Benefits and Risks of Corticosteroid Prophylaxis in Adult Cardiac Surgery

Hydrocortisone cardioprotection in ischaemia/reperfusion injury involves antioxidant mechanisms

BACKGROUND

Glucocorticoid (GR) and mineralocorticoid (MR) receptors are highly expressed in cardiac tissue, and both can be activated by corticosteroids. MR activation, in acute myocardial infarction (AMI), worsens cardiac function, and increase NHE activity contributing to the deleterious process. In contrast, effects of GR activation are not fully understood, probably because of the controversial scenario generated by using different doses or potencies of corticosteroids.

AIMS

We tested the hypothesis that an acute dose of hydrocortisone (HC), a low-potency glucocorticoid, in a murine model of AMI could be cardioprotective by regulating NHE1 activity, leading to a decrease in oxidative stress.

MATERIALS AND METHODS

Isolated hearts from Wistar rats were subjected to regional ischemic protocol. HC (10 nmol/L) was added to the perfusate during early reperfusion. Infarct size and oxidative stress were determined. Isolated papillary muscles from non-infarcted hearts were used to evaluate HC effect on sodium-proton exchanger 1 (NHE1) by analysing intracellular pH recovery from acute transient acidosis.

RESULTS

HC treatment decreased infarct size, improved cardiac mechanics, reduced oxidative stress after AMI, while restoring the decreased level of the pro-fusion mitochondrial protein MFN-2. Co-treatment with the GR-blocker Mifepristone avoided these effects. HC reduced NHE1 activity by increasing the NHE1 pro-inhibiting Ser648 phosphorylation site and its upstream kinase AKT. HC restored the decreased AKT phosphorylation and anti-apoptotic BCL-2 protein expression detected after AMI.

CONCLUSIONS

Our results provide the first evidence that acute HC treatment during early reperfusion induces cardioprotection against AMI, associated with a non-genomic HC-triggered NHE1 inhibition by AKT and antioxidant action that might involves mitochondrial dynamics improvement.

Prevention of Atrial Fibrillation After Cardiac Surgery: A Review of Literature and Comparison of Different Treatment Modalities

Atrial fibrillation is the most common arrhythmia to occur after cardiac surgery, with an incidence of 10% to 50%. It is associated with postoperative complications including increased risk of stroke, prolonged hospital stays and increased costs. Despite new insights into the mechanisms of atrial fibrillation, no specific etiologic factor has been identified as the sole perpetrator of the arrhythmia. Current evidence suggests that the pathophysiology of atrial fibrillation in general, as well as after cardiac surgery, is multifactorial. Studies have also shown that new-onset postoperative atrial fibrillation following cardiac surgery is associated with a higher risk of short-term and long-term mortality. Furthermore, it has been demonstrated that prophylactic medical therapy decreases the incidence of postoperative atrial fibrillation after cardiac surgery. Of note, the incidence of postoperative atrial fibrillation has not changed during the last decades despite the numerous preventive strategies and operative techniques proposed, although the perioperative and postoperative care of cardiac patients as such has improved.

The neutrophil-to-lymphocyte ratio is a potential biomarker for the occurrence of atrial fibrillation in patients with obstructive sleep apnea: A BIOMARKER OF AF IN OSA PATIENTS

BACKGROUND

Obstructive sleep apnea (OSA) affects the occurrence of atrial fibrillation (AF) and usually coexists with AF. Chronic inflammation has been identified as an important factor in the development of AF, and the neutrophil-to-lymphocyte ratio (NLR) has been identified as a biomarker that positively correlates with the degree of inflammation. However, little information regarding how NLR correlates with AF in OSA patients.

METHODS

Our study enrolled 368 patients with OSA between September 2018 and April 2023. All data were collected after admission. Independently associated factors were assessed by multivariate logistic regression and then constructed a nomogram to predict AF risk. Nomogram's calculation model was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). The correlation between CHA2DS2-VASc scores and NLR was assessed using Spearman correlation.

RESULTS

Multivariate logistic regression showed that high level log-transformed NLR (OR, 1.664; 95% CI, 1.026-2.699; P = 0.039) was independently associated with the presence of AF in patients with OSA. The concordance index (0.817, 95% CI, 0.770-0.864), ROC curve, calibration curve, and DCA of the nomogram indicated this model had well clinical utility. Also, the nomogram's calculation model could identify patients who are at a higher risk of developing AF, and the CHA2DS2-VASc score was positively correlated with NLR in patients with AF (P < 0.05).

CONCLUSION

The elevated NLR may serve as a promising biomarker for assessing the risk of AF in individuals with OSA. The nomogram's calculation model may be utilized as a tool to estimate the probability of AF occurrence in OSA patients.

Does methylprednisolone provide protective effect in total aortic arch replacement requiring hypothermia circulatory arrest and selective cerebral perfusion?

BACKGROUND

Glucocorticoids (GC)were applied in total aortic arch replacement (TAAR) at various dosages in many centers, but with limited evidence.

METHODS

The retrospective study was aimed to evaluate whether methylprednisolone was associated with better postoperative outcomes in patients undergoing TAAR. Patients undergoing TAAR with moderate hypothermia and selective cerebral perfusion between 2017.1 to 2018.12 in Fuwai hospital were classified into three groups according to doses of methylprednisolone given in the surgery: large-GC group (1500-3000 mg); medium-GC group (500-1000 mg) and no-GC group (0 mg). Postoperative outcomes were compared among three groups. Multivariable analysis was performed to identify the association of methylprednisolone with outcomes.

RESULTS

Three hundred twenty-eight patients were enrolled. Two hundred twenty-eight were in the large-GC group, 34 were in the medium-GC group, and 66 were in the no-GC group. The incidences of major adverse outcomes in large-GC, medium-GC and no-GC groups were 22.8%, 17.6% and 18.2%, respectively, with no statistical difference. A significant difference was observed in post-cardiopulmonary bypass (CPB) fresh frozen plasma (FFP) transfusion (p < .001) and chest drainage volume (p < .001). Multivariable analysis demonstrated that methylprednisolone was not associated with better outcomes (p = .455), while large doses of methylprednisolone were significantly associated with excessive chest drainage (over 2000 mL) [OR (99% CI) 4.282 (1.66-11.044), p < .001] and excessive post-CPB FFP transfusion (over 400 mL) [OR (99% CI) 2.208 (1.027-4.747), p = .008].

CONCLUSIONS

Large doses of methylprednisolone (1500-3000 mg) did not show a protective effect in TAAR with moderate hypothermia arrest plus selective cerebral perfusion and might increase postoperative bleeding and FFP transfusion.

Impact of CytoSorb® on interleukin-6 in cardiac surgery

Objective

Cardiac surgery is known to activate a cascade of inflammatory mediators leading to a systemic inflammatory response. Hemadsorption (HA) devices such as CytoSorb® have been postulated to mitigate an overshooting immune response, which is associated with increased morbidity and mortality, and thus improve outcome. We aimed to investigate the effect of CytoSorb® on interleukin (IL)-6 levels in patients undergoing complex cardiac surgery in comparison to a control group.

Methods

A total of 56 patients (28 CytoSorb®, 28 control) undergoing acute and elective cardiac surgery between January 2020 and February 2021 at the Department of Cardiac and Vascular Surgery, Clinic Floridsdorf, Vienna, were retrospectively analyzed. The primary endpoint was the difference in IL-6 levels between the CytoSorb® and control group. Secondary endpoint was periprocedural mortality.

Results

CytoSorb®, installed in the bypass circuit, had no significant effect on IL-6 levels. IL-6 peaked on the first postoperative day (HA: 775.3 ± 838.4 vs. control: 855.5 ± 1,052.9 pg/ml, p = 0.856). In total, three patients died in the HA group, none in the control (logistic regression model, p = 0.996). Patients with an increased Euroscore II of 7 or more showed a reduced IL-6 response compared to patients with an Euroscore II below 7 (178.3 ± 63.1 pg/ml vs. 908.6 ± 972.6 pg/ml, p-value = 0.00306).

Conclusions

No significant reduction of IL-6 levels or periprocedural mortality through intraoperative HA with CytoSorb® in patients undergoing cardiac surgery was observed. However, this study was able to show a reduced immunologic response in patients with a high Euroscore II. The routine application of CytoSorb® in cardiac surgery to reduce inflammatory mediators has to be scrutinized in future prospective randomized studies.

Postoperative systemic inflammatory dysregulation and corticosteroids: a narrative review

In some patients, the inflammatory-immune response to surgical injury progresses to a harmful, dysregulated state. We posit that postoperative systemic inflammatory dysregulation forms part of a pathophysiological response to surgical injury that places patients at increased risk of complications and subsequently prolongs hospital stay. In this narrative review, we have outlined the evolution, measurement and prediction of postoperative systemic inflammatory dysregulation, distinguishing it from a healthy and self-limiting host response. We reviewed the actions of glucocorticoids and the potential for heterogeneous responses to peri-operative corticosteroid supplementation. We have then appraised the evidence highlighting the safety of corticosteroid supplementation, and the potential benefits of high/repeated doses to reduce the risks of major complications and death. Finally, we addressed how clinical trials in the future should target patients at higher risk of peri-operative inflammatory complications, whereby corticosteroid regimes should be tailored to modify not only the a priori risk, but also further adjusted in response to markers of an evolving pathophysiological response.

Characteristics of immune clusters and cell abundance in patients with different subtypes of nonparoxysmal atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice. Inflammation plays an important role in the initiation and perpetuation of AF. The present study was conducted to characterize immune clusters in nonparoxysmal AF and to distinguish immune subtypes of nonparoxysmal AF. Immune-related algorithms (CIBERSORT, ESTIMATE, and ssGSEA) were used to evaluate the immune cluster characterization and cell abundance, and multivariable logistics analysis was performed to determine the most relevant immune cells. We identified differentially expressed genes (DEGs) and used consensus clustering analysis to identify nonparoxysmal AF subtypes. Weighted gene coexpression network analysis (WGCNA) was used for finding highly correlated gene sets and attach to external sample traits. And it was conducted twice to identify the immune- and subtype- related modules. Finally, Metascape was used to compare the biological functions of the two nonparoxysmal AF subtypes we obtained. CytoHubba was used to identify the hub genes of these two subtypes. Based on the results of bioinformatics analysis, regulatory T cells, resting NK cells, active mast cells and neutrophils were considered to be closely related to nonparoxysmal AF. The brown module was identified as the most relevant module to the above immune cells by WGCNA. We identified two major nonparoxysmal AF subtypes by consensus clustering analysis and their enriched biological functions by Metascape. The hub genes are TYROBP, PTPRC, ITGB2, SPI1, PLEK, and CSF1R in permanent AF and JAM3, S100P, ARPC5, TRIM34, and GREB1L in persistent AF. This study revealed two major nonparoxysmal AF subtypes and eleven hub genes, which provide potential therapeutic targets for anti-inflammatory treatments of nonparoxysmal AF.

Colchicine for prevention of post-operative atrial fibrillation: Meta-analysis of randomized controlled trials

Objective

This study intended to assess the efficacy of colchicine for prevention of post-operative atrial fibrillation (AF).

Background

Post-operative AF is a common complication of surgery operations. Inflammation plays a crucial role in the pathogenesis of post-operative AF. Colchicine, a potent anti-inflammatory drug, may have a role in mitigating the incidence of post-operative AF.

Methods

We searched Cochrane Library, Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), Database of Chinese sci-tech periodicals (COVIP), and Wanfang Database for randomized controlled trials (RCTs) comparing colchicine versus placebo, or usual care for prevention of post-operative AF. The main outcome was the occurrence of AF post operation, which includes cardiac surgery, lung surgery, or pulmonary vein isolation. The estimated risk ratio (RR) for the occurrence of post-operative AF was evaluated using a random-effects model. The safety end point was the development of any side effects.

Results

A total of 12 RCTs with 2274 patients were eventually included in this meta-analysis, where 1141 patients received colchicine and 1133 patients received placebo or usual care. Perioperative colchicine treatment was related to a decreased incidence of post-operative AF (RR: 0.65; 95% confidence interval [CI]: 0.56 to 0.75, p<0.001). Although the incidence of gastrointestinal side effects was increased with colchicine therapy when compared to placebo (RR = 2.49, 95% CI 1.85 to 3.34, p < 0.001), the incidence of major adverse events was not increased (RR = 0.86, 95% CI 0.46 to 1.60, p = 0.64).

Conclusion

In conclusion, the results of our meta-analysis suggest that colchicine treatment could lower the incidence of post-operative AF. Further studies are needed to determine the optimal colchicine treatment regime to minimize the incidence of adverse events.

Colchicine for cardiovascular medicine: a systematic review and meta-analysis

Aim: Colchicine, a microtubule-disassembling (antitubulin) agent used for centuries for the treatment of gout and autoimmune diseases, is a drug of growing interest in the cardiovascular field. While in the last decades it has become cornerstone of pericarditis treatment, it has also emerged in the last few years as a promising drug in the management of coronary artery disease, atrial fibrillation and heart failure. This systematic review and meta-analysis aimed to assess the efficacy of colchicine in patients with cardiovascular diseases. Methods: Systematic search in electronic databases (MEDLINE/PubMed, Scopus, BioMed Central, the Cochrane Collaboration Database of Randomized Trials, ClinicalTrials.gov, EMBASE, Google Scholar) was performed to identify randomized controlled trials (RCTs) up to February 2021. Random-effects meta-analysis was performed to assess the risk of cardiovascular events, defined according to clinical setting. Results: Among 15,569 pooled patients from 21 RCTs, colchicine was superior to placebo in the reduction of cardiovascular events. In the setting of pericardial diseases, it was associated with a lower risk of recurrent pericarditis (17 vs 34%, RR = 0.50, 95% CI: 0.42-0.60, I² = 10%). In other studies assessing coronary artery disease patients, colchicine was associated with a reduced risk of major adverse cardiovascular events (MACE) such as myocardial infarction, stroke, cardiovascular death, coronary revascularisation and hospitalization (6.3 vs 9%, RR = 0.67, 95% CI: 0.54-0.84, I² = 55). Among patients with atrial fibrillation, it was associated with lower rates of recurrence (20 vs 30%, RR = 0.68, 95% CI: 0.58-0.81, I² = 0). In the single RCT on heart failure, colchicine was not associated with improved NYHA class. Conclusion: Colchicine is a valuable anti-inflammatory agent for the prevention of cardiovascular events in patients with inflammatory cardiac conditions such as pericardial diseases, coronary artery disease and atrial fibrillation.

Corticosteroids in patients undergoing cardiac surgery: A meta-analysis of 12,559 patients

OBJECTIVE

Corticosteroids can attenuate the inflammatory response to cardiopulmonary bypass, but their benefits on clinical outcomes are unclear. We conducted a meta-analysis to evaluate whether corticosteroid therapy affects outcomes in patients undergoing cardiac surgery.

METHODS

We searched PubMed, Embase, EBSCO and Cochrane databases from 1 January 2010 to 14 March 2022 for randomized controlled trials (RCTs) that assessed corticosteroid versus non- corticosteroid therapy in patients undergoing cardiac surgery. The primary outcome was in-hospital mortality. Secondary outcomes were renal failure, infection, delirium, intensive care unit (ICU) and hospital stay.

RESULTS

Four RCTs including 12,559 patients (6265 randomized to corticosteroid therapy and 6294 to non-corticosteroid therapy) were included. One-hundred and 92 of 6265 patients (3.1%) randomized to the corticosteroid group versus 221 of 6294 patients (3.5%) randomized to the non-corticosteroid group experienced death during hospitalization. Compared the control group, corticosteroid therapy did not significantly reduce in-hospital mortality, with an RR of 0.87 (0.72-1.06), p = .16. There was no difference in the incidence of infection (RR 0.78 (0.56-1.10), p = .16), delirium during hospitalization (RR 1.01 (0.90-1.14), p = .85), or the length of hospital stay (MD -0.13 (-0.32 to 0.05), p = .17). However, corticosteroid therapy significantly reduced the risk of renal failure ( RR 0.82 (0.67-0.99), p = .04), and the length of ICU stay (MD -0.41 (-0.65 to -0.17), p < .01).

CONCLUSIONS

Corticosteroids did not significantly reduce the rates of in-hospital mortality, infection, or delirium, but reduce the incidence of renal failure and the length of ICU stay.

Meta-Analysis: Shouldn't Prophylactic Corticosteroids be Administered During Cardiac Surgery with Cardiopulmonary Bypass?

Background

Corticosteroids can effectively inhibit systemic inflammation induced by cardiopulmonary bypass. Recently clinical trials and meta-analyses and current guidelines for cardiac surgery do not support corticosteroids prophylaxis during cardiac surgery because of an increase in myocardial infarction and no benefit for patients. The aim of this study is to determine whether specific corticosteroids dose ranges might provide clinical benefits without increasing myocardial infarction.

Methods

The PubMed, Web of Science, Embase, Clinical Trials, and Cochrane databases were searched for randomized controlled trials (RCTs) published before August 1, 2021.

Results

88 RCTs with 18,416 patients (17,067 adults and 1,349 children) were identified. Relative to placebo and high-dose corticosteroids, low-dose corticosteroids (≤20 mg/kg hydrocortisone) during adult cardiac surgery did not increase the risks of myocardial infarction (odds ratio [OR]: 0.96, 95% confidence interval [CI]: 0.43-2.17; p = 0.93). However, low-dose corticosteroids were associated with lower risks of atrial fibrillation (OR: 0.58, 95% CI: 0.44-0.76; p < 0.0001) and kidney injury (OR: 0.29, 95% CI: 0.09-0.96; p = 0.04). Furthermore, low-dose corticosteroids significantly shortened the mechanical ventilation times (mean difference [MD]: -2.74 h, 95% CI: -4.14, -1.33; p = 0.0001), intensive care unit (ICU) stay (MD: -1.48 days, 95% CI: -2.73, -0.22; p = 0.02), and hospital stay (MD: -2.29 days, 95% CI: -4.51, -0.07; p = 0.04).

Conclusion

Low-dose corticosteroids prophylaxis during cardiac surgery provided significant benefits for adult patients, without increasing the risks of myocardial infarction and other complications.

Role of Inflammation in the Pathogenesis of Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common arrhythmias encountered in clinical practice. AF is a major risk factor for stroke, which is associated with high mortality and great disability and causes a significant burden on society. With the development of catheter ablation, AF has become a treatable disease, but its therapeutic outcome has been limited so far. In persistent and long-standing AF, the expanded AF substrate is difficult to treat only by ablation, and a better understanding of the mechanism of AF substrate formation will lead to the development of a new therapeutic strategy for AF. Inflammation is known to play an important role in the substrate formation of AF. Inflammation causes and accelerates the electrical and structural remodeling of the atria via pro-inflammatory cytokines and other inflammatory molecules, and enhances the AF substrate, leading to the maintenance of AF and further inflammation, which forms a vicious spiral, so-called “AF begets AF”. Breaking this vicious cycle is expected to be a key therapeutic intervention in AF. In this review, we will discuss the relationship between AF and inflammation, the inflammatory molecules included in the AF-related inflammatory process, and finally the potential of those molecules as a therapeutic target.

Prednisone Ameliorates Atrial Inflammation and Fibrosis in Atrial Tachypacing Dogs

Atrial inflammation and fibrosis have long been considered culprits in the development of atrial fibrillation (AF). Prior clinical studies showed that corticosteroid therapy is beneficial in patients with AF. Here we sought to determine whether prednisone treatment prevents atrial tachypacing (ATP) induced atrial fibrosis.Dogs were randomized into the sham, ATP, ATP + low-dose prednisone (ALP), and ATP + high-dose prednisone (AHP) groups. After 6 days of recovery from surgery, dogs were subjected to ATP at 400 beats per minute for 4 weeks while being treated with prednisone (15 or 40 mg/day) or a placebo. Pacemakers were not activated in the sham group.Compared with the ATP group, the expression of collagen I, collagen III, α-smooth muscle actin, transforming growth factor-β1 and connective tissue growth factor were significantly reduced in the ALP and AHP groups. Fluorescence assays showed that reactive oxygen species formation in the right atrium was suppressed in the ALP and AHP groups compared with the ATP group. The protein level of NADPH oxidase 2 was reduced in the ALP and AHP groups' versus ATP group, while NOX4 and NOX5 were unchanged. ATP-induced downregulation of BH4 and eNOS uncoupling in the atria was partially restored in the prednisone-treated groups.Our study demonstrated that atrial fibrosis induced by ATP were suppressed by prednisone. Low-dose prednisone was also effective in suppressing the development of atrial fibrosis.

Inflammation and Oxidative Stress in the Context of Extracorporeal Cardiac and Pulmonary Support

Extracorporeal circulation (ECC) systems, including cardiopulmonary bypass, and extracorporeal membrane oxygenation have been an irreplaceable part of the cardiothoracic surgeries, and treatment of critically ill patients with respiratory and/or cardiac failure for more than half a century. During the recent decades, the concept of extracorporeal circulation has been extended to isolated machine perfusion of the donor organ including thoracic organs (ex-situ organ perfusion, ESOP) as a method for dynamic, semi-physiologic preservation, and potential improvement of the donor organs. The extracorporeal life support systems (ECLS) have been lifesaving and facilitating complex cardiothoracic surgeries, and the ESOP technology has the potential to increase the number of the transplantable donor organs, and to improve the outcomes of transplantation. However, these artificial circulation systems in general have been associated with activation of the inflammatory and oxidative stress responses in patients and/or in the exposed tissues and organs. The activation of these responses can negatively affect patient outcomes in ECLS, and may as well jeopardize the reliability of the organ viability assessment, and the outcomes of thoracic organ preservation and transplantation in ESOP. Both ECLS and ESOP consist of artificial circuit materials and components, which play a key role in the induction of these responses. However, while ECLS can lead to systemic inflammatory and oxidative stress responses negatively affecting various organs/systems of the body, in ESOP, the absence of the organs that play an important role in oxidant scavenging/antioxidative replenishment of the body, such as liver, may make the perfused organ more susceptible to inflammation and oxidative stress during extracorporeal circulation. In the present manuscript, we will review the activation of the inflammatory and oxidative stress responses during ECLP and ESOP, mechanisms involved, clinical implications, and the interventions for attenuating these responses in ECC.

Atrial fibrillation following coronary artery bypass graft: Where do we stand?

Atrial fibrillation (AF) is the most common atrial arrhythmia following coronary artery bypass graft (CABG). Its prevalence is 15-45% and is associated with poor long-term prognosis. Risk factors can be patient-related, intraoperative, and/or postoperative. Therapeutic and preventive strategies have been developed to curtail AF burden. Cardioversion is recommended for unstable or symptomatic patients and rate control if asymptomatic. Anticoagulation is challenging with risk of thromboembolism and bleeding. However, patients should be anticoagulated after cardioversion or if AF persists >48 h and risk factors of stroke exist. A minimum of 4 weeks is recommended but longer duration should be considered in patients at high risk of stroke irrespective of recurrence of AF.

The Use of Corticosteroids for Cardiopulmonary Bypass in Adults

Purpose of Review

Cardiopulmonary bypass for on-pump cardiac surgery induces a systemic inflammation that may contribute to postoperative major complications. To reduce this inflammatory response in patients undergoing heart surgery, the perioperative use of anti-inflammatory corticosteroids has long been recommended to improve clinical outcomes. However, the efficacy and safety of steroids remain still unclear.

Recent Findings

We reviewed recent published literature, including the large clinical trials DECS and SIRS and the two meta-analysis by Dvirnik et al. (2018) and Ng et al. (2020), on mortality and major postoperative complications, such as myocardial complications, atrial fibrillation, stroke, pulmonary adverse events, length of ICU and hospital stay, renal failure, and infection.

Summary

The perioperative application of corticosteroids did not improve mortality rates beyond standard care or other secondary outcomes, such as myocardial infarction, stroke, renal failure, and infection. The observed increased risk of myocardial damage in patients receiving corticosteroids in the SIRS trial is mainly related to the author-defined CK-MB threshold as indicator for early myocardial injury. Interestingly, the use of steroids may have some beneficial effects on secondary outcomes: they significantly decreased the risk of respiratory failure and pneumonia and shortened the length of ICU and hospital stay, but the mechanism involved in pulmonary injury is multifactorial and it is difficult to evaluate this result. Patients receiving steroids did not have a decreased incidence of atrial fibrillation shown by the two large trials unlike some previous small sample size trials have demonstrated.

Inflammation, atrial fibrillation, and the potential role for colchicine therapy

Increasing evidence suggests that the "NACHT-LRR and PYD domain-containing protein 3" (NLRP3) inflammasome plays an important role in atherosclerotic cardiovascular disease (ASCVD). Recent preclinical evidence has suggested that the NLRP3 inflammasome may play a prominent role in the pathogenesis of atrial fibrillation (AF). As such, the therapies that have shown efficacy in reducing ASCVD events may also prove beneficial in AF. In this article, we review the findings that implicate the NLRP3 inflammasome in the pathogenesis of AF, discuss existing evidence behind the use of anti-inflammatory agents for AF, and discuss the future role that colchicine and other anti-inflammatory agents may play in the prevention and treatment of AF.

Electroimmunology and cardiac arrhythmia

Conduction disorders and arrhythmias remain difficult to treat and are increasingly prevalent owing to the increasing age and body mass of the general population, because both are risk factors for arrhythmia. Many of the underlying conditions that give rise to arrhythmia - including atrial fibrillation and ventricular arrhythmia, which frequently occur in patients with acute myocardial ischaemia or heart failure - can have an inflammatory component. In the past, inflammation was viewed mostly as an epiphenomenon associated with arrhythmia; however, the recently discovered inflammatory and non-canonical functions of cardiac immune cells indicate that leukocytes can be arrhythmogenic either by altering tissue composition or by interacting with cardiomyocytes; for example, by changing their phenotype or perhaps even by directly interfering with conduction. In this Review, we discuss the electrophysiological properties of leukocytes and how these cells relate to conduction in the heart. Given the thematic parallels, we also summarize the interactions between immune cells and neural systems that influence information transfer, extrapolating findings from the field of neuroscience to the heart and defining common themes. We aim to bridge the knowledge gap between electrophysiology and immunology, to promote conceptual connections between these two fields and to explore promising opportunities for future research.

Nonalcoholic Fatty Liver Disease: An Emerging Driver of Cardiac Arrhythmia

Cardiac arrhythmias and the resulting sudden cardiac death are significant cardiovascular complications that continue to impose a heavy burden on patients and society. An emerging body of evidence indicates that nonalcoholic fatty liver disease (NAFLD) is closely associated with the risk of cardiac arrhythmias, independent of other conventional cardiometabolic comorbidities. Although most studies focus on the relationship between NAFLD and atrial fibrillation, associations with ventricular arrhythmias and cardiac conduction defects have also been reported. Mechanistic investigations suggest that a number of NAFLD-related pathophysiological alterations may potentially elicit structural, electrical, and autonomic remodeling in the heart, contributing to arrhythmogenic substrates in the heart. NAFLD is now the most common liver and metabolic disease in the world. However, the upsurge in the prevalence of NAFLD as an emerging risk factor for cardiac arrhythmias has received little attention. In this review, we summarize the clinical evidence and putative pathophysiological mechanisms for the emerging roles of NAFLD in cardiac arrhythmias, with the purpose of highlighting the notion that NAFLD may serve as an independent risk factor and a potential driving force in the development and progression of cardiac arrhythmias.

Arrhythmia prevalence among patients with polymyositis-dermatomyositis in the United States: An observational study

BACKGROUND

Systemic inflammation has been associated with atherosclerotic cardiovascular diseases (ASCVD) and arrhythmia occurrence in rheumatologic conditions such as rheumatoid arthritis. Polymyositis and dermatomyositis (PD) are rare rheumatologic conditions characterized by symmetrical proximal muscle weakness and, in the case of dermatomyositis, cutaneous eruption. Although there is literature associating PD with ASCVD, no population-level studies have analyzed arrhythmia risk in PD.

OBJECTIVE

The purpose of this study was to assess the prevalence of arrhythmia and its subtypes by age and sex in patients with PD and to determine associations between arrhythmia and PD.

METHODS

This retrospective cohort study included adults for whom hospitalizations had been recorded in the National Inpatient Sample database in the United States between 2016 and 2018. Patients with PD were matched (1:10) by age to patients without PD. Prevalence of arrhythmia was calculated in the 2 groups and compared by sex and age groups. Associations between PD and arrhythmia were determined after adjustment for common arrhythmia risk factors.

RESULTS

From 107,001,355 hospitalizations, 32,085 adults with PD were matched to 320,850 controls. Patients with PD aged <70 years had a higher prevalence of arrhythmia and higher adjusted odds of arrhythmia compared with controls. This increased risk was only seen for supraventricular arrhythmias. Adults with PD had increased odds of in-hospital mortality if they had an arrhythmia diagnosis (odds ratio 3.3; 95% confidence interval 2.5-4.5; P <.001).

CONCLUSION

We found a higher prevalence and odds of arrhythmias, particularly supraventricular arrhythmias, in young and middle-aged patients with PD compared with matched controls. Arrhythmias were associated with significant mortality among patients with PD.

Effect of Low-dose ColchiciNe on the InciDence of Atrial Fibrillation in Open Heart Surgery Patients: END-AF Low Dose Trial

Background

Studies using 1 mg of colchicine to prevent postoperative atrial fibrillation (POAF) reported conflicting results. Moreover, colchicine was associated with significant gastrointestinal (GI) side effects. This study examined whether low-dose colchicine effectively prevents POAF and whether low-dose therapy is associated with lower rates of colchicine-induced GI side effects.

Methods

In this prospective, randomized, double-blind, placebo-controlled study, consecutive adult patients admitted for elective cardiac surgeries randomly received a 1-mg dose of colchicine (n = 81) or placebo (n = 71) orally 12 to 24 hours before surgery followed by a daily dose of 0.5 mg until hospital discharge. The primary efficacy endpoint was the development of at least one episode of POAF of ≥5 minutes. The primary safety endpoint was the development of adverse events, especially diarrhea.

Results

The in-hospital mortality rate was 3.9%. POAF occurred in 13 patients (16.1%) in the colchicine group and 13 patients (18.3%) in the placebo group (odds ratio 0.85 [95% Confidence Interval = 0.37−1.99]). Diarrhea occurred in two patients in each group and necessitated treatment discontinuation in one patient in each group.

Conclusion

Low-dose colchicine did not prevent POAF in patients undergoing cardiac surgery. These results should be interpreted cautiously because of the small sample size and early study termination.

ClinicalTrials.gov Unique Identifier number: NCT03015831

Perioperative Implications of the 2020 American Heart Association Scientific Statement on Drug-Induced Arrhythmias-A Focused Review

The recently released American Heart Association (AHA) scientific statement on drug-induced arrhythmias discussed medications commonly associated with bradycardia, supraventricular tachycardias, and ventricular arrhythmias. The foundational data for this statement were collected from general outpatient and inpatient populations. Patients undergoing surgical and minimally invasive treatments are a unique subgroup, because they may experience hemodynamic changes associated with anesthesia and their procedure, receive multiple drug combinations not given in either inpatient or outpatient settings, or experience postprocedural inflammatory syndromes. Accordingly, the generalizability of the AHA scientific statement to this perioperative population is unclear. This focused review highlights important aspects of the new AHA scientific statement and their application to the perioperative setting. The authors review medications frequently encountered and given by anesthesiologists and their risk of drug-induced arrhythmias and discuss common anesthetic and adjunctive medications and their associated risks of bradycardia, atrial fibrillation, torsades de pointes, and drug-induced Brugada syndrome. In many instances, the risk of arrhythmia reported by the AHA scientific statement in the general population appeared to be higher than found in perioperative arenas. Furthermore, the authors discuss the arrhythmia risk of additional medications commonly ordered or administered by anesthesiologists that are not included in the AHA scientific statement. As patient and procedural complexity increases and novel anesthetic combinations propagate, further research and observational studies will be required to delineate further perioperative risks for drug-induced arrhythmia.

Arrhythmias and Conduction Disturbances in Autoimmune Rheumatic Disorders

Rhythm and conduction disturbances and sudden cardiac death are important manifestations of cardiac involvement in autoimmune rheumatic diseases (ARD), which have a serious impact on morbidity and mortality. While the underlying arrhythmogenic mechanisms are multifactorial, myocardial fibrosis plays a pivotal role. It accounts for a substantial portion of cardiac mortality and may manifest as atrial and ventricular arrhythmias, conduction system abnormalities, biventricular cardiac failure or sudden death. In patients with ARD, myocardial fibrosis is considered to be the hallmark of cardiac involvement as a result of inflammatory process or to coronary artery occlusive disease. Myocardial fibrosis constitutes the pathological substrates for reentrant circuits. The presence of supraventricular extra systoles, tachyarrhythmias, ventricular activity and conduction disturbances are not uncommon in patients with ARDs, more often in systemic lupus erythematosus, systemic sclerosis, rheumatoid arthritis, inflammatory muscle disorders and anti-neutrophil cytoplasm antibody-associated vasculitis. In this review, the type, the relative prevalence and the underlying mechanisms of rhythm and conduction disturbances in the emerging field of cardiorheumatology are provided.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

The increased risk of atrial fibrillation in inflammatory arthritis: a systematic review and meta-analysis of cohort studies

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia contributing to stroke and sudden cardiac death. Numbers of studies indicated that patients with inflammatory arthritis have an increased risk of AF. The present study aims to assess the risk of AF in inflammatory arthritis patients.Methods: We systematically searched cohort studies regarding the risk of AF in patients with rheumatoid arthritis, or spondyloarthritis through PubMed, Web of Science, Cochrane Library, Clinical Trials Registry, and China National Knowledge from inception to August 1, 2019. Meta-analysis was performed using fixed effect model, estimating both crude and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs). Subgroup analysis and meta-regression based on geographic characteristics, comorbidities, and medication use were conducted to explore the source of heterogeneity.Results: Literature search identified 388 potentially relevant studies, and five studies containing seven cohorts of rheumatoid arthritis or spondyloarthritis were included in the meta-analysis. The AF risk of inflammatory arthritis patients was significantly increased compared with health controls (HR = 1.42, 95% CI: 1.36 to 1.49, Z = 14.17, P < .001), and the pooled HR of studies adjusted factor, like demographic characteristics, medications use, and comorbidities, was 1.37 (95% CI: 1.29 to 1.46; Z = 9.82, P < .001).Conclusion: Patients with inflammatory arthritis have increased risk of AF, probably due to the underlying chronic inflammation. Although various confounders have been adjusted like medications use and comorbidities, the risk of AF is still significantly increased in inflammatory arthritis patients.Abbreviations: AF: Atrial fibrillation; AS: Ankylosing spondylitis; CI: Confidence interval; HR: Hazard ratio; NOS: Newcastle-Ottawa scale; NSAIDs: Non-steroid anti-inflammatory drugs; PsA: Psoriatic arthritis; RA: Rheumatoid arthritis; SpA: Spondyloarthritis; TNFi: Tumor necrosis factors inhibitor; uSpA: Undifferentiated spondyloarthritis.

Efficacy and safety of corticosteroids prophylaxis in cardiac surgery: A protocol for systematic review and meta-analysis

BACKGROUND

Although corticosteroid prophylaxis in adult cardiac surgery has been studied extensively for 40 years, its role remains controversial, and the optimal dose remains uncertain. The objective of this meta-analysis was to estimate the clinical benefits and risks of corticosteroid use in cardiopulmonary bypass.

METHODS

We will search Pubmed, Web of Science, Embase, Clinical Trials, and Cochrane Central Register of Controlled Trials for relevant clinical trials published in any language before August 1, 2020. Randomized controlled trials (RCTs) of interest which meet inclusion criteria published or unpublished will be included. We will divide the included studies into child and adult groups for analysis. If sufficient data are available, the included trials will be divided into 4 subgroups: ≤20 mg/kg (low dose), 20-40 mg/kg (slightly high dose), 40-100 mg/kg (high dose), and >100 mg/kg (ultra high dose) based on the equivalent hydrocortisone dose. INPLASY registration number: INPLASY2020100044.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

This study will compare the efficacy of tprophylactic corticosteroids for adults and children undergoing cardiac surgery with CPB. Due to the nature of the disease and intervention methods, randomized controlled trials may be inadequate, and we will carefully consider inclusion in high-quality, non-randomized controlled trials, but this may result in high heterogeneity and affect the reliability of the results.

Effectivity of dexamethasone in patients undergoing off-pump coronary artery bypass surgery

BACKGROUND

Based on our previous pilot study, systemic inflammatory response syndrome is more common in off-pump compared to on-pump coronary artery bypass. Therefore, we conducted a clinical trial of dexamethasone in patients undergoing off-pump coronary artery bypass.

METHODS

Sixty consecutive patients undergoing off-pump coronary artery bypass were enrolled from August 2018 to January 2019 and randomized to a dexamethasone or placebo group of 30 each. Clinical outcomes were analyzed.

RESULTS

There was a lower incidence of major adverse cardiac events in the dexamethasone group compared to the placebo group (17% versus 43%, p = 0.024). Clinical outcomes in the dexamethasone group were better than those in the placebo group, in terms of duration of mechanical ventilation (p = 0.029), intensive care unit stay (p = 0.028), hospital stay (p = 0.04), and vasoactive-inotropic score (p = 0.045). There were significant differences in inflammatory markers between the two groups: interleukin-6 (p = 0.0001), procalcitonin (p = 0.0001), and C-reactive protein (p = 0.0001) were lower in the dexamethasone group. There was a significant association between the incidence of major adverse cardiac events and both interleukin-6 (p = 0.005) and procalcitonin (p = 0.007).

CONCLUSION

Preoperative dexamethasone in patients undergoing off-pump coronary artery bypass is effective in improving clinical outcomes and controlling the postoperative inflammatory reaction.

Systematic review of pre-clinical therapies for post-operative atrial fibrillation

BACKGROUND

Post-operative atrial fibrillation (POAF) is a frequent cardiothoracic surgery complication that increases hospital stay, mortality and costs. Despite decades of research, there has been no systematic overview and meta-analysis of preclinical therapies for POAF in animal models.

METHODS

We performed a systematic search of MEDLINE and EMBASE from their inception through September 2020 to determine the effect of preclinical POAF therapies on primary efficacy outcomes using a prospectively registered protocol (CRD42019155649). Bias was assessed using the SYRCLE tool and CAMARADES checklist.

RESULTS

Within the 26 studies that fulfilled our inclusion criteria, we identified 4 prevention strategies including biological (n = 5), dietary (n = 2), substrate modification (n = 2), and pharmacological (n = 17) interventions targeting atrial substrate, cellular electrophysiology or inflammation. Only one study altered more than 1 pathophysiological mechanism. 73% comprised multiple doses of systemic therapies. Large animal models were used in 81% of the studies. Preclinical therapies altogether attenuated atrial fibrosis (SMD -2.09; 95% confidence interval [CI] -2.95 to -1.22; p < 0.00001; I2 = 47%), AF inducibility (RR 0.40; 95% CI 0.21 to 0.79; p = 0.008; I2 = 39%), and AF duration (SMD -2.19; 95% CI -3.05 to -1.32; p < 0.00001; I2 = 50%). However, all the criteria needed to evaluate the risk of bias was unclear for many outcomes and only few interventions were independently validated by more than 1 research group.

CONCLUSION

Treatments with therapies targeting atrial substrate, cellular electrophysiology or inflammation reduced POAF in preclinical animal models compared to controls. Improving the quality of outcome reporting, independently validating promising approaches and targeting complimentary drivers of POAF are promising means to improve the clinical translation of novel therapies for this highly prevalent and clinically meaningful disease.

The preablation monocyte/ high density lipoprotein ratio predicts the late recurrence of paroxysmal atrial fibrillation after radiofrequency ablation

Background

The monocyte/high-density lipoprotein ratio (MHR) has emerged as a promising alternative biomarker in the fields of cardiovascular disease and atrial fibrillation (AF). This retrospective study was aimed to explore the predictive value of the MHR for the late recurrence of AF after radiofrequency ablation.

Methods

From April 2015 to October 2018, patients with paroxysmal AF who had undergone radiofrequency catheter ablation at Subei People’s Hospital of Jiangsu Province were enrolled in our study. All the participants were observed until November 2019 after the procedure. During the postoperative follow up, the patients were categorized into the recurrence group and maintenance of sinus rhythm group based on who had experienced AF recurrence.

Results

One hundred twenty-five patients were diagnosed with paroxysmal AF, with an average age of 61.2 ± 9.3 years. Forty-seven patients had developed late recurrence during a mean follow up of 25.1 ± 12.0 months. The AF recurrence event rates were significantly increased in the highest MHR tertile compared with those in the lowest MHR tertile (22.0% vs. 57.1%; P < 0.05). On multivariate logistic regression analysis, the preablation MHR (OR = 1.34; 95% CI = 1.12 ~ 1.60; P = 0.001) and left atrial diameter (LAD) (OR = 1.21, 95% CI = 1.08 ~ 1.35; P = 0.001) were independent risk factors predicting the recurrence of AF after radiofrequency ablation. Furthermore, receiver operating characteristic (ROC) curve analysis revealed that the area under the curve (AUC) of the MHR was 0.712 (95% CI = 0.618 ~ 0.806; P = 0.000) and that of LAD was 0.739 (95% CI = 0.653 ~ 0.814; P = 0.000). Z-test found no significant difference between the MHR and LAD regarding the AUC (Z = 0.451; P = 0.652).

Conclusion

An elevated preablation MHR was associated with an increased risk of the postoperative recurrence of AF. Additionally, the MHR independently predicted the late recurrence of paroxysmal AF after radiofrequency ablation, with the same predictive value as LAD.

P Wave Dispersion and Silent Atrial Fibrillation in Cryptogenic Stroke: The Pathogenic Role of Inflammation

BACKGROUND

Cryptogenic stroke (CS) represents 25% of ischemic strokes. Especially after CS, the detection of atrial fibrillation (AF) is important because it provides clues to the mechanism of stroke. However, the relationship between AF and stroke appears more complex than a simple cause-effect mechanism, suggesting that the association between AF and stroke may be due to other systemic and atrial factors including systemic inflammation that may lead to atrial remodeling and subsequent atrial cardiopathy.

OBJECTIVE

The aim of this study was to evaluate the relationship among different electrocardiographic parameters, inflammatory markers and in-hospital AF occurrence after acute CS.

METHODS

222 patients with CS underwent 12-lead resting ECG at admission and 7-day in-hospital ECG monitoring. The following indices were evaluated: P-wave dispersion (PWD), P-wave index, P-wave axis, atrial size and high-sensitivity-C reactive protein (CRP).

RESULTS

AF was detected in 44 patients. AF-group had significantly higher PWD, P-wave index, PR interval, CRP and greater frequency of abnormal P-wave axis in comparison with no-AF group. There was a significant correlation between CRP and PWD (r=0.28). By using the mediation analysis, performed according to the "bootstrapping" method, we found that PWD is a significant mediator variable of the relationship between CRP and AF occurrence, accounting for 40% of the association.

CONCLUSIONS

In cryptogenic stroke, high PWD is partly due to systemic inflammation that increases AF risk possibly via atrial electric remodeling. These findings could also suggest inflammation as a possible therapeutic target in order to prevent atrial electrical alterations and finally AF occurrence in CS.

Atrial fibrillation in COVID-19: A review of possible mechanisms

A relationship between COVID-19 infection and an increasing incidence of atrial fibrillation has been observed. However, the underlying pathophysiology as a precipitant to AF has not been reviewed. This paper will consider the possible pathological and immunological AF mechanisms as a result, of COVID-19 infection. We discuss the role myocardial microvascular pericytes expressing the ACE-2 receptor and their potential for an organ-specific cardiac involvement with COVID-19. Dysfunctional microvascular support by pericytes or endothelial cells may increase the propensity for AF via increased myocardial inflammation, fibrosis, increased tissue edema, and interstitial hydrostatic pressure. All of these factors can lead to electrical perturbances at the tissue and cellular level. We also consider the contribution of Angiotensin, pulmonary hypertension, and regulatory T cells as additional contributors to AF during COVID-19 infection. Finally, reference is given to two common drugs, corticosteroids and metformin, in COVID-19 and how they might influence AF incidence.

Inflammatory and Infectious Processes Serve as Links between Atrial Fibrillation and Alzheimer's Disease

Atrial fibrillation (AF) is one of the most prevalent forms of arrhythmia that carries an increased risk of stroke which, in turn, is strongly associated with cognitive decline. The majority of dementia cases are caused by Alzheimer's disease (AD) with obscure pathogenesis. While the exact mechanisms are unknown, the role of inflammatory processes and infectious agents have recently been implicated in both AD and AF, suggesting a common link between these maladies. Here, we present the main shared pathways underlying arrhythmia and memory loss. The overlapping predictive biomarkers and emerging joint pharmacological approaches are also discussed.

Thermal distribution, physiological effects and toxicities of extracorporeally induced whole-body hyperthermia in a pig model

Background

Extracorporeally induced whole‐body hyperthermia (eWBH) might be a beneficial treatment in cancer patients. Objectives of this pig study were to assess thermal distribution, (patho‐)physiological effects, and safety of eWBH with a new WBH device.

Methods

Fourteen healthy adult pigs were anesthetized, mechanically ventilated, and cannulated; 12 were included in the analysis. Blood was heated in 11 pigs (one pig served as control) using a WBH device (Vithèr Hyperthermia B.V.) containing two separate fluidic circuits and a heat exchanger. Temperature was monitored on nine different sites, including the brain. Core temperature (average of 4 deep probes) was elevated to 42°C for 2 hr.

Results

Elevation of core body temperature to 42°C took on average (± standard deviation) 38 ± 8 min. Initially observed temperature spikes diminished after lowering maximal blood temperature to 45°C. Hereafter, brain temperature spikes never exceeded 42.5°C, mean brain temperature was at highest 41.9°C during maintenance. WBH resulted in increased heart rates and decreased mean arterial pressures. The vast amounts of fluids required to counter hypotension tended to be smaller after corticosteroid administration. Hemodialysis was started in three animals (potassium increase prevention in two and hyperkalemia treatment in one). Severe rhabdomyolysis was observed in all pigs (including the control). All animals survived the procedure until planned euthanasia 1, 6, or 24 hr post procedure.

Conclusion

Fast induction of eWBH with homogenous thermal distribution is feasible in pigs using the Vithèr WBH device. Severe hemodynamic disturbances, rhabdomyolysis, and hyperkalemia were observed.

High hydrostatic pressure induces atrial electrical remodeling through upregulation of inflammatory cytokines

AIMS

Hypertension is an independent risk factor for atrial fibrillation (AF). However, the direct effect of hydrostatic pressure on atrial electrical remodeling is unclear. The present study investigated whether hydrostatic pressure is responsible for atrial electrical remodeling and addressed a potential role of inflammation in this pathology.

MAIN METHODS

Whole-cell patch-clamp recordings and biochemical assays were used to study the regulation and expression of ion channels in left atrial appendages in patients with AF, spontaneously hypertensive rats (SHRs), and atrium-derived cells (HL-1 cells) exposed to standard (0 mmHg) and elevated (20, 40 mmHg) hydrostatic pressure.

KEY FINDINGS

Both TNF-α and MIF were highly expressed in patients with AF and SHRs. AF inducibility in SHRs was higher after atrial burst pacing, accompanied by a decrease in the L-type calcium current (I_Ca,L), an increase in the transient outward K⁺ current (I_to) and ultra-rapid delayed rectifier K⁺ current (I_Kur), and a shortened action potential duration (APD), which could be inhibited by atorvastatin. Furthermore, exposure to elevated pressure was associated with electrical remodeling of the HL-1 cells. The peak current density of I_Ca,L was reduced, while I_to and I_Kur were increased. Moreover, the expression levels of Kv4.3, Kv1.5, TNF-α, and MIF were upregulated, while the expression of Cav1.2 was downregulated in HL-1 cells after treatment with high hydrostatic pressure (40 mmHg). Atorvastatin alleviated the electrical remodeling and increased inflammatory markers in HL-1 cells induced by high hydrostatic pressure.

SIGNIFICANCE

Elevated hydrostatic pressure led to atrial electrical remodeling and increased AF susceptibility by upregulating inflammation.

Anti-inflammatory drugs in the prevention of post-operative atrial fibrillation: a literature review

Atrial fibrillation (AF) is a serious and common complication following heart surgery. Cardiac surgery triggers inflammation in the heart and makes it susceptible to the incidence of AF. Therefore, anti-inflammatory drugs may reduce the rate of AF incidence in the post-surgery conditions. Immunosuppressant agents, steroidal anti-inflammatory drugs (corticosteroids), non-aspirin non-steroid anti-inflammatory drugs (NSAIDs), colchicine and omega-3 unsaturated fatty acids (n-3 UFA) are drugs with well-known anti-inflammatory properties. The efficacy, safety and other aspects of using these drugs in the prevention of post-operative AF (POAF) have been reviewed here. Studies evaluating the efficacy of colchicine have shown that it could be effective in the prevention of POAF. However, there is a need for additional studies to find a colchicine regimen with optimal efficacy and higher tolerability. The use of corticosteroids may also be of value based on the most of meta-analyses. In the case of n-3 polyunsaturated fatty acids and NSAIDs, current data fail to support their efficacy in POAF prevention. Moreover, perioperative administration of NSAIDs may be associated with some severe safety considerations. Immunosuppressant agents have not been used for the prevention of POAF. Further studies are needed to find the most effective strategy for POAF prevention with the least safety considerations and the highest health benefits.

Effect of low-dose dexamethasone on extra vascular lung water in patients following on-pump elective primary coronary artery bypass graft surgery

Background

The primary objective was to compare the effect of a low-dose dexamethasone as against a saline placebo on extravascular lung water index (EVLWI) in patients undergoing elective primary coronary artery bypass surgery. The secondary endpoints were to assess the effect of dexamethasone on other volumetric parameters (pulmonary vascular permeability index, global end diastolic volume index, and intrathoracic blood volume index), Vasoactive Inotrope Scores, hemodynamic parameters and serum osmolality in both groups.

Settings and Design

Prospective observational study performed at a single tertiary cardiac care center.

Materials and Methods

Twenty patients were randomized to receive either dexamethasone (steroid group, n = 10) or placebo (nonsteroid group, n = 10) twice before the institution of cardiopulmonary bypass (CPB). EVLWI and other volumetric parameters were obtained with the help of VolumeView™ Combo Kit connected to EV 1000 clinical platform at predetermined intervals. Hemodynamic parameters, vasoactive-inotropic Scores, hematocrit values were recorded at the predetermined time intervals. Baseline and 1^st postoperative day serum osmolality values were also obtained.

Results

The two groups were evenly matched in terms of demographic and CPB data. Intra- and inter-group comparison of the baseline EVLWI including other volumetric and hemodynamic parameters with those recorded at subsequent intervals revealed no statistical difference and was similar. Generalized estimating equation model was obtained to compare the changes between the groups over the entire study period which showed that on an average the changes between the steroid and nonsteroid group in terms of all volumetric parameters were not statistically significant.

Conclusions

There were no beneficial effects of low-dose dexamethasone on EVLWI or other volumetric parameters in patients subjected to on-pump primary coronary bypass surgery. Hemodynamic parameters were also not affected. Probably, the advanced hemodynamic monitoring aided in optimal fluid management in the nonsteroidal group impacting EVLW accumulation.

C-reactive protein promotes inflammation through TLR4/NF-κB/TGF-β pathway in HL-1 cells

Atrial fibrillation (AF) is the most common type of heart arrhythmia. Currently, the pathogenesis of AF is not fully understood yet. A growing body of evidence highlighted the strong association between inflammation and the pathogenesis of AF. C-reactive protein (CRP) is an inflammation marker with increased expression in AF. Therefore, the aim of this study was to determine if CRP promotes inflammation, which may sequentially mediate the onset of AF and the concurrent atrial fibrosis, through TLR4/NF-κB/TGF-β pathway. HL-1 cells were treated with either 25 or 50 μg/ml recombinant human CRP. TGF-β1 and NF-κB inhibitors were given either solely or together to the 50 μg/ml CRP-treated cells. Cell proliferation, apoptosis, the expression of apoptotic factors and TLR4, IL-6, TGF-β1, Smad2, and the phosphorylation of Smad2 were determined. Data showed that CRP induced dose-dependent inhibition on cell proliferation and promoted cell apoptosis, which was induced through both intrinsic and extrinsic pathways. Such effects were reversed by inhibiting TGF-β1 and/or NF-κB. Inhibition of TGF-β1 and/or NF-κB also reduced the expression of TLR4 and IL-6. Inhibition of NF-κB alone weakened the expression of TGF-β1 and phosphorylation of Smad2. Our study demonstrated that CRP is not only a marker, but also an important mediator in the induction of inflammation and likely the pathogenesis of AF. We for the first time reported CRP-induced activation and cross-talk between TLR4 and NF-κB/TGF-β1 signaling pathway in a cardiomyocyte model. Reducing CRP and targeting TLR4/NF-κB/TGF-β1 pathway may provide new insights in the therapeutic interventions to inflammation-induced AF.

Association of Preoperative Renin-Angiotensin System Inhibitors With Prevention of Postoperative Atrial Fibrillation and Adverse Events: A Systematic Review and Meta-analysis

IMPORTANCE

Postoperative atrial fibrillation (POAF) is a well-known complication after cardiac surgery. Renin-angiotensin system inhibitors (RASIs) have been suggested as an upstream therapy for selected patients with AF; however, evidence in the surgical setting is limited.

OBJECTIVE

To evaluate the role of preoperative RASIs in prevention of POAF and adverse events for patients undergoing cardiac surgery.

DATA SOURCES

The PubMed database and the Cochrane Library from inception until December 31, 2018, were searched by using the keywords renin-angiotensin system inhibitors OR angiotensin-converting enzyme inhibitors OR angiotensin receptor blocker OR aldosterone antagonist AND cardiac surgery. ClinicalTrials.gov was searched from inception until December 31, 2018, by using the keywords postoperative atrial fibrillation.

STUDY SELECTION

Randomized clinical trials (RCTs) and observational studies comparing the association between preoperative RASI treatment vs no preoperative RASI treatment (control group) and the incidence of POAF were identified. Eleven unique studies met the selection criteria.

DATA EXTRACTION AND SYNTHESIS

Pooled analysis was performed using a random-effects model. Sensitivity and subgroup analyses of RCTs were performed to test the stability of the overall effect. Metaregression was conducted to explore potential risk of bias.

MAIN OUTCOMES AND MEASURES

The primary outcome was POAF, and the secondary outcomes included rates of stroke and mortality and duration of hospitalization.

RESULTS

Eleven unique studies involving 27 885 unique patients (74.4% male; median age, 65 years [range, 58.5-74.5 years]) were included. Compared with the control group, the RASI group did not have a significantly reduced risk of POAF (odds ratio [OR], 1.04; 95% CI, 0.91-1.19; P = .55; z = 0.60), stroke (OR, 0.86; 95% CI, 0.62-1.19; P = .37; z = 0.90; without significant heterogeneity, P = .11), death (OR, 1.07; 95% CI, 0.85-1.35; P = .56; z = 0.59; without significant heterogeneity, P = .12), composite adverse cardiac events (OR, 1.04; 95% CI, 0.91-1.18; P = .58; z = 0.56), or a reduced hospital stay (weighted mean difference, -0.04; 95% CI, -1.05 to 0.98; P = .94; z = 0.07) using a random-effects model. Pooled analysis focusing on RCTs showed consistent results. The primary overall effect was maintained in sensitivity and subgroup analyses. Metaregression showed that male sex was significantly associated with POAF (τ2 = 0.0065; z = 3.47; Q = 12.047; P < .001) and that use of β-blockers was associated with a significantly reduced risk in developing POAF (τ2 = 0.018; z = -2.24; Q = 5.0091; P = .03).

CONCLUSIONS AND RELEVANCE

The findings from this study suggest that preoperative RASI treatment does not offer additional benefit in reducing the risk of POAF, stroke, death, and hospitalization in the setting of cardiac surgery. The results provide no support for conventional use of RASIs for the possible prevention of POAF and adverse events in patients undergoing cardiac surgery; further randomized data, particularly among those patients with heart failure, are needed.

The effect of methylprednisolone prophylaxis on inflammatory monocyte subsets and suppressive regulatory T cells of patients undergoing cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) during open-heart surgery triggers an inflammatory response that can cause significant morbidity and mortality. Human monocytes and regulatory T (Treg) cells are phenotypically and functionally heterogeneous and have been shown to play a significant role in the inflammatory dysfunction triggered by CPB. Glucocorticoids (GCs) have been widely administered for decades in patients undergoing CPB to reduce this inflammatory response. However, it has not been clearly established how routine prophylactic administration of glucocorticoids (GCs) affects monocyte and Treg subsets.

METHODS

Thirty-six patient who underwent heart surgery with CPB were randomly assigned to a methylprednisolone group (MG, N = 18; 500 mg in the CPB priming) and a non-methylprednisolone group (NMG, N = 18). The circulating monocyte and Treg subsets were analyzed by flow cytometry.

RESULTS

The MG and NMG groups had comparable percentages of monocyte subsets and similar expression levels of HLA-DR, CD86, CD64 and toll-like receptor 4 (TLR4). Remarkably, methylprednisolone increased the percentage of CD4+CD25+ Treg cells among CD4+ T cells in patients undergoing CPB, but did not increase the proportion of suppressive Treg cells, either resting or activated, in these patients undergoing CPB.

CONCLUSIONS

Our results showed that prophylactic administration of methylprednisolone neither decreased the percentages and counts of inflammatory monocyte subsets nor did it induce the expansion of suppressive Treg cells in patients undergoing CPB. These results clarified the effects of GCs on cell-mediated immune responses and provided additional evidence in practice.

TRIAL REGISTRATION

Clinicaltrials.gov : NCT01296074. Registered 14 February 2011.