Safety of amiodarone in the prevention of postoperative atrial fibrillation: A meta-analysis

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

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

Post-Cardiac Surgery Atrial Fibrillation: Risks, Mechanisms, Prevention, and Management

Atrial fibrillation (AF) is the most common complication of cardiac surgery (CS). There are numerous risk factors, proposed mechanisms, and financial/clinical implications of post-CS AF (PCSAF). Management involves 2 arms: prevention and treatment. This review highlights and summarizes previous literature on PCSAF and challenges the standard dogma regarding anticoagulation, particularly in the short term.

Reducing New-Onset Atrial Fibrillation After Coronary Artery Bypass Graft Surgery

Postoperative atrial fibrillation is the most common dysrhythmia to occur after coronary artery bypass graft surgery. It develops in 10% to 40% of patients and can lead to complications such as hemodynamic instability, heart failure, and stroke. Risk factors include hypertension, diabetes, chronic kidney disease, and obesity. Patients who experience postoperative atrial fibrillation often have longer hospital stays, are at higher risk for readmission, and have increased mortality. Protocols designed to reduce the incidence of the condition can decrease hospital costs, improve patient outcomes, and increase overall quality of care. This quality improvement project took place in a tertiary care center located in southeastern Michigan and focused on the development and implementation of an evidence-based postoperative atrial fibrillation prophylaxis protocol using amiodarone. The outcomes of this project suggest that amiodarone prophylaxis can reduce the incidence of postoperative atrial fibrillation in patients with no previous history of atrial fibrillation undergoing coronary artery bypass graft surgery.

Postoperative Atrial Fibrillation and Flutter in Liver Transplantation: An Important Predictor of Early and Late Morbidity and Mortality

Postoperative atrial fibrillation/flutter (POAF) is the most common perioperative arrhythmia and may be particularly problematic after liver transplantation (LT). This study is a single-center retrospective analysis of POAF to determine its incidence following LT, to identify risk factors, to assess its impact on clinical outcomes, and to summarize management strategies. The records of all patients who underwent LT between 2010 and 2018 were reviewed. Extracted data included pre-LT demographics and cardiac evaluation, in-hospital post-LT cardiac events, early and late complications, and survival. Among 1011 patients, the incidence of post-LT POAF was 10%. Using binary logistic regression, pre-LT history of atrial fibrillation was the strongest predictor of POAF (odds ratio [OR], 6.72; 95% confidence interval [CI], 2.00-22.57; P < 0.001), followed by history of coronary artery disease (CAD; OR, 2.52; 95% CI, 1.10-5.81; P = 0.03). Cardiac stress testing abnormality and CAD on cardiac catheterization were also associated with higher risk. Median time to POAF onset after LT was 3 days with 72% of cases resolving within 48 hours. POAF patients had greater hospital length of stay, death during the LT admission, and 90-day and 1-year mortality. POAF was an independent risk factor for post-LT mortality (OR, 2.0; 95% CI, 1.3-3.0; P < 0.01). Amiodarone was administered to 73% of POAF patients with no evidence of increased serum alanine aminotransferase levels. POAF occurred in 10% of post-LT patients with early onset and rapid resolution in most affected patients. POAF patients, however, had significant morbidity and mortality, suggesting that POAF is an important marker for worse early and late post-LT outcomes.

New-onset atrial fibrillation: an update

New-onset atrial fibrillation (NOAF) is the most common perioperative complication of heart surgery, typically occurring in the perioperative period. NOAF commonly occurs in patients who are elderly, or have left atrial enlargement, or left ventricular hypertrophy. Various factors have been identified as being involved in the development of NOAF, and numerous approaches have been proposed for its prevention and treatment. Risk factors include diabetes, obesity, and metabolic syndrome. For prevention of NOAF, β-blockers and amiodarone are particularly effective and are recommended by guidelines. NOAF can be treated by rhythm/rate control, and antithrombotic therapy. Treatment is required in patients with decreased cardiac function, a heart rate exceeding 130 beats/min, or persistent NOAF lasting for ≥ 48 h. It is anticipated that anticoagulant therapies, as well as hemodynamic management, will also play a major role in the management of NOAF. When using warfarin as an anticoagulant, its dose should be adjusted based on PT-INR. PT-INR should be controlled between 2.0 and 3.0 in patients aged < 70 years and between 1.6 and 2.6 in those aged ≥ 70 years. Rate control combined with antithrombotic therapies for NOAF is expected to contribute to further advances in treatment and improvement of survival.

Topical amiodarone during cardiac surgery: Does epicardial application of amiodarone prevent postoperative atrial fibrillation?

OBJECTIVES

Atrial fibrillation (AF) is a common complication after cardiac surgery. Topical amiodarone on the epicardium may help prevent postoperative AF while avoiding the side effects of its systemic administration. The purpose of this study was to evaluate the all-comer strategy of epicardial amiodarone application for the prevention of postoperative AF.

METHODS

A retrospective observational study was performed that evaluated the incidence of new-onset AF in a consecutive series of cardiac surgery patients who were treated with either no amiodarone (historical control, n = 100), epicardial application of amiodarone mixed in a topical hydrogel (n = 50), or epicardial application of an amiodarone-soaked sealant patch (n = 50). Perioperative data were compared between the 3 groups, with all patients receiving continuous postoperative telemetry to monitor for new-onset AF.

RESULTS

The cohort consisted of 200 cardiac surgery patients (coronary bypass 82%, valve surgery 24%) who had no history of AF (mean age 71.0 years, 28% female). Among the 3 groups, the incidence of postoperative AF did not significantly differ, with 29 of 100 (29%) patients in the historical control group having new AF, compared with 18 of 50 (36%) in the amiodarone-hydrogel group, and 18 of 50 (36%) in the amiodarone-patch group (P = .56). The results did not differ when the analysis was restricted to coronary bypass patients only (n = 142, 27% vs 38% vs 32%, no-amiodarone vs amiodarone-hydrogel vs amiodarone-patch, respectively, P = .56). In multivariate logistic regression analysis, only older age (P = .001) was significantly associated with new-onset AF, but the use of topical amiodarone was not.

CONCLUSIONS

Routine epicardial application of topical amiodarone was not associated with a reduction in the incidence of new-onset postoperative AF in this observational study of older patients, leading us to question its role in contemporary cardiac surgical practice.

Cardiology: Post-Cardiothoracic Surgery Atrial Fibrillation: A Review of Preventive Strategies

Objective:

To review the available literature addressing preventive strategies of post-cardiothoracic surgery atrial fibrillation (post-CTS atrial fibrillation).

Data Sources:

Pertinent articles related to the etiology, risk factors, and preventive strategies were identified through a MEDLINE search (1966–March 2007) using the MeSH terms atrial fibrillation, cardiothoracic surgery, cardiac surgery, etiology, neurohormonal, sympathetic, volume, fluid, inflammation, risk factors, operative, pacing, β-adrenergic blockers, amiodarone, sotalol, calcium-channel blockers, magnesium, HMG-CoA reductase inhibitors, statins, fatty acids, PUFA, steroids, and nonsteroidal antiinflammatory drugs.

Study Selection and Data Extraction:

Articles evaluated were limited to human studies, published in the English language, with a Jadad score greater than 3. References of identified articles were reviewed for additional pertinent articles.

Data Synthesis:

Post-CTS atrial fibrillation most commonly occurs on the second or third postoperative day, with an incidence of 20–50%. Etiology theories include neurohormonal activation, volume overload, and inflammation. Studies examining nonpharmacologic therapies have shown that maintenance of the anterior epicardial fat pad is not a viable prophylactic strategy. Biatrial cardiac pacing, especially in combination with amiodarone, is a viable preventive option. Withdrawal of preoperative β-blockers places patients at higher risk for atrial fibrillation; these drugs should be continued postoperatively. Evidence exists supporting the use of amiodarone, sotalol, and magnesium in addition to β-blockers. Since most of these strategies work by attenuating neurohormonal activation, adverse events, including hypotension and bradycardia, are of concern. Adding agents with antiinflammatory properties, including hydroxymethylglutaryl coenzyme A reductase inhibitors or corticosteroids, may prove to be of benefit. Additional studies using novel therapies are needed in addition to established preventive strategies.

Conclusions:

Available evidence supports the continuation of preoperative β-blockers, as well as prophylactic amiodarone, sotalol, and magnesium. Other novel therapies, mostly targeting inflammation, are under investigation and may provide additional strategies.

Effect of Angiotensin-Converting Enzyme Inhibitors or Angiotensin Receptor Blockers on the Frequency of Post-Cardiothoracic Surgery Atrial Fibrillation

Background:

A recent meta-analysis demonstrated that angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) reduce the incidence of new-onset atrial fibrillation by nearly 50%. However, the ability of ACE inhibitors or ARBs to prevent post-cardiothoracic surgery (CTS) atrial fibrillation, when used postoperatively, has yet to be evaluated.

Objective:

To evaluate the impact of postoperative ACE inhibitor or ARB use on the incidence of post-CTS atrial fibrillation.

Methods:

We performed a retrospective cohort study of propensity score matched patients who underwent CTS at a single institution from January 2004 through December 2005. Patients who received either an ACE inhibitor or an ARB within 24 hours of surgery were propensity score matched for common predictors of post-CTS atrial fibrillation (age >70 y, preoperative digoxin use, postoperative β-blocker or amiodarone use, β-blockor intolerance, valve surgery, male sex, and history of diabetes mellitus, smoking, chronic obstructive pulmonary disease, prior cardiothoracic surgery) in a 1:1 ratio with patients who did not receive an ACE inhibitor or an ARB. Multivariate logistic regression was used to generate adjusted odds ratios to minimize the impact of baseline confounders.

Results:

A total of 1469 patients underwent CTS during the study evaluation period. Postoperatively, 188 received an ACE inhibitor or an ARB and were matched to 188 control patients. Mean ± SD age of matched patients was 68.1 ± 11.8 years, 66% were men, 42% underwent valve surgery, and 69% and 35% received postoperative β-blockade and amiodarone, respectively. Patients who received an ACE inhibitor or an ARB did not experience a significant reduction in post-CTS atrial fibrillation compared with control patients (adjusted OR 0.95; 95% CI 0.57 to 1.56; p = 0.83).

Conclusions:

In this evaluation, postoperative ACE inhibitor or ARB use was not associated with a reduction in post-CTS atrial fibrillation. A study of preoperative, longer-term ACE inhibitor and/or ARB therapy is needed to determine the benefits of that strategy.

Pharmacological strategies for prevention of postoperative atrial fibrillation

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

A multistudy analysis investigating systematic differences in cardiovascular trial results between Europe and Asia

OBJECTIVE

To assess whether there are differences in the results of cardiovascular trials between Europe and Asia using data from an extensive collection of randomised controlled trials.

STUDY DESIGN AND SETTING

All meta-analyses containing randomised controlled trials (RCT's) for the treatment or prevention of cardiovascular diseases were searched for in The Cochrane Library (2000-2008) and MEDLINE (2005-2008). Analysis was then conducted within and over each meta-analysis which satisfied given criteria. Separate estimates of treatment effect were calculated for Europe and Asia in each meta-analysis and then compared. Estimates of a common inter-continental difference over all meta-analyses were also calculated and meta-regression was performed. This was performed for both fatal and non-fatal end points.

RESULTS

The literature search identified 59 meta-analyses that satisfied the inclusion criteria. After exclusion, the number of meta-analyses reporting greater effect sizes in Asia than in Europe was significantly more than would be expected by chance (fatal 12/14, p=0.013; non-fatal 23/32, p=0.020).

CONCLUSIONS

This study provides some evidence that for cardiovascular interventions treatment effect estimation differs between Europe and Asia, with respect to both fatal and non-fatal end points.

Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons

BACKGROUND

It is often assumed that differences in the efficacy of treatments between countries (or regions) will be neither negligible nor minor and therefore cannot be overlooked when assessing the potential benefit of treatments in one country (or region) on the basis of trials conducted in another country (or region).

AIM

To assess differences in the results of cardiovascular trials between Europe and North America on the basis of data from an extensive collection of trials.

METHODS

A systematic search was conducted of Medline (from the year 2005 to 2008) and the Cochrane Library (from 2000 to 2008) for all meta-analyses of randomized controlled trials aimed at treating and preventing cardiovascular disease. Within each meta-analysis that satisfied given criteria, trial results were compared between Europe and North America with respect to a fatal and/or non-fatal endpoint by forming separate estimates of treatment efficacy for each of these continents.

RESULTS

The literature search found 59 meta-analyses that satisfied all the inclusion criteria. For most meta-analyses, it was the case that relative to the control, the intervention was more favoured in trials conducted in Europe than in North America with regard to both fatal endpoints (28 out of 43 meta-analyses) and non-fatal endpoints (28 out of 40 meta-analyses). However, it was only with regard to non-fatal endpoints that this imbalance turned out to be statistically significant at the 5% level (P=0.017). Also, the lack of statistically significant differences in trial results between Europe and North America within individual meta-analyses meant that it was not possible to determine for which types of intervention these intercontinental differences are likely to be more pronounced than others.

CONCLUSION

There is some evidence to support the theory that, relative to controls, interventions are more favoured in cardiovascular trials conducted in Europe than in North America, when treatment efficacy is measured in terms of a non-fatal endpoint. However, the overall support for systematic differences in cardiovascular trial results between Europe and North America is weak, which may be surprising given the amount of data collected.

Management strategies in cardiac surgery for postoperative atrial fibrillation: contemporary prophylaxis and futuristic anticoagulant possibilities

With more than a third of patients expected to endure the arrhythmia at any given time point, atrial fibrillation after cardiac surgery becomes a vexing problem in the postoperative care of cardiac surgery patients. The impact on patient care covers a spectrum from the more common clinically insignificant sequelae to debilitating embolic events. Despite this, postoperative atrial fibrillation generally masquerades as being insignificant, or at most as an anticipated inherent risk, merely extending one's hospital stay by a few days. As an independent risk factor for stroke, early and late mortality, and being a multibillion dollar strain on the healthcare system annually, postoperative atrial fibrillation is far more flagrant than a mere inherent risk. It is a serious medical quandary, which is not recognized as such. Though complete prevention is unrealistic, a step-wise treatment strategy that incorporates multiple preventative modalities can significantly reduce the impact of postoperative atrial fibrillation on patient care. The aims of this review are to present a brief overview of the arrhythmia's etiology, risk factors, and preventative strategies to reduce associated morbidities. Newer anticoagulants and the potential role of these drugs on future treatment paradigms are also discussed.

Post-operative Atrial Fibrillation - Pathophysiology, Treatment and Prevention

Atrial fibrillation occurring after cardiac surgery has been the subject of intensive research over the past decades. However, the incidence remains high, despite numerous preventive and treatment strategies. In addition, several reports show that the impact of post-operative atrial fibrillation (POAF) is high. It is an independent risk factor for mortality after several years. These findings make clear that the pathophysiology of POAF is not fully understood and POAF-associated risks to some extent might be underestimated. On the one hand, excessive triggers during the acute post operative phase after cardiac surgery might initiate AF even in atria with low vulnerability. On the other hand, many patients undergoing surgery have an atrial substrate at the time of operation promoting AF not only in the post-operative phase but also in the days and weeks thereafter. Progress in our understanding of the AF mechanisms in general has provided valuable insights into processes involved in atrial structural remodeling due to advanced age, hypertension, obesity, and congestive heart failure. These patient characteristics strongly contribute to cardiac disease, predict POAF and likely have an impact on the risk of thrombus formation in the weeks and months after cardiac surgery. For a better understanding of the mechanisms involved, it is important to not only recognize the occurrence of POAF by continuous monitoring after surgery, but also to identity the extent of atrial vulnerability to AF in these patients.

Atrial Fibrillation in the Intensive Care Setting

Atrial fibrillation (AF) is the commonest cardiac arrhythmia both in the general population and in the intensive care unit (ICU) setting. Its incidence continues to rise, affecting up to 10% of patients admitted to a general ICU and up to 50% of those admitted to a cardiac ICU. Uncontrolled AF has detrimental effects on the cardiovascular system, including heart failure, thromboembolic events, reduced quality of life and prolonged hospital stay. This article reviews the risk factors for developing AF, possible underlying mechanisms, clinical features and diagnosis, and focuses particularly on its management according to the latest guidelines with a specific focus on the ICU patient. We also discuss novel anticoagulants that will revolutionise the management of antithrombotic therapy in AF patients by replacing warfarin.

Use of preoperative CHA2 DS2 -VASc score to predict the risk of atrial fibrillation after cardiothoracic surgery: a nested case-control study from the Atrial Fibrillation Suppression Trials (AFIST) I, II, and III

STUDY OBJECTIVE

To evaluate whether the preoperative CHA2 DS2 -VASc score predicts the risk of atrial fibrillation (AF) after cardiothoracic surgery (CTS).

DESIGN

Retrospective, nested case-control study.

PATIENTS

A total of 560 patients undergoing coronary artery bypass grafting and/or valvular surgery from the Atrial Fibrillation Suppression Trials I, II, and III.

MEASUREMENTS AND MAIN RESULTS

All variables showing a univariate association (p≤0.20) with AF occurrence were entered into a backward stepwise multivariate logistic regression analysis to control for potential confounders and to calculate adjusted odds ratios (AORs) with 95% confidence intervals (CIs). The population was age 67.8 ± 8.6 (mean ± SD) years and 77.1% male, with CHA2 DS2 -VASc scores of 0-1 (low) in 34 patients (6.1%), 2-3 (medium) in 261 patients (46.6%), and more than 3 (high) in 265 patients (47.3%). Post-CTS AF occurred in 177 patients (31.6%), with 27%, 23%, and 41% in the low-, medium-, and high-CHA2 DS2 -VASc score groups, respectively. The high-score group had a 2.3-fold increased odds of developing AF versus the medium-score group (p<0.0001). The differences between the high- and medium-score groups when each group was compared with the low-score group were not statistically significant. On the multivariate logistic regression analysis, CHA2 DS2 -VASc score was associated with development of AF (AOR 1.20, 95% CI 1.06-1.36).

CONCLUSION

Increasing CHA2 DS2 -VASc score was an independent predictor for the development of post-CTS AF, with patients in the high-score group having the highest overall incidence.

Intravenous magnesium prevents atrial fibrillation after coronary artery bypass grafting: a meta-analysis of 7 double-blind, placebo-controlled, randomized clinical trials

Background

Postoperative atrial fibrillation (POAF) is the most common complication after coronary artery bypass grafting (CABG). The preventive effect of magnesium on POAF is not well known. This meta-analysis was undertaken to assess the efficacy of intravenous magnesium on the prevention of POAF after CABG.

Methods

Eligible studies were identified from electronic databases (Medline, Embase, and the Cochrane Library). The primary outcome measure was the incidence of POAF. The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity.

Results

Seven double-blind, placebo-controlled, randomized clinical trials met the inclusion criteria including 1,028 participants. The pooled results showed that intravenous magnesium reduced the incidence of POAF by 36% (RR 0.64; 95% confidence interval (CI) 0.50-0.83; P = 0.001; with no heterogeneity between trials (heterogeneity P = 0.8, I² = 0%)).

Conclusions

This meta-analysis indicates that intravenous magnesium significantly reduces the incidence of POAF after CABG. This finding encourages the use of intravenous magnesium as an alternative to prevent POAF after CABG. But more high quality randomized clinical trials are still need to confirm the safety.

Evaluation of an evidence-based practice implementation: prophylactic amiodarone following coronary artery revascularization

Postoperative atrial fibrillation is the most frequent dysrhythmia following coronary artery bypass grafting and is associated with complications, additional therapy, and longer hospital stays. Prophylactic amiodarone protocols have been validated as safe and beneficial in the prevention of atrial fibrillation following cardiac surgery. This study evaluates the use of our current treatment protocol, given prophylactically, as feasible and effective in producing similar outcomes in postoperative atrial fibrillation reduction as well as identifies any perioperative risk factors associated with this arrhythmia.

Management of postoperative atrial fibrillation

The impact of postoperative atrial fibrillation (PAF) on patient outcomes has prompted intense investigation into the optimal methods for prevention and treatment of this complication. In the prevention of PAF, β-blockers and amiodarone are particularly effective and are recommended by guidelines. However, their use requires caution due to the possibility of drug-related adverse effects. Aside from these risks, perioperative prophylactic treatment with statins seems to be effective for preventing PAF and is associated with a low incidence of adverse effects. PAF can be treated by rhythm control, heart-rate control, and antithrombotic therapy. For the purpose of heart rate control, β-blockers, calcium-channel antagonists, and amiodarone are used. In patients with unstable hemodynamics, cardioversion may be performed for rhythm control. Antithrombotic therapy is used in addition to heart-rate maintenance therapy in cases of PAF >48-h duration or in cases with a history of cerebrovascular thromboembolism. Anticoagulation is the first choice for antithrombotic therapy, and anticoagulation management should focus on maintaining international normalized ratio (INRs) in the 2.0–3.0 range in patients <75 years of age, whereas prothrombin-time INR should be controlled to the 1.6–2.6 range in patients ≥75 years of age. In the future, dabigatran could be used for perioperative management of PAF, because it does not require regular monitoring and has a quick onset of action with short serum half-life. Preventing PAF is an important goal and requires specific perioperative management as well as other approaches. PAF is also associated with lifestyle-related diseases, which emphasizes the ongoing need for appropriate lifestyle management in individual patients.

Review: Beyond the Guidelines: New and Novel Agents for the Prevention of Atrial Fibrillation After Cardiothoracic Surgery

Postoperative atrial fibrillation (POAF), a common complication of cardiac surgery, can increase the morbidity and mortality, as well as the costs of the surgery being preformed. Guidelines recommend the use of β-blockers, amiodarone, or sotalol to decrease the risk of experiencing POAF. However, none of these agents fully protect the patient from POAF, thus newer agents are needed to be used in combination with them. Many different agents have been studied to fit this role and may be grouped into 2 categories: agents with antiarrhythmic activity such as magnesium and polyunsaturated fatty acids and agents with anti-inflammatory activity such as statins and free radical scavengers. Most of these novel agents have been studied in a wide variety of trials; however, some clearly have more effect than others. Although none of these newer agents have the data required to make blanket recommendations for use at this point, given the safety profile and low costs of some, many continue to be evaluated in randomized-controlled trials.

Pharmacologic prophylaxis for atrial fibrillation following cardiac surgery: a systematic review

Atrial Fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. Its incidence varies depending on type of surgery. Postoperative AF may cause hemodynamic deterioration, predispose to stroke and increase mortality. Effective treatment for prophylaxis of postoperative AF is vital as reduces hospitalization and overall morbidity. Beta-blockers, have been proved to prevent effectively atrial fibrillation following cardiac surgery and should be routinely used if there are no contraindications. Sotalol may be more effective than standard b-blockers for the prevention of AF without causing an excess of side effects. Amiodarone is useful when beta-blocker therapy is not possible or as additional prophylaxis in high risk patients. Other agents such as magnesium, calcium channels blocker or non-antiarrhythmic drugs as glycose-insulin--potassium, non-steroidal anti-inflammatory drugs, corticosteroids, N-acetylcysteine and statins have been studied as alternative treatment for postoperative AF prophylaxis.

Systemic vascular cell adhesion molecule-1 predicts the occurrence of post-operative atrial fibrillation

BACKGROUND

Post-operative atrial fibrillation occurs in 30% of patients after on-pump heart surgery and is associated to elevated inflammatory markers. We have evaluated if the systemic biomarkers of inflammation and endothelial damage, vascular cell adhesion molecule-1 (VCAM-1) and soluble thrombomodulin may help in identifying patients prone to development of post-operative atrial fibrillation.

METHODS

One hundred and forty-four patients in sinus rhythm submitted to elective coronary artery bypass surgery. Systemic inflammatory, oxidative stress and endothelial damage markers were measured at baseline and 72 h after surgery. During the procedure, a sample of the right atrial appendage was obtained for histochemistry. Electrocardiogram was monitored for 72 h after surgery for event adjudication.

RESULTS

22% of the patients developed post-operative atrial fibrillation. Baseline systemic inflammatory markers did not differ between patients with or without post-operative atrial fibrillation. However, baseline plasma VCAM-1 and thrombomodulin levels were significantly higher in patients who developed post-operative atrial fibrillation. After adjustment for age, gender, comorbidities and concurrent medication, circulating VCAM-1 remained as an independent predictor for post-operative atrial fibrillation development. No association was observed between systemic plasma VCAM-1 and VCAM-1 tissue expression in the right atrial appendage.

CONCLUSIONS

In patients undergoing coronary artery bypass surgery, elevated VCAM-1 levels predict a higher risk for post-operative atrial fibrillation. Plasma VCAM-1 elevation is not related to its expression in the right atria, suggesting that systemic endothelial damage rather than local changes pre-exist in patients who develop the arrhythmia.

Effect of Statins in Preventing Postoperative Atrial Fibrillation Following Cardiac Surgery

Background: Postoperative occurrence of AF has been associated with less favorable outcomes in patients undergoing cardiac surgery and may result in increased postoperative morbidity and mortality. Objectives: A focused clinical question was designed and a Meta-analysis of published studies was performed to identify the effect of preoperative use of statins on the occurrence of AF after cardiac surgery. Methods: Using the Medline database, the Cochrane clinical trials database and online clinical trial databases, we reviewed all RCTs and observational studies examining the effect of statins on AF occurrence following cardiac surgery. We searched for literature published before April 2009 and earlier. Results: This analysis identified 6 studies (observational studies) which examined the effect of preoperative use of statins on AF occurrence following cardiac surgery, involving 10165 patients. Contradictory to most of previous studies, the overall outcomes suggested that the statins group did not have a significant decrease in AF occurrence following cardiac surgery comparing to control group (P = 0.19). Conclusions: The preoperative medication of statins showed no significant decrease in AF occurrence following cardiac surgery in this Meta-analysis result. More prospective studies and researches are needed to explore and demonstrate the accurate mechanism and effect of statins on postoperative AF.

Atrial Fibrillation After Cardiac Surgery: Does Prophylactic Therapy Decrease Adverse Outcomes Associated With Atrial Fibrillation

Atrial fibrillation is a common problem following cardiac surgery. Atrial fibrillation occurs in 30% to 50% patients during postoperative period. Postoperative atrial fibrillation often results in increased length of hospital stay, increased cost of postoperative hospitalization, heart failure, and, less frequently, cerebrovascular accident and death. Because postoperative atrial fibrillation is such a significant problem, several studies have attempted to find a safe and effective treatment for its prevention. In this article, we review the evidence for various prophylactic therapies and make an attempt to answer the following: (1) Can postoperative atrial fibrillation be prevented? (2) Is prophylactic therapy for postoperative atrial fibrillation safe? (3) Does prevention of postoperative atrial fibrillation prevent adverse outcomes associated with it? Evidence for safety and efficacy or lack of β-blockers, sotalol, amiodarone, intravenous magnesium, and atrial pacing is reviewed and current recommendations by the American College of Cardiology/American Heart Association/European Society of Cardiology are presented.

Post-operative atrial fibrillation management by selective epicardial vagal fat pad stimulation

PURPOSE

Post-operative atrial fibrillation (POAF) is a common complication after cardiac surgery and often leads to poorly tolerated fast ventricular rates. Negative dromotropic drugs are not always effective and may not be well tolerated in heart failure patients. Aim of this study is to verify if high-frequency stimulation of the right inferior fat pad (RIFPS) allows an effective decrease in ventricular rate (VR) during POAF.

METHODS

We enrolled 32 consecutive patients submitted to bypass; during surgery, a temporary heart wire was implanted in a site where RIFPS evoked a functional AV block. During POAF, RIFPS was delivered from the heart wire to decrease VR.

RESULTS

Intra-operative RIFPS evoked complete AV block in 29 patients (91%). Fourteen patients (44%) developed POAF (mean VR 127 +/- 12 bpm). In these patients, RIFPS achieved a 25% reduction of VR and complete AV block with 6.0 +/- 1.9 and 7.5 +/- 1.8 V (duration 0.2 ms, frequency 50 Hz), respectively.

CONCLUSION

Epicardial RIFPS represents an effective and feasible technique to decrease VR during POAF.

Amiodarone Prophylaxis: Impact on Atrial Fibrillation and Outcomes after Cardiac Surgery

This continuing feature will update readers on recent developments in cardiovascular pharmacotherapy. Cardiovascular disease remains the number one killer in the United States, and more clinical outcome trials have been conducted in cardiology than in any other field of medicine. Given this rapidly expanding knowledge base, pharmacists can have a significant impact on prevention and treatment—if they keep current with developments in drug therapy.

Prophylactic therapy to prevent atrial arrhythmia after cardiac surgery

PURPOSE OF REVIEW

Atrial fibrillation after cardiac surgery is associated with adverse outcomes and increased costs. Accordingly, therapy should be provided to prevent postoperative atrial fibrillation. The evaluation of therapies to do so is an area of active investigation with significant recent advances. The purpose of this review is to summarize these recent advances in the context of our previous knowledge base regarding the prevention of postoperative atrial fibrillation.

RECENT FINDINGS

Recent evaluations of therapy to prevent postoperative atrial fibrillation have raised the prominence of prophylactic amiodarone, redefined the efficacy of prophylactic standard beta-blockers in contemporary cardiac surgical populations, provided further evidence for the use of prophylactic sotalol, magnesium, and atrial pacing, and identified new approaches, including the use of combination therapy, for the prevention of postoperative atrial fibrillation.

SUMMARY

According to newly released ACC/AHA/ESC guidelines, use of standard beta-blockers or amiodarone to prevent postoperative atrial fibrillation have a level of evidence of A. Use of prophylactic sotalol has a level of evidence of B, while the use of prophylactic intravenous magnesium or atrial pacing has a lower level of evidence. The use of novel and combination therapies continues to be an area of active investigation.

Effect of perioperative corticosteroid use on the incidence of postcardiothoracic surgery atrial fibrillation and length of stay

BACKGROUND

While the mechanism underlying the development of post-cardiothoracic surgery atrial fibrillation has not been fully elucidated, it has been suggested that inflammation may play a causative role. Corticosteroids have been traditionally used to reduce inflammation, and when administered perioperatively, they may decrease the incidence of atrial fibrillation.

OBJECTIVE

The purpose of this study was to investigate the effects of corticosteroid administration on the incidence of post-cardiothoracic surgery atrial fibrillation and resultant hospital length of stay.

METHODS

A systematic literature search of MEDLINE, EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews through July 2006 was conducted using specific search terms. A review of cardiology abstracts and a manual review of references were also performed. Studies that met the following criteria were included: randomized, controlled trials comparing patients receiving perioperative corticosteroids or placebo and reporting data on post-cardiothoracic surgery atrial fibrillation. A random-effects model was used.

RESULTS

Nine of the 1396 citations initially identified, representing 990 patients, met the inclusion criteria. Upon meta-analysis, corticosteroids significantly lowered patients' odds of developing post-cardiothoracic surgery atrial fibrillation by 45% (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.39-0.78) and reduced hospital length of stay by approximately 1.6 days (weighted mean difference -1.59; 95% CI -2.96 to -0.21). Reductions in the incidence of post-cardiothoracic surgery atrial fibrillation appeared greatest in patients receiving intermediate doses of corticosteroid (50-210 mg dexamethasone equivalent), while both lower (up to 8 mg) and higher (236-2850 mg) dosing resulted in blunted effects.

CONCLUSION

Corticosteroids appear to reduce the incidence of post-cardiothoracic surgery atrial fibrillation and shorten hospital length of stay in randomized controlled trials.

Prophylactic Amiodarone for Prevention of Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis

Amiodarone has been proposed to decrease atrial fibrillation after cardiac surgery. The literature was systematically reviewed for randomized trials comparing amiodarone with control for prevention of atrial fibrillation. Data were extracted on study characteristics, quality, and incidence of atrial fibrillation, cardiovascular outcomes, and length of hospitalization. Nineteen trials were included. Amiodarone reduced the odds ratio of atrial fibrillation (0.50; 95% confidence interval [CI]: 0.43 to 0.59, p < 0.0001), ventricular tachyarrhythmias (0.39; 95% CI: 0.26 to 0.58, p < 0.0001), and strokes (0.53; 95% CI: 0.30 to 0.92, p = 0.02). Amiodarone reduced hospital stay (0.6 days; 95% CI: 0.4 to 0.8, p < 0.0001). Amiodarone decreased atrial fibrillation, reduced perioperative ventricular tachyarrhythmias and strokes, and reduced duration of hospitalization. The current evidence supports recommending the routine use of perioperative amiodarone for cardiac surgery.