Oxidative status, inflammation, and postoperative atrial fibrillation with metoprolol vs carvedilol or carvedilol plus N-acetyl cysteine treatment

N-Acetylcysteine and Atherosclerosis: Promises and Challenges

Atherosclerosis remains a leading cause of cardiovascular diseases. Although the mechanism for atherosclerosis is complex and has not been fully understood, inflammation and oxidative stress play a critical role in the development and progression of atherosclerosis. N-acetylcysteine (NAC) has been used as a mucolytic agent and an antidote for acetaminophen overdose with a well-established safety profile. NAC has antioxidant and anti-inflammatory effects through multiple mechanisms, including an increase in the intracellular glutathione level and an attenuation of the nuclear factor kappa-B mediated production of inflammatory cytokines like tumor necrosis factor-alpha and interleukins. Numerous animal studies have demonstrated that NAC significantly decreases the development and progression of atherosclerosis. However, the data on the outcomes of clinical studies in patients with atherosclerosis have been limited and inconsistent. The purpose of this review is to summarize the data on the effect of NAC on atherosclerosis from both pre-clinical and clinical studies and discuss the potential mechanisms of action of NAC on atherosclerosis, as well as challenges in the field.

Predictive Values of Systemic Immune-Inflammation Index in New-Onset Atrial Fibrillation Following Coronary Artery Bypass Grafting

INTRODUCTION

We investigated the relationship between the newly-defined systemic immune-inflammation index and the new-onset atrial fibrillation in patients undergoing coronary artery bypass grafting.

METHOD

This study included 392 patients who underwent coronary artery bypass grafting. We divided the participants into two groups as those with and without new-onset atrial fibrillation. Prior to coronary artery bypass grafting, we evaluated blood samples, including systemic immune-inflammation index, and other laboratory parameters of the patients. We formulized the systemic immune-inflammation index score as platelet × neutrophil/lymphocyte counts.

RESULTS

The findings revealed that new-onset atrial fibrillation occurred in 80 (20.4%) of 392 patients during follow-ups. Such patients had higher systemic immune-inflammation index, neutrophil/lymphocyte ratio, and C-reactive protein levels than those who did not develop new-onset atrial fibrillation (P<0.001, P<0.001, P=0.010, respectively). In receiver operating characteristic curve analysis, systemic immune-inflammation index levels > 712.8 predicted new-onset atrial fibrillation with a sensitivity of 85% and a specificity of 61.2% (area under the curve: 0.781, 95% confidence interval: 0.727-0.835; P<0.001).

CONCLUSION

Overall, systemic immune-inflammation index, a novel inflammatory marker, may be used as a decisive marker to predict the development of atrial fibrillation following coronary artery bypass grafting.

Comparing the efficacy of N-acetylcysteine plus carvedilol versus carvedilol in the prevention of atrial fibrillation following coronary artery bypass graft surgery

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia following open-heart surgery. Agents with antioxidant properties may reduce postoperative complications like postoperative AF (POAF) in patients undergoing open-heart surgery. This study was conducted to assess the effect of N-acetylcysteine (NAC) in prevention of AF following coronary artery bypass graft (CABG) surgery.

METHODS

Three hundred patients who underwent CABG surgery were entered in the study. Patients with contraindications for beta-blockers and patients were simultaneously replacing or repairing the valve with open-heart surgery were excluded. The patients were randomly divided into two groups (n = 150) and they were received NAC plus carvedilol or carvedilol. The patients were monitored for 5 days after surgery and the incidence of AF during hospitalization was recorded.

RESULTS

AF was detected in 14 patients in the NAC with Carvedilol group (9.33%) and 23 patients in Carvedilol group (15.33%). There was no significant difference in the incidence of POAF between the two groups (p value = 0.112). The result of multivariable regression model represented that although the incidence of POAF was lower in NAC plus carvedilol group, it wasn't statistically significant (p value = 0.10).

CONCLUSIONS

NAC was not associated with a decreased incidence of AF following CABG surgery.

N-Acetylcysteine for Cardiac Protection During Coronary Artery Reperfusion: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Coronary artery reperfusion is essential for the management of symptoms in the patients with myocardial ischemia. However, the benefit of reperfusion often comes at an expense of paradoxical injury, which contributes to the adverse events, and sometimes heart failure. Reperfusion is known to increase the production of reactive oxygen species (ROS). We address whether N-acetylcysteine (NAC) reduces the ROS and alleviates reperfusion injury by improving the clinical outcomes. A literature search for the randomized controlled trials (RCTs) was carried out in the five biomedical databases for testing the effects of NAC in patients undergoing coronary artery reperfusion by percutaneous coronary intervention, thrombolysis, or coronary artery bypass graft. Of 787 publications reviewed, 28 RCTs were identified, with a summary of 2,174 patients. A meta-analysis using the random effects model indicated that NAC administration during or prior to the reperfusion procedures resulted in a trend toward a reduction in the level of serum cardiac troponin (cTn) [95% CI, standardized mean difference (SMD) −0.80 (−1.75; 0.15), p = 0.088, n = 262 for control, 277 for NAC group], and in the incidence of postoperative atrial fibrillation [95% CI, relative risk (RR) 0.57 (0.30; 1.06), p = 0.071, n = 484 for control, 490 for NAC group]. The left ventricular ejection fraction or the measures of length of stay in intensive care unit (ICU) or in hospital displayed a positive trend that was not statistically significant. Among the nine trials that measured ROS, seven showed a correlation between the reduction of lipid peroxidation and improved clinical outcomes. These lines of evidence support the potential benefit of NAC as an adjuvant therapy for cardiac protection against reperfusion injury.

New-onset atrial fibrillation during COVID-19 infection predicts poor prognosis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to a paradigm shift in healthcare worldwide. Little is known about the impact on the cardiovascular system, and the incidence and consequences of new onset of atrial fibrillation (AF) in infected patients remain unclear. The aim of this study was to analyze the cardiovascular outcomes of patients with newonset AF and coronavirus disease 2019 (COVID-19) infection.

METHODS

This observational study analyzed a sample of 160 consecutive patients hospitalized due to COVID-19. A group with new-onset AF (n = 12) was compared with a control group (total: n = 148, sinus rhythm: n = 118, previous AF: n = 30). New-onset AF patients were significantly older and hypertensive, as well as presenting more frequently with a history of acute coronary syndrome and renal dysfunction. This group showed a higher incidence of thromboembolic events (41.7% vs. 4.1%; p < 0.001), bleeding (33.3% vs. 4.7%, p = 0.005), a combined endpoint of thrombosis and death (58.3% vs. 19.6%, p = 0.006) and longer hospital stays (16.4 vs. 8.6 days, p < 0.001), with no differences in all-cause mortality.

RESULTS

In multivariate analysis, adjusted by potential confounding factors, new-onset AF demonstrated a 14.26 odds ratio for thromboembolism (95% confidence interval 2.86-71.10, p < 0.001).

CONCLUSIONS

New-onset AF in COVID-19 patients presumably has a notable impact on prognosis. The appearance of new-onset AF is related to worse cardiovascular outcomes, considering it as an independent predictor of embolic events. Further studies are needed to identify patients with COVID-19 at high risk of developing "de novo" AF, provide early anticoagulation and minimize the embolic risk of both entities.

Predictive values of C-reactive protein/albumin ratio in new-onset atrial fibrillation after coronary artery bypass grafting

OBJECTIVE

This study aimed to investigate the predictive value of the newly defined C-Reactive Protein (CRP)/Albumin Ratio (CAR) in determining the development of atrial fibrillation (AF) in comparison with other inflammatory markers, such as Neutrophil/Lymphocyte (N/L) Ratio and Platelet/Lymphocyte (P/L) Ratio, in patients undergoing Coronary Artery Bypass Grafting (CABG) surgery.

METHODS

The population of this observational study consisted of 415 patients undergoing CABG. The study cohort was subdivided into two groups based on the development of AF. Complete blood counts, serum CRP, and serum albumin levels were evaluated before the CABG. The CAR, N/L, and P/L ratios of all the patients were calculated. Predictors of postoperative AF were determined by multiple logistic regression analysis (MLRA).

RESULTS

During follow-up, 136 patients (32.8%) developed postoperative AF. With MLRA, independent risk factors for postoperative AF were determined as follows: fasting glucose level (OR: 1.01; 95 % CI: 1.00-1.01, P <0.001), age (OR: 1.12; 95 % CI: 1.07-1.17, P <0.001), left ventricle ejection fraction (OR: 0.90; 95 % CI: 0.87-0.94, P <0.001), male gender (OR: 3.32; 95 % CI: 1.39-7.90, P = 0.007), 24-hour drainage amount (OR: 1.004; 95 % CI: 1.002-1.005, P <0.001), and CAR (OR: 1.82; 95 % CI: 1.53-2.16, P <0.001). Receiver Operating Characteristic curve analysis showed that CAR (C-statistic: 0.75; 95% CI: 0.71-0.79, p< 0.001) was a significant predictor of AF.

CONCLUSION

Novel inflammatory marker CAR can be used as a reliable marker to predict the development of AF following CABG.

Relationship between c-reactive protein/albumin ratio and new-onset atrial fibrillation after coronary artery bypass grafting

OBJECTIVE

This study aimed to investigate the predictive value of the newly defined C-Reactive Protein (CRP)/Albumin Ratio (CAR) in determining the development of atrial fibrillation (AF) in comparison with other inflammatory markers, such as Neutrophil/Lymphocyte (N/L) Ratio and Platelet/Lymphocyte (P/L) Ratio, in patients undergoing Coronary Artery Bypass Grafting (CABG) surgery.

METHODS

The population of this observational study consisted of 415 patients undergoing CABG. The study cohort was subdivided into two groups based on the development of AF. Complete blood counts, serum CRP, and serum albumin levels were evaluated before the CABG. The CAR, N/L, and P/L ratios of all the patients were calculated. Predictors of postoperative AF were determined by multiple logistic regression analysis (MLRA).

RESULTS

During follow-up, 136 patients (32.8%) developed postoperative AF. With MLRA, independent risk factors for postoperative AF were determined as follows: fasting glucose level (OR: 1.01; 95 % CI: 1.00-1.01, P <0.001), age (OR: 1.12; 95 % CI: 1.07-1.17, P <0.001), left ventricle ejection fraction (OR: 0.90; 95 % CI: 0.87-0.94, P <0.001), male gender (OR: 3.32; 95 % CI: 1.39-7.90, P = 0.007), 24-hour drainage amount (OR: 1.004; 95 % CI: 1.002-1.005, P <0.001), and CAR (OR: 1.82; 95 % CI: 1.53-2.16, P <0.001). Receiver Operating Characteristic curve analysis showed that CAR (C-statistic: 0.75; 95% CI: 0.71-0.79, p< 0.001) was a significant predictor of AF.

CONCLUSION

Novel inflammatory marker CAR can be used as a reliable marker to predict the development of AF following CABG.

The Role of Oxidative Stress in Cardiac Disease: From Physiological Response to Injury Factor

Reactive oxygen species (ROS) are highly reactive chemical species containing oxygen, controlled by both enzymatic and nonenzymatic antioxidant defense systems. In the heart, ROS play an important role in cell homeostasis, by modulating cell proliferation, differentiation, and excitation-contraction coupling. Oxidative stress occurs when ROS production exceeds the buffering capacity of the antioxidant defense systems, leading to cellular and molecular abnormalities, ultimately resulting in cardiac dysfunction. In this review, we will discuss the physiological sources of ROS in the heart, the mechanisms of oxidative stress-related myocardial injury, and the implications of experimental studies and clinical trials with antioxidant therapies in cardiovascular diseases.

Oxidative stress and atrial fibrillation: an update

Atrial remodelling involves electrophysiological and structural abnormalities that promote the development and perpetuation of atrial fibrillation. Experimental and clinical data indicate that oxidative stress is implicated in the pathophysiology of atrial remodelling. The mechanistic links between atrial remodelling and oxidative stress are complex with several underlying diseases and conditions may affect these pathways. Therefore, the development of antioxidant interventions in this setting remains difficult. Besides classical antioxidant compounds, several agents with pleiotropic effects, including anti-inflammatory and antioxidant, have been tested in experimental and clinical settings with variable results. Strategies applying conventional antioxidants in specific situations such as postoperative atrial fibrillation show beneficial effects, especially the two-step regimen of antioxidants combination. Of note, there are limited data on the development of strategies that target specific sources of reactive oxygen species implicated in atrial remodelling. Lifestyle, diet, and risk factors modification is a complementary promising approach. This updated review provides a concise and critical overview of all available data regarding oxidative stress and its modulation in atrial fibrillation. Future directions on this exciting field are also discussed.

Pharmacological strategies for prevention of postoperative atrial fibrillation

Atrial fibrillation (AF) complicating cardiac surgery continues to be a major problem that increases the postoperative risk of stroke, myocardial infarction, heart failure and costs and can affect long-term survival. The incidence of AF after surgery has not significantly changed over the last two decades, despite improvement in medical and surgical techniques. The mechanism and pathophysiology underlying postoperative AF (PoAF) is incompletely understood and results from a combination of acute and chronic factors, superimposed on an underlying abnormal atrial substrate with increased interstitial fibrosis. Several anti-arrhythmic and non-anti-arrhythmic medications have been used for the prevention of PoAF, but the effectiveness of these strategies has been limited due to a poor understanding of the basis for the increased susceptibility of the atria to AF in the postoperative setting. In this review, we summarize the pathophysiology underlying the development of PoAF and evidence behind pharmacological approaches used for its prevention in the postoperative setting.

Monocyte-platelet aggregates and CD11b expression as markers for thrombogenicity in atrial fibrillation

BACKGROUND

A strong interdependence is known between atrial fibrillation (AF), inflammation and thrombogenesis. Monocyte-platelet aggregates (MPAs) are sensitive markers of platelets and monocyte activation. It is not known whether MPAs are associated with thrombogenicity in AF. Therefore, we examined differences in the content of MPAs and CD11b expression in patients with AF in dependence of the presence of atrial thrombus formation.

METHODS

107 patients with symptomatic AF underwent transesophageal echocardiography (TEE) before planned cardioversion or pulmonary vein isolation. Flow-cytometric quantification analysis was done on the day of performed TEE to determine the content of MPAs and the expression of CD11b on monocytes and granulocytes.

RESULTS

Compared to patients without thrombus (n = 80) those with an echocardiographic proven left atrium (LA) thrombus (n = 27) showed an increased extent of the risk factors age, diabetes and heart failure. The content of MPAs (147 ± 12 vs. 311 ± 29 cells/µl, p < 0.001) as well as the CD11b expression on monocytes (p < 0.05) and granulocytes (p < 0.05) were strongly associated with the existence of a LA thrombus. The content of MPAs and the CD11b expression remained independent predictors for LA thrombus after adjustment in logistic regression analysis and negatively correlated with left atrial appendage flow velocity. MPAs above 170 cells/µl (OR 34.2, p = 0.01) had a sensitivity of 96 % and a specificity of 73 % for predicting LA-thrombus.

CONCLUSIONS

The content of MPAs and the CD11b expression on monocytes and granulocytes are increased in AF-patients with proven thrombus formation. They seem to be appropriate biomarkers for stratification of thromboembolic risk in patients with AF.

Improved oxidative status in major abdominal surgery patients after N-acetyl cystein supplementation

Background

Increased levels of reactive oxygen species during and after surgery may affect inflammatory response, post-operative adhesion molecule formation, and hemodynamic stability. The glutathione redox cycle is an important regulator in oxidative stress and its reduced forms scavenge free radicals. N-acetyl cysteine, a precursor of reduced glutathione, is considered as a potentially therapeutic wide spectrum agent in clinical practice. We therefore examined whether N-acetyl cysteine improves some biochemical parameters in cancer patients undergoing major abdominal surgery.

Methods

Thirty-three patients diagnosed with pancreas, stomach, rectum, colon malignancies, and undergoing major abdominal surgery at Ankara Numune Training and Research Hospital were randomly divided into two groups; control (CON) and N-acetyl cysteine (NAC). The NAC group had 1,200 mg N-acetyl cysteine starting two days before the operation day, in addition to isonitrogenous and isocaloric total parenteral nutrition of 1.2 g/kg protein, 25 kcal/kg, and 60:40 carbohydrate/fat ratio. Blood and urine samples were drawn two days before the operation, on operation day, and on the first, third, and fifth days post-operation.

Results

Plasma malondialdehyde was significantly lower in the NAC group (P < 0.001). N-acetyl cysteine treatment did not affect plasma levels of vitamin A, C or E. The NAC group exhibited a higher ratio of reduced glutathione to oxidised glutathione (P = 0.019). Urinary nitrate level was also significantly lower in the NAC group (P = 0.016).

Conclusion

The study demonstrated the clinical importance of N-acetyl cysteine supplementation on antioxidant parameters in abdominal surgery patients. In these patients N-acetyl cysteine and vitamin administration can be considered as an effective method for improvement of oxidative status.