Management of postoperative atrial fibrillation

Perioperative N-acetylcysteine: evidence and indications

Nonopioid analgesics serve to improve analgesia and limit side effects and risks of perioperative opioids. N-acetylcysteine (NAC), the primary treatment of acetaminophen toxicity, may have perioperative indications, including analgesia. NAC impacts glutathione synthesis, oxidant scavenging, glutamate receptor modulation and neuroinflammation. Potential perioperative benefits include arrhythmia prevention after cardiac surgery, decreased contrast-induced nephropathy, improved post-transplant liver function and superior pulmonary outcomes with general anesthesia. NAC may improve perioperative analgesia, with some studies displaying a reduction in postoperative opioid use. NAC is generally well tolerated with an established safety profile. NAC administration may predispose to gastrointestinal effects, while parenteral administration may carry a risk of anaphylactoid reactions, including bronchospasm. Larger randomized trials may clarify the impact of NAC on perioperative analgesic outcomes.

Understanding Post-Esophagectomy Complications and Their Management: The Early Complications

Esophagectomy is a technically complex operation performed for both benign and malignant esophageal disease. Medical and surgical advancements have led to improved outcomes in esophagectomy patients over the past several decades; however, surgeons must remain vigilant as complications happen often and can be severe. Post-esophagectomy complications can be grouped into early and late categories. The aim of this review is to discuss the early complications of esophagectomy along with their risk factors, work-up, and management strategies with special attention given to anastomotic leaks.

Myocardial Blush Grade Predicts Postoperative Atrial Fibrillation following Mitral Valve Replacement: A Novel Perspective

Background: Atrial fibrillation (AF) remains the most common arrhythmia following mitral valve surgery. Although numerous clinical and laboratory indicators and possible mechanisms of postoperative AF (PoAF) have been described, the role of microvascular dysfunction in pathogenesis has not been assessed. We aimed to evaluate the association between microvascular dysfunction and PoAF in patients undergoing isolated mitral valve replacement. Methods: 188 patients undergoing mitral valve replacement were included in this retrospective study. Demographic characteristics of the patients were recorded. Angiographic assessment of microvascular perfusion was performed using the myocardial blush grading technique for each patient. Univariate and multivariate logistic regression analyses were utilized to determine predictors of PoAF. Results: Of 188 patients (56.69 ± 8.9 years, 39.4% male) who underwent mitral valve replacement, 64 (34%) patients developed PoAF. In the PoAF group, a lower basal hemoglobin level (12.64 ± 0.89 vs. 14.46 ± 0.91 g/dL; p < 0.001), a higher left atrial diameter [5.9 (5.2-6.47) vs. 4.9 (4.5-5.8) cm; p < 0.001], and a lower total blush score (TBS) (8.33 ± 0.84 vs. 8.9 ± 0.31; p < 0.001) were detected. Multivariate logistic regression analysis revealed that preoperative LA diameter (OR:2.057; 95% CI: 1.166-3.63; p = 0.013), preoperative hemoglobin (OR:0.12; 95% CI: 0.058-0.245; p < 0.001), and abnormal TBS (OR:15.1; 95% CI: 1.602-142.339; p = 0.018) were independent predictors of PoAF. Conclusions: Our findings demonstrated that TBS at the preoperative period was an independent predictor of PoAF in patients undergoing isolated mitral valve replacement.

Effect of Perioperative Oral Vitamin C Supplementation on In-Hospital Postoperative Medication Costs for Cardiac Surgery Patients: A Prospective, Single-Centre, Randomised Clinical Trial

BACKGROUND

Due to its antioxidant properties, vitamin C might be a promising and effective strategy for preventing postoperative atrial fibrillation (POAF) after cardiac surgery. This study was aimed at evaluating whether vitamin C supplementation is effective in reducing the cost of in-hospital postoperative medication used for patients undergoing coronary artery bypass (CABG) or valve surgery (±CABG).

OBJECTIVE

The primary goal of this study was to evaluate the impact of perioperative vitamin C supplementation in patients undergoing cardiac surgery on in-hospital postoperative medication costs, while secondary endpoints were the effects on length of stay (LOS) in both the intensive care unit (ICU) and the hospital, and the incidence of POAF.

MATERIAL AND METHODS

From November 2018 to January 2021, 253 patients planned for CABG or valve surgery (±CABG) in AZ Maria Middelares, Ghent, Belgium, and who met the inclusion criteria (≥18 years of age, all having cardiac sinus rhythm, and who provided written informed consent) were randomised into a placebo group or vitamin C group. The medication was administered orally (1 g twice daily), starting from 5 days preoperatively until 10 days postoperatively. The medication used, LOS in the hospital/ICU, and development of clinically relevant POAF in the ICU were registered.

RESULTS

Mean medication costs were €264.6 ± 98.1 for patients in the vitamin C group and €294.9 ± 267.3 for patients in the placebo group. When stratifying according to the type of surgery (CABG or valve surgery [±CABG]), these costs did not significantly differ. There was no significant difference in LOS or the incidence of clinically relevant POAF.

CONCLUSION

Our data did not identify any short-term financial impact on postoperative medication costs after oral perioperative vitamin C supplementation (1 g twice daily) for patients undergoing a CABG procedure or valve surgery (±CABG). No effect was found on the LOS or the incidence of clinically relevant POAF. Potential effects in the longer term, after intravenous administration of vitamin C or in other types of (cardiac) surgery, are still to be investigated.

CLINICAL TRIALS REGISTRATION NUMBER

NCT03592680.

Predictive Values of Systemic Immune-Inflammation Index in New-Onset Atrial Fibrillation Following Coronary Artery Bypass Grafting

INTRODUCTION

We investigated the relationship between the newly-defined systemic immune-inflammation index and the new-onset atrial fibrillation in patients undergoing coronary artery bypass grafting.

METHOD

This study included 392 patients who underwent coronary artery bypass grafting. We divided the participants into two groups as those with and without new-onset atrial fibrillation. Prior to coronary artery bypass grafting, we evaluated blood samples, including systemic immune-inflammation index, and other laboratory parameters of the patients. We formulized the systemic immune-inflammation index score as platelet × neutrophil/lymphocyte counts.

RESULTS

The findings revealed that new-onset atrial fibrillation occurred in 80 (20.4%) of 392 patients during follow-ups. Such patients had higher systemic immune-inflammation index, neutrophil/lymphocyte ratio, and C-reactive protein levels than those who did not develop new-onset atrial fibrillation (P<0.001, P<0.001, P=0.010, respectively). In receiver operating characteristic curve analysis, systemic immune-inflammation index levels > 712.8 predicted new-onset atrial fibrillation with a sensitivity of 85% and a specificity of 61.2% (area under the curve: 0.781, 95% confidence interval: 0.727-0.835; P<0.001).

CONCLUSION

Overall, systemic immune-inflammation index, a novel inflammatory marker, may be used as a decisive marker to predict the development of atrial fibrillation following coronary artery bypass grafting.

Predictive Value of Systemic Immune Inflammation Index for Postoperative Atrial Fibrillation in Patients Undergoing Isolated Coronary Artery Bypass Grafting

Objective:

Inflammation plays an important role in the initiation of postoperative atrial fibrillation (PoAF) in individuals undergoing cardiac surgery, Thus, this study aimed to investigate the predictive value of the systemic immune inflammation index (SII) to develop PoAF in such patients.

Methods:

In total, 391 consecutive patients undergoing an isolated coronary artery bypass grafting (CABG) were retrospectively analyzed. PoAF was defined according to the current guideline. The SII is determined using the following equation: neutrophil (N) × platelet (P) ÷ lymphocyte (L).

Results:

The incidence of PoAF in the present study was 24% (n=97 cases). Multivariate logistic regression analysis revealed that the SII was an independent predictor of PoAF (Odds ratio: 1.002 95% confidence interval: (1.001-1.002), p<0.01). The optimal value of the SII in detecting PoAF was established by a receiver operating characteristic curve assessment, and it was >807.8 with 60.8% sensitivity and 80.9% specificity [area under the curve (AUC): 0.7107]. The AUC value of SII in detecting PoAF was much greater than the AUC values of both the neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) (AUC: 0.6740 and AUC: 0.6426, respectively).

Conclusions:

This study revealed that SII was an independent predictor of PoAF in patients who were operated on for isolated CABG. Additionally, SII had a better discriminative ability for PoAF compared to either NLR or PLR among these cases.

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

BACKGROUND

Atrial fibrillation (AF) is associated with adverse events after cardiac surgery. Multiple studies have reported that posterior pericardiotomy (PP) may be effective for preventing AF after coronary artery bypass grafting (CABG), but some conflicting results have been reported and the quality of evidence from previous meta-analyses has been limited. The present study aimed to systematically evaluate the safety and efficacy of PP for preventing AF after CABG in adults.

METHODS

We conducted a quantitative meta-analysis of randomized controlled trials (RCTs) published before May 31, 2021. The primary outcome was AF after CABG under cardiopulmonary bypass. Secondary outcomes included early pericardial effusion, late pericardial effusion, pericardial tamponade, pleural effusion, length of hospital stay, length of intensive care unit (ICU) stay, pulmonary complications, intra-aortic balloon pump use, revision surgery for bleeding, and mortality.

RESULTS

Ten RCTs with 1829 patients (910 in the PP group and 919 in the control group) were included in the current meta-analysis. The incidence of AF was 10.3% (94/910) in the PP group and 25.7% (236/919) in the control group. A random-effects model indicated that incidence of AF after CABG significantly lower in the PP group than in the control group (risk ratio = 0.45, 95% confidence interval 0.29-0.64, P < 0.0001). PP also effectively reduced the post-CABG occurrence of early pericardial effusion (RR = 0.28, 95% CI 0.15-0.50; P < 0.05), late pericardial effusion (RR = 0.06, 95% CI 0.02-0.16; P < 0.05), and pericardial tamponade (RR = 0.08, 95% CI 0.02-0.33; P < 0.05) as well as the length of ICU stay (weighted mean difference [WMD] = 0.91,95% CI 0.57-1.24; P < 0.05), while increasing the occurrence pleural effusion (RR = 1.51, 95% CI 1.19-1.92; P < 0.05). No significant differences length of hospital stay (WMD =  - 0.45, 95% CI - 2.44 to 1.54, P = 0.66), pulmonary complications (RR = 0.99, 95% CI 0.71-1.39, P = 0.97), revision surgery for bleeding (RR = 0.84, 95% CI 0.43-1.63, P = 0.60), use of IABP (RR = 1, 95% CI 0.61-1.65, P = 1.0), or death (RR = 0.45, 95% CI 0.07-3.03, P = 0.41) were observed between the PP and control groups.

CONCLUSIONS

PP may be a safe, effective, and economical method for preventing AF after CABG in adult patients.

Pulmonary Delivery of Antiarrhythmic Drugs for Rapid Conversion of New-Onset Atrial Fibrillation

Pharmacologic management of atrial fibrillation (AF) is a pressing problem. This arrhythmia afflicts >5 million individuals in the United States and prevalence is estimated to rise to 12 million by 2050. Although the pill-in-the-pocket regimen for self-administered AF cardioversion introduced over a decade ago has proven useful, significant drawbacks exist. Among these are the relatively long latency of effects in the range of hours along with potential for hypotension and other adverse effects. This experience prompted development of a new strategy for increasing plasma concentrations of antiarrhythmic drugs rapidly and for a limited time, namely, pulmonary delivery. In preclinical studies in Yorkshire pigs, intratracheal administration of flecainide was shown to cause a rapid, reproducible increase in plasma drug levels. Moreover, pulmonary delivery of flecainide converted AF to normal sinus rhythm by prolonging atrial depolarization, which slows intra-atrial conduction and seems to be directly correlated with efficacy in converting AF. The rapid rise in plasma flecainide levels optimizes its anti-AF effects while minimizing adverse influences on ventricular depolarization and contractility. A more concentrated and soluble formulation of flecainide using a novel cyclodextrin complex excipient reduced net drug delivery for AF conversion when compared to the acetate formulation. Inhalation of the beta-adrenergic blocking agent metoprolol slows ventricular rate and can also terminate AF. In human subjects, oral inhalation of flecainide acetate with a hand-held, breath-actuated nebulizer results in signature prolongation of the QRS complex without serious adverse events. Thus, pulmonary delivery is a promising advance in pharmacologic approach to management of AF.

Postoperative New-Onset Atrial Fibrillation following Noncardiac Operations: Prevalence, Complication, and Long-Term MACE

BACKGROUND

Postoperative new-onset atrial fibrillation (POAF) is a common complication following cardiothoracic surgery, but little is known regarding its occurrence and outcome following noncardiothoracic surgery. This study was intended to examine the incidence of POAF in noncardiothoracic surgeries performed under general anesthesia and its effects on the length of hospitalization stay, short-term and long-term morbidity, and mortality. Methodology. We conducted a retrospective observational descriptive study. The study population consists of patients hospitalized in surgical wards from January 2014 to December 2017. Surgery was defined as noncardiac or thoracic procedure conducted under general anesthesia.

RESULTS

A total of 24,125 general anesthesia operations were performed at 7 surgical wards. About two-fifth of the operations (40%) were operated electively, and the rest underwent emergency surgery. The mean age was 63.78 ± 11.50, and more than half (56.9%) of the participants were female. The prevalence of POAF was 2.69 per 1000 adult patients (95% CI: 2.11-3.43) and vary significantly among wards. The highest prevalence was observed after hip fixation and laparotomy surgeries (54.9 and 26.7 per 1000 patients, respectively). The median length of hospitalization was significantly higher in POAF patients (21.0 vs. 4.8 days, p < 0.001). Patients who developed POAF had significantly higher mortality rates, both inhospital (200 vs. 7.56 deaths per 1000, p=0.001) and 1 year (261.5 vs. 33.3 per 1000, p=0.001, respectively). There was no significant association between outcome and treatment modalities such as rate or rhythm control and anticoagulant use.

CONCLUSION

New-onset AF following noncardiac surgery is rare, yet poses significant clinical implications, both immediate and long-term. POAF is associated with a longer length of hospitalization and a significantly higher mortality rate, both in short- and long-term.

Path to precision: prevention of post-operative atrial fibrillation

Development of post-operative atrial fibrillation (POAF) following open-heart surgery is a significant clinical and economic burden. Despite advancements in medical therapies, the incidence of POAF remains elevated at 25-40%. Early work focused on detecting arrhythmias from electrocardiograms as well as identifying pre-operative risk factors from medical records. However, further progress has been stagnant, and a deeper understanding of pathogenesis and significant influences is warranted. With the advent of more complex machine learning (ML) algorithms and high-throughput sequencing, we have an unprecedented ability to capture and predict POAF in real-time. Integration of multimodal heterogeneous data and application of ML can generate a paradigm shift for diagnosis and treatment. This will require a concerted effort to consolidate and streamline real-time data. Herein, we will review the current literature and emerging opportunities aimed at predictive targets and new insights into the mechanisms underlying long-term sequelae of POAF.

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

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

Cost-Effectiveness Analysis of Landiolol, an Ultrashort-Acting Beta-Blocker, for Prevention of Postoperative Atrial Fibrillation for the Germany Health Care System

OBJECTIVES

Landiolol is an ultrashort-acting beta-blocker with high beta-1 receptor affinity and less blood pressure-lowering properties than other beta-blockers available for intravenous use in Germany. The present analysis aimed to determine whether perioperative treatment with landiolol in cardiac surgical patients is cost-effective under the conditions of the German Diagnosis-Related Groups health cost reimbursement system.

DESIGN

On the basis of clinical outcome data from a meta-analysis that included 622 patients from 7 randomized controlled trials, a decision-model was developed to determine the cost-effectiveness of landiolol versus standard-of-care (SoC).

SETTING

Hospital setting.

PARTICIPANTS

Hospital patients undergoing a representative mix of cardiac surgical procedures (MIX-CS) and isolated coronary artery bypass grafting (CABG).

INTERVENTIONS

Landiolol versus SoC in prevention of atrial fibrillation immediately after cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

The model benefit was expressed in a reduction of postoperative atrial fibrillation (POAF) episodes and reduced complications. The model calculated total inpatient costs over the hospital length of stay. Costs from published sources were used for the German hospital perspective. SoC was associated with POAF rates of 36.0% to 39.2% and 24.4% to 30.1% in the MIX-CS and CABG populations, respectively. Patients with POAF had a higher morbidity and mortality. Estimated total costs for SoC patients in the MIX-CS and CABG groups were 28.792 € and 25.630 €, respectively. Landiolol reduced the incidence of POAF to 12.6% in the MIX-CS and 12.1% in the CABG groups. This was associated with a cost reduction of 2.209 € and 1.470 €.

CONCLUSIONS

This analysis suggests that preventing POAF with landiolol is highly cost-effective. Additional studies are needed to assess whether a comparable reduction in POAF and associated cost savings may be achieved using conventional intravenous beta-blockers or amiodarone.

Statin use is associated with less postoperative cardiac arrhythmia after total hip arthroplasty

INTRODUCTION

While statins have been found to reduce postoperative atrial fibrillation after cardiac surgery, little is known about their use in total hip arthroplasty (THA). This study investigated if statins would similarly reduce postoperative arrhythmias in patients undergoing THA.

METHODS

We queried a large Medicare and private-payer database from 2005 to 2012 and identified 12,075 patients who were on a statin prior to THA. We then age and sex matched 34,446 non-statin users who underwent THA. Baseline comorbidities and postoperative complications were obtained and assessed via standard descriptive statistics.

RESULTS

The statin users had more preoperative comorbidities including congestive heart failure, valvular heart disease, pulmonary and renal disease, diabetes, hypertension, obesity, and anaemia (all p values < 0.001). Postoperatively, the statin users had a statistically higher 90-day incidence of transfusion, acute renal failure, heart failure, pneumonia, and sepsis/shock. All new-onset cardiac arrhythmia was significantly less frequent in the statin group at 2 weeks (3.88% vs. 4.72%, p < 0.001), 30 days (4.47% vs. 5.29%, p < 0.001), and 90 days (5.44% vs. 6.31%, p = 0.001) postoperative. There was no difference in the frequency of venous thromboembolism, myocardial infarction, postoperative anaemia, or bleeding at 90 days postoperative.

DISCUSSION

Despite being medically sicker at baseline with multiple risk factors for atrial fibrillation compared to the non-statin users, the statin users displayed a consistently lower occurrence of postoperative cardiac arrhythmia in this retrospective cohort study. Statins may therefore be beneficial in the preoperative optimisation of medically complex patients undergoing THA.

Respiratory failure caused by impending tension pneumothorax after extrapleural pneumonectomy: a case report

Background

Case presentation

Conclusions

On-pump transapical cardioscopic mitral valve replacement with cardiac arrest: short-term results in a porcine survival model

OBJECTIVES

Favourable outcomes with mitral annuloplasty have been achieved with transapical cardioscopic (TAC) surgery in a survival animal model. In addition, experimental TAC on a non-survival animal model also showed adequate access to remove the native mitral valve and implant a prosthetic valve, but the surgical procedure took a long time and lacked follow-up data. The goal of this study was to develop a clinically translatable TAC mitral valve replacement (MVR) procedure using technical and instrumental refinements to reduce the surgical time and to evaluate functional recovery and short-term durability using a survival porcine model. We hypothesized that MVR could be achieved with subannular implantation of the bioprosthesis via the TAC approach.

METHODS

TAC MVR using the Hancock II™ (Medtronic)® mitral prosthesis was performed in 6 pigs via an incision over the xiphoid process, under cardiopulmonary bypass and cardiac arrest. COR-KNOT® and minimally invasive cardiac surgery instruments were used. Haemodynamics, echocardiography, cardiac computed tomography, ventriculography and electrocardiography were used to evaluate the function of the mitral prosthesis and left ventricle, coronary system and conduction system in the perioperative period and 4 weeks later.

RESULTS

A postimplant examination showed that the mitral prosthesis was competent, without a paravalvular leak. The left ventricular ejection fraction was comparable to preoperative values (65.2 ± 4.1 vs 67.2 ± 7.9). The bypass, cross-clamp and implant times were 177.2 ± 44.2 min, 135.3 ± 47.6 min and 94.0 ± 41.2 min, respectively. The prosthesis was in a good position. The apical scar was intact and not aneurysmal 4 weeks after the implant. The valve was properly sutured to the annulus, without a postimplant paravalvular leak. All animals recovered after 1 month of follow-up with preserved ventricular function and normal wall motion.

CONCLUSIONS

We successfully managed to replace the mitral valve with a biological prosthesis via the apex with encouraging bypass and cross-clamp times. This technique may provide an alternative for a selected group of patients with diseased mitral valves who have indications for MVR and still in a high-risk redo setting with conventional sternotomy or minimally invasive cardiac surgery-MVR.

Impact and treatment success of new-onset atrial fibrillation with rapid ventricular rate development in the surgical intensive care unit

BACKGROUND

Atrial fibrillation (AF) with rapid ventricular rate (RVR; heart rate >100) in noncardiac postoperative surgical patients is associated with poor outcomes. The objective of this study was to evaluate the practice patterns of AF management in a surgical intensive care unit to determine practices associated with rate and rhythm control and additional outcomes.

MATERIALS AND METHODS

Adult patients (≥18 y) admitted to the surgical intensive care unit (SICU) from June 2014 to June 2015 were retrospectively screened for the development of new-onset AF with RVR. Demographics, hospital course, evaluation and treatment of AF with RVR, and outcome were evaluated and analyzed.

RESULTS

Thousand seventy patients were admitted to the SICU during the study period; 33 met inclusion criteria (3.1%). Twenty-six patients (79%) had rate and rhythm control within 48 h of AF with RVR onset. β-Blockers were the most commonly used initial medication (67%) but were successful at rate and rhythm control in only 27% of patients (6/22). Amiodarone had the highest rate of success if used initially (5/6, 83%) and secondarily (11/13, 85%). Failure to control rate and rhythm was associated with a greater likelihood of comorbidities (100% versus 57%; P = 0.06).

CONCLUSIONS

New-onset AF with RVR in the noncardiac postoperative patient is associated with a high mortality (21%). Amiodarone is the most effective treatment for rate and rhythm control. Failure to establish rate and rhythm control was associated with cardiac comorbidities. These results will help to form future algorithms for the treatment of AF with RVR in the SICU.

New-onset atrial fibrillation: an update

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

A retrospective study on atrial fibrillation after coronary artery bypass grafting surgery at The National Heart Institute, Kuala Lumpur

Background: Atrial fibrillation (AF) is common after cardiac surgery and has been associated with poor outcome and increased resource utilization. The main objective of this study is to determine the incidence of POAF in Malaysia and identify the predictors of developing POAF. The secondary outcome of this study would be to investigate the difference in mortality and morbidity rates and the duration of intensive care unit (ICU), high dependency unit (HDU) and hospital stay between the two. Methods: This is a retrospective single-center, cross sectional study conducted at the National Heart Institute, Malaysia. Medical records of 637 who underwent coronary artery bypass grafting (CABG) surgery in 2015 were accrued. Pre-operative, operative and post-operative information were subsequently collected on a pre-formulated data collection sheet. Data were then analyzed using IBM SPSS v23. Results: The incidence of POAF in our study stands at 28.7% with a mean onset of 45±33 hours post operatively. Variables with independent association with POAF include advancing age, Indian population, history of chronic kidney disease, left ventricular ejection fraction and beta-blocker treatment. The mortality rate is significantly higher statistically ( p < 0.05), and similarly the incidence of stroke. The incidence of other post-operative complications was also significantly higher statistically. The duration of ICU, HDU and hospital stays were statistically longer ( p < 0.001) with higher rates of ICU readmissions and reintubations seen. Conclusion: We conclude that the incidence of POAF in Malaysia is comparable to the figures in Western countries, making POAF one of the most commonly encountered condition after CABG with similar higher rates of mortality, poor outcomes and longer duration of stay, and therefore increased cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.

A retrospective study on atrial fibrillation after coronary artery bypass grafting surgery at The National Heart Institute, Kuala Lumpur

Background: Atrial fibrillation (AF) is common after cardiac surgery and has been associated with poor outcome and increased resource utilization. The main objective of this study is to determine the incidence of POAF in Malaysia and identify the predictors of developing POAF. The secondary outcome of this study would be to investigate the difference in mortality and morbidity rates and the duration of intensive care unit (ICU), high dependency unit (HDU) and hospital stay between the two. Methods: This is a retrospective single-center, cross sectional study conducted at the National Heart Institute, Malaysia. Medical records of 637 who underwent coronary artery bypass grafting (CABG) surgery in 2015 were accrued. Pre-operative, operative and post-operative information were subsequently collected on a pre-formulated data collection sheet. Data were then analyzed using IBM SPSS v23. Results: The incidence of POAF in our study stands at 28.7% with a mean onset of 45±33 hours post operatively. Variables with independent association with POAF include advancing age, Indian population, history of chronic kidney disease, left ventricular ejection fraction and beta-blocker treatment. The mortality rate is significantly higher statistically ( p < 0.05), and similarly the incidence of stroke. The incidence of other post-operative complications was also significantly higher statistically. The duration of ICU, HDU and hospital stays were statistically longer ( p < 0.001) with higher rates of ICU readmissions and reintubations seen. Conclusion: We conclude that the incidence of POAF in Malaysia is comparable to the figures in Western countries, making POAF one of the most commonly encountered condition after CABG with similar higher rates of mortality, poor outcomes and longer duration of stay, and therefore increased cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.

The clinical benefits of perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery: a meta-analysis

The clinical benefits of perioperative antioxidant vitamin therapy in cardiac patients remain controversial. Here, we conducted a meta-analysis to determine the strength of the evidence supporting the perioperative use of antioxidant vitamins in patients undergoing cardiac surgery. We searched 4 databases (PubMed, EMBASE, Science Citation Index and Cochrane Library) for randomized controlled trials that reported the effects of antioxidant vitamin therapy on patients undergoing cardiac surgery until 6 June 2016. Risk ratio (RR) or mean difference (MD) and its 95% confidence interval (95% CI) served as the summarized results. Heterogeneity among included studies was evaluated using the I2 statistic, which help determine which effect model to apply. We constructed a funnel plot to assess the existence of publication bias. Sensitivity analyses were also conducted to evaluate the robustness of the outcomes. Twelve trials with 1584 cardiac patients were included. Compared with placebo or no antioxidant vitamin therapy, administration of antioxidant vitamin therapy resulted in a reduction in postoperative atrial fibrillation (POAF) (RR 0.55, 95% CI 0.42, 0.73, P < 0.0001), duration of hospital stay (MD -0.68, 95% CI -0.98, -0.39, P < 0.00001), intensive care unit length of stay (MD -0.21, 95% CI -0.30, -0.12, P < 0.00001) and intubation time (MD -2.41, 95% CI -3.83, -0.98, P = 0.001). Our results also showed a trend towards a decrease in postoperative complications (RR 0.72, 95% CI 0.48, 1.08, P = 0.11) and duration of POAF (MD -1.950, 95% CI -3.28, 0.29, P = 0.10). This meta-analysis demonstrated that perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery can reduce the incidence of POAF, duration of hospital stay, intensive care unit length of stay and intubation time.

Prevention of atrial fibrillation after cardiac surgery using low-dose landiolol: A systematic review and meta-analysis

STUDY OBJECTIVE

Atrial fibrillation (AF) is associated with mortality after cardiac surgery. Several studies have reported that landiolol might help to prevent postoperative AF. The objective of this study was to investigate whether low-dose landiolol is useful in terms of balance of benefit and risk.

DESIGN

We conducted a meta-analysis after systematically searching the PubMed, the Cochrane library and the ICHUSHI to identify randomized, controlled trials investigating the preventive effect of landiolol on incidence of AF after cardiac surgery.

PATIENTS

Six randomized trial with 571 patients were included.

MEASUREMENTS

The primary outcome was incidence of AF after surgery, while secondary outcomes were mortality and complications.

MAIN RESULTS

Incidence of AF within 1week after surgery was significantly lower in the landiolol group than in the control group (odds ratio, 0.27; 95% confidence interval, 0.18-0.42; p<0.001). Three of the 6 studies reported data regarding in-hospital mortality and complications, showing no significant differences between groups (0.7 vs 3.0%; OR, 0.45; 95% CI, 0.07-2.74; p=0.39; and 4.5 vs 9.7%; OR, 0.45; 95% CI, 0.16-1.23; p=0.12, respectively).

CONCLUSIONS

Our systematic review revealed that low-dose landiolol might help to prevent AF after cardiac surgery and further large trials are needed to evaluate safety because mortality and morbidity rate were very low in included studies.

Design, Challenges, and Implications of Quality Improvement Projects Using the Electronic Medical Record: Case Study: A Protocol to Reduce the Burden of Postoperative Atrial Fibrillation

Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery, which results in increased morbidity, mortality, length of stay, and hospital costs. We developed and followed a process map to implement a protocol to decrease POAF: (1) identify stakeholders and form a working committee, (2) formal literature and guideline review, (3) retrospective analysis of current institutional data, (4) data modeling to determine expected effects of change, (4) protocol development and implementation into the electronic medical record, and (5) ongoing review of data and protocol adjustment. Retrospective analysis demonstrated that POAF occurred in 29.8% of all cardiovascular surgery cases. Median length of stay was 2 days longer (P<0.001), and median total variable costs $2495 higher (P<0.001) in POAF patients. Modeling predicted that up to 60 cases of POAF and >$200 000 annually could be saved. A clinically based electronic medical record tool was implemented into the electronic medical record to aid preoperative clinic providers in identifying patients eligible for prophylactic amiodarone. Initial results during the 9-month period after implementation demonstrated a reduction in POAF in patients using the protocol, compared with those who qualified but did not receive amiodarone and those not evaluated (11.1% versus 38.7% and 38.8%; P=0.022); however, only 17.3% of patients used the protocol. A standardized methodological approach to quality improvement and electronic medical record integration has potential to significantly decrease the incidence of POAF, length of stay, and total variable cost in patients undergoing elective coronary artery bypass graft and valve surgeries. This framework for quality improvement interventions may be adapted to similar clinical problems beyond POAF.

Atrial arrhythmias after lung transplantation: Incidence and risk factors in 652 lung transplant recipients

OBJECTIVES

Atrial arrhythmia (AA) after lung transplantation (LTx) is a potentially morbid event often associated with increased length of hospital stay. Predictors of postsurgical AA, however, are incompletely understood. We characterized the incidence and predisposing risk factors for AA in patients undergoing LTx.

METHODS

A retrospective analysis of prospectively collected data was conducted to identify LTx recipients between January 2008 and October 2013. Patients were divided into 2 groups on the basis of postoperative AA development. Univariable and multivariable analyses were performed to define differences between groups and identify factors associated with AA. Survival differences were assessed by the use of competing risks methodology.

RESULTS

A total of 198 of 652 (30.4%) patients developed AA at a median onset of 5 days after transplant. Increasing age (hazard ratio [HR] 1.03 per additional year, P < .001) and previous coronary artery bypass grafting (HR 2.77, P = .002) were found to be independent risk factors. Counterintuitively, patients with a medical history of AA before LTx had a lower incidence of postoperative AA. Preoperative beta-blocker usage was not a significant predictor of postoperative AA. Postoperative AA was a significant predictor of long-term mortality (HR 1.63, P = .007) when we adjusted for other risk factors.

CONCLUSIONS

AA is a common occurrence after LTx, occurring with greatest frequency in the first postoperative week, and results in a significant reduction in long-term survival. Increasing age and before coronary artery bypass grafting were identified as independent risk factors for AA development. Better understanding of these risk factors may improve identification of patients at heightened risk after transplantation.

Perioperative ascorbic acid supplementation does not reduce the incidence of postoperative atrial fibrillation in on-pump coronary artery bypass graft patients

BACKGROUND

Atrial fibrillation is the most common arrhythmia following cardiac surgery. It is associated with increased hemodynamic instability, systemic embolization, and complications linked to anticoagulant therapy. Oxidative stress and consequent electrophysiological remodeling have been proposed as a cause of postoperative atrial fibrillation. Ascorbic acid supplementation was suggested as a novel and effective preventive agent. The aim of this study was to evaluate the capability of ascorbic acid to reduce the incidence of postoperative atrial fibrillation in coronary artery bypass grafting (CABG) patients.

METHODS

A prospective randomized single-center trial was conducted in patients scheduled for an elective on-pump CABG surgery. Subjects in the ascorbic acid group received 2g of ascorbic acid 24h and 2h before the surgery and 1g twice a day for five days after the surgery. Postoperatively, the patients were monitored for atrial fibrillation and other complications.

RESULTS

The ascorbic acid group consisted of 52 patients and the control group included 53 patients. The groups were well matched for baseline demographics, preoperative medications, comorbidities, and had similar intraoperative characteristics. The incidence of atrial fibrillation in the ascorbic acid group was 13.5% and 18.9% in the control group (p=0.314). No difference was found between groups in the time of occurrence of atrial fibrillation (3.71±1.89 vs. 2.91±1.58 days after the surgery; p=0.342). There was also no difference in the other observed postoperative complications.

CONCLUSIONS

The results of this study do not support the effectiveness of ascorbic acid supplementation in reducing the incidence of postoperative atrial fibrillation in elective on-pump CABG patients.

CHADS2 and CHA2DS2-VASc scoring systems for predicting atrial fibrillation following cardiac valve surgery

Objective

Clinical use of CHADS₂ and CHA₂DS₂-VASc scoring systems for predicting AF following cardiac surgery have been reported in previous studies and demonstrated well-validated predictive value. We sought to investigate whether the two scoring systems are effective for predicting new-onset of AF following cardiac valve surgery and to demonstrate its potential utility of clinical assessment.

Methods

Medical records of all patients underwent cardiac valve surgeries during the period of January 2003 and December 2013 without preoperative AF at the cardiac center of our university were reviewed. The main outcome end point of our study was the early new-onset of AF following cardiac valve surgery.

Results

There were overall 518 patients involved in this study, with 234 (45.17%) developed POAF following valve surgery. Patients with POAF had older age (P=0.23) and higher BMI (P=0.013) than those without POAF. History of heart failure (P=0.025), hypertension (P=0.021), previous stroke or TIA (P=0.032), coronary artery disease (P=0.001), carotid artery disease (P=0.024) and preoperative medication of statins (P=0.021) were significantly more recorded in POAF group. Patients with POAF also had higher LAD (P=0.013) and E/e’ ratio (P<0.001). The CHADS₂ and CHA₂DS₂-VASc scores were significantly higher in patients with POAF (P=0.002; P<0.001), and under univariate and multivariate regression analysis the CHADS₂ and CHA₂DS₂-VASc scores were significant predictors of POAF (P=0.001; P<0.001). Based on stratification of CHADS₂ and CHA₂DS₂-VASc scores, the Kaplan-Meier analysis obtained a higher POAF rate on patients with higher stratification of CHADS₂ and CHA₂DS₂-VASc scores (P<0.001; P<0.001).

Conclusion

In conclusion, CHADS₂ and CHA₂DS₂-VASc scores were directly associated with the incidence of POAF following valve surgery and a higher score was strongly predictive of POAF.

The impact of an algorithm on the optimization of beta-blockers after cardiac surgery

OBJECTIVE

To evaluate the impact of a simple written algorithm of early postoperative beta-blocker administration on daily practices.

DESIGN

A prospective, single center observational study.

SETTING

A 16-bed cardiac surgical intensive care unit in a university teaching hospital.

PATIENTS

One hundred twenty-five consecutive adult patients chronically treated with beta-blockers and scheduled for conventional cardiac surgery.

INTERVENTIONS

Two successive 4-month phases: Phase 1 = uncontrolled early postoperative beta-blocker administration (n = 73) and phase 2 = beta-blocker administration by an institutional written algorithm using incremental doses of bisoprolol and/or esmolol (n = 52).

MEASUREMENTS AND MAIN RESULTS

The main endpoint was the number of patients receiving beta-blockers on the morning of postoperative day 1. Secondary endpoints were the number of patients receiving beta-blockers on the morning of postoperative day 1 and reaching the targeted therapeutic goal and the incidence of postoperative atrial fibrillation in the intensive care unit. A 79% increase in the number of patients receiving beta-blockers on the morning of postoperative day 1 (42% v 75%, p<0.001) was observed during the second phase of the study. The number of patients receiving beta-blockers on the morning of postoperative day 1 and reaching the targeted therapeutic goal was increased significantly by 127% (33% v 75%, p<0.001). The incidence of atrial fibrillation was similar between both phases of the study: 37% versus 31%, p = 0.567.

CONCLUSIONS

A simple written algorithm markedly improved early postoperative continuation of beta-blockers in chronically treated patients undergoing conventional cardiac surgery.

Posterior pericardiotomy in cardiac surgery: systematic review and meta-analysis

This systematic review with meta-analysis sought to determine the impact of posterior pericardiotomy on incidences of atrial fibrillation and supraventricular arrhythmias, pericardial effusion, pleural effusion, tamponade, and the length of hospital stay after cardiac surgery. We searched for randomized controlled trials, using Medline, Embase, Elsevier and Sciences online databases as well as Google Scholar literature. The effect sizes measured were odds ratio for categorical variables and standard mean difference with 95% confidence interval for calculating differences between mean values of hospital stay in intervention and control groups. A value of p < 0.1 for Q test or I2 > 50% indicated significant heterogeneity between the studies. The literature search of all major databases retrieved 20 studies. After screening, 12 suitable trials were identified, which reported outcomes of 2052 patients undergoing cardiac surgery. Posterior pericardiotomy had an odds ratio of 0.33 [95% confidence interval: 0.18–0.61] p < 0.001 for atrial fibrillation; odds ratio 0.32 [0.15–0.67] p = 0.003 for supraventricular arrhythmias; odds ratio 0.09 [0.04–0.19] p = 0.000 for early pericardial effusion and odds ratio 0.04 [0.02–0.08] p < 0.001 for late pericardial effusion; odds ratio 1.64 [1.23–2.20] p = 0.001 for pleural effusion, odds ratio 0.07 [0.02–0.27] p < 0.001 for tamponade, and standard mean difference = 0.01 [−0.12 to 0.14] p = 0.8 for hospital stay. Posterior pericardiotomy is a simple intraoperative technique that can improve postoperative clinical outcomes. However, the incidence of pleural effusion associated with posterior pericardiotomy might be higher.

[Perioperative management of atrial fibrillation]

Atrial fibrillation is a frequent complication in the perioperative period. When it appears there is an increased risk of perioperative morbidity due to stroke, thromboembolism, cardiac arrest, myocardial infarction, anticoagulation haemorrhage, and hospital readmissions. The current article focuses on the recommendations for the management of perioperative atrial fibrillation based on the latest Clinical Practice Guidelines on atrial fibrillation by the European Society of Cardiology and the Spanish Society of Cardiology. This article pays special attention to the preoperative management, as well as to the acute perioperative episode. For this reason, the latest recommendations for the control of cardiac frequency, antiarrhythmic treatment and anticoagulation are included.

Efficacy of N-acetylcysteine in preventing atrial fibrillation after cardiac surgery: a meta-analysis of published randomized controlled trials

Background

Atrial fibrillation is a common complication after cardiac surgery. The aim of this study is to evaluate whether N-acetylcysteine (NAC) could prevent postoperative atrial fibrillation (POAF).

Methods

PubMed, Embase and Cochrane Center Register of Controlled Trials were searched from the date of their inception to 1 July 2013 for relevant randomized controlled trials (RCTs), in which NAC was compared with controls for adult patients undergoing cardiac surgery. Outcome measures comprised the incidence of POAF, all-cause mortality, length of intensive care unit (ICU) stay, hospital length of stay, and the incidence of cerebrovascular events. The meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.

Results

We retrieved ten studies enrolling a total of 1026 patients. Prophylactic NAC reduced the incidence of POAF (OR 0.56; 95% CI 0.40 to 0.77; P < 0.001) and all-cause mortality (OR 0.40; 95% CI 0.17 to 0.93; P = 0.03) compared with controls, but failed to reduce the stay in ICU and overall stay in hospital. No difference in the incidence of cerebrovascular events was observed.

Conclusions

Prophylactic use of NAC could reduce the incidence of POAF and all-cause mortality in adult patients undergoing cardiac surgery. However, larger RCTs evaluating these and other postoperative complication endpoints are needed.

Management of postoperative complications: cardiovascular disease and volume management

Postoperative cardiovascular complications are common, predictable, and typically treatable in geriatric patients who have sustained fractures. Although intervention-specific data are sparse, observational evidence from high-performing geriatric fracture centers coupled with an understanding of geriatric principles can serve as a basis for treatment guidelines. Many patients can be safely and effectively managed with close attention to intravascular volume status, heart rate control, and minimization of other physiologic stresses, including pain and delirium. Many chronic cardiovascular therapies may be harmful in the immediate postoperative period, and can usually be safely omitted or attenuated until hemodynamic stability and mobility have been restored.

Antioxidant supplementations for prevention of atrial fibrillation after cardiac surgery: an updated comprehensive systematic review and meta-analysis of 23 randomized controlled trials

This systematic review with meta-analysis sought to determine the impact of antioxidants (N-acetylcysteine [NAC], polyunsaturated fatty acids [PUFAs] and vitamins) on incidence of postoperative atrial fibrillation (POAF) and duration of length of hospital stay. Medline, Embase, Elsevier, Sciences online database and Google Scholar literature search was made for studies in randomized controlled trials. The effect sizes measured were odds ratio (OR) for categorical variable and standard mean difference (SMD) with 95% confidence interval (CI) for calculating differences between mean values of duration of hospitalization in intervention and control groups. A value of P < 0.1 for Q-test or I(2) > 50% indicated significant heterogeneity between the studies. Literature search of all major databases retrieved 355 studies. After screening, a total of 23 trials were identified that reported outcomes of 4278 patients undergoing cardiac surgery. Pooled effects estimates on POAF showed a significant reduction after NAC (OR: 0.56, 95% CI: 0.40-0.77, P < 0.001), PUFA (OR: 0.84, 95% CI: 0.71-0.99, P = 0.03) and vitamin C treatment (OR: 0.50, 95% CI: 0.27-0.91, P = 0.02). Hospital length of stay was not reduced after NAC therapy (SMD: 0.082, 95% CI -0.09 to 0.25, P = 0.3), but could be decreased with PUFA (SMD: -0.185, 95% CI: -0.35 to -0.018, P = 0.03) and vitamin C (SMD: -0.325, 95% CI -0.50 to -0.14, P < 0.01). In conclusion, perioperative antioxidant supplementations with NAC, PUFA and vitamin C prevent atrial fibrillation after cardiac surgery. Moreover, PUFA and vitamin C are capable to reduce hospital stay, whereas NAC lacks this capacity.

Suspected intraoperative formation of left atrial thrombus in a patient with atrial fibrillation receiving bridging anticoagulation therapy

We present a patient with atrial fibrillation (AF) in whom a left atrial (LA) thrombus might have formed during laparotomy despite bridging anticoagulation therapy. No evidence of thrombus was detected by transesophageal echocardiography (TEE) at the start of surgery; however, a thrombus measuring 13 × 10 mm was found in the LA appendage by the end of the procedure, suggesting that thrombus might develop intraoperatively in patients with AF even when bridging anticoagulation is properly established. Intraoperative TEE can assist in detecting intracardiac thrombus in patients with AF regardless of their anticoagulation status and provides a tool for intervention to prevent systemic embolization.