Atrial arrhythmias after lung transplant: Underlying mechanisms, risk factors, and prognosis

Practicality and Safety of Electrical Pulmonary Vein Isolation and Left Atrial Appendage Ligation in Lung Transplant Recipients With Pretransplant Atrial Fibrillation

Background

Lung transplant surgery creates surgical pulmonary vein isolation (PVI) as a routine part of the procedure. However, many patients with pretransplant atrial fibrillation continue to have atrial fibrillation at 1 y. We hypothesized that the addition of electrical PVI and left atrial appendage isolation/ligation (LAL) to the lung transplant procedure restores sinus rhythm at 1 y in patients with pretransplant atrial fibrillation.

Methods

We retrospectively reviewed all adult lung transplant recipients at the University of California Los Angeles from April 2006 to August 2021. All patients with pretransplant atrial fibrillation underwent concomitant PVI/LAL and were compared with lung transplant recipients without preoperative atrial fibrillation. In-hospital outcomes; 1-y survival; and the incidence of stroke, cardiac readmissions, repeat ablations, and sinus rhythm (composite endpoint) were examined at 1 y for the PVI/LAL cohort.

Results

Sixty-one lung transplant recipients with pretransplant atrial fibrillation underwent concomitant PVI/LAL. No patient in the PVI/LAL cohort required cardiac-related readmission or catheter ablation for atrial fibrillation within 1 y of transplantation. Freedom from the composite endpoint of death, stroke, cardiac readmission, and repeat ablation for atrial fibrillation at 1 y was 85% (95% confidence interval, 73%-92%) for lung transplant recipients treated with PVI/LAL.

Conclusions

The addition of PVI/LAI to the lung transplant operation in patients with pretransplant atrial fibrillation was safe and effective in maintaining sinus rhythm and baseline risk of stroke at 1 y.

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.

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.

Atrial arrhythmias following lung transplant: a single pediatric center experience

Background

Outcomes after lung transplant (LTx) in children have slowly improved. Although atrial arrhythmia (AA) is a common and adverse complication following LTx among adults, there is limited data on pediatric recipients. We detail our pediatric single-center experience while providing further insights on occurrence and management of AA following LTx.

Methods

A retrospective analysis of LTx recipients at a pediatric LTx program from 2014 to 2022 was performed. We investigated timing of occurrence and management of AA following LTx, and its effect on post-LTx outcome.

Results

Three out of nineteen (15%) pediatric LTx recipients developed AA. The timing of occurrence was 9-10 days following LTx. Those patients in the older age group (age >12 years old) were the only ones who developed AA. Developing AA did not have a negative effect on hospital stay duration or short-term mortality. All LTx recipients with AA were discharged home on therapy that was discontinued at 6 months for those who was on mono-therapy without recurrence of AA.

Conclusions

AA is an early post-operative complication in older children and younger adults undergoing LTx at a pediatric center. Early recognition and aggressive management can mitigate any morbidity or mortality. Future investigations should explore factors that place this population at risk for AA in order to prevent this complication post-operatively.

Preemptive antiviral therapy in lung transplantation from hepatitis C donors results in a rapid and sustained virologic response

Objective

The study objective was to assess the safety and efficacy of a preemptive direct-acting antiviral therapy in lung transplants from hepatitis C virus donors to uninfected recipients.

Methods

This study is a prospective, open-label, nonrandomized, pilot trial. Recipients of hepatitis C virus nucleic acid test positive donor lungs underwent preemptive direct-acting antiviral therapy with glecaprevir 300 mg/pibrentasvir 120 mg for 8 weeks from January 1, 2019, to December 31, 2020. Recipients of nucleic acid test positive lungs were compared with recipients of lungs from nucleic acid test negative donors. Primary end points were Kaplan-Meier survival and sustained virologic response. Secondary outcomes included primary graft dysfunction, rejection, and infection.

Results

Fifty-nine lung transplantations were included: 16 nucleic acid test positive and 43 nucleic acid test negative. Twelve nucleic acid test positive recipients (75%) developed hepatitis C virus viremia. Median time to clearance was 7 days. All nucleic acid test positive patients had undetectable hepatitis C virus RNA by week 3, and all alive patients (n = 15) remained negative during follow-up with 100% sustained virologic response at 12 months. One nucleic acid test positive patient died of primary graft dysfunction and multiorgan failure. Three of 43 nucleic acid test negative patients (7%) had hepatitis C virus antibody positive donors. None of them developed hepatitis C virus viremia. One-year survival was 94% for nucleic acid test positive recipients and 91% for nucleic acid test negative recipients. There was no difference in primary graft dysfunction, rejection, or infection. One-year survival for nucleic acid test positive recipients was similar to a historical cohort of the Scientific Registry of Transplant Recipients (89%).

Conclusions

Recipients of hepatitis C virus nucleic acid test positive lungs have similar survival as recipients of nucleic acid test negative lungs. Preemptive direct-acting antiviral therapy results in rapid viral clearance and sustained virologic response at 12 months. Preemptive direct-acting antiviral may partially prevent hepatitis C virus transmission.

Adverse Outcomes Associated With Atrial Arrhythmias After Veno-Venous Extracorporeal Membrane Oxygenation

Veno-venous extracorporeal membrane oxygenation (VV ECMO) is used as a treatment modality in those who fail to respond to conventional care. Hypoxia and medications used in the intensive care unit may increase risk for atrial arrhythmias (AA). This study aims to evaluate the impact of AA on post-VV ECMO outcome. A retrospective review of patients who were placed on VV ECMO between October 2016 and October 2021. One hundred forty-five patients were divided into two groups, AA and no AA. Baseline characteristic and potential risk factors were assessed. Uni- and multivariate analysis using logistic regression models were constructed to evaluate the predictors of mortality between groups. Survival between groups was estimated by the Kaplan-Meier method using the log-rank test. Advanced age with history of coronary artery disease and hypertension were associated with increased risk to develop AA post-VV ECMO placement ( p value < 0.05). Length on ECMO, time intubated, hospital length of stay, and sepsis were significantly increased in patients in the AA group ( p value < 0.05). There was no difference in the overall mortality between the two groups. AAs were associated with worse hospital course and complications but no difference in overall mortality rate. Age and cardiovascular disease seem to be predisposing risk factors for this. Further studies are needed to investigate potential strategies to prevent AAs development in this population.

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.

Atrial tachyarrhythmias after lung transplantation in children: A common occurrence

BACKGROUND

Atrial arrhythmia's (AA) following lung transplant in adults are a well-described clinical finding. In pediatrics, however, there are limited data with some reports suggesting that arrhythmias are rare.

METHODS

We performed a single-center retrospective review of lung transplant recipients from January 2013 to June 2020. A detailed evaluation of clinical characteristics, presence of arrhythmias, and outcomes was completed. Arrhythmias were documented based on inpatient telemetry or remote Holter monitoring. Analyses assessing risk factors for arrhythmias and associations with clinical outcomes were performed.

RESULTS

Ninety-one lung transplants were performed in 90 patients. Post-operative AA occurred following 19% transplants. Ectopic atrial tachycardia was seen in 14%, atrial flutter in 2%, and a combination in 2%. The majority of these arrhythmias occurred within the first 45 days post-operatively. Antiarrhythmic treatment was required in 59%, but none required ablation or electrical cardioversion. In patients followed for a year or more, 88% had resolution of their arrhythmia. Arrhythmias were not associated with mortality. In further analysis, however, the presence of arrhythmia was associated with an increased length of ICU stay (median of 12 days (IQR 6, 23) versus 5 days (IQR 4, 9); p = .019) and overall length of hospital stay (median of 26 days (IQR 19, 36) versus 17 days (IQR 19, 36); p = .043).

CONCLUSIONS

Atrial tachyarrhythmias after lung transplantation are common in the pediatric population and usually occur early. Although they frequently require medical therapy and are associated with longer stays, there is no associated increased mortality. In addition, the arrhythmias typically self-resolve.

Recipient selection, timing of referral, and listing for lung transplantation

Recipient selection for lung transplantation is a balance between providing access to transplantation to maximum patients, while utilizing this limited resource in the most optimal way. This review summarizes the current literature and recommendations about referral, listing, and evaluation of lung transplant candidates, with a focus on patients considered to have high risk characteristics.

Postoperative Management of Lung Transplant Recipients in the Intensive Care Unit

The number of lung transplantations is progressively increasing worldwide, providing new challenges to interprofessional teams and the intensive care units. The outcome of lung transplantation recipients is critically affected by a complex interplay of particular pathophysiologic conditions and risk factors, knowledge of which is fundamental to appropriately manage these patients during the early postoperative course. As high-grade evidence-based guidelines are not available, the authors aimed to provide an updated review of the postoperative management of lung transplantation recipients in the intensive care unit, which addresses six main areas: (1) management of mechanical ventilation, (2) fluid and hemodynamic management, (3) immunosuppressive therapies, (4) prevention and management of neurologic complications, (5) antimicrobial therapy, and (6) management of nutritional support and abdominal complications. The integrated care provided by a dedicated multidisciplinary team is key to optimize the complex postoperative management of lung transplantation recipients in the intensive care unit.

Cough in Idiopathic Pulmonary Fibrosis

Chronic cough is experienced by most patients with idiopathic pulmonary fibrosis (IPF). It is often the first symptom and is associated with reduced quality of life, increased rates of depression and anxiety, more severe physiological impairment, and disease progression. Although not fully understood, recent gains in understanding the pathophysiology of chronic cough in IPF have been made. The pathophysiology is likely multifactorial and includes alterations in mucous production and clearance, architectural distortion, and increased cough reflex sensitivity, suggesting a role for targeted therapies and multidisciplinary treatment. Modifiable comorbidities can also induce cough in patients with IPF. There is a renewed emphasis on measuring cough in IPF, with clinical trials of novel and repurposed therapies for chronic cough emerging in this population. This review provides an update on the clinical characteristics, pathophysiology, and measurement of chronic cough in patients with IPF and summarizes recent developments in non-pharmacological and pharmacological therapies.

Traumatic injury and atrial fibrillation among deployed service members

INTRODUCTION

Atrial fibrillation and atrial flutter (AF/AFL), the most common atrial arrhythmias, have never been examined in combat casualties. In this study, we investigated the impact of traumatic injury on AF/AFL among service members with deployment history.

METHODS

Sampled from the Department of Defense (DoD) Trauma Registry (n = 10,000), each injured patient in this retrospective cohort study was matched with a non-injured service member drawn from the Veterans Affairs/DoD Identity Repository. The primary outcome was AF/AFL diagnosis identified using ICD-9-CM and ICD-10-CM codes. Competing risk regressions based on Fine and Gray subdistribution hazards model with were utilized to assess the association between injury and AF/AFL.

RESULTS

There were 130 reported AF/AFL cases, 90 of whom were injured and 40 were non-injured. The estimated cumulative incidence rates of AF/AFL for injured was higher compared to non-injured patients (hazards ratio [HR] = 2.04; 95% confidence interval [CI] = 1.44, 2.87). After adjustment demographics and tobacco use, the association did not appreciably decrease (HR = 1.90; 95% CI = 1.23, 2.93). Additional adjustment for obesity, hypertension, diabetes, and vascular disorders, the association between injury and AF/AFL was no longer statistically significant (HR = 1.51; 95% CI = 0.99, 2.52).

CONCLUSION

Higher AF/AFL incidence rate was observed among deployed service members with combat injury compared to servicemembers without injury. The association did not remain significant after adjustment for cardiovascular-related covariates. These findings highlight the need for combat casualty surveillance to further understand the AF/AFL risk within the military population and to elucidate the potential underlying pathophysiologic mechanisms.

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.

Need for anticoagulation and use of direct oral anticoagulants in lung transplant recipients

Limited information is available about use of direct oral anticoagulants (DOACs) in lung transplant recipients (LTRs). The purpose of this study is to describe the indications and use of long-term anticoagulation, including the safety and tolerability of DOACs, in LTRs. This was a single-center retrospective study. LTRs who received therapeutic anticoagulation were identified. Patient characteristics, indications for treatment, and complications of therapy were obtained. A total of 203 patients underwent lung transplantation of which 118 patients (58.1%) had an indication for anticoagulation. Patients with an indication for anticoagulation were older than those without (59 ± 14 years versus 48 ± 17 years, p < 0.001) and were more likely to be male (72.0% versus 50.6%, p = 0.002). Of the patients with indication for anticoagulation, 74 (62.7%) received it. Fifty-one (68.9%) of patients receiving anticoagulation were treated with DOACs. In the patients receiving anticoagulation, there were 14 major bleeding events in 13 patients, of which 3 were receiving DOACs and the remainder were receiving heparin or warfarin. The need for anticoagulation is common in LTRs for both atrial arrhythmias and venous thromboembolism. However, many patients with atrial arrhythmias do not receive anticoagulation. The use of DOACs is well tolerated and safe in LTRs.

Catheter ablation of atrial arrhythmias following lung transplant: Electrophysiological findings and outcomes

INTRODUCTION

Data on the mechanisms of atrial arrhythmias (AAs) and outcomes of catheter ablation (CA) in lung transplantation (LT) patients are insufficient. We evaluated the electrophysiologic features and outcomes of CA of AAs in LT patients. METHODS AND RESULTS: We conducted a retrospective study of all the LT patients who underwent CA for AAs at our institution between 2004 and 2019. A total of 15 patients (43% males, age: 61 ± 10 years) with a history of LT (60% bilateral and 40% unilateral) were identified. All patients had documented organized AA on surface electrocardiogram and seven patients also had atrial fibrillation (AF; 47% with >1 clinical arrhythmia). At electrophysiological study, 19 organized AAs were documented (48% focal and 52% macro-re-entrant). Focal atrial tachycardias/flutters were targeted along the pulmonary vein (PV) anastomotic site at the left inferior PV (n = 2), ridge and carina of the left superior PV (n = 2), left atrium (LA) posterior wall (n = 3), LA roof (n = 1), and tricuspid annulus (n = 1). Macro-re-entrant AAs included cavotricuspid isthmus-dependent flutter (n = 2), incisional LA flutter (n = 4), LA roof-dependent flutter (n = 1), and mitral annular flutter (n = 3). In patients with LA mapping (n = 13), PV reconnection on the side of the LT was found in six patients (40%, all with clinically documented AF), with a mean of 2.1 ± 0.9 PVs reconnected per patient. Patients with AF underwent successful PV isolation. After a median follow-up of 19 months (range: 6-86 months), 75% of patients remained free from recurrent AAs. No procedural major complications occurred.

CONCLUSION

In patients with prior LT, recurrent AAs are typically associated with substrate surrounding the surgical anastomotic lines and/or chronically reconnected PVs. CA of AAs in this population is safe and effective to achieve long-term arrhythmia control.

The Year in Cardiothoracic Transplantation Anesthesia: Selected Highlights from 2019

The highlights in cardiothoracic transplantation focus on the recent research pertaining to heart and lung transplantation, including expansion of the donor pool, the optimization of donors and recipients, the use of mechanical support, the perioperative and long-term outcomes in these patient populations, and the use of transthoracic echocardiography to diagnose rejection.

Late atrial arrhythmias after lung transplantation: a meta-analysis

BACKGROUND

Atrial arrhythmias are common following noncardiac thoracic surgery. In particular, early postoperative atrial arrhythmias after lung transplantation are very frequent, especially atrial fibrillation (AFib). Late atrial arrhythmia occurrence following lung transplantation, instead, has been less commonly reported.

METHODS

The aim of the present systematic review and meta-analysis is to analyse the incidence rate of late atrial arrhythmia and AFib in lung transplantation patients, with a special focus on double lung transplant (DLT), also to assess potential predictors of AFib occurrence. After bibliographic search (PUBMED/Medline and Embase databases), a random-effect model meta-analysis was performed: seven studies were finally included, including 2068 lung transplantation patients.

RESULTS

The pooled incidence rate of late atrial arrhythmia was 4.3%/year [95% confidence interval (CI) 2.8-6.1%/year, I = 69%], whereas late AFib incidence rate was 1.5%/year (95% CI 0.7-2.6%/year, I = 87%). In patients undergoing DLT, the pooled incidence rate of late atrial arrhythmia was 4.1%/year (95% CI 2.5-6.0%/year, I = 67%), while the AFib incidence rate was 0.9%/year (95% CI 0.1-2.4%/year, I = 92%). A longer follow-up duration significantly related to the reduced incidence rate of AFib (P = 0.02). History of AFib (hazard ratio 11.2, 95% CI 5.9-21.3) and early postoperative AFib (hazard ratio 10.3, 95% CI 5.9-18.0) emerged, instead, as relevant predictors of AFib occurrence.

CONCLUSION

Late atrial arrhythmia occurrence is not infrequent in lung transplantation patients; however, late Afib incidence was rare and showed a time-dependent decrease, particularly in DLT patients, suggesting that a transmural pulmonary veins isolation, the mainstay of transcatheter ablation, is effective in decreasing the likelihood of experiencing AFib.

Clinical significance of postoperative atrial arrhythmias in patients who underwent lung transplantation

BACKGROUND/AIMS

Atrial arrhythmia (AA) occasionally occurs after lung transplantation (LT); however, risk factors for AA and their impact on clinical outcomes are inconsistent. We aimed to investigate the incidence, predisposing factors, and clinical outcomes of AA after LT.

METHODS

We retrospectively evaluated 153 consecutive patients who underwent LT between January 2010 and August 2016. An AA episode was defined as a documented atrial fibrillation (AF), atrial flutter, or atrial tachycardia on 12-lead electrocardiography or episodes lasting ≥ 30 seconds on telemetry monitoring.

RESULTS

The mean follow-up time was 22.0 ± 19.1 months. Postoperative AA occurred in 46 patients (30.1%) after LT. Patients with postoperative AA were older, had larger body surface area, and had an increased incidence of paroxysmal AF prior to transplantation, idiopathic pulmonary fibrosis, and postoperative tracheostomy than patients without AA. Preoperative right atrial pressure (RAP) (odds ratio [OR], 1.19; p = 0.005) and longer periods of mechanical ventilation (OR, 1.03; p = 0.008) were found to be independent risk factors for AA after surgery. Development of AA was a significant predictor of long-term overall mortality (hazard ratio, 2.75; p = 0.017).

CONCLUSION

Patients with elevated preoperative RAP and long-term ventilator care had a higher risk of AA after LT. Further, AA after LT was associated with poor long-term survival.

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.

Postoperative management of lung transplant recipients

Despite advances in surgical technique, lung transplantation is associated with worse survival when compared with other solid organ transplantations. Graft dysfunction and infection are the leading causes of mortality in the first 30 days following transplantation. Primary graft dysfunction (PGD) is a form of reperfusion injury that occurs early after transplantation. Management of PGD is mainly supportive with use of lung protective ventilation. Inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation may be used in severe cases. Bacterial pneumonias are the most common infectious complication in the immediate post transplant period, but invasive fungal infections may also occur. Other potential complications in the postoperative period include atrial arrhythmias and neurologic complications such as stroke. There is a lack of multicenter, randomized trials to guide ventilation strategies, infection prophylaxis, and treatment of atrial arrhythmias, therefore prevention and management of post-transplant complications vary by transplant center.

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.

Drug-Drug Interaction Study of Apixaban with Cyclosporine and Tacrolimus in Healthy Volunteers

Apixaban is metabolized by cytochrome P450 (CYP) 3A4 in the liver and intestine, undergoes direct intestinal excretion, and is a substrate to permeability glycoprotein (P-gp) and breast cancer resistance protein (BCRP) transporters. We examined the drug interactions between cyclosporine and tacrolimus (combined inhibitors of CYP3A4, P-gp, and BCRP) with apixaban in 12 healthy adult male volunteers. Apixaban 10 mg was administered orally alone, in combination with 100 mg cyclosporine or 5 mg tacrolimus. Co-administration with cyclosporine resulted in increase in apixaban maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve from time zero to the last quantifiable concentration (AUC(0-tlast) ) with associated geometric mean ratios (GMRs) and 90% confidence intervals (CIs) of 143% (112, 183) and 120% (97, 148), respectively. Co-administration with tacrolimus resulted in reduction in apixaban Cmax and AUC(0-tlast) with associated GMRs (90% CI) of 87% (69, 112) and 78% (63, 97), respectively. The observed changes in apixaban exposure margins with cyclosporine or tacrolimus are within the range of the historical clinical development program, therefore, apixaban dose adjustments are not warranted.

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.

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.

Evaluation of Enoxaparin Dosing as a Risk Factor for Bleeding in Lung Transplant Recipients

Background: Lung transplant recipients commonly develop complications that lead to anticoagulation. Standard FDA-approved enoxaparin dosing in this population results in a high incidence of above-goal anti-Xa levels, but its association with bleeding remains unclear. Objective: To evaluate the association between enoxaparin dosing and bleeding in lung transplant recipients and assess the relationship between dosing and anti-Xa levels. Methods: We conducted a single-center retrospective cohort study of adult lung transplant recipients who received therapeutic enoxaparin between 2000 and 2012 at a tertiary academic center. We dichotomized enoxaparin dosing regimens into standard dose (FDA-approved doses with a 10% rounding margin) and reduced dose. Clinicians ordered anti-Xa levels as deemed clinically appropriate. The primary outcome was major bleeding or clinically relevant nonmajor bleeding. Results: Of 222 patients treated with enoxaparin, 33 (14.9%) had bleeding events, of which half (17/33) were major. Bleeding occurred in 25/146 (17.1%) patients who received standard-dose enoxaparin versus 8/76 (10.5%) patients who received reduced-dose enoxaparin ( P = 0.190). Multiple logistic regression demonstrated an independent association between standard-dose enoxaparin and bleeding, after adjusting for confounders (adjusted odds ratio = 3.04; 95% CI = 1.14-8.10). The median enoxaparin dose in patients with above-goal versus at-goal anti-Xa levels was 0.89 versus 0.76 mg/kg every 12 hours; P = 0.006. However, doses yielding at-goal anti-Xa levels had an interquartile range of 0.67 to 0.90 mg/kg, which overlapped with doses yielding above- and below-goal anti-Xa levels. Conclusions: Enoxaparin dose reduction and anti-Xa level monitoring can improve drug safety and facilitate individualized dose optimization in lung transplant recipients.

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.

Cardiac manifestations of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, parenchymal disease of the lung with an estimated prevalence of 14-43 per 100,000. Patient usually presents with coughing and exertional dyspnea, which can lead to acute respiratory failure. IPF has been associated with various co-morbidities such as lung cancer, emphysema, obstructive sleep apnea (OSA), GERD and multiple cardiovascular consequences. The cardiovascular manifestations of IPF include pulmonary hypertension, heart failure, coronary artery disease, cardiac arrhythmias & cardiac manifestations of drugs used to treat IPF. This review will outline evidence of the association between IPF and cardiovascular conditions and attempt to provide insights into the underlying pathophysiology. We also discuss the impact of these cardiovascular diseases on patients with IPF including increased morbidity and mortality.

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.

Incidence, Risk Factors, Prognosis, and Electrophysiological Mechanisms of Atrial Arrhythmias after Lung Transplantation

OBJECTIVE

To investigate incidence and timing, risk factors, prognostic significance, and electrophysiological mechanisms of atrial arrhythmia (AA) after lung transplantation.

BACKGROUND

Although new-onset AA is common after thoracic surgery and is associated with poorer outcomes, prognostic and mechanistic data is sparse in lung transplant populations.

METHOD

A total of 293 consecutive isolated lung transplant recipients without known AA were retrospectively reviewed. Mean follow-up was 28±17 months. Electrophysiology studies (EPS) were performed in 25 patients with AA.

RESULTS

The highest incidence of new-onset AA after lung transplantation occurred within 30 days postoperative AA, (25 % of all patients). In multivariable analysis, postoperative AA was associated with double lung transplantation (OR 2.79; p=0.005) and lower mean pulmonary artery pressure (OR 0.95; p=0.027). Patients with postoperative AA had longer hospital stays (21 days vs 12 days; p<0.001). Postoperative AA was independently associated with late AA (HR 13.52; p<0.001) but not mortality (HR 1.55; p=0.14). In EPS, there were 14 patients with atrial flutter alone and 11 with atrial flutter and fibrillation. Of all EPS patients, 20 (80%) had multiple AA mechanisms, including peritricuspid flutter (48%), perimitral flutter (36%), right atrial incisional reentry (24%), focal tachycardia from recipient pulmonary vein (PV) antrum (32 %), focal PV fibrillation (24%), and left atrial roof flutter (20%). Left atrial mechanisms were present in 80% (20/25) of EPS patients and originated from the anastomotic PV antrum.

CONCLUSIONS

Postoperative AA was independently associated with longer length of stay and late AA but not mortality. Pleomorphic PV antral arrhythmogenesis from native PV antrum is the main cause of AA after lung transplantation.