Contemporary analysis of incidence of post-operative atrial fibrillation, its predictors, and association with clinical outcomes in lung transplantation

Impact of delayed veno-venous extracorporeal membrane oxygenation weaning on postoperative rehabilitation of lung transplantation: a single-center comparative study

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a reliable and effective extracorporeal life support during lung transplantation (LTx). However, the clinical benefit of delayed VV-ECMO weaning remains unclear. The current study aims to investigate whether delayed weaning of VV-ECMO is more beneficial to the rehabilitation for lung transplant patients. Patients who underwent LTx with VV-ECMO between January 2017 and January 2019 were included. Enrollment of patients was suitable for weaning off ECMO immediately after surgery. Randomization was performed in the operating room. Postoperative outcomes were compared between the two groups. Besides, univariate and multivariable logistic regressions were performed to estimate risk of postoperative complications. Compared to VV-ECMO weaning immediately after LTx, delayed weaning was associated with shorter hospital length of stay (days, 31 vs. 46; P < 0.05), lower incidence of noninvasive ventilation (4.3% vs. 24.4%; P < 0.05), primary graft dysfunction (PGD) (6.4% vs. 29.3%; P < 0.05), atrial fibrillation (AF) (4.3% vs. 22%, P < 0.05), and respiratory failure (4.3% vs. 19.5%; P < 0.05). Multivariable logistic regressions revealed that VV-ECMO weaning after LTx was independently correlated with increased risk of developing PGD [odds ratio (OR), 5.97, 95% CI 1.16-30.74], AF (OR, 6.87, 95% CI 1.66-28.47) and respiratory failure (OR, 6.02, 95% CI 1.12-32.49) by comparison of delayed VV-ECMO weaning. Patients with delayed VV-ECMO weaning are associated with lower complications and short hospital length of stay, while it relates to longer mechanical ventilation. These findings suggest that delayed VV-ECMO after LTx can facilitate rehabilitation.

Considerations for Left Atrial Appendage Occlusion During Cardiac Surgery

Atrial fibrillation is associated with an increased risk of stroke secondary to thrombus formation in the left atrial appendage. Left atrial appendage occlusion (LAAO) is an effective method of reducing the risk of stroke in patients with atrial fibrillation. Although LAAO does not remove the requirement for anticoagulation, it reduces the risk of stroke when compared to anticoagulation alone. We critically analyze the data on LAAO in cardiac surgery. We also discuss the methods of LAAO, the risks of LAAO, and patient populations that could benefit from LAAO. We discuss high-level evidence that LAAO at the time of cardiac surgery reduces the risk of stroke in patients with a history of atrial fibrillation. In patients without a history of atrial fibrillation undergoing cardiac surgery, we suggest that LAAO should be considered in select patients at high risk of atrial fibrillation and stroke, when technically feasible.

Management of Atrial Arrhythmias After Lung Transplant

The overall survival in patients undergoing lung transplantation is poor. Although postsurgical atrial arrhythmias seem to play a major role in the morbidity and mortality of this population, data regarding the clinical and interventional management of this complication are still controversial. Through a review of the literature in the field, we observed that not only the surgical technique is clearly arrhythmogenic, but the new administration of peri-procedure beta-blockers and amiodarone for arrhythmia prevention and treatment, respectively, seems harmful in these postsurgical patients. However, low-dose beta-blockers administered after surgery seem feasible in arrhythmia prevention in specific patient subgroups, and, aside from amiodarone, alternative antiarrhythmic agents can be safely and effectively used to treat symptomatic patients on top of adequate rate control. Finally, as to complex atrial arrhythmias occurring late after lung transplant surgery, radiofrequency catheter ablation seems a feasible treatment option. In light of this evidence and considering the absence of clear recommendations in the field, we suggest a practical approach that may help the clinician in the management of this postsurgical complication. However, as most of these considerations are drawn from small-sized and retrospective studies, more evidence is needed in the future to clarify which medical and interventional strategies may best treat these postsurgical arrhythmias and thus potentially improve the outcome of these frail patients.

Critical Care Management of the Lung Transplant Recipient

Lung transplantation is often the only treatment option for patients with severe irreversible lung disease. Improvements in donor and recipient selection, organ allocation, surgical techniques, and immunosuppression have all contributed to better survival outcomes after lung transplantation. Nonetheless, lung transplant recipients still experience frequent complications, often necessitating treatment in an intensive care setting. In addition, the use of extracorporeal life support as a means of bridging critically ill patients to lung transplantation has become more widespread. This review focuses on the critical care aspects of lung transplantation, both before and after surgery.

Impact of cerebrovascular accidents on lung transplant survival

BACKGROUND

Cerebrovascular accidents (CVA) are a source of postoperative morbidity. Existing data on CVA after lung transplantation (LT) are limited. We aimed to evaluate the impact of CVA on LT survival.

METHODS

A retrospective analysis of LT recipients at the University of Texas Southwestern Medical Center was performed. Data was obtained from the institutional thoracic transplant database between January 2012 and December 2018, which consisted of 476 patients. Patients were stratified by the presence of a postoperative CVA. Univariate comparisons of baseline characteristics, operative variables, and postoperative outcomes between the cohorts were performed. Survival was analyzed by Kaplan-Meier method. Aalen's additive regression model was utilized to assess mortality hazard over time.

RESULTS

The incidence of CVA was 4.2% (20/476). Lung allocation score was higher in the CVA cohort (46.2 [41.7, 57.3] vs. 41.5 [35.8, 52.2], p = 0.04). There were no significant differences in operative variables. CVA patients had longer initial intensive care unit (ICU) stays (316 h [251, 557] vs. 124 [85, 218], p < 0.001) and longer length of stay (22 days [17, 53] vs. 15 [11, 26], p = 0.007). CVA patients required more ICU readmissions (35% vs. 15%, p = 0.02) and had a lower rates of home discharge (35% vs. 71%, p < 0.001). Thirty-day mortality was higher in the CVA cohort (20% vs. 1.3%, p < 0.001). Overall survival was lower in the CVA cohort (log rank p = 0.044).

CONCLUSIONS

Postoperative CVA following LT was associated with longer ICU stays, more ICU readmissions, longer length of stay, and fewer home discharges. Thirty day and long-term mortality were significantly higher in the CVA group.

Early postoperative complications in lung transplant recipients

Lung transplantation has become an established therapy for end-stage lung diseases. Early postoperative complications can impact immediate, mid-term, and long-term outcomes. Appropriate management, prevention, and early detection of these early postoperative complications can improve the overall transplant course. In this review, we highlight the incidence, detection, and management of these early postoperative complications in lung transplant recipients.

Association Between Perioperative Atrial Fibrillation and Long-term Risks of Stroke and Death in Noncardiac Surgery: Systematic Review and Meta-analysis

BACKGROUND

Atrial fibrillation (AF) is frequently reported as a complication of noncardiac surgery. It is unknown whether new-onset perioperative AF is associated with an increased risk of stroke and death beyond the perioperative period. We performed a systematic review and meta-analysis to assess the long-term risks of stroke and mortality associated with new-onset perioperative AF after noncardiac surgery.

METHODS

MEDLINE and EMBASE were searched from inception to March 2020 for studies reporting on the association between perioperative AF and the risk of stroke and death occurring beyond 30 days after noncardiac surgery. Reference screening, study selection, data extraction, and quality assessment were performed in duplicate. Data were pooled using inverse variance-weighted random-effects models and presented as risk ratios (RRs).

RESULTS

From 7344 citations, we included 31 studies (3,529,493 patients). The weighted mean incidence of perioperative AF was 0.7%. During a mean follow-up of 28.1 ± 9.4 months, perioperative AF was associated with an increased risk of stroke (1.5 vs 0.9 strokes per 100 patient-years; RR: 2.9, 95% confidence interval [CI]: 2.1-3.9, I2 = 78%). Perioperative AF was also associated with a significantly higher risk of all-cause mortality (21.0 vs 7.6 deaths per 100 patient-years; RR: 1.8, 95% CI: 1.5-2.2, I2 = 94%). The pooled adjusted hazard ratios for stroke and all-cause mortality were 1.9 (95% CI: 1.6-2.2, I2 = 31%) and 1.5 (95% CI: 1.3-1.7, I2 = 20%), respectively.

CONCLUSIONS

Patients who had perioperative AF after noncardiac surgery had a higher long-term risk of stroke and mortality compared with patients who did not. Whether this risk is modifiable with oral anticoagulation therapy should be investigated.

Comparison of mechanical cardiopulmonary support strategies during lung transplantation

INTRODUCTION

Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy.

AREAS COVERED

This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation.

EXPERT OPINION

The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Atrial Flutter and Fibrillation Following Lung Transplantation: Incidence, Associations and a Suggested Therapeutic Algorithm

BACKGROUND

Atrial arrhythmias are relatively common following lung transplantation and confer considerable perioperative risk, specifically haemodynamic instability, pulmonary congestion, dyspnoea, and can mask other post-transplant complications such as infection or acute rejection. However, for most patients, arrhythmias are limited to the short-term perioperative period.

METHODS

We present a retrospective case-control analysis of 200 lung transplant recipients and using multivariate regression analysis, document the present incidence, risk factors, and outcomes between the two groups.

RESULTS

Twenty-five per cent (25%) of lung transplantation patients developed atrial flutter or fibrillation, most frequently at day 5-7 post lung transplantation, and more commonly present in older recipients and those with underlying chronic obstructive pulmonary disease (COPD), but not in those with previously noted structural heart disease, or in those undergoing single rather than double lung transplants. Atrial arrhythmias were associated with increased intensive care unit and overall length of stay, but were not associated with increased risk of in-hospital stroke, or mortality. Based on our experience, we propose a suggested management algorithm for pharmacological and mechanical rate/rhythm control strategies, for anticoagulation, and discuss the appropriate duration of treatment.

CONCLUSIONS

Atrial arrhythmias are relatively common post lung transplantation. Carefully managed, the associated risk of perioperative morbidity and mortality can be mitigated. Further prospective studies are required to validate these strategies.

Medical Course and Complications After Lung Transplantation

Lung transplant prolongs life and improves quality of life in patients with end-stage lung disease. However, survival of lung transplant recipients is shorter compared to patients with other solid organ transplants, due to many unique features of the lung allograft. Patients can develop a multitude of noninfectious (e.g., primary graft dysfunction, pulmonary embolism, rejection, acute and chronic, renal insufficiency, malignancies) and infectious (i.e., bacterial, fungal, and viral) complications and require complex multidisciplinary care. This chapter discusses medical course and complications that patients might experience after lung transplantation.

Atrial arrhythmias after lung transplantation

Atrial arrhythmias are a common complication after lung transplant (LT), occurring in about 16-46% of LT patients early postoperatively, and in about 14% during longer-term follow-up. They have a significant impact on postoperative in-hospital length of stay and may have an impact on overall mortality. In this report, we review the incidence and risk factors of post lung transplant AA, their pathogenesis and their impact on short- and long-term outcomes. Pharmacological management options are reviewed. In brief, early atrial arrhythmias tend to be mostly atrial fibrillation and are treated acutely with a rate control strategy followed if needed by rhythm control for 4-6 weeks. Late atrial arrhythmias >6 months after LT tend to be more frequently organized atrial flutters amenable to ablation therapy. Long-term anticoagulation is controversial especially in patients with bilateral lung transplant who received surgical pulmonic vein isolation, however anticoagulation is still favored especially in single LT patients. More studies are needed to further document the pathophysiology of early versus late atrial arrhythmias and whether long-term anticoagulation is needed.

Stroke Prevention for Patients with Atrial Fibrillation: Beyond the Guidelines

Atrial fibrillation (AF) is the most common serious heart rhythm disorder, with a lifetime incidence of 1 in 4 for patients >40 years of age[1]. AF is a major cause of death and disability, as it is associated with a 4-5 fold increase in the risk of ischemic stroke[2]. In patients with AF, oral anticoagulation (OAC) therapy can reduce the risk of stroke by about two-thirds and the risk of all-cause mortality by approximately one-quarter, but is associated with an increased risk of bleeding[3], [4]. Atrial fibrillation (AF) is the most common serious heart rhythm disorder and is associated with an increased risk of ischemic stroke. This risk can be moderated with oral anticoagulation therapy, but the decision to do so must be balanced against the risks of bleeding. Herein, we discuss three emerging areas where more high-quality evidence is required to guide risk stratification: 1) the relationships between the pattern and burden of AF and stroke 2) the risk conferred by short episodes of device-detected "sub-clinical" atrial fibrillation (SCAF) and 3) the significance of AF that occurs transiently with stress (AFOTS), as is often detected during medical illness or after surgery. Risk stratification is important to identify patients with AF who can benefit from OAC therapy. There are, however, several common clinical scenarios where guidelines do not yet provide direction for stroke prevention; or do so based on limited high-quality evidence.

Adverse outcomes associated with postoperative atrial arrhythmias after lung transplantation: A meta-analysis and systematic review of the literature

BACKGROUND

Postoperative atrial arrhythmias (AAs) are common after lung transplantation, but studies are mixed regarding their impact on outcomes. We therefore performed this systematic review and meta-analysis to determine whether AAs after lung transplantation impede postoperative recovery.

METHODS

MEDLINE, EMBASE, CINAHL, and the Cochrane Register were searched to identify studies comparing outcomes in adult patients undergoing lung transplantation who experienced postoperative AAs in the immediate postoperative period vs those without postoperative AAs. Our primary outcome was perioperative mortality, and secondary outcomes were length of stay (LOS), postoperative complications, and mid-term (1-6 years) mortality.

RESULTS

Nine studies including 2653 patients were included in this analysis. Of this group, 791 (29.8%) had postoperative AAs. Patients with postoperative AAs had significantly higher perioperative (OR 2.70 [95% CI: 1.73-4.19], P<.0001) mortality, longer hospital LOS (MD 8.29 [95% CI: 4.37-12.21] days, P<.0001), more frequent requirement for tracheostomy (OR 4.67 [95% CI: 2.59-8.44], P<.0001), and higher mid-term mortality (OR 1.71 [95% CI: 1.28-2.30], P=.0003).

CONCLUSIONS

AAs after lung transplantation are frequent and associated with significantly higher mortality, longer hospital LOS, and requirement for tracheostomy. Given their impact on recovery, prophylactic strategies against AAs need to be developed.

Incidence, Predictors, and Outcomes of Early Atrial Arrhythmias After Lung Transplant: A Systematic Review and Meta-Analysis

OBJECTIVES

This study sought to determine the incidence, predictors, and prognostic implications of early post-lung transplant atrial arrhythmias (AAs).

BACKGROUND

Although frequently encountered, the prognostic implications of early AAs after lung transplant remain uncertain.

METHODS

A systematic review of MEDLINE and the Cochrane Library was conducted for all studies that reported early post-lung transplant AAs. Random-effects DerSimonian-Laird risk ratios (RRs) were calculated for categorical variables and standardized mean difference (SMD) for continuous variables.

RESULTS

A total of 12 studies with 3,203 patients (mean age 57 ± 3 years; 52% males) were included. The incidence of early post-lung transplant AAs during hospitalization was 26.6% at mean follow-up duration of 6.7 days. Predictors of post-lung transplant AAs included advanced age (SMD: 0.50; 95% confidence interval [CI]: 0.35 to 0.64), male gender (RR: 1.37; 95% CI: 1.28 to 1.47), history of smoking (RR: 1.23; 95% CI: 1.05 to 1.46), hypertension (RR: 1.35; 95% CI: 1.13 to 1.59), hyperlipidemia (RR: 1.39; 95% CI: 1.18 to 1.63), coronary artery disease (RR: 1.40; 95% CI: 1.12 to 1.7), left atrial diameter (SMD: 0.25; 95% CI: 0.07 to 0.44), and restrictive lung disease (RR: 1.34; 95% CI: 1.13 to 1.59). Post-lung transplant AAs were associated with increased all-cause mortality (adjusted RR: 1.63; 95% CI: 1.22 to 2.19) at mean follow-up of 27.8 months and length of hospital stay (36.5 ± 16.5 days vs. 26.1 ± 14.3 days; p < 0.001).

CONCLUSIONS

Early AAs post-lung transplant are associated with increased mortality and length of hospital stay. Advanced age, male sex, smoking, hypertension, hyperlipidemia, coronary artery disease, increased left atrial diameter, and restrictive lung disease are independent predictors of early AAs in post-lung transplant patients.

Incidence, risk factors and prognosis of postoperative atrial arrhythmias after lung transplantation: a systematic review and meta-analysis

Postoperative atrial arrhythmia is the most common dysrhythmia seen after lung transplantation. However, risk factors for postoperative atrial arrhythmias and their impact on outcomes were inconsistent. The aim of our study was to conduct a meta-analysis to analyse risk factors of postoperative atrial arrhythmias and the impact of postoperative atrial arrhythmias on outcomes after lung transplantation. All eligible articles from MEDLINE, EMBASE, CENTRAL and the Chinese BioMedical Literature Database (until November 2015) were incorporated into this study. We extracted the data from the included studies and performed a meta-analysis to evaluate predictors for postoperative atrial arrhythmias and their impact on outcomes. R software and STATA 13.0 software were used for the meta-analysis. A total of 2094 patients from 11 studies were included in this meta-analysis. The pooled incidence of postoperative atrial arrhythmias after lung transplantation was 31% [95% confidence interval (CI), 25-37%]. We found that gender (female versus male) with an odds ratio (OR) of 0.44 (95% CI 0.35-0.56, P < 0.001), age (>50 vs ≤50 or atrial arrhythmias versus non-atrial arrhythmias) with OR of 2.73 (95% CI 1.86-4.00, P < 0.001) and weighted mean difference (WMD) of 5.88 years (95% CI 3.69-8.07, P < 0.001), history of atrial arrhythmias with OR of 1.76 (95% CI 1.34-2.32, P = 0.002), vasopressor use with OR of 1.76 (95% CI 1.34-2.32, P < 0.001), cystic fibrosis with OR of 0.32 (95% CI 0.18-0.59, P < 0.001), interstitial lung disease with OR of 1.85 (95% CI 1.27-2.71, P = 0.001), hypertension with OR of 1.49 (95% CI 1.12-1.97, P = 0.006), coronary artery disease with OR of 1.58 (95% CI 1.20-2.08, P = 0.001), hyperlipidaemia with OR of 1.52 (95% CI 1.06-2.20, P = 0.025) and left atrial enlargement with OR of 2.99 (95% CI 1.91-4.67, P < 0.001) were significantly associated with postoperative atrial arrhythmias after lung transplantation. Postoperative atrial arrhythmias had a significant influence on length of stay (WMD 9.72, 95% CI 5.07-14.38, P < 0.001) and overall survival (OS) (hazard ratio 1.72, 95% CI 1.39-2.12, P < 0.001) after lung transplantation. In conclusion, the significant risk factors for postoperative atrial arrhythmias were gender, age, history of atrial arrhythmias, vasopressor use, cystic fibrosis, interstitial lung disease, hypertension, coronary artery disease, hyperlipidaemia, cardiac index and left atrial size. Development of postoperative atrial arrhythmias has prognostic implications for length of stay and overall survival after lung transplantation. Prospective and randomized trials are needed to address these issues in the future.