Post-cardiac Surgery Atrial Fibrillation Research Articles

Neuromodulation for Atrial Fibrillation Control.

Trigger and functional substrate are related to the tone of autonomic nervous system, and the role of the autonomic nerve is more significant in paroxysmal atrial fibrillation (AF) compared to non-paroxysmal AF. We have several options for neuromodulation to help to manage patients with AF. Neuromodulation targets can be divided into efferent and afferent pathways. On the efferent side, block would be an intuitive approach. However, permanent block is hard to achieve due to completeness of the procedure and reinnervation issues. Temporary block such as botulinum toxin injection into ganglionated plexi would be a possible option for post-cardiac surgery AF. Low-level subthreshold stimulation could also prevent AF, but the invasiveness of the procedure is the barrier for the general use. On the afferent side, block is also an option. Various renal denervation approaches are currently under investigation. Auditory vagus nerve stimulation is one of the representative low-level afferent stimulation methods. This technique is noninvasive and easy to apply, so it has the potential to be widely utilized if its efficacy is confirmed.

Patterns of cytokine release and association with new onset of post-cardiac surgery atrial fibrillation.

Postoperative Atrial Fibrillation (POAF) is a common complication of cardiac surgery, associated with increased mortality, stroke risk, cardiac failure and prolonged hospital stay. Our study aimed to assess the patterns of release of systemic cytokines in patients with and without POAF. A post-hoc analysis of the Remote Ischemic Preconditioning (RIPC) trial, including 121 patients (93 males and 28 females, mean age of 68 years old) who underwent isolated coronary artery bypass grafting (CABG) and aortic valve replacement (AVR). Mixed-effect models were used to analyze patterns of release of cytokines in POAF and non-AF patients. A logistic regression model was used to assess the effect of peak cytokine concentration (6 h after the aortic cross-clamp release) alongside other clinical predictors on the development of POAF. We found no significant difference in the patterns of release of IL-6 (p = 0.52), IL-10 (p = 0.39), IL-8 (p = 0.20) and TNF-α (p = 0.55) between POAF and non-AF patients. Also, we found no significant predictive value in peak concentrations of IL-6 (p = 0.2), IL-8 (p = >0.9), IL-10 (p = >0.9) and Tumour Necrosis Factor Alpha (TNF-α)(p = 0.6), however age and aortic cross-clamp time were significant predictors of POAF development across all models. Our study suggests no significant association exists between cytokine release patterns and the development of POAF. Age and Aortic Cross-clamp time were found to be significant predictors of POAF.

Deep-Learning for Epicardial Adipose Tissue Assessment With Computed Tomography: Implications for Cardiovascular Risk Prediction

BackgroundEpicardial adipose tissue (EAT) volume is a marker of visceral obesity that can be measured in coronary computed tomography angiograms (CCTA). The clinical value of integrating this measurement in routine CCTA interpretation has not been documented. ObjectivesThis study sought to develop a deep-learning network for automated quantification of EAT volume from CCTA, test it in patients who are technically challenging, and validate its prognostic value in routine clinical care. MethodsThe deep-learning network was trained and validated to autosegment EAT volume in 3,720 CCTA scans from the ORFAN (Oxford Risk Factors and Noninvasive Imaging Study) cohort. The model was tested in patients with challenging anatomy and scan artifacts and applied to a longitudinal cohort of 253 patients post-cardiac surgery and 1,558 patients from the SCOT-HEART (Scottish Computed Tomography of the Heart) Trial, to investigate its prognostic value. ResultsExternal validation of the deep-learning network yielded a concordance correlation coefficient of 0.970 for machine vs human. EAT volume was associated with coronary artery disease (odds ratio [OR] per SD increase in EAT volume: 1.13 [95% CI: 1.04-1.30]; P = 0.01), and atrial fibrillation (OR: 1.25 [95% CI: 1.08-1.40]; P = 0.03), after correction for risk factors (including body mass index). EAT volume predicted all-cause mortality (HR per SD: 1.28 [95% CI: 1.10-1.37]; P = 0.02), myocardial infarction (HR: 1.26 [95% CI:1.09-1.38]; P = 0.001), and stroke (HR: 1.20 [95% CI: 1.09-1.38]; P = 0.02) independently of risk factors in SCOT-HEART (5-year follow-up). It also predicted in-hospital (HR: 2.67 [95% CI: 1.26-3.73]; P ≤ 0.01) and long-term post–cardiac surgery atrial fibrillation (7-year follow-up; HR: 2.14 [95% CI: 1.19-2.97]; P ≤ 0.01). ConclusionsAutomated assessment of EAT volume is possible in CCTA, including in patients who are technically challenging; it forms a powerful marker of metabolically unhealthy visceral obesity, which could be used for cardiovascular risk stratification.

The ideal environment for the development of postcardiac surgery atrial fibrillation: evidence for endothelial activation and poor cell-cell interaction

Abstract Introduction The development of post-operative atrial fibrillation (POAF) after cardiac surgeryis associated with pre-existing endothelial activation and systemic inflammation due to adhesion and transmigration of leukocytes into the interstitium. The electrical remodelling associated with AF causes changes in connexins, resulting in ineffective electrical coupling between cells and thus ineffective cell-cell communication.There is also an association between the inflammatory state, and the presence of cardiac fibrosis, oxidative stress and myocyte apoptosis. Purpose Our aim was to investigate the pathophysiologicaland regulatory mechanisms of AF through endothelial activation and inflammatory status, as well as cell-cell interactions (connexins) in relation to POAF amongst a cohort of patients undergoing cardiac surgery. Methods We studied prospective patients who underwent CABG (52.9%) or cardiac valve (47.1%) surgery without previous documented AF. Patients with permanent AF who underwent CABG or cardiac valve surgery were also included as positive controls. Plasma samples were collected at baseline and 24 hours after surgery, to assess the impact of surgery. To detect endothelial activation, vascular cell adhesion protein-1 (VCAM-1 (CD106)) was evaluated by ELISA assay in plasma samples. Expression of connexin 40 and 43 were measured by inmunohistochemistry in atrial tissue samples. Results We included 117 patients (75.2% males, median age 67 [IQR 59.5–73.0] years), of whom17 (14.5%) patients had permanent AF; 27 (23.1%) developed POAF and 73 (62.4%) had no AF detected. We found higher baseline VCAM-1 levels versus 24-hour samples overall (p=0.001). When comparing groups, baseline VCAM-1 levels were higher in patients with permanent AF compared to non-AF (p=0.035); and in permanent AF compared to POAF (p=0.049). VCAM-1 levels at 24h followed the same trends between permanent AF and non-AF (p=0.001), and permanent AF versus POAF (p=0.013) (Table 1). VCAM-1 levels over the third tertile (i.e.>49.77 ng/ml) increased the risk of AF almost 3-fold (OR 2.85, 95% CI 1.06–7.70; p=0.039). There was a significant decrease in the expression of connexion 40 in patients with AF (ie. patients with permanent AF or POAF) compared to non-AF patients (1.00 [0.50–2.31] vs. 2.48 [1.94–3.00], p=0.044), while connexin 43 was non-significantly different (1.07 [0.41–1.75] vs. 2.00 [0.63–2.25], p=0.289) (Table 2). Conclusions VCAM-1 levels were upregulated in patients with permanent AF and POAF compared to patients without AF, and remained higher even after surgery, thus demonstrating a relevantendothelial activation. The pro-inflammatory state presented in these patients with AF, along with decreased connexin 40 expression impacting cell-to-cell conduction, suggests a potential combination for atrial remodelling and incident AF. Funding Acknowledgement Type of funding sources: None.

Preventive Role of Posterior Pericardiotomy in Early Post-Cardiac Surgery Atrial Fibrillation and Pericardial Collection

Preventive Role of Posterior Pericardiotomy in Early Post-Cardiac Surgery Atrial Fibrillation and Pericardial Collection

Statin and Postcardiac Surgery Atrial Fibrillation Prevention: A Systematic Review and Meta-Analysis.

Postoperative atrial fibrillation (POAF) is a frequently reported postcardiac surgery complication leading to increased in-hospital and long-term mortality rates. Many randomized controlled trials (RCTs) have recently suggested using statins to protect against POAF. Therefore, we performed a systematic literature search and meta-analysis in electronic databases for eligible studies published between January 2006 and January 2022. The principal inclusion criteria were as follows: RCTs' study design, statin-naive patients, total study participants ≥50 units, and statin pretreatment started no more than 21 days before cardiac surgery. In the primary analysis, statin pretreatment reduced the incidence of POAF compared with placebo. Analyzing different molecules, atorvastatin was associated with lower incidence of POAF but rosuvastatin was not. We therefore performed a sensitivity analysis excluding RCTs affected by important risk of biases. Thus, studies whose participants were ≥199 were those eligible for the secondary analysis. No statistically significant difference between statin pretreatment and placebo (OR 0.87; 95% CI: 0.71-1.07, P = 0.18) as well as for atorvastatin (OR 0.88; 95% CI: 0.61-1.28; P = 0.48; I 2 = 84%) and rosuvastatin (OR 0.87; 95% CI: 0.68-1.12, P = 0.29) was observed. To conclude, statin pretreatment before cardiac surgery is not associated with a significant reduction in POAF occurrence.

Anticoagulation management of post-cardiac surgery new-onset atrial fibrillation.

New-onset post-cardiac surgery atrial fibrillation (PCSAF) is a frequent complication with estimated incidence of 17% to 64%, depending on type of surgery. It is associated with higher mortality, morbidity, and predisposition to stroke and systemic embolism postoperatively. Standard care involves rate or rhythm control, in addition to antithrombotic therapy in those with history of stroke, transient ischemic attack, or high risk of systemic thromboembolism. However, risk of bleeding is not negligible, and treating physicians should weigh the risks and benefits before committing to postoperative anticoagulation therapy. More investigations are warranted to explore antithrombotic therapy benefit, particularly postoperative anticoagulation, considering the potentially self-limited nature of the arrhythmia and high risk of postoperative bleeding.

Stroke risk and anticoagulation in the setting of post-cardiac surgery atrial fibrillation: a systematic review of the literature

Postoperative atrial fibrillation (POAF) affects up to 50% of patients undergoing cardiac surgery. It remains unclear to what extent POAF increases the stroke risk and whether anticoagulation is warranted in this setting. The primary objective of this review was to conduct a systematic review of the evidence for a correlation between POAF and stroke. Further, we sought to evaluate the published evidence on anticoagulation in the setting of POAF to prevent stroke. To this end, we performed a comprehensive literature search to identify studies on POAF in patients undergoing cardiac surgery with stroke as an outcome. To date, eight meta-analyses providing pooled estimates of the stroke risk associated with POAF in patients undergoing cardiac surgery have been published. The reported pooled odds ratios range from 1.36 to 4.09 for unadjusted estimates. Additionally, five studies were identified that evaluated the impact of anticoagulation on stroke in the setting of POAF. Of these, three supported the use of anticoagulants, and two studies were inconclusive. This systematic review did not find strong supporting evidence that POAF is causally related to stroke, despite a strong correlation with comorbidities and all-cause mortality in the literature. Available evidence to date suggests an elevated risk of bleeding with no clear reduction in stroke or other thromboembolic events when anticoagulation is initiated in the setting of POAF. An upcoming randomized clinical trial by the Cardiothoracic Surgery Network group will hopefully provide clarification on the recommendations for anticoagulation in the setting of POAF after cardiac surgery.

Safety of Direct Oral Anticoagulants Compared to Warfarin for Atrial Fibrillation after Cardiac Surgery: A Systematic Review and Meta-Analysis

The evidence for use of direct oral anticoagulants (DOACs) in the management of post-operative cardiac surgery atrial fibrillation is limited and mostly founded on clinical trials that excluded this patient population. We performed a systematic review and meta-analysis of clinical trials and observational studies to evaluate the hypothesis that DOACs are safe compared to warfarin for the anticoagulation of patients with post-operative cardiac surgery atrial fibrillation. We searched PubMed, EMBASE, Web of Science, clinicaltrials.gov, and the Cochrane Library for clinical trials and observational studies comparing DOAC with warfarin in patients ≥18 years old who had post-cardiac surgery atrial fibrillation. Primary outcomes included stroke, systemic embolization, bleeding, and mortality. We performed a random-effects meta-analysis of all outcomes. The meta-analysis for the primary outcomes showed significantly lower risk of stroke with DOAC use (6 studies, 7143 patients, RR 0.64; 95% CI 0.50-0.81, I2: 0.0%) compared to warfarin, a trend towards lower risk of systemic embolization (4 studies, 7289 patients, RR 0.64, 95% CI 0.41-1.01, I2: 31.99%) and similar risks of bleeding (14 studies, 10182 patients, RR 0.91; 95% CI 0.74-1.10, I2: 26.6%) and mortality (12 studies, 9843 patients, relative risk [RR] 1.01; 95% CI 0.74-1.37, I2: 26.5%). Current evidence suggests that DOACs, compared to warfarin, in the management of atrial fibrillation after cardiac surgery is associated with lower risk of stroke and a strong trend for lower risk of systemic embolization, and no evidence of increased risk for hospital readmission, bleeding and mortality.

Optimising risk factors for atrial fibrillation post-cardiac surgery.

Postoperative atrial fibrillation (POAF) is an ongoing complication following cardiac surgery, with an incidence of 15%-60%. It is associated with substantial mortality and morbidity, as well increased hospital stays and healthcare costs. The pathogenesis is not fully understood, but the literature suggests that POAF occurs when transient, postoperative triggers act on vulnerable atrial tissue produced by preoperative, procedure-induced and postoperative processes such as inflammation, oxidative stress, autonomic dysfunction and electrophysiological remodelling of the atrial tissues. This sets the stage for arrhythmogenic mechanisms, such as ectopic firing secondary to triggered activity and re-entry mechanisms generating POAF. Preoperative factors include advanced age, sex, ethnicity, cardiovascular risk factors, preoperative drugs, electrocardiogram and echocardiogram abnormalities. Procedural factors include: the use of cardiopulmonary bypass and aortic cross clamp, type of cardiac surgery, use of hypothermia, left ventricular venting, bicaval cannulation and exclusion of the left atrial appendage. Postoperative factors include postoperative drugs, electrolyte and fluid balance and infection. This review explores the pathogenesis of POAF and the contribution of these perioperative factors in the development of POAF. Patients can be risk stratified for targeted treatment and prophylaxis, and how these factors can be attenuated to improve POAF outcomes following cardiac surgery.

Non–Vitamin K Antagonist Oral Anticoagulant vs Warfarin for Post Cardiac Surgery Atrial Fibrillation

BackgroundTreatment guidelines for nonvalvular atrial fibrillation (AF) recommend use of non–vitamin K antagonist oral anticoagulants (NOACs) over warfarin, yet clinical trials excluded individuals with post cardiac surgery AF. We sought to compare outcomes with NOACs vs warfarin for new onset post cardiac surgery AF. MethodsWe examined 26,522 patients from The Society of Thoracic Surgeons’ database with post cardiac surgery AF who were discharged on oral anticoagulation from July 2017–December 2018. Three primary outcomes were evaluated: 30-day mortality, major bleeding complications, and stroke/transient ischemic attack. Secondary outcomes included postoperative length of stay, 30-day myocardial infarction, venous thromboembolism, and pericardial effusion/tamponade. ResultsA total of 9769 (36.8%) participants were prescribed NOACs and 16,753 (63.2%) warfarin. In multivariable analysis, there was no association between type of anticoagulant and 30-day major bleeding complications (odds ratio [OR]NOAC/warfarin 0.76, 95% confidence interval [CI] 0.49-1.18), stroke/transient ischemic attack (ORNOAC/warfarin 0.94, 95% CI 0.53-1.67) or mortality (ORNOAC/warfarin 1.08, 95% CI 0.80-1.45). After stratification by renal function or isolated coronary bypass vs valve surgery, there remained no difference in the primary outcomes. Additionally, there was no difference in 30-day myocardial infarction (ORNOAC/warfarin 1.17, 95% CI 0.62-2.22), venous thromboembolism (ORNOAC/warfarin 0.91, 95% CI 0.47-1.78), or pericardial effusion/tamponade (ORNOAC/warfarin 1.09, 95% CI 0.80-1.47) between the 2 groups. NOAC therapy was associated with a half-day reduction in postoperative length of stay (βNOAC/warfarin –0.47, 95% CI –0.62 to –0.33). ConclusionsNOACs are associated with a reduction in postoperative length of stay, without excess bleeding or other short-term complications, compared with warfarin. These findings support the broader use of NOACs as a safe alternative to warfarin in patients with post cardiac surgery AF at elevated stroke risk and acceptable bleeding risk.

Abstract 17301: Safety of Direct Oral Anticoagulants Compared to Warfarin for Atrial Fibrillation After Cardiac Surgery: A Systematic Review and Meta-Analysis

Introduction: The evidence for use of direct oral anticoagulants (DOACs) in the management of post-operative cardiac surgery atrial fibrillation (POAF) is limited and mostly founded on clinical trials that excluded this patient population. Hypothesis: We performed a systematic review and meta-analysis of clinical trials and observational studies to evaluate the hypothesis that DOACs are safe compared to warfarin for the anticoagulation of patients with POAF. Methods: We searched PubMed, EMBASE, Web of Science, clinicaltrials.gov, and the Cochrane Library for clinical trials and observational studies comparing DOAC with warfarin in patients ≥18 years old who had post-cardiac surgery atrial fibrillation. Primary outcomes included stroke, systemic embolization, bleeding, and mortality, with secondary outcome of hospital readmission. We performed a random-effects meta-analysis. Results: We found 3 clinical trials, 1 prospective and 12 retrospective cohort studies eligible for inclusion with a total of 10,538 patients (3,207 DOAC patients and 7,331 warfarin patients). The meta-analysis for the primary outcomes showed significantly lower risk of stroke with DOAC use (6 studies, 7143 patients, RR 0.64; 95% CI 0.50 to 0.81, I2: 0.0%) compared to warfarin, a trend towards lower risk of systemic embolization (4 studies, 7289 patients, RR 0.64, 95% CI 0.41 to 1.01, I2: 31.99%) and similar risks of bleeding (14 studies, 10182 patients, RR 0.91; 95% CI 0.74 to 1.10, I2: 26.6%) and mortality (12 studies, 9843 patients, relative risk [RR] 1.01; 95% CI 0.74 to 1.37, I2: 26.5%) The secondary outcome of hospital readmission had similar risk between groups. Conclusions: Current evidence suggests that DOACs, compared to warfarin, in the management of atrial fibrillation after cardiac surgery is associated with lower risk of stroke and a strong trend for lower risk of systemic embolization, and no evidence of increased risk for hospital readmission, bleeding or mortality.

Prospective Evaluation of Clinico-Pathological Predictors of Postoperative Atrial Fibrillation: An Ancillary Study From the OPERA Trial.

Postoperative atrial fibrillation (POAF) occurs in 30% to 50% of patients undergoing cardiac surgery and is associated with increased morbidity and mortality. Prospective identification of structural/molecular changes in atrial myocardium that correlate with myocardial injury and precede and predict risk of POAF may identify new molecular pathways and targets for prevention of this common morbid complication. Right atrial appendage samples were prospectively collected during cardiac surgery from 239 patients enrolled in the OPERA trial (Omega-3 Fatty Acids for Prevention of Post-Operative Atrial Fibrillation), fixed in 10% buffered formalin, and embedded in paraffin for histology. We assessed general tissue morphology, cardiomyocyte diameters, myocytolysis (perinuclear myofibril loss), accumulation of perinuclear glycogen, interstitial fibrosis, and myocardial gap junction distribution. We also assayed NT-proBNP (N-terminal pro-B-type natriuretic peptide), hs-cTnT, CRP (C-reactive protein), and circulating oxidative stress biomarkers (F2-isoprostanes, F3-isoprostanes, isofurans) in plasma collected before, during, and 48 hours after surgery. POAF was defined as occurrence of postcardiac surgery atrial fibrillation or flutter of at least 30 seconds duration confirmed by rhythm strip or 12-lead ECG. The follow-up period for all arrhythmias was from surgery until hospital discharge or postoperative day 10. Thirty-five percent of patients experienced POAF. Compared with the non-POAF group, they were slightly older and more likely to have chronic obstructive pulmonary disease or heart failure. They also had a higher European System for Cardiac Operative Risk Evaluation and more often underwent valve surgery. No differences in left atrial size were observed between patients with POAF and patients without POAF. The extent of atrial interstitial fibrosis, cardiomyocyte myocytolysis, cardiomyocyte diameter, glycogen score or Cx43 distribution at the time of surgery was not significantly associated with incidence of POAF. None of these histopathologic abnormalities were correlated with levels of NT-proBNP, hs-cTnT, CRP, or oxidative stress biomarkers. In sinus rhythm patients undergoing cardiac surgery, histopathologic changes in the right atrial appendage do not predict POAF. They also do not correlate with biomarkers of cardiac function, inflammation, and oxidative stress. Graphic Abstract: A graphic abstract is available for this article.

Temporal trend and associated risk factors for new-onset atrial fibrillation following cardiac valve surgery.

Post cardiac surgery atrial fibrillation (POAF) is common, with adverse implications. However, relatively little is known regarding the time varying nature of risk factors associated with POAF. We describe variation in POAF along with its associated risk factors. Medical records of adult patients undergoing cardiac valve surgery from 2003-13, without a history of pre-operative AF were analyzed retrospectively. POAF was adjudicated using inpatient and outpatient electrocardiograms (EKG). Risk of AF over time along with time-varying risk factors were estimated using multiphase non-linear logistic mixed effects model. 10,461 patients with 100,149 EKGs were analyzed [median follow-up 4 months (IQR 48 hours-2 years)]. AF prevalence changed with time since surgery and two distinct phases were identified. Prevalence peaked to 13% at 2 weeks (early phase) and 9% near 7 years post-operatively (late phase). Older age, greater severity of preoperative tricuspid valve (TV) regurgitation, mitral valve replacement and prior cardiac surgery were time-independent risk factors for POAF. TV repair was associated with a decreased risk of early phase POAF. Pre-operative blood urea nitrogen, peripheral vascular disease and hypertension were associated with a higher risk of late phase POAF. POAF risk shows two distinct phases with an early peak and a late gradual rise, each associated with a different set of risk factors.

DIRECT ORAL ANTICOAGULANTS VS. WARFARIN FOR NEW ONSET POST-CARDIAC SURGERY NON-VALVULAR ATRIAL FIBRILLATION

Randomized clinical trials of direct oral anticoagulants (DOAC) vs. warfarin in non-valvular atrial fibrillation (NVAF) excluded individuals with post-cardiac surgery atrial fibrillation. We sought to compare short-term outcomes with DOACs vs. warfarin for new onset post-cardiac surgery NVAF.

Remote ischemic preconditioning and its role in the prevention of new onset atrial fibrillation post-cardiac surgery. A meta-analysis of randomized control trials.

BackgroundThe denouement of remote ischemic preconditioning on new onset atrial fibrillation (NOAF) post‐cardiac surgery is not well‐established. An updated meta‐analysis of randomized control trials was performed by comparing remote ischemic preconditioning with controls and the outcome of interest was NOAF.MethodsThe systemic review was performed in accordance with the PRISMA (Preferred reporting items for systemic review) and AHA (American Heart Association) guidelines. PubMed database was searched to include relevant randomized control trials from inception to July 2019. We used Mantel‐Haenzsel method with random error model to calculate risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was assessed using the I 2 test> 50% or χ 2 P < .05. Publication bias was visually assessed using a funnel plot.ResultsTwelve randomized control trials were included in the final analysis. Remote ischemic preconditioning did not alter the risk of NOAF post‐cardiac surgery [RR: 0.95, CI: 0.83‐1.09, P = .48, I 2 = 37%, χ 2 P = .09].ConclusionIn conclusion, the present meta‐analysis failed to provide any evidence for the beneficial effect of remote ischemic preconditioning in the prevention of NOAF.

Management of atrial fibrillation after cardiac surgery.

A best evidence topic in cardiac surgery was written according to a structured protocol addressing the question 'for post-cardiac surgery atrial fibrillation (AF), do clinical outcomes differ between rate or rhythm control strategies?' Altogether, 2174 papers were found using the reported searches, of which 5 represented the best evidence to answer the clinical question. Hospital length of stay ranged from 5.0 to 13.2 days for rate control and 5.2 to 10.3 days for rhythm control. Freedom from AF at follow up was achieved in 84.2-91 and 84.2-96% in rate and rhythm control groups respectively. Minimal serious adverse events were noted in all studies analysed and there was no difference between rate and rhythm control groups. We conclude that in the management of post-cardiac surgery, AF, rate control and rhythm control are equivalent in terms of hospital length of stay, freedom from arrhythmia at follow up and complication rates.

P07-11 - Management of Atrial Fibrillation post cardiac surgery

Atrial Fibrillation post cardiac surgery is associated with morbidity and long term sequalae. It is common post Cardiac surgery especially following valvular surgery. There is clear guidance from the National Institute of Health and Clinical Excellence (NICE) about management of patients to prevent and manage postoperative Atrial Fibrillation. "Unless contraindicated, offer a rhythm-control strategy as the initial management option for the treatment of postoperative atrial fibrillation following cardiothoracic surgery".

P999Amiodarone plus ranolazine for conversion of post-cardiac surgery atrial fibrillation: enhanced effectiveness in low versus preserved ejection fraction patients

P999Amiodarone plus ranolazine for conversion of post-cardiac surgery atrial fibrillation: enhanced effectiveness in low versus preserved ejection fraction patients

Sleep disordered breathing and post-cardiac surgery atrial fibrillation.

We thank the editor for inviting an editorial on our recent publication in Chest. We also appreciate and thank Chan et al . for a very thoughtful editorial. We hereby take the liberty of making a few observations for the readership of this journal as well as the investigators in this particular area. Postoperative atrial fibrillation (AF) is a growing problem and most predictors appear to be non-modifiable. The relation between obstructive sleep apnea (OSA) and new onset postoperative AF is complex and requires further characterization, but is also important as it may be a salient modifiable factor with potential benefit realized from the treatment of OSA.