Do high levels of n-3 polyunsaturated fatty acids in cell membranes increase the risk of postoperative atrial fibrillation?

Comprehensive Analysis of Factors Associated with New Episode of Postoperative Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

The aim of the study was to perform a comprehensive fundamental analysis of the factors of inflammation, oxidative stress, fibrosis, myocardial dysfunction, ischemia and omega-3 index associated with postoperative atrial fibrillation (POAF) after coronary artery bypass graft (CABG) surgery in patients with coronary artery disease. The study involved 158 patients who were admitted to the hospital to undergo CABG surgery. Patients were divided into two groups: group 1 comprised 111 patients without POAF (82% males, median age-62.0 (56.0; 66.0) years), and group 2 comprised 47 patients with POAF (84.4% males, median age-65.0 (61.0; 70.0) years). POAF occurred 5.2 (2.0; 7.0) days after CABG. In all the patients, we evaluated laboratory tests before and 3-4 days after CABG. All the patients also underwent echocardiography. According to results of multifactorial regression analysis, the odds ratio of POAF development for left atrial diameter >41 mm was 4.3 (95% confidence interval (CI) 2.0-9.7, p < 0.001), interleukin (IL)-6 postoperative levels >22.07 pg/mL-3.0 (95% CI 1.4-8.2, p = 0.006), IL-8 postoperative levels >9.67 pg/mL-2.3 (95% CI 1.2-7.3, p = 0.006), superoxide dismutase postoperative levels in plasma >1100.5 U/g-3.2 (95% CI 1.4-9.2, p = 0.03), glutathione postoperative levels ≤0.194 micromole/g of hemoglobin-1.9 (95% CI 1.2-6.3, p < 0.001), glutathione peroxidase postoperative levels ≤17.36 millimole/g of hemoglobin-2.2 (95% CI 1.1-8.2, p < 0.001), glutathione reductase postoperative levels ≤2.99 millimole/g of hemoglobin-2.3 (95% CI, 1.1-5.7, p < 0.001), malondialdehyde postoperative levels >1.25 micromole/g of hemoglobin-2.0 (95% CI, 1.2-7.9, p < 0.001), NO postoperative levels in plasma >36.4 micromole/L-1.5 (95% CI, 1.1-5.9, p < 0.001) and omega-3 index ≤1.59%-2.6 (95% CI 1.5-9.1, p < 0.001). Our study showed that increased left atrial diameter, high postoperative levels of inflammatory factors, oxidative stress, fibrosis indicators and omega-3 index were associated with POAF in patients who underwent CABG.

A Prediction Rule Including Interleukin-6 in Pericardial Drainage Improves Prediction of New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting

OBJECTIVE

To test the hypothesis that a prediction rule including levels of interleukin-6 in pericardial drainage (pdIL-6) would improve the discrimination in classifying patients undergoing coronary artery bypass grafting (CABG) into different postoperative atrial fibrillation (POAF) risk levels.

DESIGN

Prospective cohort study.

SETTING

A university-affiliated tertiary hospital.

PARTICIPANTS

Patients undergoing CABG.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We prospectively recruited patients who underwent CABG into derivation and validation cohorts. The independent predictors were identified in the derivation cohort using multiple logistic regression and tested in the validation cohort. The performance of the predictive model was tested using area under the receiver operating characteristic curve (AUC) in both cohorts. A prediction rule was created by assigning points to each predictor. Patients were classified in various risk levels according to their total risk scores. We enrolled 302 and 207 patients in the derivation and validation cohorts, respectively. Multiple logistic regression analysis identified six predictors: age ≥61 y, left atrial diameter ≥49 mm, right atrial diameter ≥45 mm, number of grafts ≥3, and serum uric acid ≥226 µmol/L and pdIL-6 levels ≥166 ng/mL at postoperative 12 h. The AUC of the model was 0.78 and 0.77 for the derivation and validation cohort, respectively, which was greatly increased by adding pdIL-6. Patients were stratified into low-risk, moderate-risk and high-risk groups.

CONCLUSIONS

A POAF prediction rule including pdIL-6 had good performance for stratifying CABG patients into various risk groups for POAF. The inclusion of pdIL-6 resulted in clinically meaningful improvement in risk prediction.

A novel case of impaired C-reactive protein response following open-heart surgery: A case report and review of the literature

BACKGROUND

C-reactive protein (CRP) is expected to increase in response to a range of inflammatory stimuli such as infections or extensive tissue trauma.

CASE REPORT

We present a novel case of severely impaired CRP response following NSTEMI, influenza A infection and open-heart surgery in which serum CRP concentrations remained < 1 mg/L during an observational period of 28 days.

CONCLUSION

To our knowledge, no previous publications exists describing patients with a lack of CRP response following cardiothoracic surgery. We believe this to be a novel finding warranting further investigations regarding the etiology and prevalence of this phenomenon.

Novel Combined Antioxidant Strategy against Hypertension, Acute Myocardial Infarction and Postoperative Atrial Fibrillation

Reactive oxygen species (ROS) play a physiological role in the modulation of several functions of the vascular wall; however, increased ROS have detrimental effects. Hence, oxidative stress has pathophysiological impacts on the control of the vascular tone and cardiac functions. Recent experimental studies reported the involvement of increased ROS in the mechanism of hypertension, as this disorder associates with increased production of pro-oxidants and decreased bioavailability of antioxidants. In addition, increased ROS exposure is found in ischemia-reperfusion, occurring in acute myocardial infarction and cardiac surgery with extracorporeal circulation, among other settings. Although these effects cause major heart damage, at present, there is no available treatment. Therefore, it should be expected that antioxidants counteract the oxidative processes, thereby being suitable against cardiovascular disease. Nevertheless, although numerous experimental studies agree with this notion, interventional trials have provided mixed results. A better knowledge of ROS modulation and their specific interaction with the molecular targets should contribute to the development of novel multitarget antioxidant effective therapeutic strategies. The complex multifactorial nature of hypertension, acute myocardial infarction, and postoperative atrial fibrillation needs a multitarget antioxidant strategy, which may give rise to additive or synergic protective effects to achieve optimal cardioprotection.

The role of the right atrium in development of postoperative atrial fibrillation: A speckle tracking echocardiography study

PURPOSE

Atrial fibrillation (AF) is relatively frequent in the postoperative period, and is associated with an increased frequency of adverse events. The role of right atrial (RA) volume and functions in the development of AF is unknown. In this study, we investigated the effect of RA echocardiographic indices on AF development in the postoperative period.

METHOD

We enrolled 142 consecutive patients who underwent coronary artery bypass surgery, and assigned them into two groups depending on the occurrence or not of AF development in the postoperative period.

RESULTS

A propensity score matching analysis was performed to balance the groups, and 37 pairs were eventually included in the analysis. The median age was 67.5 (63-75) years and 73.3% of them were males. In the univariate analysis, right atrial volume index (RAVi), right atrial strain during reservoir phase (RASr), left ventricular global longitudinal strain, right ventricular strain, left atrial volume index, left atrial strain during reservoir phase, and systolic pulmonary artery pressure were associated with AF development. In the regression analysis, we found that RAVi (OR: 3.1, 95% CI: 2.2-6.3, P: .033) and RASr (OR: 0.82, 95% CI: 0.67-0.93, P: .048) were independent predictors of AF development.

CONCLUSIONS

RA structure and functions are closely associated with AF development in the postoperative period, and screening of RA functions prior to surgery may be useful for preventing AF development.

Atrial fibrillation and its complications in arterial hypertension: The potential preventive role of ω-3 polyunsaturated fatty acids

Atrial fibrillation (AF) is the most common type of arrhythmia in the general population with a prevalence that reaches one third of patients with arterial hypertension. Several risk factors frequently associated with hypertension predispose the myocardium to AF by inducing atrial inflammation and fibrosis and altering atrial electrical and mechanical characteristics. AF influences the quality of life of hypertensive patients since it increases incidence of stroke and other thromboembolic events, and mortality. Polyunsaturated fatty acids of the ω-3 family (ω-3 PUFA) have been demonstrated to be beneficial in cardiovascular disease prevention by reducing plasma lipids and blood pressure levels and decreasing the risk of sudden death. These fatty acids can act as potent anti-inflammatory and anti-arrhythmic agents. Many studies have investigated a possible preventive effect of ω-3 PUFA on incident AF reporting contradictory results. This article overviews the evidence currently available on this important topic and provides some conclusive remarks on the possibility that these fatty acids could be beneficial in hypertensive patients.

Immunomodulation by dietary long chain omega-3 fatty acids and the potential for adverse health outcomes

Recommendations to consume fish for prevention of cardiovascular disease (CVD), along with the U.S. Food and Drug Administration-approved generally recognized as safe (GRAS) status for long chain omega-3 fatty acids, may have had the unanticipated consequence of encouraging long-chain omega-3 (ω-3) fatty acid [(eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] supplementation and fortification practices. While there is evidence supporting a protective role for EPA/DHA supplementation in reducing sudden cardiac events, the safety and efficacy of supplementation with LCω-3PUFA in the context of other disease outcomes is unclear. Recent studies of bacterial, viral, and fungal infections in animal models of infectious disease demonstrate that LCω-3PUFA intake dampens immunity and alters pathogen clearance and can result in reduced survival. The same physiological properties of EPA/DHA that are responsible for the amelioration of inflammation associated with chronic cardiovascular pathology or autoimmune states, may impair pathogen clearance during acute infections by decreasing host resistance or interfere with tumor surveillance resulting in adverse health outcomes. Recent observations that high serum LCω-3PUFA levels are associated with higher risk of prostate cancer and atrial fibrillation raise concern for adverse outcomes. Given the widespread use of supplements and fortification of common food items with LCω-3PUFA, this review focuses on the immunomodulatory effects of the dietary LCω-3PUFAs, EPA and DHA, the mechanistic basis for potential negative health outcomes, and calls for biomarker development and validation as rational first steps towards setting recommended dietary intake levels.