Prophylaxis Against Atrial Fibrillation after Cardiac Surgery: Beneficial Effect of Perioperative Metoprolol

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.

Combination prophylactic amiodarone with beta-blockers versus beta-blockers in atrial fibrillation after cardiac surgery: A systematic-review and meta-analysis

BACKGROUND

Guideline recommendations regarding the preferred preventive measures for postoperative atrial fibrillation (POAF) are unclear, nor have we found any review articles addressing the combination of amiodarone and beta-blockers for the prevention of POAF.

OBJECTIVES

To investigate the efficacy and safety of combination beta-blockers and amiodarone in the prevention of POAF while also comparing the use of amiodarone and beta-blockers individually.

METHODS

We used Pubmed as the primary resource. POAF incidence was the primary outcome of this study. The secondary outcomes were hospital length of stay (LOS), ICU LOS, treatment-related drug discontinuation (TRDD), and mortality. The random-effects model assessed all pooled outcomes with 95% confidence intervals. Statistical significance was set at p≤0.05.

RESULTS

The amiodarone subgroup of POAF incidence saw a Risk Ratio (RR) of 0.81 [0.63, 1.06], p=0.12, while the combination subgroup resulted in a RR of 0.63 [0.49, 0.80], p <0.001. TRDD for the amiodarone subgroup resulted in a RR of 0.68 [0.25, 1.82], p=0.44, while the combination subgroup saw a RR of 0.84 [0.57, 1.23], p=0.36. For mortality, the amiodarone subgroup resulted in a RR of 0.97 [0.48, 1.98], p=0.93, while the combination subgroup resulted in a RR of 1.04 [0.27, 4.05], p=0.96. Both hospital and ICU LOS saw no significant difference between treatment arms for both the combination subgroup and amiodarone alone. Except for the incidence of postoperative atrial fibrillation (POAF) in the combination prophylaxis group, most of the measured outcomes did not meet the optimized information size (OIS) that was estimated.

CONCLUSION

Combination prophylaxis with amiodarone and beta-blockers significantly lowered risks of POAF incidence in comparison to beta-blockers alone while also having comparative mortality and TRDD outcomes.

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.

Mechanisms, Prevention, and Treatment of Atrial Fibrillation After Cardiac Surgery: A Narrative Review

New onset of postoperative atrial fibrillation (AF) generally is recognized as a frequent and debilitating complication after cardiac surgery, contributing to a considerable health- care cost. Extensive research has been conducted to study the underlying mechanisms and risk factors of AF in the perioperative period. Many options have been suggested to lower the incidence, and the concurrent cost in health resources. This review attempts to synthesize the large body of existing literature on AF, as well as expand and illustrate the available knowledge on its management strategies. The latter incorporates recent developments in the anesthesthetic approach as well as in the pharmacologic arsenal. In addition, the current review provides a tool for understanding the pathophysiology of AF and for reducing the occurrence after cardiac surgery. By using it, clinicians can manage patients with AF in the perioperative period of cardiac surgery and minimize the relatively high economic cost that accompanies it.

Meta-analysis of the benefit of beta-blockers for the reduction of isolated atrial fibrillation incidence after cardiac surgery

Objectives

Postoperative atrial fibrillation (POAF) is a common problem of cardiac surgery. Beta-blockers are recognized as effective prophylactic agents available for POAF management. To better understand its effect on isolated atrial fibrillation after cardiac surgery, a meta-analysis was conducted.

Methods

Randomized controlled trials (RCTs) were searched and filtered by comparing the efficacy of beta-blockers and control users in isolated POAF for cardiac surgery. Seventeen RCTs were identified and analyzed by typical meta-analysis methods. The search was performed from inception to May 31, 2020. Subgroup analyses were conducted for type of surgery and beta-blocker, starting time and route of administration of beta-blocker, and dosage of intravenous landiolol hydrochloride.

Results

Beta-blockers were effective in reducing isolated POAF risk (risk ratio [RR], 0.52 [0.41, 0.66], P = .31, I² = 12%). In subgroup analyses, beta-blocker administration during postoperative period (RR, 0.43 [0.29, 0.62], P = .84, I² = 0%) and on-pump coronary artery bypass graft (RR, 0.34 [0.04, 3.15], P = .56, I² = 0%) had lowest risk of isolated POAF incidence. Intravenous landiolol hydrochloride at 2 μg/kg/min also had low risk of isolated POAF occurrence.

Conclusions

Beta-blocker treatment helps to reduce isolated atrial fibrillation incidence after cardiac surgery. Our subgroup analyses also reveal postoperative beta-blocker administration after on-pump coronary artery bypass graft surgery is most effective in reducing isolated POAF risk. Intravenous landiolol hydrochloride at a dosage of 2 μg/kg/min has also displayed favorable results. Further trials may be required to explore these factors.

Perioperative Beta-Blocker for Atrial Fibrillation after Cardiac Surgery: A Meta-Analysis

Background This meta-analysis was conducted to evaluate the impact of perioperative use of beta-blocker (BB) on postoperative atrial fibrillation (POAF) after cardiac surgery other than isolated coronary artery bypass grafting (CABG).

Methods Five online databases were searched. Studies were included if they (1) enrolled patients who underwent cardiac surgery other than isolated CABG and (2) demonstrated the impact of perioperative use of BB on POAF based on the randomized controlled trial or adjusted analysis. The primary outcome was the occurrence rates of POAF after cardiac surgery. A meta-regression and subgroup analysis were performed according to the proportion of patients with cardiac surgery other than isolated CABG and the timing of BB use, respectively.

Results Thirteen articles (5 randomized and 8 nonrandomized studies: n = 25,496) were selected. Proportion of enrolled patients undergoing cardiac surgery other than isolated CABG ranged from 7 to 100%. The BBs were used in preoperative, postoperative, and both periods in 5, 5, and 3 studies, respectively. The pooled analyses showed that the risk of POAF was significantly lower in patients with perioperative BB than those without (odds ratio, 95% confidence interval = 0.56, 0.35–0.91 and 0.70, 0.55–0.91 in randomized and nonrandomized studies, respectively). The risk of POAF was lower in the BB group irrespective of the proportion of nonisolated CABG. Benefit regarding in-hospital mortality was inconclusive. Perioperative stroke and length of stay were not significantly different between BB and non-BB groups.

Conclusions Perioperative use of BB is effective in preventing POAF even in patients undergoing cardiac surgery other than isolated CABG, although it did not translate into improved clinical outcomes.

Perioperative beta-blockers for preventing surgery-related mortality and morbidity in adults undergoing cardiac surgery

BACKGROUND

Randomized controlled trials (RCTs) have yielded conflicting results regarding the ability of beta-blockers to influence perioperative cardiovascular morbidity and mortality. Thus routine prescription of these drugs in unselected patients remains a controversial issue. A previous version of this review assessing the effectiveness of perioperative beta-blockers in cardiac and non-cardiac surgery was last published in 2018. The previous review has now been split into two reviews according to type of surgery. This is an update and assesses the evidence in cardiac surgery only.

OBJECTIVES

To assess the effectiveness of perioperatively administered beta-blockers for the prevention of surgery-related mortality and morbidity in adults undergoing cardiac surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Biosis Previews and Conference Proceedings Citation Index-Science on 28 June 2019. We searched clinical trials registers and grey literature, and conducted backward- and forward-citation searching of relevant articles.

SELECTION CRITERIA

We included RCTs and quasi-randomized studies comparing beta-blockers with a control (placebo or standard care) administered during the perioperative period to adults undergoing cardiac surgery. We excluded studies in which all participants in the standard care control group were given a pharmacological agent that was not given to participants in the intervention group, studies in which all participants in the control group were given a beta-blocker, and studies in which beta-blockers were given with an additional agent (e.g. magnesium). We excluded studies that did not measure or report review outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 63 studies with 7768 participants; six studies were quasi-randomized and the remaining were RCTs. All participants were undergoing cardiac surgery, and in most studies, at least some of the participants were previously taking beta-blockers. Types of beta-blockers were: propranolol, metoprolol, sotalol, esmolol, landiolol, acebutolol, timolol, carvedilol, nadolol, and atenolol. In twelve studies, beta-blockers were titrated according to heart rate or blood pressure. Duration of administration varied between studies, as did the time at which drugs were administered; in nine studies this was before surgery, in 20 studies during surgery, and in the remaining studies beta-blockers were started postoperatively. Overall, we found that most studies did not report sufficient details for us to adequately assess risk of bias. In particular, few studies reported methods used to randomize participants to groups. In some studies, participants in the control group were given beta-blockers as rescue therapy during the study period, and all studies in which the control was standard care were at high risk of performance bias because of the open-label study design. No studies were prospectively registered with clinical trials registers, which limited the assessment of reporting bias. We judged 68% studies to be at high risk of bias in at least one domain.Study authors reported few deaths (7 per 1000 in both the intervention and control groups), and we found low-certainty evidence that beta-blockers may make little or no difference to all-cause mortality at 30 days (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.47 to 1.90; 29 studies, 4099 participants). For myocardial infarctions, we found no evidence of a difference in events (RR 1.05, 95% CI 0.72 to 1.52; 25 studies, 3946 participants; low-certainty evidence). Few study authors reported cerebrovascular events, and the evidence was uncertain (RR 1.37, 95% CI 0.51 to 3.67; 5 studies, 1471 participants; very low-certainty evidence). Based on a control risk of 54 per 1000, we found low-certainty evidence that beta-blockers may reduce episodes of ventricular arrhythmias by 32 episodes per 1000 (RR 0.40, 95% CI 0.25 to 0.63; 12 studies, 2296 participants). For atrial fibrillation or flutter, there may be 163 fewer incidences with beta-blockers, based on a control risk of 327 incidences per 1000 (RR 0.50, 95% CI 0.42 to 0.59; 40 studies, 5650 participants; low-certainty evidence). However, the evidence for bradycardia and hypotension was less certain. We found that beta-blockers may make little or no difference to bradycardia (RR 1.63, 95% CI 0.92 to 2.91; 12 studies, 1640 participants; low-certainty evidence), or hypotension (RR 1.84, 95% CI 0.89 to 3.80; 10 studies, 1538 participants; low-certainty evidence).We used GRADE to downgrade the certainty of evidence. Owing to studies at high risk of bias in at least one domain, we downgraded each outcome for study limitations. Based on effect size calculations in the previous review, we found an insufficient number of participants in all outcomes (except atrial fibrillation) and, for some outcomes, we noted a wide confidence interval; therefore, we also downgraded outcomes owing to imprecision. The evidence for atrial fibrillation and length of hospital stay had a moderate level of statistical heterogeneity which we could not explain, and we, therefore, downgraded these outcomes for inconsistency.

AUTHORS' CONCLUSIONS

We found no evidence of a difference in early all-cause mortality, myocardial infarction, cerebrovascular events, hypotension and bradycardia. However, there may be a reduction in atrial fibrillation and ventricular arrhythmias when beta-blockers are used. A larger sample size is likely to increase the certainty of this evidence. Four studies awaiting classification may alter the conclusions of this review.

Metoprolol in the treatment of cardiovascular disease: a critical reappraisal

BACKGROUND

Extensive clinical experience on metoprolol has been gained in different cardiovascular conditions.

REVIEW

This paper discusses the use of metoprolol, with a focus on the extended-release formulation, in clinical practice in the light of existing evidence and current recommendations. This is a narrative review based on existing evidence and clinical experience of the author. Evidence on the use of metoprolol in heart failure, ischemic artery disease, arterial hypertension, and atrial fibrillation is well-established.

CONCLUSIONS

Metoprolol still appears to be a suitable pharmacological option in different cardiovascular conditions. Research on this molecule is still active and new, promising settings of use are being explored and may provide relevant results in the years to come.

Effect of ColchiciNe on the InciDence of Atrial Fibrillation in Open Heart Surgery Patients: END-AF Trial

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia in patients undergoing cardiac surgery and may result in significant morbidity and increased hospital stay. This study was conducted to determine if colchicine administered preoperatively to patients undergoing cardiac surgery and continued during hospitalization is effective in reducing the incidence of postoperative AF.

METHODS

In this multicenter prospective randomized open-label study, consecutive patients with no history of AF and scheduled to undergo elective cardiac surgery (n = 360) were randomized to colchicine (n = 179) or no-colchicine (n = 181). Main exclusion criteria were history of AF or supraventricular arrhythmias or absence of sinus rhythm at enrolment, and contraindications to colchicine. Colchicine was orally administered 12 to 24 hours preoperatively and continued until hospital discharge. The primary efficacy end point was documented AF lasting more than 5 minutes. Safety end point was colchicine adverse effects.

RESULTS

In-hospital mortality was 3.3%. The primary end point of AF occurred in 63 patients (17.5%): 26 (14.5%) in the colchicine group and 37 (20.5%) in the no-colchicine group (relative risk reduction 29.3% [P = .14]). Diarrhea occurred in 54 patients, 44 (24.6%) on colchicine and 10 (5.5%) on no-colchicine (P < .001). Diarrhea led to discontinuation of colchicine in 23 (52%) of the 44 patients.

CONCLUSION

Colchicine administered preoperatively to patients undergoing cardiac surgery and continued until hospital discharge failed to significantly reduce the incidence of early postoperative AF. Diarrhea was the most common adverse effect of colchicine leading to its discontinuation in more than half of the patients with this adverse effect.

Are beta-blockers effective for preventing post-coronary artery bypass grafting atrial fibrillation? Direct and network meta-analyses

BACKGROUND

Atrial fibrillation is the most common arrhythmia in clinical practice and is a major contributor to mortality. Recently, several studies have reported different results for treatments aimed at reducing the risk of postoperative AF.

AIMS

The aim of this study was to evaluate the efficacy of beta-blockers (BBs) in preventing post-coronary artery bypass grafting (CABG) AF and to compare the efficacies of different BB treatments using a network meta-analytical approach.

METHODS

The PubMed, EMBASE and Cochrane Library databases were searched (Jan 1995 to May 2014) to identify randomized controlled trials. Two independent investigators separately extracted the data using a seven-point scoring system to assess randomization, allocation concealment, blinding, withdrawals and dropouts. A direct meta-analysis of these randomized controlled trials was conducted. Then, six trials comparing different BB treatments for the prevention of postoperative AF were added to perform a Bayesian network meta-analysis with mixed treatment comparisons.

RESULTS

Treatment with BBs was associated with a significant reduction in the postoperative incidence of AF compared with placebo/control [22.37 % compared with 34.45 %, relative risk (RR) = 0.53, 95 % confidence interval (CI): 0.37-0.75, p < 0.00001].

CONCLUSIONS

The network meta-analysis revealed no significant differences among eight types of BB treatments but did provide a ranking. BB treatments could significantly reduce the occurrence of post-CABG AF. Insufficient evidence was available to show that one BB treatment was more effective than the others were. According to our network meta-analysis, bisoprolol and landiolol+bisoprolol are better alternatives compared with the other treatments.

Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care

OBJECTIVES

Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.

DATA SOURCE AND SYNTHESIS

Narrative review of relevant English-language peer-reviewed medical literature.

CONCLUSIONS

Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.

Insights into onco-cardiology: atrial fibrillation in cancer

Atrial fibrillation (AF) has been found to occur with an increased frequency in patients with malignancies, particularly in those undergoing cancer surgery. The occurrence of AF in cancer may be related to comorbid states or a direct tumor effect or may represent a complication of cancer surgical or medical therapy, whereas inflammation may be a common denominator for both conditions. Treating AF in patients with malignancies is a challenge, especially in terms of antithrombotic therapy, because cancer may result in an increased risk of either thrombosis or hemorrhage and an unpredictable anticoagulation response, whereas thromboembolic risk prediction scores such as CHADS2 (Cardiac Failure, Hypertension, Age, Diabetes, and Stroke [doubled]) may not be applicable. The general lack of evidence imposes an individualized approach to the management of AF in those patients, although some general recommendations based on current guidelines in noncancer patients and the existing evidence in cancer patients, where available, may be outlined.