Posterior pericardiotomy to prevent new-onset atrial fibrillation after coronary artery bypass grafting: a systematic review and meta-analysis of 10 randomized controlled trials

Surgical Methods and Devices for Atrial Fibrillation

As technology advances, surgical approaches for atrial fibrillation have diversified. Surgical treatments include Cox-Maze surgery, left atrial appendage occlusion, or closure using a clip. Cox-Maze surgery removes excessive cardiac electrical conduction pathways, ensures electrical signals propagate exclusively through the predetermined maze channel and restores normal heart rhythm. Left atrial appendage closure reduces the risk of long-term disability or death caused by left atrial appendage thromboembolism in patients with atrial fibrillation. These devices are constantly being refined, including bipolar radiofrequency clamps (monopolar or bipolar radiofrequency), left atrial appendage closure devices (external excision using staplers, internal ligation with biomatrix patch occlusion, external device placement with the AtriClip and Endoloop ligature). In addition to surgical interventions, surgical biomaterial materials with biocompatibility and electrical conductivity have emerged in the basic research phase of atrial fibrillation treatment. This review delineates the primary surgical techniques, emphasizing their safety and efficacy in treating atrial fibrillation. An introduction to commonly used surgical equipment is provided as a reference for the clinical management of atrial fibrillation.

A posterior pericardial chest tube is associated with reduced incidence of postoperative atrial fibrillation after cardiac surgery: A propensity score-matched study

Objective

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery that is associated with other adverse outcomes. Recent studies have shown that drainage of pericardial effusion by a posterior pericardial incision reduces the incidence of POAF. An alternative approach is a chest tube placed posteriorly in the pericardium. We evaluated whether the use of a posterior pericardial drain was associated with reduced risk of POAF in patients undergoing coronary artery bypass graft (CABG) and/or aortic valve replacement (AVR).

Methods

This observational study included 2535 patients who underwent CABG (n = 1997), AVR (n = 293), or combined CABG and AVR (n = 245) in Iceland from 2002 to 2020. From our study population, 553 (22%) received a 20-Fr posterior pericardial chest tube in addition to standard mediastinal and left pleural drains. The incidence of POAF in patients with and without a posterior pericardial drain was compared before and after 1:1 propensity score matching.

Results

Of 2535 patients, 1100 were included in the matched cohort. The incidence of POAF was lower in patients receiving posterior pericardial chest tube drainage compared with the control group, both before (34% vs 43%, P < .001) and after (33% vs 43%, P = .002) matching. In a multivariable analysis, posterior pericardial chest tube drainage was independently associated with a reduced risk for POAF (adjusted odds ratio 0.67; 95% confidence interval, 0.52-0.88; P = .003).

Conclusions

This observational study suggested that posterior pericardial chest tube drainage is associated with a significant reduction of POAF after routine CABG and/or AVR procedures. The results are hypothesis-generating and must be confirmed in prospective randomized trials.

[Predictors of New-Onset Atrial Fibrillation in Patients With Chronic Coronary Artery Disease After Coronary Artery Bypass Grafting: a Prospective, Observational, Single-Centre, Non-Randomized Study]

AIM

To study the factors that influence the occurrence of postoperative atrial fibrillation (POAF) in patients with chronic ischemic heart disease (IHD) after coronary artery bypass grafting (CABG).

MATERIAL AND METHODS

This single-center prospective observational non-randomized study included 152 patients with chronic IHD. Mean age of patients was 64.4±5.9 years. All patients after CABG were divided into two groups based on the occurrence of atrial fibrillation (AF) in the early postoperative period: group 1, with POAF (n=43; 28.3%) and group 2, without POAF (n=109; 71.7%). The primary study endpoint was new-onset POAF in the early postoperative (hospital) period after CABG. The secondary study endpoint was in-hospital postoperative complications (non-fatal/fatal acute coronary syndrome (ACS), non-fatal/fatal stroke, major bleeding, death).

RESULTS

Patients with POAF had significantly more pronounced structural and functional changes in the heart than patients with preserved sinus rhythm after CABG: larger left ventricular (LV) volume, greater LV myocardial mass, lower LV systolic function parameters and impaired diastolic function, and an enlarged left atrial (LA) cavity. Analysis of in-hospital complications did not show any differences between the groups associated with the development of POAF. The following risk factors for POAF were identified: age older than 65 years (p=0.022), body mass index ≥30.5 kg/m2 (p=0.020), epicardial adipose tissue thickness >10.5 mm (p=0.015), indexed LA volume >33 ml/m2 (p<0.001), LV myocardial mass index >115 g/m2 (p=0.042), left main coronary artery disease >50% (p=0.043), duration of cardiopulmonary bypass during CABG >60 min (p=0.019), blood potassium concentration in the early postoperative period after CABG (on the first day) <3.6 mmol/l (p<0.001), and pericardial effusion volume in the early postoperative period >88 ml (p<0.001).

CONCLUSION

Determining the risk of developing POAF is important and necessary for the closest monitoring of a patient with chronic IHD in the postoperative period.

Posterior pericardiotomy and the prevention of post-operative atrial fibrillation and cardiac tamponade in isolated coronary artery bypass grafting - A retrospective analysis

BACKGROUND

Post-Operative Atrial Fibrillation (POAF) is the most frequent complication of cardiac surgery and is associated with reduced survival, increased rates of cognitive changes and cerebrovascular accidents, heart failure, renal dysfunction, infection, length of stay and hospital costs. Cardiac tamponade although less common, carries high morbidity and mortality. Shed mediastinal blood in the pericardial space is a major source of intrapericardial oxidative stress and inflammation that triggers POAF. The utilisation of a posterior pericardiotomy (PP) aims to shunt blood from pericardium into the pleural space and have a role in the prevention of POAF as well as cardiac tamponade.

METHODS

2168 patients had undergone isolated Coronary Artery Bypass Grafting at Royal Hobart Hospital from 2008 to 2022. They were divided into PP group vs. control group. Patient baseline demographics, intraoperative data and post-operative outcomes were reviewed retrospectively.

RESULTS

Total incidence of new POAF and cardiac tamponade was 24% and 0.74% respectively. Primary outcome of both the incidence of POAF (20.2% vs. 26.3%, p < 0.05) and Cardiac Tamponade (0% vs. 1.1%, p < 0.05) were less in the pericardiotomy group. A subgroup analysis of patients with recent myocardial infarction showed reduced incidence of POAF in the PP group (p < 0.05). Increasing age, Body Mass Index, poor left ventricular ejection fraction (EF < 30%) and return to theatre were independent predictors of developing POAF. There were similar rates of return to theatre for bleeding however, no cases of tamponade in the pericardiotomy group. There were no complications attributable to left posterior pericardiotomy and the time added to the duration of surgery was minimal.

CONCLUSION

Posterior pericardiotomy is associated with a significant reduction in the incidence of POAF and cardiac tamponade which is safe and efficient.

Postoperative atrial fibrillation (POAF) after cardiac surgery: clinical practice review

Postoperative atrial fibrillation (POAF) after cardiac surgery is associated with elevated morbidity and mortality. Although current prediction models have limited efficacy, several perioperative interventions can reduce patients' risk of POAF. These begin with preoperative medications, including beta-blockers and amiodarone. Moreover, patients should be screened for preexisting atrial fibrillation (AF) so that concomitant surgical ablation and left atrial appendage occlusion can be performed in appropriate candidates. Intraoperative interventions such as posterior pericardiectomy can reduce mediastinal fluid accumulation, which is a trigger for POAF. Furthermore, many preventive strategies for POAF are implemented in the immediate postoperative period. Initiating beta-blockers, amiodarone, or both is reasonable for most patients. Overdrive atrial pacing, colchicine, and steroids have been used by some, although the evidence base is less robust. For patients with POAF, rate-control and rhythm-control strategies have comparable outcomes. Decision-making regarding anticoagulation should recognize that the stroke risk associated with POAF appears to be lower than that for general nonvalvular AF. The evidence that oral anticoagulation reduces stroke risk is less clear for POAF patients than for patients with general nonvalvular AF. Given that POAF tends to be shorter-lived and is associated with greater bleeding risks in the perioperative period, decisions regarding anticoagulation should be individualized. Finally, wearable technology and machine learning algorithms for better predicting and managing POAF appear to be coming soon. These technologies and a comprehensive clinical program could meaningfully reduce the incidence of this common complication.

Pericardial Inflammatory Mediators That Can Drive Postoperative Atrial Fibrillation in Cardiac Surgery Patients

Postoperative atrial fibrillation (POAF) is a common dysrhythmia that affects a significant number of patients undergoing cardiac surgery. Many studies aim to better understand this complex postsurgical complication by analysing circulating biomarkers in patients who develop POAF. More recently, the pericardial space was shown to contain inflammatory mediators that could trigger POAF. In this review we summarise recent studies that examine the immune mediators present in the pericardial space and their potential implications for the pathophysiology of POAF in cardiac surgery patients. Ongoing research in this area should better delineate the multifactorial etiology of POAF, where specific markers may be targeted to reduce the incidence of POAF and improve outcomes for this patient population.

Posterior pericardiotomy for the prevention of atrial fibrillation after cardiac surgery: a systematic review and meta-analysis of 25 randomised controlled trials

BACKGROUND

Atrial fibrillation (AF) associated with postoperative pericardial effusion is the most commonly reported adverse event after cardiac surgery.

AIMS

We aimed to determine the role of posterior pericardiotomy in preventing postoperative AF (POAF).

METHODS

We searched PubMed, Scopus, Web of Science, Ovid, and EBSCO from inception until 30 June 2022. We included randomised clinical trials (RCTs) that compared posterior pericardiotomy (PP) versus control (no PP) in patients undergoing cardiac surgery. The primary endpoint was the incidence of POAF after cardiac surgery. The secondary endpoints were supraventricular arrhythmias, early/late pericardial effusion, pericardial tamponade, pleural effusion, length of hospital/intensive care unit stay, intra-aortic balloon pump use, revision surgery for bleeding, and mortality.

RESULTS

Twenty-five RCTs comprising 4,467 patients were included in this systematic review and meta-analysis. The overall incidence rate of POAF was 11.7% in the PP group compared with 23.67% in the no PP or control group, with a significant decrease in the risk of POAF following PP (odds ratio [OR] 0.49, 95% confidence interval [CI]: 0.38-0.61). Compared with the control group, the risk of supraventricular tachycardia (OR 0.66, 95% CI: 0.43-0.89), early pericardial effusion (OR 0.32, 95% CI: 0.22-0.46), late pericardial effusion (OR 0.15, 95% CI: 0.09-0.25), and pericardiac tamponade (OR 0.18, 95% CI: 0.10-0.33) were lower in the PP group.

CONCLUSIONS

PP is an effective intervention for reducing the risk of POAF after cardiac surgery. Also, PP is economically efficient in terms of decreasing the length of hospital stay.

Postoperative pericardial effusion, pericardiotomy, and atrial fibrillation: An explanatory analysis of the PALACS trial

BACKGROUND

In the Posterior left pericardiotomy for the prevention of atrial fibrillation after cardiac surgery (PALACS) trial, posterior pericardiotomy was associated with a significant reduction in postoperative atrial fibrillation (POAF) after cardiac surgery. We aimed to investigate the mechanisms underlying this effect.

METHODS

We included PALACS patients with available echocardiographic data (n = 387/420, 92%). We tested the hypotheses that the reduction in POAF with the intervention was associated with 1) a reduction in postoperative pericardial effusion and/or 2) an effect on left atrial size and function. Spline and multivariable logistic regression analyses were used.

RESULTS

Most patients (n = 307, 79%) had postoperative pericardial effusions (anterior 68%, postero-lateral 51.9%). The incidence of postero-lateral effusion was significantly lower in patients undergoing pericardiotomy (37% vs 67%; P < .001). The median size of anterior effusion was comparable between patients with and without POAF (5.0 [IQR 3.0-7.0] vs 5.0 [IQR 3.0-7.5] mm; P = .42), but there was a nonsignificant trend towards larger postero-lateral effusion in the POAF group (5.0 [IQR 3.0-9.0] vs 4.0 [IQR 3.0-6.4] mm; P = .06). There was a non-linear association between postero-lateral effusion and POAF at a cut-off at 10 mm (OR 2.70; 95% CI 1.13, 6.47; P = .03) that was confirmed in multivariable analysis (OR 3.5, 95% CI 1.17, 10.58; P = 0.02). Left atrial dimension and function did not change significantly after posterior pericardiotomy.

CONCLUSIONS

Reduction in postero-lateral pericardial effusion is a plausible mechanism for the effect of posterior pericardiotomy in reducing POAF. Measures to reduce postoperative pericardial effusion are a promising approach to prevent POAF.

The effect of posterior pericardiotomy after thoracic aortic surgery

Background

Postoperative pericardial effusion is common after cardiovascular surgery. We aimed to examine the effectiveness of posterior pericardiotomy in reducing the incidence of postoperative pericardial effusion and postoperative atrial fibrillation after thoracic aortic surgery.

Methods

This study included 201 patients who underwent thoracic aortic open surgery between January 2014 and November 2021. We compared surgical outcomes between patients who underwent posterior pericardiotomy and those who did not.

Results

The group that did not undergo posterior pericardiotomy had significantly longer mechanical ventilation duration than the group who did, both in the overall (p = 0.005) and in the propensity-matched cohorts (p = 0.001). The lengths of intensive care unit and hospital stays were significantly longer in the group that did not undergo posterior pericardiotomy compared to the group that did, both in the overall and in the propensity-matched cohorts. The occurrence of postoperative atrial fibrillation and stroke did not differ significantly between the two groups. The amount of pericardial drainage was not significantly lower in the group that underwent posterior pericardiotomy in the overall cohorts (p = 0.09), but the difference was significant in the propensity-matched cohorts (p = 0.04). The amount of mediastinal drainage was significantly lower in the group that underwent posterior pericardiotomy, both in the overall cohorts (< 0.001) and in the propensity-matched cohort (< 0.001). Late pericardial tamponade occurred significantly more frequently in the group that did not undergo posterior pericardiotomy than in the group that did, both in the overall (p = 0.03) and in the propensity-matched cohorts (p = 0.03).

Conclusions

Posterior pericardiotomy has no effect on reducing postoperative atrial fibrillation after thoracic aortic surgery. However, posterior pericardiotomy reduced the occurrence of late pericardial tamponade, length of ICU stay, length of hospital stay, and mechanical ventilation duration after surgery.

Cerebral infarction after cardiac surgery

Cerebral infarction, a common central nervous system complication after adult cardiac surgery, is one of the main factors leading to the poor prognosis of cardiac surgery patients besides cardiac insufficiency. However, there is currently no effective treatment for cerebral infarction. Therefore, early prevention and diagnosis of postoperative cerebral infarction are particularly important. There are many factors and mechanisms during and after cardiac surgery that play an important role in the occurrence of postoperative cerebral infarction, such as intraoperative embolism, systemic inflammatory response syndrome, atrial fibrillation, temperature regulation, blood pressure control, use of postoperative blood products, and so forth. The mechanism by which most risk factors act on the human body, leading to postoperative cerebral infarction, is not well understood, and further research is needed. Therefore, this paper aims to summarize and explain the relevant risk factors, mechanisms, clinical signs, imaging characteristics, and early diagnosis methods of cerebral infarction complications after cardiac surgery, and provides useful data for the establishment of related diagnosis and treatment standards.