cardiovascular diseases. Antihypertrophic and antifibrotic actions of NPs appear to be mediated by specific signaling pathways within a more complex cellular network. Elucidation of the molecular mechanisms underlying the effects of NPs on cardiac remodeling represents an important research objective in order to gain more insights on the complex network leading to cardiac hypertrophy, ventricular dysfunction, and transition to heart failure, and in the attempt to develop novel therapeutic agents. The aim of the present article is to review well-characterized molecular mechanisms underlying the antihypertrophic and antifibrotic effects of NPs in the heart that appear to be mainly mediated by guanylyl cyclase type A receptor. In particular, we discuss the calcineurin/NFAT, the sodium exchanger NHE-1, and the TGFβ1/Smad signaling pathways. The role of guanylyl cyclase type B receptor, along with the emerging functional significance of natriuretic peptide receptor type C as mediators of CNP antihypertrophic and antifibrotic actions in the heart are also considered.

Landiolol hydrochloride for prevention of atrial fibrillation after coronary artery bypass grafting: new evidence from the PASCAL trial

OBJECTIVE

Atrial fibrillation occurs frequently after cardiac surgery and not only prolongs hospitalization but also influences the prognosis. We investigated whether landiolol hydrochloride, an ultrashort-acting beta-blocker, could reduce postoperative atrial fibrillation in a randomized controlled trial.

METHODS

The subjects were 140 patients undergoing coronary artery bypass grafting at the Nihon University School of Medicine. The primary end point was occurrence/non-occurrence of atrial fibrillation up to 1 week postoperatively. Logistic regression analysis was performed to investigate risk factors for atrial fibrillation among preoperative, perioperative, and postoperative variables.

RESULTS

Atrial fibrillation occurred in 7 patients (10%) in the landiolol group versus 24 patients (34.3%) in the placebo group; the landiolol group had a significantly lower incidence (P = .0006). Postoperative heart rate was significantly lower in the landiolol group than in the placebo group. On returning to the intensive care unit, the landiolol group had significantly lower inflammatory and ischemic parameters. Medical costs were also significantly lower in the landiolol group. Multivariate analysis revealed that significant risk factors for atrial fibrillation were a European System for Cardiac Operative Risk Evaluation of 10 or more, preoperative non-use of angiotensin receptor blockers, and non-use of landiolol.

CONCLUSIONS

Postoperative atrial fibrillation was reduced by treatment with landiolol hydrochloride. Amelioration of ischemia, an anti-inflammatory effect, and inhibition of sympathetic hypertonia by landiolol presumably reduced the occurrence of atrial fibrillation. Hypotension or bradycardia did not develop in any of the patients, indicating the safety of this beta-blocker. These findings suggest that landiolol hydrochloride could be useful in the perioperative management of patients undergoing 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.

Prevention and treatment of acute kidney injury in patients undergoing cardiac surgery: a systematic review

BACKGROUND

Acute kidney injury (AKI) is common in patients undergoing cardiac surgery and is associated with a high rate of death, long-term sequelae and healthcare costs. We conducted a systematic review of randomized controlled trials for strategies to prevent or treat AKI in cardiac surgery.

METHODS

We screened Medline, Scopus, Cochrane Renal Library, and Google Scholar for randomized controlled trails in cardiac surgery for prevention or treatment of AKI in adults.

RESULTS

We identified 70 studies that contained a total of 5,554 participants published until November 2008. Most studies were small in sample size, were single-center, focused on preventive strategies, and displayed wide variation in AKI definitions. Only 26% were assessed to be of high quality according to the Jadad criteria. The types of strategies with possible protective efficacy were dopaminergic agents, vasodilators, anti-inflammatory agents, and pump/perfusion strategies. When analyzed separately, dopamine and N-acetylcysteine did not reduce the risk for AKI.

CONCLUSIONS

This summary of all the literature on prevention and treatment strategies for AKI in cardiac surgery highlights the need for better information. The results advocate large, good-quality, multicenter studies to determine whether promising interventions reliably reduce rates of acute renal replacement therapy and mortality in the cardiac surgery setting.

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).

Mast cells, peptides and cardioprotection - an unlikely marriage?

1 Mast cells have classically been regarded as the 'bad guys' in the setting of acute myocardial ischaemia, where their released contents are believed to contribute both to tissue injury and electrical disturbances resulting from ischaemia. Recent evidence suggests, however, that if mast cell degranulation occurs in advance of ischaemia onset, this may be cardioprotective by virtue of the depletion of mast cell contents that can no longer act as instruments of injury when the tissue becomes ischaemic. 2 Many peptides, such as ET-1, adrenomedullin, relaxin and atrial natriuretic peptide, have been demonstrated to be cardioprotective when given prior to the onset of myocardial ischaemia, although their physiological functions are varied and the mechanisms of their cardioprotective actions appear to be diverse and often ill defined. However, one common denominator that is emerging is the ability of these peptides to modulate mast cell degranulation, raising the possibility that peptide-induced mast cell degranulation or stabilization may hold the key to a common mechanism of their cardioprotection. 3 The aim of this review was to consolidate the evidence implying that mast cell degranulation could play both a detrimental and protective role in myocardial ischaemia, depending upon when it occurs, and that this may underlie the cardioprotective effects of a range of diverse peptides that exerts physiological effects within the cardiovascular system.

Could atrial natriuretic peptide be a useful drug therapy for high-risk patients after cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether atrial natriuretic peptide (ANP) or brain natriuretic peptide (BNP) could be a useful alternative diuretic for patients post cardiac surgery. Altogether more than 250 papers were found using the reported search, of which eight RCTs represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that the RCTs consistently showed a diuretic effect with increased creatinine clearance, and increased urine volume and reduced usage of conventional diuretics. Lower urea and creatinine levels were also found postoperatively and also reduced decreases in glomerular filtration rate compared to placebo, both in studies of patients with preoperatively normal renal function and those who had impaired function. In addition, two studies found a reduction in the incidence of AF, and renin/aldosterone levels were lower. The NAPA trial of 272 CABG patients with LV dysfunction was the only study to show a shorter ICU stay and reduced early mortality with nesiritide compared to placebo.

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 carperitide on the long-term prognosis of patients with acute decompensated chronic heart failure: the PROTECT multicenter randomized controlled study

BACKGROUND

Carperitide is used to treat acute decompensated heart failure (ADHF), but its effects on long-term prognosis have not been studied.

METHODS AND RESULTS

A multicenter randomized controlled study of 49 patients with ADHF was performed to clarify the drug's effects on long-term prognosis. Low-dose carperitide (0.01-0.05 microg x kg(-1 ) x min(-1)) was infused for 72 h as the initial treatment (n=26), whereas in the control group (n=23), standard medical treatment other than carperitide was given without limitation. Anti-aldosterone drugs were prohibited in both groups. During carperitide infusion, significant increases of the atrial natriuretic peptide and cyclic GMP levels and a significant decrease in the heart-type fatty acid-binding protein/serum creatinine ratio were observed, suggesting inhibition of myocyte cell membrane damage. On the other hand, no significant differences in the plasma brain natriuretic peptide, troponin T, and creatinine levels were noted in either group. During 18-month follow-up, significant reductions of death and rehospitalization occurred in the carperitide vs control group (11.5% vs 34.8%; p=0.0359). Cox regression analysis revealed that randomization to carperitide (p=0.020), pretreatment systolic blood pressure >or=140 mmHg (p=0.043), and beta-blocker therapy (p=0.016) were independent predictors for freedom from cardiac events.

CONCLUSIONS

Acute-phase low-dose carperitide infusion improved the long-term prognosis of patients with ADHF.