Postoperative Atrial Fibrillation: Features, Mechanisms, and Clinical Management

Scores predicting atrial fibrillation after mitral valve surgery: Do we need a more specific score?

Background

Atrial fibrillation after cardiac surgery (POAF) is associated with increased morbidity and mortality. Several scores were used to predict POAF, with variable results. Thus, this study assessed the performance of several scoring systems to predict POAF after mitral valve surgery. Additionally, we identified the risk factors for POAF in those patients.

Methods

This retrospective cohort included 1381 recruited from 2009 to 2021. The patients underwent mitral valve surgery, and POAF occurred in 233 (16.87%) patients. The performance of CHADS2, CHA2DS2-VASc, POAF, EuroSCORE II, and HATCH scores was evaluated.

Results

The median age was higher in patients who developed POAF (60 vs. 54 years; p < .001). CHA2-DS2-VASc, POAF, EuroSCORE II, and HATCH scores significantly predicted POAF, with areas under the curve of the receiver operator curve (AUCROC) of 0.56, 0.61, 0.58, and 0.54, respectively. We identified age > 58 years, body mass index > 28 kg/m2, creatinine clearance < 90 mL/min, reoperative surgery, and preoperative inotropic and intra-aortic balloon pump use as predictors of POAF. We constructed a score from these variables (PSCC-AF). A score > 2 significantly predicted POAF (p < .001). The AUCROC of this score was 0.67, which was significantly higher than the AUCROC of the POAF score (p = .009).

Conclusion

POAF after mitral valve surgery can be predicted based on preoperative patient characteristics. The new PSCC-AF score significantly predicted POAF after mitral valve surgery and can serve as a bedside diagnostic tool for POAF risk screening. Further studies are needed to validate the PSCC-AF-mitral score externally.

Frequency and risk factors of atrial fibrillation after acute abdominal surgery: A prospective cohort study

BACKGROUND AND AIM

Scarce data exist on the true incidence of postoperative atrial fibrillation (POAF) after acute abdominal surgery and associated outcomes. The current study aimed to identify the frequencies of clinically recognized POAF and associated complications, along with their risk factors.

METHODS

This study was a prospective, single-center cohort study of unselected adult patients referred for acute abdominal surgery during a 3-month period. Through careful review, demographics, comorbidity, and surgical characteristics were prospectively drawn from medical charts. The primary outcome was clinically recognized POAF occurring in-hospital. Logistic regression was used to determine the risk factors of POAF and associated complications. A subgroup was enrolled in a feasibility study of peri- and postoperative continuous cardiac rhythm monitoring.

RESULTS

In total, 450 patients were enrolled. Clinically recognized in-hospital POAF was observed in 22 patients (4.9%). All cases were observed in patients aged ≥60 years, corresponding to 22 of 164 patients (13.4%). Multiple risk factors were observed, such as age, prior atrial fibrillation, heart failure, hypertension, diabetes mellitus, chronic renal disease, and major (vs. minor) surgery. POAF was associated with severe in-hospital complications (POAF group 45.5% vs. non-POAF group 8.6%, p < .001) and in-hospital mortality (POAF group 13.6% vs. non-POAF group 3.0%, p = .043). In total, 295 patients were monitored by continuous cardiac rhythm monitoring for 12,148 h, yielding five patients with asymptomatic AF.

CONCLUSIONS

In conclusion, this prospective study of POAF in patients undergoing acute abdominal surgery showed that one in 20 patients developed clinically recognized in-hospital POAF. Multiple risk factors of POAF were identified. POAF was associated with severe complications up to 30 days after surgery.

[Perioperative atrial fibrillation : Diagnosis with underestimated relevance]

Atrial fibrillation (AF) is the most common cardiac arrhythmia in adults, both in general and perioperatively and is associated with significant morbidity and mortality. The age of the patients is a major risk factor. The prevalence of AF in noncardiac surgery (NCS) varies widely from 0.4% to 30% and for cardiac surgery, especially major combined procedures, up to approximately 50%. Ectopic excitation centers and reentry mechanisms at the atrial level are favored as the main process of uncoordinated electrical atrial activity. The loss of atrial contraction can lead to a reduction in cardiac output of up to 20-25%. The increased risk of thromboembolism due to AF extends beyond the perioperative period. Medication-based prevention strategies have not yet gained widespread acceptance. Treatment strategies include frequency and rhythm control as well as the avoidance of thromboembolisms through anticoagulation.

The Management of Postoperative Atrial Fibrillation (POAF): A Systematic Review

Postoperative atrial fibrillation (POAF) refers to new-onset atrial fibrillation (AF) that develops after surgery and is associated with an increased risk of mortality and thromboembolic events. The optimal management and treatment methods for POAF complications are not yet fully established. This systematic review aimed to evaluate the various treatment and management approaches currently available in terms of their suitability, efficacy, and side effects in handling POAF incidence post-surgery. Google Scholar and PubMed electronic databases were searched extensively for relevant articles examining the various management techniques currently used to manage POAF and published between 2018 and 2023. Data were collected on the type of surgery the patients underwent, POAF definition period, intervention, and outcome of interest. Following a systematic assessment guided by the inclusion criteria, 10 of the 579 studies retrieved were included in this study, and 293,417 POAF cases were recorded. Three of these studies used different rhythm control and rate control treatments to manage POAF cases, while seven studies used various anticoagulation therapies to manage POAF incidence. For asymptomatic patients within one to three days of surgery, rate control is sufficient to manage POAF, and routine rhythm control is not needed; rhythm control should be reserved for patients who develop complications such as hemodynamic instability. Anticoagulation was performed in patients whose POAF exceeded four days after surgery. Anticoagulation was associated with an increased risk of mortality, stroke, thromboembolic events, and major bleeding in patients who underwent coronary artery bypass graft (CABG) surgery. In contrast, in a few other studies, anticoagulation treatment led to improved outcomes in patients who developed POAF. A wide range of management methods are available for POAF after different types of surgery. However, there is only limited evidence to guide the clinical practice. The data available are mainly retrospective and insufficient to accurately evaluate the efficacy of the various management methods available for POAF. Future research should make efforts to standardize the treatment for this condition.

Atorvastatin and the influence on postoperative atrial fibrillation after surgical aortic valve replacement (STARC) in adults at Odense University Hospital, Denmark: study protocol for a randomised controlled trial

INTRODUCTION

Atrial fibrillation (AF) is the most common postoperative complication after surgical aortic valve replacement (SAVR) and occurs in up to 50% of the patients. Development of postoperative AF (POAF) is associated with a 2-3 fold increased risk of adverse events, including stroke, myocardial infarction and death.Several studies have implied that prophylactic Atorvastatin therapy could prevent POAF in patients undergoing coronary artery bypass graft. These studies suggest that Atorvastatin has rapid and significant pleiotropic actions that reduce the risk of POAF. However, prophylactic treatment with statins has yet to be understood in SAVR. The aim of this study is to investigate whether prophylactic administration of torvastatin reduces POAF in patients undergoing SAVR.

METHODS AND ANALYSIS

In this investigator-initiated, prospective, parallel-group, randomised, double-blind, placebo-controlled single-centre trial, 266 patients undergoing elective solitary SAVR with bioprosthetic valve, with no prior history of AF, and statin-naïve will be randomised (1:1) to treatment with Atorvastatin (80 mg once daily) or matching placebo for 1-2 weeks prior to and 30 days after surgery. The primary endpoint is POAF defined as an episode of irregular RR-intervals without a traceable p-wave of at least 30 s duration. After discharge and until day 30 after surgery, POAF will be documented by either rhythm strip or 12-lead ECG.

ETHICS AND DISSEMINATION

Protocol approval has been obtained from the Regional Scientific Ethical Committee for Southern Denmark (S-20210159), The Danish Medicines Agency (2021103821) and the Data Protection Agency (21/65621).The trial is conducted in accordance with the Declaration of Helsinki, the ICH-GCP (International Conference on Harmonisation Good Clinical Practice) guidelines and the legal regulations of Denmark. Study findings will be shared via peer-reviewed journal publication and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05076019.

Evidence of Failed Resolution Mechanisms in Arrhythmogenic Inflammation, Fibrosis and Right Heart Disease

Inflammation is a complex program of active processes characterized by the well-orchestrated succession of an initiation and a resolution phase aiming to promote homeostasis. When the resolution of inflammation fails, the tissue undergoes an unresolved inflammatory status which, if it remains uncontrolled, can lead to chronic inflammatory disorders due to aggravation of structural damages, development of a fibrous area, and loss of function. Various human conditions show a typical unresolved inflammatory profile. Inflammatory diseases include cancer, neurodegenerative disease, asthma, right heart disease, atherosclerosis, myocardial infarction, or atrial fibrillation. New evidence has started to emerge on the role, including pro-resolution involvement of chemical mediators in the acute phase of inflammation. Although flourishing knowledge is available about the role of specialized pro-resolving mediators in neurodegenerative diseases, atherosclerosis, obesity, or hepatic fibrosis, little is known about their efficacy to combat inflammation-associated arrhythmogenic cardiac disorders. It has been shown that resolvins, including RvD1, RvE1, or Mar1, are bioactive mediators of resolution. Resolvins can stop neutrophil activation and infiltration, stimulate monocytes polarization into anti-inflammatory-M2-macrophages, and activate macrophage phagocytosis of inflammation-debris and neutrophils to promote efferocytosis and clearance. This review aims to discuss the paradigm of failed-resolution mechanisms (FRM) potentially promoting arrhythmogenicity in right heart disease-induced inflammatory status.

The Impact of Left Atrial Mechanics on Adverse Events and Clinical Outcome After Cardiac Surgery

OBJECTIVES

Post-operative atrial fibrillation (POAF) represents a common complication after cardiac surgery that is associated with unfavorable clinical outcome. Identifying patients at risk for POAF is crucial but challenging. This study aimed to investigate the prognostic potential of speckle tracking echocardiography (STE) on POAF and fatal adverse events from a long-term perspective.

METHODS

A total of 124 patients undergoing elective cardiac surgery were prospectively enrolled and underwent pre-operative STE. Patients were followed prospectively for the occurrence of POAF within the entire hospitalization and reaching the secondary end-points cardiovascular (CV) and all-cause mortality.

RESULTS

Within the study population 43.5% (n = 53) of enrolled individuals developed POAF. After a median follow-up of 3.9 years, 25 (20.2%) patients died. We observed that patients presenting with POAF had lower global peak atrial longitudinal strain (PALS) values compared to the non-POAF arm (POAF: 14.8% [95% CI : 10.9-17.8] vs non-POAF: 19.4% [95% CI : 14.8-23.5], p < 0.001). Moreover, global PALS was a strong and independent predictor for POAF (adjusted Odds Ratio per 1-SD: 0.37 [95% CI : 0.22-0.65], p < 0.001), and independently associated with mortality (adjusted Hazard Ratio per 1-SD: 0.63 [95% CI : 0.40-0.99], p = 0.048). CART analysis revealed a cut-off value of < 17% global PALS as high-risk for both POAF and mortality.

CONCLUSION

Global PALS is associated with the development of POAF following surgery in an unselected patient population undergoing CABG and/or valve surgery. Since patients with global PALS <17% face a poor long-term prognosis, routine assessment of global PALS needs to be considered in terms of proper secondary prevention in the era of personalized medicine.

Nurse Staffing Practices and Postoperative Atrial Fibrillation Among Cardiac Surgery Patients: A Multisite Cohort Study

Background

Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery that is associated with increased morbidity, mortality, and costs. Recent studies suggest that nurse staffing practices are associated with adverse postoperative events, but whether these practices are also related to POAF occurrence is unknown.

Methods

To fill this knowledge gap, a cohort of 6401 cardiac surgery patients admitted to 2 Canadian university health centres (UHC A and UHC B) between 2014 and 2018 was studied. Patients’ cumulative exposure to 4 staffing practices (registered nurse [RN] understaffing, education, experience, and non-RN skill mix) was measured every shift over the first 6 postoperative days, during which 96% of POAF cases occur. The associations of these exposures with in-hospital POAF occurrence were estimated using site-specific multivariable logistic regression models and a mixed-effect model combining data from both sites.

Results

Overall, 563 (27.2%) and 1336 (30.8%) cases of POAF occurred at UHC A and UHC B, respectively. In site-specific models, every 5% increase in the cumulative proportion of understaffed shifts over the first 6 postoperative days was associated with a 3.5% increase in the odds of POAF (adjusted odds ratio [aOR] for UHC A: 1.035; 95% confidence interval [CI]: 1.000-1.070, P = 0.0472; aOR for UHC B: 1.035; 95% CI: 1.013-1.057, P = 0.0019). In the mixed-effect model combining data from both sites, RN understaffing remained significant and was associated with a 3.1% increase in the odds of POAF (aOR: 1.031; 95% CI: 1.014-1.048, P = 0.0003). No other staffing practices were significantly associated with POAF occurrence.

Conclusion

Higher RN understaffing postoperatively is associated with increased POAF occurrence among cardiac surgery patients.

Influence of Dexmedetomidine on Post-operative Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

Background: Previous clinical studies and meta-analysis evaluating the influence of dexmedetomidine on postoperative atrial fibrillation showed inconsistent results. We performed an updated meta-analysis to evaluate the influence of dexmedetomidine on incidence of postoperative atrial fibrillation after cardiac surgery.

Methods: Randomized controlled trials that evaluated the potential influence of dexmedetomidine on the incidence of atrial fibrillation after cardiac surgery were obtained by search of PubMed, Embase, and Cochrane's Library databases from inception to April 12, 2021. A random-effects model incorporating the potential publication bias was used to pool the results. Influences of patient or study characteristics on the efficacy of dexmedetomidine on atrial fibrillation after cardiac surgery were evaluated by meta-regression and subgroup analyses.

Results: Fifteen studies with 2,733 patients were included. Pooled results showed that dexmedetomidine significantly reduced the incidence of atrial fibrillation compared to control (OR: 0.72, 95% CI: 0.55–0.94, p = 0.02) with mild heterogeneity (I² = 26%). Subgroup analysis showed that dexmedetomidine significantly reduced the incidence of atrial fibrillation in studies from Asian countries (OR: 0.41, 95% CI: 0.26–0.66, p < 0.001), but not in those from non-Asian countries (OR: 0.89, 95% CI: 0.71–1.10, p = 0.27; p for subgroup difference = 0.004). Meta-regression analysis showed that the mean age and proportion of male patients may modify the influence of dexmedetomidine on POAF (coefficient = 0.028 and 0.021, respectively, both p < 0.05). Subgroup analysis further showed that Dex was associated with reduced risk of atrial fibrillation after cardiac surgery in studies with younger patients (mean age ≤ 61 years, OR = 0.44, 95% CI: 0.28–0.69, p = 0.004) and smaller proportion of males (≤74%, OR = 0.55, 95% CI: 0.36–0.83, p = 0.005), but not in studies with older patients or larger proportion of males (p for subgroup difference = 0.02 and 0.04).

Conclusions: Current evidence supports that perioperative administration of dexmedetomidine may reduce the risk of incidental atrial fibrillation after cardiac surgery, particularly in Asians.