C-reactive protein is a risk indicator for atrial fibrillation after myocardial revascularization

[Colchicine-Phoenix from the ashes]

Colchicine is an anti-inflammatory herbal medicine with a history stretching back thousands of years. It is a cornerstone in the acute and prophylactic treatment of gout and has secured a permanent place in the standard pharmacological repertoire for familial Mediterranean fever, pericarditis, neutrophilic dermatoses, Behçet's disease and severe aphthous ulcers refractory to oral treatment. The US Food and Drug Administration (FDA) has recently approved colchicine to reduce the risk of myocardial infarction, stroke, coronary revascularization and cardiovascular death in adult patients with established atherosclerotic disease or with multiple risk factors for cardiovascular diseases. The recommendation level for cardiovascular prophylaxis was raised from IIb to IIa in the current European Society of Cardiology (ESC) guidelines from 2024. Clinical studies in recent years also demonstrated an effect for acute coronary syndrome and atrial fibrillation. This review article highlights the efficacy and safety profile of colchicine and provides insights into recent and potential future evidence-based fields of application.

Relationship between platelet mass index and postoperative atrial fibrillation after elective coronary artery bypass surgery: a retrospective study

BACKGROUND

Atrial fibrillation (AF) is the most common complication after cardiac surgery. The pathogenesis of postoperative atrial fibrillation (POAF) is multifactorial and one of the known factors is inflammation. Platelet mass index (PMI) is an indicator of platelet activation and a better inflammatory marker than mean platelet volume (MPV). In this retrospective study, we investigated the relationship between POAF and PMI.

METHODS

The study included 848 consecutive patients (655 male and 193 female) who had elective isolated coronary artery by-pass grafting (CABG) or combined CABG and valvular surgery. Platelet count and MPV were measured from preoperative blood samples to calculate PMI. Post-operative atrial fibrillation was defined as irregular and fibrillatory P waves occurring 48-96 h after cardiac surgery and lasting at least 30 s. The PMI values in patients who developed POAF were compared with those in patients who did not develop POAF.

RESULTS

Patients who developed POAF had higher PMI values (2549.3 ± 1077.1) when compared with patients in sinus rhythm (2248.1 ± 683.4; p < 0.01). In multivariate regression analysis, age (OR: 1.05; 95% CI: 1.02-1.09; p = 0.01), left atrial diameter (OR: 1.05; 95% CI: 1.03-1.09; p = 0.02), hs-CRP (OR: 1.09; 95%CI: 1.05-1.13; p < 0.01), EuroSCORE II (OR: 1.27; 95% CI: 1.14-1.41; p < 0.01), and PMI (OR: 1.01; 95% CI: 1.001-1.02; p < 0.01) were independent predictors of POAF. In ROC analysis, PMI ≥ 2286 predicted POAF development with a sensitivity of 69% and a specificity of 58% (AUC: 0.66; p < 0.01) CONCLUSION: A significant relationship was found between preoperatively calculated PMI and POAF. We showed that PMI may be used to predict patients who are at high risk of developing POAF.

The Effect of Colchicine on Atrial Fibrillation: A Systematic Review and Meta-Analysis

Colchicine is a potent anti-inflammatory agent whose benefits have been explored for various conditions, including atrial fibrillation (AF). In this article, we tried to understand why colchicine might be beneficial in AF and reviewed various studies that looked at the effect of colchicine against AF. We followed the PRISMA algorithm and undertook a literature search to identify studies with control groups that looked at the effect of colchicine against AF and conducted a meta-analysis. We identified six studies on post-cardiac surgical patients, three on post-pulmonary vein isolation (PVI)/ablation patients, and two on coronary artery disease. In patients who underwent cardiac surgery, we found that colchicine is beneficial against postoperative atrial fibrillation (POAF) with a relative risk (RR) of 0.70 (95% CI of 0.58 to 0.84) and a p-value of 0.0001. We also found that in patients who underwent PVI/ablation, colchicine is beneficial in decreasing AF recurrence over three months with an RR of 0.57 (95% CI of 0.39 to 0.83) and a p-value of 0.0032 and over 12 months follow-up with an RR of 0.58 (95% CI of 0.42 - 0.80) and a p-value of 0.0008. Our meta-analysis showed that in patients with coronary artery disease, colchicine had no significant benefit in decreasing the incidence of AF with a hazard ratio (HR) of 0.86 (95% CI of 0.69 - 1.06) and a p-value of 0.16. From this study, we conclude that colchicine may be beneficial for decreasing the incidence of AF in post-cardiac surgery patients and post-PVI/ablation patients. It may not decrease the incidence of AF in patients with coronary artery disease.

Beta-Blocker Landiolol Hydrochloride in Preventing Atrial Fibrillation Following Cardiothoracic Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this article was to assess the benefit of perioperative administration of the intravenous beta-blocker landiolol hydrochloride in preventing atrial fibrillation (AF) after cardiothoracic surgery.

METHODS

We performed a systematic search in PubMed, Web of Science, CNKI, and OVID to identify randomized controlled trials (RCTs) and cohorts up to January 2021. Data regarding postoperative atrial fibrillation (POAF) and safety outcomes were extracted. Odds ratios (ORs) with 95% confidence intervals (CIs) were determined using the Mantel-Haenszel method. Meanwhile, subgroup analyses were conducted according to surgery type including lung cancer surgery, esophageal cancer surgery, and cardiac surgery.

RESULTS

Seventeen eligible articles involving 1349 patients within 13 RCTs and four cohorts were included in our meta-analysis. Compared with control group, landiolol administration was associated with a significant reduction of the occurrence of AF after cardiothoracic surgery (OR = 0.32, 95% CI 0.23-0.43, P <0.00001). In addition, the results demonstrated that perioperative administration of landiolol hydrochloride minimized the occurrence of postoperative complications (OR = 0.48, 95% CI 0.33-0.70, P = 0.0002). Funnel plots indicated no obvious publication bias.

CONCLUSIONS

Considering this analysis, landiolol was effective in the prevention of AF after cardiothoracic surgery and did not increase the risk of major postoperative complications.

Prehabilitation to prevent complications after cardiac surgery - A retrospective study with propensity score analysis

Background

The rising prevalence of modifiable lifestyle-related risk factors (e.g. overweight and physical inactivity) suggests the need for effective and safe preoperative interventions to improve outcomes after cardiac surgery. This retrospective study explored potential short-term postoperative benefits and unintended consequences of a multidisciplinary prehabilitation program regarding in-hospital complications.

Methods

Data on patients who underwent elective cardiac surgery between January 2014 and April 2017 were analyzed retrospectively. Pearson’s chi-squared tests were used to compare patients who followed prehabilitation (three times per week, at a minimum of three weeks) during the waiting period with patients who received no prehabilitation. Sensitivity analyses were performed using propensity-score matching, in which the propensity score was based on the baseline variables that affected the outcomes.

Results

Of 1201 patients referred for elective cardiac surgery, 880 patients met the inclusion criteria, of whom 91 followed prehabilitation (53.8% ≥ 65 years, 78.0% male, median Euroscore II 1.3, IQR, 0.9–2.7) and 789 received no prehabilitation (60.7% ≥ 65 years, 69.6% male, median Euroscore II 1.6, IQR, 1.0–2.8). The incidence of atrial fibrillation (AF) was significantly lower in the prehabilitation group compared to the unmatched and matched standard care group (resp. 14.3% vs. 23.8%, P = 0.040 and 14.3% vs. 25.3%, P = 0.030). For the other complications, no between-group differences were found.

Conclusions

Prehabilitation might be beneficial to prevent postoperative AF. Patients participated safely in prehabilitation and were not at higher risk for postoperative complications. However, well-powered randomized controlled trials are needed to confirm and deepen these results.

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.

Preoperative Platelet-to-Lymphocyte Ratio Is Not Associated With Postoperative Atrial Fibrillation

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass grafting (CABG) and is associated with increased short-term and long-term mortality. While the precise etiology of POAF remains unclear, inflammation is a known contributing factor. Preliminary studies have suggested that an elevated preoperative platelet-to-lymphocyte ratio (PLR), an inexpensive and readily available novel inflammatory biomarker, may be associated with increased incidence of POAF after CABG. This study sought to further investigate this hypothesis.

METHODS

The study cohort included all patients undergoing isolated CABG, with no prior history of arrhythmia, who were operated on between August 1, 2010, and December 31, 2018, at a major Australian tertiary center (n = 1457). Patients were divided into low (<86) or high (≥86) PLR groups based on an optimal cutoff derived from receiver-operating characteristic curve analysis. The incidence of POAF was then compared. Categorical variables were analyzed using the chi-square test and continuous variables using logistic regression.

RESULTS

Of 1457 patients, 495 (34.0%) developed POAF. There was no statistically significant difference in the incidence of POAF between patients in the high-PLR and low-PLR groups (34.8% vs 31.0%; P = .22). Using multivariable logistic regression analysis, high PLR was not independently associated with POAF (odds ratio, 1.04; P = .78).

CONCLUSIONS

Elevated preoperative PLR is not independently associated with POAF in patients undergoing isolated CABG. The findings of this study differ from those of 2 previous smaller studies.

Postoperative Atrial Fibrillation Following Cardiac Surgery: From Pathogenesis to Potential Therapies

Postoperative atrial fibrillation (POAF) is a major complication after cardiac surgery which can lead to high rates of morbidity and mortality, an enhanced length of hospital stay, and an increased cost of care. POAF is postulated to be a multifactorial phenomenon; however, some major pathogeneses have been proposed, including inflammatory pathways, oxidative stress, and autonomic dysfunction. Genetic studies also showed that inflammatory pathways, beta-1 adrenoreceptor variants, G protein-coupled receptor kinase 5 gene variants, and non-coding single-nucleotide polymorphisms in the 4q25 chromosomal locus are involved in this phenomenon. Moreover, several predisposing factors lead to the development of POAF, consisting of pre-, intra-, and postoperative contributors. The main predisposing factors comprise age, prior history of major cardiovascular risk factors, and ischemia-reperfusion injury during surgery. The management of POAF is based on the usual therapies used for non-surgical AF, including medications for either rate control or rhythm control in hemodynamically unstable patients. The perioperative administration of β-blockers and some antiarrhythmic agents has been recommended in major international guidelines. In addition, upstream therapies consisting of colchicine, magnesium, statins, and antioxidants have attenuated the incidence of POAF; however, some uncomfortable side effects developed in large randomized trials. The use of anticoagulation has also resulted in less mortality in patients with POAF at higher risk of thromboembolic events. Despite these recommendations, the actual regimen for the prevention of POAF remains controversial. In this review, we highlight the pathogenesis, predisposing factors, and potential therapeutic options for the management of patients at risk for or with POAF following cardiac surgery.

Perioperative Biomarkers Predicting Postoperative Atrial Fibrillation Risk After Coronary Artery Bypass Grafting: A Narrative Review

Postoperative atrial fibrillation (POAF) after cardiac surgery remains a highly prevalent and costly condition that negatively impacts patient quality of life and survival. Numerous retrospective studies, meta-analysis, and review papers have been reported identifying POAF risk based on patients' risk factors and clinical biomarkers. In this narrative review, the authors report significant variations among selected pre- and perioperative biomarkers used to predict POAF incidence in patients without a history of atrial fibrillation (AF). POAF prediction based on B-type natriuretic peptide, N-terminal pro B-type natriuretic peptide, C-reactive protein, interleukin-6, creatinine, and plasminogen activator inhibitor-1 differs significantly among different studies, thereby limiting their clinical utility to predict POAF risk with high accuracy. Conversely, soluble vascular endothelial cells adhesion molecule-1, soluble CD40 ligand, Galectin-3, and aldosterone show promise for better POAF prediction. However, the current datasets for these selected biomarkers are not of sufficient size to validate the broad clinical application specifically for patients with no prior history of AF.

Platelet to Lymphocyte Ratio in Cardiovascular Diseases: A Systematic Review

The platelet to lymphocyte ratio (PLR) is an integrated reflection of 2 opposite thrombotic/inflammatory pathways that are easily calculated from a complete blood count. The PLR initially served as a systemic inflammatory biomarker to predict the prognosis of neoplastic diseases. In recent years, the PLR has been used as a prognostic marker in cardiovascular (CV) conditions. In this review, we consider the evidence regarding the association of the PLR with CV disease (CVD) and its possible use as a prognostic marker of CVD. The role of PLR has been investigated in CV conditions in several studies. We assessed clinical trials using PubMed, EMBASE, and Web of Science (up to April 18, 2018) to evaluate the association between PLR and mortality/major adverse cardiac events in these conditions. Most of these studies reported significant relationships between a high PLR and diverse outcomes. In conclusion, we suggest that PLR is a cheap and easily available systemic inflammatory marker that can predict distinct outcomes in different types of CVD.

Clinical significance and risk factors for new onset and recurring atrial fibrillation following cardiac surgery - a retrospective data analysis

Background

Although mortality after cardiac surgery has significantly decreased in the last decade, patients still experience clinically relevant postoperative complications. Among others, atrial fibrillation (AF) is a common consequence of cardiac surgery, which is associated with prolonged hospitalization and increased mortality.

Methods

We retrospectively analyzed data from patients who underwent coronary artery bypass grafting, valve surgery or a combination of both at the University Hospital Muenster between April 2014 and July 2015. We evaluated the incidence of new onset and intermittent/permanent AF (patients with pre- and postoperative AF). Furthermore, we investigated the impact of postoperative AF on clinical outcomes and evaluated potential risk factors.

Results

In total, 999 patients were included in the analysis. New onset AF occurred in 24.9% of the patients and the incidence of intermittent/permanent AF was 59.5%. Both types of postoperative AF were associated with prolonged ICU length of stay (median increase approx. 2 days) and duration of mechanical ventilation (median increase 1 h). Additionally, new onset AF patients had a higher rate of dialysis and hospital mortality and more positive fluid balance on the day of surgery and postoperative days 1 and 2. In a multiple logistic regression model, advanced age (odds ratio (OR) = 1.448 per decade increase, p < 0.0001), a combination of CABG and valve surgery (OR = 1.711, p = 0.047), higher C-reactive protein (OR = 1.06 per unit increase, p < 0.0001) and creatinine plasma concentration (OR = 1.287 per unit increase, p = 0.032) significantly predicted new onset AF. Higher Horowitz index values were associated with a reduced risk (OR = 0.996 per unit increase, p = 0.012). In a separate model, higher plasma creatinine concentration (OR = 2.125 per unit increase, p = 0.022) was a significant risk factor for intermittent/permanent AF whereas higher plasma phosphate concentration (OR = 0.522 per unit increase, p = 0.003) indicated reduced occurrence of this arrhythmia.

Conclusions

New onset and intermittent/permanent AF are associated with adverse clinical outcomes of elective cardiac surgery patients. Different risk factors implicated in postoperative AF suggest different mechanisms might be involved in its pathogenesis. Customized clinical management protocols seem to be warranted for a higher success rate of prevention and treatment of postoperative AF.

Electronic supplementary material

The online version of this article (10.1186/s12871-017-0455-7) contains supplementary material, which is available to authorized users.

Randomized clinical trial of landiolol hydrochloride for the prevention of atrial fibrillation and postoperative complications after oesophagectomy for cancer

Background

Atrial fibrillation is common after oesophageal surgery. The aim of this study was to evaluate whether landiolol hydrochloride was effective and safe in the prevention of atrial fibrillation after oesophagectomy, and to see whether a reduction in incidence of atrial fibrillation would reduce other postoperative complications.

Methods

This single-centre study enrolled patients scheduled for transthoracic oesophagectomy in a randomized, double-blind, placebo-controlled trial between March 2013 and January 2016. Enrolled patients were randomized with a 1 : 1 parallel allocation ratio to either landiolol prophylaxis or placebo. The primary endpoint was the occurrence of atrial fibrillation after oesophagectomy. Secondary endpoints were incidence of postoperative complications, and effects on haemodynamic and inflammatory indices.

Results

One hundred patients were enrolled, 50 in each group. Postoperative atrial fibrillation occurred in 15 patients (30 per cent) receiving placebo versus five (10 per cent) receiving landiolol (P = 0·012). The overall incidence of postoperative complications was significantly lower in the landiolol group (P = 0·046). In the landiolol group, postoperative heart rate was suppressed effectively, but the decrease in BP was not harmful. The interleukin 6 level was significantly lower on days 3 and 5 after surgery in the landiolol group (P = 0·001 and P = 0·002 respectively).

Conclusion

Landiolol was effective and safe in preventing atrial fibrillation after oesophagectomy. Registration number: UMIN000010648 (http://www.umin.ac.jp/ctr/).

Meta-analysis Identifies Serum C-Reactive Protein as an Indicator of Atrial Fibrillation Risk After Coronary Artery Bypass Graft

A meta-analysis-based study was conducted to examine the clinical value of serum C-reactive protein (CRP) levels in predicting postoperative atrial fibrillation (POAF) in patients with coronary artery disease (CAD) who underwent coronary artery bypass graft. Computer-based search of scientific literature databases was performed to identify relevant studies in strict accordance with our inclusion and exclusion criteria. Data extracted from the selected studies were used to perform meta-analysis using the STATA 12.0 statistical software. Standardized mean differences (SMDs) with their 95% confidence interval (95% CI) were calculated. The database search strategy initially identified 62 articles (Chinese = 17, English = 45). After multiple levels of screening and validation, 15 case-control studies (Chinese = 1, English = 14), containing of a total of 3110 atrial fibrillation patients (POAF = 925, non-POAF = 2185), were selected for our meta-analysis. The meta-analysis results confirmed that serum CRP level was remarkably higher in patients with POAF compared with non-POAF (SMD = 1.36; 95% CI, 0.44-2.28; P = 0.004). Ethnicity-stratified analysis revealed that elevated serum CRP levels were associated with an increased risk of POAF in white patients with CAD (SMD = 0.85; 95% CI, 0.12-1.58; P = 0.022), but not Asian patients with CAD (SMD = 3.31, 95% CI, -0.04 to 6.66; P = 0.053). Elevated CRP levels, indicating profound inflammation, may be associated with significantly increased risk of POAF in patients with CAD who underwent coronary artery bypass graft. Thus, serum CRP levels are important for early diagnosis and monitoring of POAF in high-risk patients.

Association of Preoperative Platelet-to-Lymphocyte Ratio with Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

OBJECTIVE

The aim of this study was to investigate the association between platelet-to-lymphocyte ratio (PLR) and atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery.

SUBJECTS AND METHODS

A total of 125 patients were retrospectively analyzed. AF was diagnosed using standard clinical criteria, and PLR was calculated as the ratio of the platelets to lymphocytes, obtained from the blood samples that were taken in the fasting state before CABG surgery. The association of different variables with postoperative AF and PLR was calculated using univariate and multivariate analysis. The receiver operating characteristics curve was used to determine the sensitivity and specificity of PLR and the optimal cutoff value for predicting post-CABG AF.

RESULTS

Of the 125 patients, 50 with AF (mean age: 67.0 ± 9.5 years, 38 males and 12 females) and 75 patients without AF (mean age: 61.1 ± 9.1 years, 58 males and 17 females) were identified, and the difference in the mean age was statistically significant (p = 0.01). PLR was also significantly higher in those with AF (152.8 ± 82.2) than those without AF (118.2 ± 32.9) (p = 0.012). Univariate analysis showed that age and PLR were associated with AF after CABG surgery (p < 0.001 and p = 0.005, respectively). Using a multivariate logistic regression model with the backward elimination method, age and PLR remained as independent predictors of AF after CABG surgery (p < 0.001 and p = 0.005, respectively). PLR levels >119.3 predicted postoperative AF with 64% sensitivity and 56% specificity (AUC: 0.634, p = 0.012).

CONCLUSION

In this study, age and PLR level were independent predictors of AF after CABG surgery. Patients with an elevated preoperative PLR were at higher risk of AF after CABG surgery.

Perioperative Outcomes, Transfusion Requirements, and Inflammatory Response After Coronary Artery Bypass Grafting With Off-Pump, Mini-Extracorporeal, and On-Pump Circulation Techniques

OBJECTIVES

Mini-extracorporeal circulation (MECC) units were developed to reduce postoperative morbidity, transfusion requirements, and inflammation associated with conventional on-pump coronary artery bypass (ONCAB) surgery without the technical demands of the off-pump (OPCAB) technique. We compared perioperative outcomes and inflammatory mediation among OPCAB, MECC, and ONCAB techniques.

METHODS

We prospectively enrolled 102 patients undergoing elective isolated coronary bypass grafting. Perfusion methods were OPCAB (n = 34), MECC (n = 34), and ONCAB (n = 34). Serial blood samples were collected to measure serum inflammatory markers.

RESULTS

There were no operative deaths or strokes. Total red blood cell (RBC) products used in OPCAB, MECC, and ONCAB patients were 0.676, 1.000, and 1.235 units, respectively. Adjusted (by splined Society of Thoracic Surgeons operative risk score) analysis showed no statistically significant differences in mean RBC product use among the different operative systems (OPCAB vs MECC, P = 0.580; OPCAB vs ONCAB, P = 0.311; MECC vs ONCAB, P = 0.633). Adjusted (by Society of Thoracic Surgeons risk score and baseline level) mean plasma level differences (24 hours postoperative - baseline) of C-reactive protein for OPCAB (117.89; 95% confidence interval [95% CI], 106.23-129.54) and for MECC (124.88; 95% CI, 113.45-136.32) were significantly higher than for ONCAB (98.82; 95% CI, 86.40-111.24). No significant adjusted differences (P = 0.304) in interleukin-6 level changes were observed.

CONCLUSIONS

Off-pump coronary artery bypass and MECC did not significantly reduce mean total RBC transfusion requirements. Off-pump coronary artery bypass and MECC were associated with greater C-reactive protein elevation than ONCAB, suggestive of an increased inflammatory response to each of these techniques.

Pentraxin 3 and other inflammatory biomarkers related to atrial fibrillation in cardiac surgery

Objectives:

The aim was to evaluate the association between perioperative inflammatory biomarkers and atrial fibrillation (AF) in cardiac surgical patients.

Methods:

Forty-two patients undergoing cardiac surgery were divided into three groups according to the occurrence of AF: Group A (n = 22) – patients with no AF, Group B (n = 11) – patients with new onset AF postoperatively and Group C (n = 9) – patients with preoperative history of atrial fibrillation. The serum levels of PTX3, CRP, TLR2, IL-8, IL-18, sFas, MMP-7 and MMP-8 were measured at the following time points: before surgery, immediately and 6 h after surgery and on the 1st, 3rd and 7th postoperative days (POD).

Results:

Serum levels of PTX3 showed a significant difference between Groups A and C on the 3rd POD (p<0.05) and on the 7th POD (p<0.0001). IL-8 levels were different between Groups A and C immediately after surgery (p<0.05), 6 hours after surgery (p<0.05) and on the 3rd POD (p<0.05). There was a difference between Groups B and C on the 1st POD in IL-8 levels (p<0.05). The sFas levels differed between Groups A and C on the 3rd POD (p<0.01) and the 7th POD (p<0.05). There was also a difference on the 7th POD (p<0.05) between the Groups B and C. No significant differences between the groups was seen for other biomarkers.

Conclusion:

This study demonstrates significantly different dynamics of PTX3, IL-8 and sFas levels after cardiac surgery in relation to AF.

Do preoperative C-reactive protein and mean platelet volume levels predict development of postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass grafting?

Introduction

Atrial fibrillation (AF) after coronary artery bypass grafting (CABG) operation is associated with increased risk of prolonged hospitalisation, health expenses and adverse clinical outcomes.

Aim

To investigate the relationship of atrial fibrillation after an isolated coronary artery bypass operation with levels of mean platelet volume and C-reactive protein.

Material and methods

Among 1240 patients who underwent operations for isolated coronary artery bypass grafting with cardiopulmonary bypass between January 2007 and May 2014, 1138 (91.8%) patients with preoperative normal sinusal rhythm were enrolled in the study. Patients were assigned to group 1 (n = 294) comprising patients who developed atrial fibrillation in the first 72 postoperative hours or group 2 (n = 844) comprising patients who remained in normal sinusal rhythm in the postoperative period.

Results

The incidence of postoperative atrial fibrillation was 25.8%. The preoperative mean platelet volume (fl) and C-reactive protein (mg/dl) values in group 1 were 9.1 ±0.5 and 1.1 ±0.9 respectively, while these values were 8.3 ±0.6 and 0.5 ±0.3 respectively in group 2, which was statistically significant (p = 0.0001). Length of stay in the hospital (p = 0.0001) was higher in group 1. The values of mean platelet volume (fl) and mean C-reactive protein (mg/dl) were 9.9 ±0.9 and 30.9 ±3.4 respectively in group 1, while the values of mean platelet volume (fl) and mean C-reactive protein (mg/dl) were 8.8 ±0.6 and 24.9 ±4.8 respectively in group 2 (p = 0.0001 for mean platelet volume, p = 0.0001 for C-reactive protein). The difference between the groups was statistically significant in terms of postoperative neurologic events (p = 0.0001) and hospital mortality (p = 0.001). Increased C-reactive protein and mean platelet volume levels were found to be independent predictors of postoperative atrial fibrillation.

Conclusions

In our study, elevated preoperative mean platelet volume and C-reactive protein levels were associated with development of postoperative atrial fibrillation.

Hemoglobin-associated oxidative stress in the pericardial compartment of postoperative cardiac surgery patients

Atherosclerosis and valvular heart disease often require treatment with corrective surgery to prevent future myocardial infarction, ischemic heart disease, and heart failure. Mechanisms underlying the development of the associated complications of surgery are multifactorial and have been linked to inflammation and oxidative stress, classically as measured in the blood or plasma of patients. Postoperative pericardial fluid (PO-PCF) has not been investigated in depth with respect to the potential to induce oxidative stress. This is important because cardiac surgery disrupts the integrity of the pericardial membrane surrounding the heart and causes significant alterations in the composition of the pericardial fluid (PCF). This includes contamination with hemolyzed blood and high concentrations of oxidized hemoglobin, which suggests that cardiac surgery results in oxidative stress within the pericardial space. Accordingly, we tested the hypothesis that PO-PCF is highly pro-oxidant and that the potential interaction between inflammatory cell-derived hydrogen peroxide with hemoglobin is associated with oxidative stress. Blood and PCF were collected from 31 patients at the time of surgery and postoperatively from 4 to 48 h after coronary artery bypass grafting, valve replacement, or valve repair (mitral or aortic). PO-PCF contained high concentrations of neutrophils and monocytes, which are capable of generating elevated amounts of superoxide and hydrogen peroxide through the oxidative burst. In addition, PO-PCF primed naive neutrophils resulting in an enhanced oxidative burst upon stimulation. The PO-PCF also contained increased concentrations of cell-free oxidized hemoglobin that was associated with elevated levels of F2α isoprostanes and prostaglandins, consistent with both oxidative stress and activation of cyclooxygenase. Lastly, protein analysis of the PO-PCF revealed evidence of protein thiol oxidation and protein carbonylation. We conclude that PO-PCF is highly pro-oxidant and speculate that it may contribute to the risk of postoperative complications.

Perioperative use of a beta blocker in coronary artery bypass grafting

OBJECTIVES

Atrial fibrillation after cardiac surgery is associated with increases in the risk of complications, length of intensive care unit stay, and cost of care. Beta blockers are effective for controlling myocardial ischemia and arrhythmia and suppressing inflammatory cytokines. The purpose of this study was to examine the effect of administrating a short-acting beta-adrenoceptor antagonist, landiolol, on postoperative atrial fibrillation.

METHODS

136 patients undergoing off-pump coronary artery bypass grafting were single-blindly assigned randomly to landiolol (n = 68) and non-landiolol (control, n = 68) groups. In the landiolol group, the beta blocker was administered from the beginning of the operation until postoperative day 2. The primary endpoint was the incidence of atrial fibrillation until postoperative day 7, and the secondary endpoints were the postoperative levels of troponin I, creatine kinase MB-isoenzyme, and C-reactive protein.

RESULTS

The incidence of atrial fibrillation was significantly lower in the landiolol group compared to the control group (13/68, 19% vs. 25/68, 37%, p = 0.02, logrank test). Landiolol also significantly reduced the postoperative peak C-reactive protein level compared to the control group (132 ± 55.4 vs. 161 ± 50.9 mgċL(-1), p = 0.004).

CONCLUSION

Low-dose continuous infusion of landiolol reduced the incidence of postoperative atrial fibrillation, and significantly suppressed inflammation.

Inflammation and C-reactive protein in atrial fibrillation: cause or effect?

Atrial fibrillation is associated with substantial morbidity and mortality rates. The incompletely understood pathogenesis of this cardiac dysrhythmia makes it difficult to improve approaches to primary and secondary prevention. Evidence has accumulated in regard to a relationship between inflammation and atrial fibrillation. Investigators have correlated the dysrhythmia with myocarditis, pericardiotomy, and C-reactive protein levels, suggesting that inflammation causes atrial fibrillation or participates in its onset and continuation. Conversely, other investigators suggest that atrial fibrillation induces an inflammatory response. In this review, we summarize and critically discuss the nature and clinical role of inflammation and C-reactive protein in atrial fibrillation.

Postoperative atrial fibrillation: incidence, mechanisms, and clinical correlates

Atrial fibrillation is the most commonly encountered arrhythmia after cardiac surgery. Although usually self-limiting, it represents an important predictor of increased patient morbidity, mortality, and health care costs. Numerous studies have attempted to determine the underlying mechanisms of postoperative atrial fibrillation (POAF) with varied success. A multifactorial pathophysiology is hypothesized, with inflammation and postoperative β-adrenergic activation recognized as important contributing factors. The management of POAF is complicated by a paucity of data relating to the outcomes of different therapeutic interventions in this population. This article reviews the literature on epidemiology, mechanisms, and risk factors of POAF, with a subsequent focus on the therapeutic interventions and guidelines regarding management.

Inflammation in new-onset atrial fibrillation after cardiac surgery: a systematic review

BACKGROUND

Postoperative new-onset atrial fibrillation (PNAF) is the most common complication following cardiac surgery. The pathogenesis of PNAF is multifactorial. The concept of the postoperative inflammatory response, as a potential underlying mechanism has been extensively studied. This review aims to provide a comprehensive summary of literature relevant to the association between the inflammatory response following cardiac surgery and PNAF.

DESIGN

MEDLINE, EMBASE and the Cochrane Central Register were systematically reviewed by two independent investigators for studies published between January 1980 and May 2012, in which an association between serum markers of inflammation and PNAF was evaluated, or the effect of drugs with anti-inflammatory properties on the risk of PNAF.

RESULTS

Sixty-three studies met selection criteria (39 observational and 24 randomized studies) including 27,363 patients. The mean incidence of PNAF after cardiac surgery was 25·5%. Elevated levels of various inflammatory mediators were associated with PNAF, and the most consistent association was found between white blood cell count and PNAF. Of the drugs with anti-inflammatory properties, statins gave the best protective effect against PNAF, followed by anti-oxidants, steroids and colchicine. Nonsteroidal anti-inflammatory drugs did not prevent PNAF significantly.

CONCLUSION

The postoperative inflammation response may play a role in the pathogenesis of PNAF. However, of the inflammation biomarkers, only elevated white blood cell count reliably predicts PNAF. Pre- and perioperative use of statins and several other drugs with anti-inflammatory properties reduce the incidence of PNAF.

Landiolol hydrochloride for prevention of atrial fibrillation after cardiac surgery: a meta-analysis

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmic complication after cardiac surgery. Several studies have compared the efficacy of landiolol and placebo or other agents in preventing new-onset AF in patients after cardiac surgery. In this study, we conducted a meta-analysis to determine whether landiolol is effective in preventing new-onset AF after cardiac surgery.

METHODS AND RESULTS

Five randomized controlled trials and two retrospective analyses were included in this study. The clinical outcomes of interest were the occurrence of AF after cardiac surgery and major complications. Meta-analysis was performed using RevMan 5.0.18 software, and pooled estimates of the effect were reported as risk ratios (RR) with 95% confidence intervals (CI). The results of this meta-analysis indicate that landiolol is significantly associated with a decreased risk of occurrence of AF after cardiac surgery (RR = 0.33; 95% CI: 0.23-0.48; P < 0.00001) and is not associated with an increased risk of major complications (RR = 0.79; 95% CI: 0.43-1.45; P = 0.45) compared with the control group.

CONCLUSION

Landiolol administration in the perioperative period can reduce the occurrence of AF after cardiac surgery without increasing the risk of major complications. It can be used to prevent new-onset AF safely after cardiac surgery.

Usefulness of right ventricular dysfunction to predict new-onset atrial fibrillation following coronary artery bypass grafting

Postoperative atrial fibrillation (AF) is a serious yet common complication after coronary artery bypass grafting (CABG) surgery. Risk factors for postoperative AF have been identified, including echocardiographic parameters, and these are relied on to implement preventative strategies that reduce the incidence of AF. There has yet to be a study examining the impact of echocardiographic right-sided cardiac parameters on the prediction of postoperative AF. Thus, a panel of right-sided cardiac parameters was measured in a cohort of patients undergoing isolated CABG surgery, excluding those who did not have echocardiographic assessment within 30 days before surgery and those with any history of AF. The primary outcome was postoperative AF defined as any episode of AF requiring treatment during the index hospitalization. Postoperative AF occurred in 197 of 768 patients (25.6%); these were older and more likely to have hypertension and chronic kidney disease. After adjustment for clinical and echocardiographic variables, left atrial volume index ≥34 ml/m(2) (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.36 to 2.87), abnormal right ventricular myocardial performance index (OR 1.50, 95% CI 1.01 to 2.24), and advancing age (OR 1.05, 95% CI 1.03 to 1.07) were found to be independent predictors of postoperative AF. In conclusion, right ventricular myocardial performance index is a novel predictor of postoperative AF in patients undergoing isolated CABG surgery and appears to be additive to established risk factors such as age and left atrial volume.

Is there any relationship between RDW levels and atrial fibrillation in hypertensive patient?

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac arrhythmia and increases the risk of stroke and death. Patients with hypertensive have an increased risk of developing atrial fibrillation. RDW (Red blood cell distribution width) levels are elevated in cardiovascular disorders including heart failure, stable coronary disease, acute coronary syndrome, slow coronary flow and stroke.

OBJECTIVE

We aimed to investigate the relation between RDW and AF in patients with hypertensive.

METHOD

We retrospectively examined 126 consecutive hypertensive patients (63 hypertensive patients with AF and 63 hypertensive patients without AF matched with age and sex.

RESULTS

The mean age of the study population was 71,09± 8,50 (af group) and 70,97±8,24 (non-af group) years. RDW level was different among patients with atrial fibrillation and without atrial fibrillation.(15,13±1,58 and 14,05±1,15 p<001) . Logistic regression analysis showed that RDW and left atrial dimension were only independently risk factory associated with atrial fibrillation. (Rdw odds ratio:1,846 CI; 1,221-2,793 p<0,05). Roc curve analyses were applied to determine the cut-off point. Cut-off point was at 14,195 and Sensitive, specificity was %71,4, %56 respectively.

CONCLUSION

RDW levels were higher in hypertensive patients with atrial fibrillation. An increased RDW level in the patient with hypertension may alert physician on developing or presence of atrial fibrillation.

Comparison of rosuvastatin versus atorvastatin for preventing postoperative atrial fibrillation

BACKGROUND

Postoperative atrial fibrillation (AF) following cardiac surgery is associated with an increased risk of stroke, prolonged hospitalization, and increased costs. Statin therapy is associated with a lower incidence of postoperative AF. We aimed to compare the preventive effects of rosuvastatin and atorvastatin on postoperative AF.

METHODS

This study included 168 patients undergoing elective cardiac surgery with cardiopulmonary bypass. Patients were divided into 2 groups according to treatment of statin. Group 1 (n = 96) was patients receiving atorvastatin, and group 2 (n = 72) was patients receiving rosuvastatin. Postoperative electrocardiographs (ECGs) and telemetry strips were examined for AF within postoperative period during hospitalization.

RESULTS

The incidences of postoperative AF were 17.9% (n = 17) in group 1 and 22.2% (n = 16) in group 2 (P = .48). Left ventricular end-diastolic diameter (LVEDD) and ejection fraction (EF) were not different between groups. Incidence of diabetes, hypertension, hyperlipidemia, smoking, myocardial infarction in past medical history, family history of atherosclerosis, male sex, drug use, and perioperative features were similar between groups.

CONCLUSIONS

The present study revealed that preoperative rosuvastatin or atorvastatin treatment did not have a different effect in preventing postoperative AF.

Pentraxin 3 is a local inflammatory marker in atrial fibrillation

Increasing evidence indicates that inflammation contributes to the pathogenesis of atrial fibrillation (AF). Pentraxin 3 (PTX3) is produced abundantly in local inflammatory lesions while C-reactive protein (CRP) is produced mainly in the liver. In this study, we investigated whether a local level of PTX3 might be a sensitive marker for the local inflammation of AF. Blood from the periphery and left atrial appendage (LAA) was sampled from 23 patients with AF undergoing pulmonary vein isolation, and from 10 control subjects with Wolff-Parkinson-White syndrome. We measured peripheral and LAA plasma concentrations of CRP, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and PTX3. Plasma PTX3 concentrations in both locations were higher in patients with AF than in control subjects. PTX3 concentrations were significantly higher in the LAA than the periphery in patients with AF (3.7 ± 1.4 vs 3.3 ± 1.2 ng/ml, P < 0.01), but not in control subjects (2.4 ± 0.5 vs 2.4 ± 0.5 ng/ml, not significant). Patients and controls showed no significant differences in CRP, IL-6, or TNF-α concentrations between the periphery and LAA. Interestingly, there was a significant positive correlation between LAA plasma concentrations of PTX3 and left atrial volume (r = 0.55, P < 0.01). These data demonstrate that local PTX3 production in the left atrium might reflect the local inflammation of AF.

Association of perioperative troponin and atrial fibrillation after coronary artery bypass grafting

OBJECTIVES

Prediction of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) may lead to preventive or early treatment and improved outcome. We investigated the association of serial perioperative cardiac troponin T (cTNT) measurements with postoperative AF in patients undergoing CABG.

METHODS

In a retrospective analysis of prospectively collected data, 3148 patients undergoing elective CABG were evaluated. cTNT values were routinely determined before the start of surgery (cTNT0), at arrival on the intensive care unit (cTNT1) and 8-12 h later (cTNT2). Measurement of cTNT was continued until the peak value was reached. The development of AF during hospital stay was scored. The association between cTNT (cTNT0, cTNT1, cTNT2 and cTNTmax in first 48 h) and AF was calculated in univariable and multivariable analysis.

RESULTS

AF occurred in 1080 (34%) patients. cTNT0, cTNT2 and cTNTmax were significantly and positively associated with postoperative AF (P < 0.001) in a univariable analysis, whereas a trend was seen for cTNT1 (P = 0.051). Advanced age, inotropic support and postoperative infection were independently associated with postoperative AF after logistic regression analysis, but cTNT was not. Categorizing patients by inotropic support into categories of inotropic support duration (none, <48 h, >48 h), the mean cTNT values were significantly higher among patients with AF in each category (all P < 0.001). Perioperative cTNT was significantly higher in patients with postoperative complications, longer hospital stay and reduced in-hospital survival.

CONCLUSIONS

Perioperative cTNT is univariably associated with postoperative AF after CABG, but not independently. Further, no clinically useful cut-off point for preventive or early treatment could be identified. Both perioperative cTNT and postoperative AF are associated with negative outcome and prolonged hospital stay.

Impact of Atrial Fibrillation On Cardiovascular Mortality in the Setting of Myocardial Infarction

Atrial fibrillation (AF) commonly occurs in patient with acute myocardial infarction (AMI). Potential triggers for AF development in this setting includes reduced left ventricular function, advanced diastolic dysfunction and mitral regurgitation leading to elevated left atrial pressures and atrial stretch. Other triggering mechanisms include inflammation and atrial ischemia. Multiple studies have shown that AF in patients with is associated with increased mortality. However, whether AF is a risk marker or a causal mediator of death remains controversial. There is relative dearth of data with regard to optimal management of AF in the setting of acute coronary syndromes. Patients with AMI who develop AF are at increased risk of stroke. However, the issue of the most appropriate antithrombotic regimens is complex given the need to balance stroke prevention against recurrent coronary events or stent thrombosis and the risk of bleeding. Presently, 'triple therapy' consisting of dual antiplatelet agents plus oral anticoagulants for 3-6 months or longer has been recommended for patients at moderate-high risk of stroke. Atrial fibrillation (AF), the most common sustained arrhythmia seen in clinical practice, often coincides with acute myocardial infarction (AMI), with a reported incidence ranging between 7% and 21%.[1] The development of atrial fibrillation in the acute phase of AMI may aggravate ischemia and heart failure, lead to clinical instability and adversely affect outcome. In the following we will review the pathophysiology, clinical characteristics and importance, and management of AF occurring in the setting of AMI.

Serum γ-glutamyltransferase activity in patients with nonvalvular atrial fibrillation

Procoagulant and prothrombotic states in patients with chronic atrial fibrillation (AF) are higher than those in patients with normal sinus rhythm. We assessed and compared serum γ-glutamyltranferase (GGT) activity in elderly patients with nonvalvular AF and control participants with normal sinus rhythm. Consecutive patients (n = 81) with nonvalvular chronic AF and 210 age- and gender-matched control participants with normal sinus rhythm were retrospectively included in the study from the outpatient cardiology clinic. Presence of coronary artery disease, hypertension, gender, hyperlipidemia, diabetes mellitus, smoking status, glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and ejection fraction were comparable between the 2 groups (P > .05 for all). However, serum γ-GGT activity was significantly higher (P = .003) in patients with AF compared with those without AF. We have shown that serum γ-GGT activity is independently associated with chronic nonvalvular AF.

Comprehensive risk reduction in patients with atrial fibrillation: emerging diagnostic and therapeutic options--a report from the 3rd Atrial Fibrillation Competence NETwork/European Heart Rhythm Association consensus conference

While management of atrial fibrillation (AF) patients is improved by guideline-conform application of anticoagulant therapy, rate control, rhythm control, and therapy of accompanying heart disease, the morbidity and mortality associated with AF remain unacceptably high. This paper describes the proceedings of the 3rd Atrial Fibrillation NETwork (AFNET)/European Heart Rhythm Association (EHRA) consensus conference that convened over 60 scientists and representatives from industry to jointly discuss emerging therapeutic and diagnostic improvements to achieve better management of AF patients. The paper covers four chapters: (i) risk factors and risk markers for AF; (ii) pathophysiological classification of AF; (iii) relevance of monitored AF duration for AF-related outcomes; and (iv) perspectives and needs for implementing better antithrombotic therapy. Relevant published literature for each section is covered, and suggestions for the improvement of management in each area are put forward. Combined, the propositions formulate a perspective to implement comprehensive management in AF.

High-sensitivity C-reactive protein, statin therapy, and risks of atrial fibrillation: an exploratory analysis of the JUPITER trial

AIMS

Increasing evidence supports a role for inflammation in promoting atrial fibrillation (AF) and statins have anti-inflammatory effects that may be relevant for the prevention of AF. However, studies of statin therapy and incident AF have yielded mixed results and not focused on individuals with an underlying pro-inflammatory response. We studied whether high-sensitivity C-reactive protein is associated with incident AF and whether treatment with rosuvastatin is associated with a lower incidence of AF compared with placebo.

METHODS AND RESULTS

We randomized men and women with LDL cholesterol <130 mg/dL and high-sensitivity C-reactive protein ≥2 mg/L to receive either rosuvastatin 20 mg daily or placebo. Atrial fibrillation was determined from treatment-blind adverse event reports. Among 17 120 participants without prior history of arrhythmia, each increasing tertile of baseline high-sensitivity C-reactive protein was associated with a 36% increase in the risk of developing AF (95% CI: 1.16-1.60; P-trend < 0.01). Allocation to rosuvastatin when compared with placebo was associated with a 27% reduction in the relative risk of developing AF during the trial period; specifically, AF was reported among 138 participants in the placebo group and 100 in the rosuvastatin group (incidence rate 0.78 vs. 0.56/100 person-years, HR: 0.73, 95% CI: 0.56-0.94, P = 0.01). The exclusion of participants who developed a major cardiovascular event prior to the report of AF yielded similar results.

CONCLUSION

Within the JUPITER trial cohort of individuals selected for underlying inflammation, increasing levels of high-sensitivity C-reactive protein were associated with an increased risk of incident AF and random allocation to rosuvastatin significantly reduced that risk.

Plasma n-3 and n-6 fatty acids and the incidence of atrial fibrillation following coronary artery bypass graft surgery

BACKGROUND

The anti-inflammatory or anti-arrhythmic effects of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) may decrease the risk of postoperative atrial fibrillation (POAF), but interventional studies have yielded conflicting results. We examined the association between n-3 LC-PUFA and n-6 LC-PUFA in plasma phospholipids (PL) and POAF in patients undergoing coronary artery bypass grafting (CABG).

METHODS

A total of 125 patients undergoing CABG were enrolled in the study. The levels of fatty acids in PL were measured preoperatively and on the third postoperative day. The endpoint was defined as POAF lasting ≥5 min. The incidence of POAF was compared between quartiles of the level of each fatty acid in plasma PL by univariate and multivariable analysis.

RESULTS

The incidence of POAF was 49·6%. By univariate analysis, the incidence of POAF increased significantly with each higher quartile of pre- and postoperative docosahexaenoic acid (DHA) and diminished significantly with each higher quartile of pre- and postoperative arachidonic acid (AA). For postoperative total n-3 LC-PUFA, there was a significant U-curve relationship where the second quartile had the lowest incidence of POAF or 25·8%. In multivariable analysis, this U-curve relationship between n-3 LC-PUFA levels and POAF risk was not significant, whereas the association between POAF and DHA or AA remained statistically significant.

CONCLUSIONS

This study suggests that n-3 LC-PUFA supplements might prevent POAF in CABG patients with low baseline levels of these fatty acids in plasma PL, but may be harmful in those with high levels. AA may play an important role in electrophysiological processes.

Post-operative atrial fibrillation: a maze of mechanisms

Post-operative atrial fibrillation (POAF) is one of the most frequent complications of cardiac surgery and an important predictor of patient morbidity as well as of prolonged hospitalization. It significantly increases costs for hospitalization. Insights into the pathophysiological factors causing POAF have been provided by both experimental and clinical investigations and show that POAF is ‘multi-factorial’. Facilitating factors in the mechanism of the arrhythmia can be classified as acute factors caused by the surgical intervention and chronic factors related to structural heart disease and ageing of the heart. Furthermore, some proarrhythmic mechanisms specifically occur in the setting of POAF. For example, inflammation and beta-adrenergic activation have been shown to play a prominent role in POAF, while these mechanisms are less important in non-surgical AF. More recently, it has been shown that atrial fibrosis and the presence of an electrophysiological substrate capable of maintaining AF also promote the arrhythmia, indicating that POAF has some proarrhythmic mechanisms in common with other forms of AF. The clinical setting of POAF offers numerous opportunities to study its mechanisms. During cardiac surgery, biopsies can be taken and detailed electrophysiological measurements can be performed. Furthermore, the specific time course of POAF, with the delayed onset and the transient character of the arrhythmia, also provides important insight into its mechanisms.

This review discusses the mechanistic interaction between predisposing factors and the electrophysiological mechanisms resulting in POAF and their therapeutic implications.