Oral amiodarone for prevention of atrial fibrillation after open heart surgery, the Atrial Fibrillation Suppression Trial (AFIST): a randomised placebo-controlled trial

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.

Navigating the Incidence of Postoperative Arrhythmia and Hospitalization Length: The Role of Amiodarone and Other Antiarrhythmics in Prophylaxis

Antiarrhythmic drugs play a pivotal role in managing and preventing arrhythmias. Amiodarone, classified as a class III antiarrhythmic, has been used prophylactically to effectively prevent atrial fibrillation postoperatively in cardiac surgeries. However, there is a lack of consensus on the use of amiodarone and other antiarrhythmic drugs as prophylaxis to reduce the occurrence of all types of postoperative arrhythmias in cardiac and non-cardiac surgeries. A comprehensive PubMed query yielded 614 relevant papers, of which 52 clinical trials were analyzed. The data collection included the class of antiarrhythmics, timing or method of drug administration, surgery type, type of arrhythmia and its incidence, and hospitalization length. Statistical analyses focused on prophylactic antiarrhythmics and their respective reductions in postoperative arrhythmias and hospitalization length. Prophylactic amiodarone alone compared to placebo demonstrated a significant reduction in postoperative arrhythmia incidence in cardiac and non-cardiac surgeries (24.01%, p<0.0001), and it was the only treatment group to significantly reduce hospitalization length versus placebo (p = 0.0441). Prophylactic use of class 4 antiarrhythmics versus placebo also demonstrated a significant reduction in postoperative arrhythmia incidence (28.01%, p<0.0001), and while there was no significant statistical reduction compared to amiodarone (4%, p=0.9941), a lack of abundant data provides a case for further research on the prophylactic use of class 4 antiarrhythmics for this indication. Amiodarone prophylaxis remains a prime cornerstone of therapy in reducing postoperative arrhythmia incidence and hospitalization length. Emerging data suggests a need for a broader exploration of alternative antiarrhythmic agents and combination therapies, particularly class 4 antiarrhythmics, in both cardiac and non-cardiac surgeries. This meta-analysis depicts the effectiveness of amiodarone, among other antiarrhythmics, in postoperative arrhythmia incidence and hospitalization length reduction in cardiac and non-cardiac surgeries.

Stroke prevention strategies for cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Stroke is a much-feared complication of cardiac surgery, but existing literature on preventive strategies is fragmented. Hence, a systematic review and meta-analysis of stroke prevention strategies for cardiac surgery was conducted.

METHODS

An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) investigating perioperative interventions for cardiac surgery, with stroke as an outcome. Random-effects meta-analyses were conducted to generate risk ratios (RRs), 95% confidence intervals (95% CI), and forest plots. Descriptive analysis and synthesis of literature was conducted for interventions not amenable to meta-analysis, focusing on risks of stroke, myocardial infarction and study-defined major adverse cardiovascular events (MACE).

RESULTS

Fifty-six RCTs (61 894 patients) were retrieved. Many included trials were underpowered to detect differences in stroke risk. Among pharmacological therapies, only preoperative amiodarone was shown to reduce stroke risk in one trial. Concomitant left atrial appendage closure (LAAC) significantly reduced stroke risk (RR = 0.55, 95% CI = 0.36-0.84, P = 0.006) in patients with preoperative atrial fibrillation, and there was no difference in on-pump versus off-pump coronary artery bypass grafting (CABG) (RR = 0.94, 95% CI = 0.64-1.37, P = 0.735). Much controversy exists in literature on the timing of carotid endarterectomy relative to CABG in patients with severe carotid stenosis. The use of preoperative remote ischemic preconditioning was not found to reduce rates of stroke or MACE.

CONCLUSION

This review presents a comprehensive synthesis of existing interventions for stroke prevention in cardiac surgery, and identifies gaps in research which may benefit from future, large-scale RCTs. LAAC should be considered to reduce stroke incidence in patients with preoperative atrial fibrillation.

Management of Atrial Fibrillation Post Transcatheter Aortic Valve Implantation

Atrial fibrillation (AF) is a common complication in patients who underwent transcatheter aortic valve implantation. Some of these patients have preexisting AF as well. The management of these patients is complex, especially after the procedure, when there is a sudden change in hemodynamics. There are no established guidelines about the management of the patients who underwent transcatheter aortic valve replacement with preexisting or new-onset AF. This review article discusses the management of these patients with rate and rhythm control strategies with medications. This article also highlights the role of newer oral anticoagulation medications and left atrial occlusion devices to prevent stroke after the procedure. We will also discuss new advances in the care of this patient population to prevent the occurrence of AF after transcatheter aortic valve implantation. In conclusion, this article is a synopsis of both pharmacologic and device interventions for the management of AF in patients who underwent transcatheter aortic valve replacement.

Non-invasive evaluation of new-onset atrial fibrillation after cardiac surgery: a protocol for the BigMap study

Aims

New‐onset atrial fibrillation (NOAF) is the most common complication after cardiac surgery, occurring in 25–50% of patients. It is associated with post‐operative stroke, increased mortality, prolonged hospital length of stay, and higher treatment costs. Previous small observational studies have identified the left atrium as a source of the electrical rotors and foci maintaining NOAF, but confirmation by a large prospective clinical study is still missing. The aim of the proposed study is to investigate whether the source of NOAF lies in the left atrium. The correct identification of NOAF‐maintaining structures in cardiac surgical patients might offer potential therapeutic targets for prophylactic perioperative ablation strategies.

Methods and results

This is a prospective single‐centre observational study of patients developing NOAF after cardiac surgery. The primary outcome is the description of NOAF‐maintaining structures within the atria. Key secondary outcomes include overall mortality, intensive care unit length of stay, hospital–ventilator‐free days, and proportion of persistent NOAF. In NOAF patients, the non‐invasive electrophysiological mapping will be conducted using a 252‐electrode electrocardiogram vest. After mapping, a low‐dose computed tomography scan of the chest will be performed to integrate the electrophysiological mapping results into a 3D picture of the heart. The study will include approximately 570 patients, of whom 30% (n = 170) are expected to develop NOAF. Sample size calculation revealed that 157 NOAF patients are necessary to assess the primary outcome. Patients will be tracked for a total of 5 years.

Conclusions

This is the largest prospective study to date describing the electrophysiological mechanisms of NOAF using non‐invasive mapping.

Atrial Fibrillation after Lung Cancer Surgery: Prediction, Prevention and Anticoagulation Management

Simple Summary

Atrial fibrillation that occurs after surgery raises further questions with respect to spontaneous atrial fibrillation, being an event unquestionably related to the surgical act itself and always quite self-limiting. The purpose of this review is to present the knowledge gained so far, including the most recent findings, regarding this peculiar form of arrhythmia. Its prognostic impact and the possibility of predicting and preventing it were the subject of our analysis, as well as the similarities and differences with spontaneous atrial fibrillation in relation to anticoagulation. Where possible, the search for evidence has focused on studies involving lung cancer patients undergoing thoracic surgery, highlighting any differences with cardiac surgery.

Abstract

Atrial fibrillation (AF) is a common complication of the early postoperative period of various types of surgery, including that for lung cancer. Although induced by the homeostatic alterations related to surgery, there is evidence that it is not a mere stand-alone transitory event, but it represents a relevant complication of surgery, bearing considerable prognostic consequences. Different methods have therefore been explored to predict the occurrence of postoperative atrial fibrillation (POAF) and prevent it. In particular, the age among clinical factors, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP), as a marker, have proven to be good predictors, and the use of beta-blockers or amiodarone in primary prevention seems to reduce its incidence significantly. There is growing evidence that POAF significantly increases the risk of stroke and global mortality in the long term; therefore, it should be managed in the same way as spontaneous atrial fibrillation. In this review, we will present the strongest evidence found so far and the most recent findings regarding the management of POAF, with a special focus on patients undergoing thoracic surgery for lung cancer.

Atrial fibrillation post cardiac bypass surgery

Atrial fibrillation occurs in 5-40% patients after coronary artery bypass graft surgery. Atrial fibrillation increases mortality and morbidity in the post-operative period. We sought to conduct a comprehensive review of literature focusing on pathophysiology, risk factors, prevention and treatment of post coronary artery bypass graft atrial fibrillation.

Metoprolol for prophylaxis of postoperative atrial fibrillation in cardiac surgery patients: systematic review and meta-analysis

PURPOSE

Postoperative atrial fibrillation (POAF) is a potentially lethal and morbid complication after open heart surgery. This systematic review and meta-analysis aimed to investigate metoprolol compared with other treatments for prophylaxis against POAF.

METHODS

We searched CENTRAL, MEDLINE, EMBASE and trial registries for randomised controlled trials that evaluated metoprolol for preventing the occurrence of POAF after surgery against other treatments or placebo. Random-effects model was used for estimating the risk ratios (RRs) and mean differences with 95% CIs.

RESULTS

Nine trials involving 1570 patients showed metoprolol reduced POAF compared with placebo (416 patients; RR 0.46, 95% CI 0.33 to 0.66; I²=21%; risk difference (RD) -0.19, 95% CI -0.28 to -0.10). However, metoprolol increased the risk of POAF compared with carvedilol (159 patients; RR 1.59, 95% CI 1.20 to 2.12; I²=4%; RD 0.13, 95% CI 0.06 to 0.20). There was no difference when compared with sotalol or amiodarone. The occurrence of cardiovascular conditions after drugs administration or death between the groups was not different. The overall quality of evidence was moderate to high. Subgroup analysis and funnel plot were not performed.

CONCLUSIONS

Metoprolol is effective in preventing POAF compared with placebo and showed no difference with class III antiarrhythmic drugs. Death and thromboembolism are associated with open heart surgery, but not significant in relation to the use of metoprolol.

PROSPERO REGISTRATION NUMBER

CRD42019131585.

Effect of Prophylaxis of Amiodarone and Magnesium to Prevent Atrial Fibrillation in Patients with Rheumatic Valve Disease Undergoing Mitral Valve Replacement Surgery

CONTEXT

Maintenance of sinus rhythm is superior to the incidence of atrial fibrillation (AF) in patients with rheumatic valve disease undergoing mitral valve replacement (MVR) surgery.

AIM

To evaluate the effect of prophylactic combination of intravenous (i.v.) amiodarone and magnesium sulfate (MgSO4) in patients undergoing MVR surgery.

MATERIALS AND METHODS

One hundred and twenty patients with valvular heart disease with or without AF were randomly divided into two groups. Group I (n = 60) received amiodarone (3 mg.kg -1 in 20 mL saline) + MgSO4 (30 mg.kg - 1 in 20 mL saline), and Group II (n = 60) received 40 mL of normal saline. The standardized protocol for cardiopulmonary bypass was maintained for all the patients.

STATISTICAL ANALYSIS

Continuous variables were expressed as mean ± standard deviation and categorical variables were summarized as frequencies and percentages. Student's independent t-test was employed for comparing continuous variables. Chi-square test was applied for comparing categorical variables.

RESULTS

Before surgery, AF was observed in 58.3% of patients in Group I and in 53.3% of patients in Group II (P = 0.581). Postoperatively, in the intensive care unit, 26.7% of the patients in Group I and 71.7% in Group II had AF (P < 0.001). At the time of discharge, 30% of patients in Group I and 73.3% of patients in Group II had AF (P < 0.001).

CONCLUSION

A single combined prophylactic intraoperative dose of i.v. amiodarone and MgSO4 decreased postbypass arrhythmia in comparison to the placebo group in patients of MVR surgery.

Dataset for amiodarone adverse events compared to placebo using data from randomized controlled trials

The dataset presented here provides a detailed description of the adverse events of amiodarone versus placebo using data from 43 randomized controlled trials. Two authors (M.M., M.R.) independently extracted the data. The dataset also includes baseline patient characteristics, amiodarone loading and maintenance doses, as well as forest plots describing the relative risk (RR) of developing an adverse event related to the pulmonary, thyroid, hepatic, cardiac, skin, gastrointestinal, neurological, and ocular systems. The Mantel-Haenszel random effects model was used to determine the relative risk of adverse events of amiodarone compared to placebo. This dataset is complementary to our article “Meta-analysis Comparing the Relative Risk of Adverse Events for Amiodarone Versus Placebo”, which was published in the American Journal of Cardiology [1]. The data can be used to assess certain adverse events and their relation to amiodarone loading and/or maintenance dose.

New-Onset Atrial Fibrillation After PCI or CABG for Left Main Disease: The EXCEL Trial

BACKGROUND

There is limited information on the incidence and prognostic impact of new-onset atrial fibrillation (NOAF) following percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for left main coronary artery disease (LMCAD).

OBJECTIVES

This study sought to determine the incidence of NOAF following PCI and CABG for LMCAD and its effect on 3-year cardiovascular outcomes.

METHODS

In the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, 1,905 patients with LMCAD and low or intermediate SYNTAX scores were randomized to PCI with everolimus-eluting stents versus CABG. Outcomes were analyzed according to the development of NOAF during the initial hospitalization following revascularization.

RESULTS

Among 1,812 patients without atrial fibrillation on presentation, NOAF developed at a mean of 2.7 ± 2.5 days after revascularization in 162 patients (8.9%), including 161 of 893 (18.0%) CABG-treated patients and 1 of 919 (0.1%) PCI-treated patients (p < 0.0001). Older age, greater body mass index, and reduced left ventricular ejection fraction were independent predictors of NOAF in patients undergoing CABG. Patients with versus without NOAF had a significantly longer duration of hospitalization, were more likely to be discharged on anticoagulant therapy, and had an increased 30-day rate of Thrombolysis In Myocardial Infarction major or minor bleeding (14.2% vs. 5.5%; p < 0.0001). By multivariable analysis, NOAF after CABG was an independent predictor of 3-year stroke (6.6% vs. 2.4%; adjusted hazard ratio [HR]: 4.19; 95% confidence interval [CI]: 1.74 to 10.11; p = 0.001), death (11.4% vs. 4.3%; adjusted HR: 3.02; 95% CI: 1.60 to 5.70; p = 0.0006), and the primary composite endpoint of death, MI, or stroke (22.6% vs. 12.8%; adjusted HR: 2.13; 95% CI: 1.39 to 3.25; p = 0.0004).

CONCLUSIONS

In patients with LMCAD undergoing revascularization in the EXCEL trial, NOAF was common after CABG but extremely rare after PCI. The development of NOAF was strongly associated with subsequent death and stroke in CABG-treated patients. Further studies are warranted to determine whether prophylactic strategies to prevent or treat atrial fibrillation may improve prognosis in patients with LMCAD who are undergoing CABG. (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization [EXCEL]; NCT01205776).

Simple Amiodarone Protocol Reduces Postoperative Atrial Fibrillation

Background

Incorporating amiodarone into an existing postoperative atrial fibrillation (AF) prevention pathway may reduce postoperative AF and length of stay (LOS).

Methods

From July 2002 through December 2002, 476 consecutive cardiac surgical patients were managed with an AF prevention protocol using aggressive potassium replacement, intraoperative/ postoperative magnesium supplementation, and postoperative resumption of β-blockers. From January 2003 through June 2003, 592 additional patients were subjected to the same protocol except amiodarone was initiated intraoperatively (150 mg intravenously) and continued postoperatively until discharge (200 mg orally three times daily). Incidence of AF, postoperative LOS, and AF risk factors were collected prospectively and compared using regression models with propensity scores to adjust for dissimilarities between groups.

Results

Incorporating amiodarone into an existing AF protocol resulted in a 45% reduction in postoperative AF (29% [136/476] versus 16% [94/592], P < 0.0001). After adjustment for covariates and propensity score, the relative risk reduction with amiodarone in this protocol remained significant (P = 0.001, RR 0.65, 95% CI 0.5–0.8). Multivariate risks for postoperative AF included no amiodarone (P = 0.0001), age (P < 0.0001), ejection fraction <40% (P = 0.0005), ventilator support >24 hours (P = 0.002), no postoperative β-blocker (P = 0.002), and mitral valve procedure (P = 0.03). When postoperative AF did occur, risk adjusted LOS was less in patients on the amiodarone protocol (mean 9.4 days versus 13.1 days, P = 0.06). Readmission after discharge for any reason (10% [49/476] versus 8% [45/592], P = 0.1) or for AF (1.1% [5/476] versus 0.7% [4/592], P = 0.5) was similar between groups.

Conclusion

Amiodarone initiated intraoperatively followed by oral dosing significantly reduces postoperative AF and tends to reduce LOS if AF occurs.

Comparison of posttransplant outcomes in patients with no, acute, or chronic amiodarone use before heart transplantation

Background

Major concerns about the safety of pretransplant amiodarone use have been raised. As a result of its long half-life, the cardiac allograft is exposed to amiodarone posing potential risks such as bradycardia, requirement for pacemaker implantation, or increased mortality after heart transplantation (HTX).

Objective

The aim of this study is to investigate the posttransplant outcomes of patients with no, acute, or chronic amiodarone use before HTX.

Methods

This retrospective single-center study included 530 adult patients who received HTX between 06/1989 and 12/2012. Patients were stratified by their amiodarone therapy before HTX: no continuous amiodarone use (≤90 days before HTX), acute amiodarone use (≤90 days before HTX), and chronic amiodarone use (>90 days before HTX). Differences between the 3 groups in demographics, posttransplant medication, echocardiographic features, heart rates including occurrences of bradycardia, permanent pacemaker implantation, atrial fibrillation (AF), and survival were analyzed.

Results

A total of 412 patients (77.7%) were in the “no amiodarone” group, 23 patients (4.4%) in the “acute amiodarone” group, and 95 patients (17.9%) in the “chronic amiodarone” group. Left ventricular ejection fraction (P=0.5819), heart rates including occurrence of bradycardia during posttransplant week 1 (P=0.0979 and P=0.2695), week 2 (P=0.1214 and P=0.8644), week 3 (P=0.1033 and P=0.8894), and week 4 (P=0.2892 and P=0.8644), permanent pacemaker implantation within 30-day (P=0.8644), or overall follow-up after HTX (P=0.8664) were not significant between groups. Patients with chronic pretransplant amiodarone therapy had the lowest rate of early posttransplant AF (P=0.0065). There was no statistically significant difference between groups in 30-day (P=0.8656), 1-year (P=1.0000), 2-year (P=0.8763), 5-year (P=0.5174), or overall posttransplant follow-up mortality (P=0.1936).

Conclusion

Administration of acute or chronic pretransplant amiodarone was not related to an increased occurrence of bradycardia, requirement for permanent pacemaker implantation, or mortality after HTX. Importantly, chronic amiodarone use effectively reduced early AF after HTX, whereas acute amiodarone use showed no such effect.

Impact of a Perioperative Prophylaxis Guideline on Post-Cardiothoracic Surgery Atrial Fibrillation

BACKGROUND

National practice guidelines do not provide clear recommendations on combination pharmacological regimens to reduce cardiothoracic surgery (CTS) postoperative atrial fibrillation (POAF).

OBJECTIVE

This study examines if there is a reduction in POAF rates after implementing a perioperative prophylaxis guideline that includes amiodarone, β-blockers, and high-intensity statins.

METHODS

Data were retrospectively collected on 400 adults (200 patients pre-guideline implementation and 200 patients post-guideline implementation) with a CHA₂DS₂-VASc (Congestive Heart Failure, Hypertension, Age, Diabetes Mellitus, and Vascular Disease) score of at least 3 points after CTS. Data were collected on the incidence of POAF lasting more than 5 minutes and secondary outcomes, including the length of hospitalization, guideline adherence rate, adverse events, and timeliness of POAF treatment.

RESULTS

Guideline implementation increased prophylactic amiodarone ( P < 0.0001), statin ( P = 0.029), and high-intensity statin ( P = 0.002) use without changing β-blocker use (64.5% vs 67.0%, P = 0.673) and reduced POAF (39.5% vs 52.0%, P = 0.016) and ventricular tachycardia (15.5% vs 24.5%, P = 0.034) compared with preguideline rates. Length of hospitalization and other postoperative adverse events, including stroke and mortality, were not statistically different. Subgroup analyses of patients who were adherent to both the amiodarone and β-blocker recommendations (28% of the total) or to all 3 recommended therapies (24% of the total) had significant decreases in POAF ( P = 0.001; P < 0.001), length of hospitalization ( P = 0.023; P = 0.049), length of intensive care unit stay ( P = 0.045; P = 0.040), and ventricular tachycardia ( P = 0.008; P = 0.017) compared with preguideline patients, respectively.

CONCLUSIONS

A perioperative guideline of amiodarone, β-blockers, and high-intensity statins reduced POAF, but better benefits may result from enhanced adherence.

Echocardiography is useful to predict postoperative atrial fibrillation in patients undergoing isolated coronary bypass surgery: A prospective study

Objective:

Postoperative atrial fibrillation is a major complication following coronary artery bypass graft. We hypothesized that, beyond clinical and electrocardiogram (ECG) data, transthoracic echocardiography could improve the prediction of postoperative atrial fibrillation.

Methods:

We prospectively studied 169 patients in sinus rhythm who underwent isolated coronary artery bypass graft in our institution. Clinical, biological, ECG and transthoracic echocardiography data were collected within 24 h before surgery. The patients were continuously monitored during the first five days, and then had daily 12-lead ECG afterwards until discharge. Postoperative atrial fibrillation was defined by any episode >10 min.

Results:

Postoperative atrial fibrillation was found in 65 patients (38%). Compared with those without, patients with postoperative atrial fibrillation were significantly older ( p=0.008), had more frequently a history of hypertension ( p=0.009), history of atrial fibrillation ( p<0.001) and New York Heart Association class ⩾III ( p=0.004). They also had longer PR interval ( p=0.005), higher preoperative NT-pro brain natriuretic peptide level ( p=0.006), left ventricle end-diastolic volume ( p=0.002), indexed left ventricle mass ( p<0.0001), indexed maximal left atrial volume ( p<0.0001), maximal right atrial area ( p<0.001) and lower left ventricle ejection fraction ( p=0.04). In multivariate analysis, history of atrial fibrillation (odds ratio =6.1, 95% confidence interval: 1.4–26.0, p=0.02) and indexed maximal left atrial volume (odds ratio =1.13, 95% confidence interval: 1.1–1.2, p=0.001) were the only two independent predictive factors of postoperative atrial fibrillation. The addition of echocardiographic parameters improved the predictive value (χ2) of the model, from 34 to 57.

Conclusion:

A history of atrial fibrillation and indexed left atrial maximal volume are the best predictors of the occurrence of postoperative atrial fibrillation following coronary artery bypass graft. The identification of high risk population of postoperative atrial fibrillation using these two factors could lead to the development of targeted strategies to limit this frequent complication in these patients.

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.

Novel Use of Ranolazine as an Antiarrhythmic Agent in Atrial Fibrillation

Objective: To review the limitations of current antiarrhythmic drugs in atrial fibrillation (AF) and discuss the rationale and clinical trials supporting the use of ranolazine in AF. Data Sources: MEDLINE was searched from 1980 to September 2016 using the terms ranolazine, atrial fibrillation, coronary artery bypass grafting, and valve surgery. Study Selection and Data Extraction: English-language studies and reviews assessing antiarrhythmic drugs, including ranolazine, were incorporated. Data Synthesis: The use of ranolazine monotherapy has been evaluated in 2 clinical trials. In the RAFFAELLO trial, higher doses of ranolazine showed a trend toward lower AF recurrence versus placebo ( P = 0.053), but further evidence is needed to support its use as a sole therapeutic agent. Ranolazine has shown utility in a limited number of studies as an adjunctive agent, which is critical for those in whom standard therapy is inadequate or the adverse event profile precludes optimized standard therapy. In the HARMONY trial, ranolazine 750 mg and dronedarone 225 mg twice daily reduced the AF burden by 59.1% from baseline ( P = 0.008 vs placebo). In a trial by Koskinas and colleagues, patients receiving ranolazine 1500 mg once and intravenous amiodarone had a higher conversion rate than those receiving amiodarone alone ( P = 0.024). There are also promising studies for the prevention and treatment of post–cardiothoracic surgery AF, which require further investigation. Conclusions: Ranolazine’s pharmacological properties and available evidence suggest potential for its use in AF.

Left ventricular shape predicts different types of cardiovascular events in the general population

OBJECTIVE

To investigate whether sphericity volume index (SVI), an indicator of left ventricular (LV) remodelling, predicts incident cardiovascular events (coronary heart disease, CHD; all cardiovascular disease, CVD; heart failure, HF; atrial fibrillation, AF) over 10 years of follow-up in a multiethnic population (Multi-Ethnic Study of Atherosclerosis).

METHODS

5004 participants free of known CVD had magnetic resonance imaging (MRI) in 2000-2002. Cine images were analysed to compute, [Formula: see text] equivalent to LV volume/volume of sphere with length of LV as the diameter. The highest (greatest sphericity) and lowest (lowest sphericity) quintiles of SVI were compared against the reference group (2-4 quintiles combined). Risk-factor adjusted hazard's ratio (HR) from Cox regression assessed the predictive performance of SVI at end-diastole (ED) and end-systole (ES) to predict incident outcomes over 10 years in retrospective interpretation of prospective data.

RESULTS

At baseline, participants were aged 61±10 years; 52% men and 39%/13%/26%/22% Cauc/Chinese/Afr-Amer/Hispanic. Low sphericity was associated with higher Framingham CVD risk, greater coronary calcium score and higher N-terminal pro-brain natriuretic peptide (NT-proBNP); while increased sphericity was associated with higher NT-proBNP and lower ejection fraction. Low sphericity predicted incident CHD (HR: 1.48, 1.55-2.59 at ED) and CVD (HR: 1.82, 1.47-2.27 at ED). However, both low (HR: 1.81, 1.20-2.73 at ES) and high (HR: 2.21, 1.41-3.46 at ES) sphericity predicted incident HF. High sphericity also predicted AF.

CONCLUSIONS

In a multiethnic population free of CVD at baseline, lowest sphericity was a predictor of incident CHD, CVD and HF over a 10-year follow-up period. Extreme sphericity was a strong predictor of incident HF and AF. SVI improved risk prediction models beyond established risk factors only for HF, but not for all CVD or CHD.

Comparison of the effects of bepridil and aprindine for the prevention of atrial fibrillation after cardiac and aortic surgery: A prospective randomized study

BACKGROUND

Approximately one-third of the patients undergoing cardiovascular surgery reportedly experience paroxysmal atrial fibrillation (AF) during the postoperative period. However, the usefulness of antiarrhythmic drugs for preventing postoperative AF recurrence in the Japanese population has not been extensively studied.

METHODS

From a total of 118 patients who developed postoperative paroxysmal AF between April 2009 and March 2011, 72 patients (45 men, mean age 68±8 years) requiring treatment for postoperative AF due to symptoms lasting ≥30 min were enrolled to prospectively investigate the efficacy of oral bepridil (100 mg/day, n=37) or aprindine (40 mg/day, n=35).

RESULT

The AF recurrence-free survival rates at 1, 3, 7, and 14 days were 100%, 94%, 57%, and 49%, respectively, in the aprindine group, and 100%, 97%, 86%, and 76%, respectively, in the bepridil group (P=0.028, aprindine vs. bepridil).

CONCLUSION

Bepridil, at a fixed dose of 100 mg/day, was considered to be more effective than a routine dose of aprindine for the prevention of postoperative AF recurrence.

Carperitide and atrial fibrillation after coronary bypass grafting: the Nihon University working group study of low-dose HANP infusion therapy during cardiac surgery trial for postoperative atrial fibrillation

BACKGROUND

Occurrence of atrial fibrillation after cardiac surgery is associated with long-term mortality. We investigated whether infusion of human atrial natriuretic peptide (carperitide) could prevent postoperative atrial fibrillation.

METHODS AND RESULTS

A total of 668 patients who underwent isolated coronary artery bypass grafting were randomized to receive infusion of carperitide or physiological saline from the initiation of cardiopulmonary bypass. Patients were monitored continuously for 1 week after surgery to detect atrial fibrillation. The risk factors were investigated by Cox proportional hazard model. Postoperative atrial fibrillation occurred in 41 of 335 patients (12.2%) from the carperitide group versus 110 of 333 patients (32.7%) from the placebo group (P<0.0001). Postoperative levels of angiotensin-II, aldosterone, creatine kinase MB isoenzyme, human heart fatty acid-binding protein, and brain natriuretic peptide were all significantly lower in the carperitide group. The risk factors for postoperative atrial fibrillation by the Cox proportional hazard model were an age ≥70 years, emergency surgery, preoperative aldosterone level >150 ng/mL, preoperative nonuse of angiotensin receptor antagonists, preoperative use of calcium antagonists, postoperative nonuse of β-blockers, postoperative nonuse of aldosterone blockers, and nonuse of carperitide.

CONCLUSIONS

-Perioperative carperitide infusion reduced the occurrence of postoperative atrial fibrillation. Accordingly, carperitide could be a useful option for preventing postoperative atrial fibrillation.

CLINICAL TRIAL REGISTRATION

-URL: http://www.umin.ac.jp. Unique Identifier: UMIN000003958.

Preventive effect of intraoperative landiolol administration on atrial fibrillation after off-pump coronary artery bypass grafting

INTRODUCTION

Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery that is associated with an increased incidence of other complications. This study evaluated the safety and efficacy of landiolol hydrochloride--an ultrashort-acting β1-selective blocker and highly regulated drug, positioned as a class 1 antiarrhythmic in Japan guidelines--for the prevention of AF after off-pump coronary artery bypass grafting (CABG).

METHODS

Between January 2011 and November 2013, 116 patients underwent CABG at Fukuoka University Hospital. They were divided into two groups: group L consisted of patients who were administered landiolol hydrochloride at 2 μg/kg/min after completion of all distal anastomoses; group C was the control group consisting of patients who were not administered landiolol. Patient backgrounds, intraoperative variables and incidence of postoperative complications were compared.

RESULTS

No significant between-group differences were observed in patient backgrounds or incidence of complications other than postoperative AF, which occurred significantly less frequently in group L. After administration of landiolol, heart rate decreased but no change was observed in arterial pressure or other parameters, and patient hemodynamics remained stable.

CONCLUSION

Intraoperative and perioperative administration of low-dose landiolol has a preventive effect on the development of AF after CABG surgery.

Acute intraoperative effect of intravenous amiodarone on right ventricular function in patients undergoing valvular surgery

BACKGROUND

Amiodarone is commonly used in the acute care setting. However the acute hemodynamic and echocardiographic effect of intravenous amiodarone administered intraoperatively on right ventricular (RV) systolic and diastolic function using transesophageal echocardiography (TEE) has not been described.

METHODS

The study design was a randomized controlled trial in elective cardiac surgical patients undergoing valvular surgery. Patients received an intravenous loading dose of 300 mg of either amiodarone or placebo in the operating room, followed by an infusion of 15 mg/kg for two days. Hemodynamic profiles, echocardiographic measurement of RV and left ventricular (LV) dimensions, Doppler interrogation of tricuspid and mitral valve, hepatic and pulmonary venous flow combined with tissue Doppler imaging of the tricuspid and mitral valve annulus were obtained before and after bolus.

RESULTS

Although more patients in the placebo group had chronic obstructive lung disease (14 vs 6, p=0.05) and diabetes (14 vs 5; p=0.0244), there was no difference in terms of baseline hemodynamic, 2D and Doppler variables. After bolus, a significant increase in pulmonary artery pressure, central venous pressure and pulmonary vascular resistance index (p<0.05) was observed in the amiodarone group with reduction in systolic to diastolic (S/D) ratio of the hepatic (p=0.0247) and pulmonary venous (p=0.0052) velocity.

CONCLUSION

Acute administration of amiodarone is associated with alteration in RV diastolic properties and has minimal negative inotropic effect on RV systolic function in cardiac surgical patients with valvular disease.

Interatrial conduction disturbance in postoperative atrial fibrillation: a comparative study of P-wave dispersion and Doppler myocardial imaging in cardiac surgery

Objective

Disturbances of interatrial conduction have been proposed as one of the contributing mechanisms of postoperative atrial fibrillation (AF). P-wave dispersion has been recognized as a sensitive tool for detecting interatrial conduction disturbances. Doppler myocardial imaging (DMI) has been validated as a non-invasive tool to indirectly reflect electrical atrial activation and therefore is used in this study to detect possible interatrial electromechanical disturbances after cardiac surgery.

Methods

30 patients (23 men, age 62 ± 1 years) admitted for coronary bypass surgery with no prior history of AF were included in this investigation. Echocardiography and electrocardiograms (ECG) were obtained on the day before and after surgery. In addition to standard echocardiography, DMI-loops were acquired from the apical window. The following time intervals were derived off-line from the free right atrial (RA), left atrial (LA) lateral and LA posterior wall: onset P-wave to start (P to A’start), to peak (P to A’peak) and to end of atrial deformation (total electromechanical activity). These intervals were compared to each other and to P-wave dispersion derived from the recorded ECGs.

Results

All patients were in sinus rhythm during their postoperative assessment, but 11 patients presented episodes of AF within the first three postoperative days. Atrial electromechanical activation was earliest in the RA and latest in the lateral LA. In patients with AF, P-wave dispersion was significantly prolonged postoperatively (mean: +18.6 ms; 95% confidence interval (CI): 12.1–25.2 ms; p < 0.001) compared to non-AF patients (mean: -2.4 ms; CI: -6.6–1.9 ms). P dispersion was closely correlated to P to A’start intervals (from RA to LA lat.: preop.: rho = 0.74, postop.: rho = 0.87; p < 0.001). Prolonged right to left conduction interval was associated with an elevated risk for AF (from RA to LA lat.: odds ratio 1.13 (CI:1.03-1.24); p: 0.007.

Conclusion

DMI enabled detection of interatrial conduction disturbances in concordance to findings of prolonged postoperative P-wave dispersion. Equally effective to P-wave dispersion, this simple and reproducible tool might help to early identify the risk for postoperative AF, thus extending the informative value of routine postoperative echocardiography.

Atrial fibrillation

Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years.

[Atrial fibrillation in the ICU. Distinct entity--special treatment?]

Atrial fibrillation (AF) is the single most frequent arrhythmia in the intensive care unit, occurring among 44-61 % of all patients with arrhythmias in the intensive care unit. The success rate of electrical cardioversion (DC-CV) early after surgery is as low as 10-35 % in postoperative AF but 6 weeks after discharge 90 % are in sinus rhythm (SR). Several guidelines recommend rate control in these patients and rate control with β-blockers and calcium channel blockers is not inferior with respect to outcome, 6 min walk test, and quality of life. DC-CV is recommended in unstable and heart failure patients. The term resistant AF is suggested for that distinct situation of AF not amenable to cardioversion solely in the acute phase of critical illness.

Atrial fibrillation and heart failure in the elderly

Atrial fibrillation (AF) is a common clinical problem in elderly patients and especially in those with heart failure (HF). It is a major risk factor for serious cardiovascular events, such as stroke, HF and premature death. Both the prevalence and incidence of AF increase with age and its prevalence in the United States are estimated at more than 2.2 million, with nearly 75% of patients aged >65 years. Aging-related atrial remodeling with fibrosis, dilation and mitochondrial DNA mutations predispose elderly patients to AF. Current management options for AF, including rate control and anticoagulation therapy, can be successfully applied to the elderly population. New antiarrhythmic and anticoagulation medications such as dronedarone and dabigatran, respectively, can impact the approach to therapy in the elderly. Non-pharmacological options such as catheter-based ablation have also gained prominence and have been incorporated into the guidelines for management of AF. However, more trials in the elderly and very elderly segments are needed to clarify the safety and long-term efficacy of the new treatment options.

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.

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.

Management of arrhythmias in the perioperative setting

Perioperative arrhythmias are a common complication of surgery, with incidence ranging from 4% to 20% for noncardiothoracic procedures, depending on the type of surgery performed. The immediate postoperative period is a dynamic time and is associated with many conditions conducive to the development of postoperative arrhythmias. The presence of postoperative atrial fibrillation is associated with increased morbidity, ICU stay, length of hospitalization, and hospital costs. The associated burdens are expected to rise in the future, given that the population undergoing cardiac surgery is getting older and sicker. Thousands of patients undergo major surgery each year and a major complication of these procedures is the occurrence of perioperative arrhythmia. It is imperative for clinicians to be up-to-date on current management of these arrhythmias.

Ranolazine: clinical applications and therapeutic basis

Ranolazine is currently approved for use in chronic angina. The basis for this use is likely related to inhibition of late sodium channels with resultant beneficial downstream effects. Randomized clinical trials have demonstrated an improvement in exercise capacity and reduction in angina episodes with ranolazine. This therapeutic benefit occurs without the hemodynamic effects seen with the conventional antianginal agents. The inhibition of late sodium channels as well as other ion currents has a central role in the potential use of ranolazine in ischemic heart disease, arrhythmias, and heart failure. Despite its QTc-prolonging action, albeit minimal, clinical data have not shown a predisposition to torsades de pointes, and the medication has shown a reasonable safety profile even in those with structural heart disease. In this article we present the experimental and clinical data that support its current therapeutic role, and provide insight into potential future clinical applications.

Interventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery

BACKGROUND

Atrial fibrillation is a common post-operative complication of cardiac surgery and is associated with an increased risk of post-operative stroke, increased length of intensive care unit and hospital stays, healthcare costs and mortality. Numerous trials have evaluated various pharmacological and non-pharmacological prophylactic interventions for their efficacy in preventing post-operative atrial fibrillation. We conducted an update to a 2004 Cochrane systematic review and meta-analysis of the literature to gain a better understanding of the effectiveness of these interventions.

OBJECTIVES

The primary objective was to assess the effects of pharmacological and non-pharmacological interventions for preventing post-operative atrial fibrillation or supraventricular tachycardia after cardiac surgery. Secondary objectives were to determine the effects on post-operative stroke or cerebrovascular accident, mortality, cardiovascular mortality, length of hospital stay and cost of treatment during the hospital stay.

SEARCH METHODS

We searched the Cochrane Central Register of ControlLed Trials (CENTRAL) (Issue 8, 2011), MEDLINE (from 1946 to July 2011), EMBASE (from 1974 to July 2011) and CINAHL (from 1981 to July 2011).

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) that included adult patients undergoing cardiac surgery who were allocated to pharmacological or non-pharmacological interventions for the prevention of post-operative atrial fibrillation or supraventricular tachycardia, except digoxin, potassium (K(+)), or steroids.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted study data and assessed trial quality.

MAIN RESULTS

One hundred and eighteen studies with 138 treatment groups and 17,364 participants were included in this review. Fifty-seven of these studies were included in the original version of this review while 61 were added, including 27 on interventions that were not considered in the original version. Interventions included amiodarone, beta-blockers, sotalol, magnesium, atrial pacing and posterior pericardiotomy. Each of the studied interventions significantly reduced the rate of post-operative atrial fibrillation after cardiac surgery compared with a control. Beta-blockers (odds ratio (OR) 0.33; 95% confidence interval) CI 0.26 to 0.43; I(2) = 55%) and sotalol (OR 0.34; 95% CI 0.26 to 0.43; I(2) = 3%) appear to have similar efficacy while magnesium's efficacy (OR 0.55; 95% CI 0.41 to 0.73; I(2) = 51%) may be slightly less. Amiodarone (OR 0.43; 95% CI 0.34 to 0.54; I(2) = 63%), atrial pacing (OR 0.47; 95% CI 0.36 to 0.61; I(2) = 50%) and posterior pericardiotomy (OR 0.35; 95% CI 0.18 to 0.67; I(2) = 66%) were all found to be effective. Prophylactic intervention decreased the hospital length of stay by approximately two-thirds of a day and decreased the cost of hospital treatment by roughly $1250 US. Intervention was also found to reduce the odds of post-operative stroke, though this reduction did not reach statistical significance (OR 0.69; 95% CI 0.47 to 1.01; I(2) = 0%). No significant effect on all-cause or cardiovascular mortality was demonstrated.

AUTHORS' CONCLUSIONS

Prophylaxis to prevent atrial fibrillation after cardiac surgery with any of the studied pharmacological or non-pharmacological interventions may be favored because of its reduction in the rate of atrial fibrillation, decrease in the length of stay and cost of hospital treatment and a possible decrease in the rate of stroke. However, this review is limited by the quality of the available data and heterogeneity between the included studies. Selection of appropriate interventions may depend on the individual patient situation and should take into consideration adverse effects and the cost associated with each approach.

Feasibility of landiolol and bisoprolol for prevention of atrial fibrillation after coronary artery bypass grafting: a pilot study

BACKGROUND

We previously performed a trial of intravenous landiolol hydrochloride during and after cardiac surgery (the PASCAL trial) and demonstrated a preventive effect on postoperative atrial fibrillation (AF). In the present study, we investigated the efficacy of increasing the dose and administration period of landiolol for prevention of postoperative AF, as well as the effect of oral bisoprolol in the early postoperative period.

PATIENTS AND METHODS

A total of 105 patients who underwent coronary artery bypass grafting were randomized to 3 groups: a group receiving intravenous landiolol perioperatively at 5 μg/kg/min for 3 days (group L), a group receiving oral bisoprolol postoperatively together with landiolol (group LB), and a control group without beta-blocker therapy (group C). The primary end point was the presence/absence of postoperative AF. Secondary end points were (1) the early clinical outcome, (2) hemodynamics, (3) cardiac enzymes (creatine kinase isoenzyme MB, troponin-I, and human heart fatty acid-binding protein), (4) high-sensitivity C-reactive protein (hs-CRP) and pentraxin-3, (5) asymmetric dimethylarginine (ADMA), and (6) brain natriuretic peptide.

RESULTS

Postoperative AF occurred in 14.5% of group L, 9.1% of group LB, and 35.3% of group C. A significant difference was observed between groups LB and C. Significantly higher levels of troponin-I, human heart fatty acid-binding protein, hs-CRP, pentraxin-3, and ADMA were noted in group C than in groups L and LB.

CONCLUSIONS

Landiolol and bisoprolol prevented postoperative AF. The anti-ischemic, anti-inflammatory, and anti-oxidant effects of these beta-blockers presumably inhibited the onset of AF.

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.

Examining the safety of amiodarone

INTRODUCTION

Amiodarone is the most widely used antiarrhythmic agent, with demonstrated effectiveness against all the spectrum of cardiac tachyarrhythmias. The risk of adverse effects acts as a limiting factor to its utilization especially in the long term. This article systematically reviews the published evidence on amiodarone versus placebo to examine its safety as an antiarrhythmic drug.

AREAS COVERED

Authors collected data on adverse effects reported in 49 randomized placebo-controlled trials with amiodarone. Adverse effects were classified according to the organ/system involved. Pooled estimates of the number needed to treat (NNT) and to harm (NNH) versus placebo were calculated.

EXPERT OPINION

Amiodarone is effective for both the acute conversion of atrial fibrillation (AF) (11 trials, NNT = 4 at 24 h; p = 0.003) and the prevention of postoperative AF (18 trials, NNT = 8; p < 0.001), although with an increased risk of bradycardia, hypotension, nausea or phlebitis (pooled NNH = 4; p < 0.001). Amiodarone administration for the maintenance of sinus rhythm has a favorable net clinical benefit (pooled NNT = 3; p < 0.001 versus pooled NNH for either thyroid toxicity, gastrointestinal discomfort, skin toxicity or eye toxicity = 11; p < 0.001). Treatment with amiodarone for the prophylaxis of sudden cardiac death has less favorable net clinical benefit (15 trials, NNT = 38; p < 0.001 versus NNH for either thyroid toxicity, hepatic toxicity, pulmonary toxicity or bradycardia = 14; p < 0.001). Amiodarone treatment in this setting should be used in only selected cases.