Antiplatelet versus anticoagulation therapy after extracardiac conduit Fontan: a systematic review and meta-analysis

A Multisite Retrospective Review of Direct Oral Anticoagulants Compared to Warfarin in Adult Fontan Patients

PURPOSE

Direct oral anticoagulants (DOACs) are not recommended in adult Fontan patients (Level of Evidence C). We hypothesized that DOACs are comparable to warfarin and do not increase thrombotic and embolic complications (TEs) or clinically significant bleeds.

METHODS

We reviewed the medical records of adult Fontan patients on DOACs or warfarin at three major medical centers. We identified 130 patients: 48 on DOACs and 107 on warfarin. In total, they were treated for 810 months on DOACs and 5637 months on warfarin.

RESULTS

The incidence of TEs in patients on DOACs compared to those on warfarin was not increased in a statistically significant way (hazard ratio [HR] 1.7 and p value 0.431). Similarly, the incidence of nonmajor and major bleeds in patients on DOACs compared to those on warfarin was also not increased in a statistically significant way (HR for nonmajor bleeds in DOAC patients was 2.8 with a p value of 0.167 and the HR for major bleeds was 2.0 with a p value 0.267). In multivariate analysis, congestive heart failure (CHF) was a risk factor for TEs across both groups (odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.3-17.6) and bleed history was a risk factor for clinically significant bleeds (OR = 6.8, 95% CI = 2.7-17.2).

CONCLUSION

In this small, retrospective multicenter study, the use of DOACs did not increase the risk of TEs or clinically significant bleeds compared to warfarin in a statistically significant way.

Acute ST-elevation myocardial infarction with Guillain-Barre syndrome in Fontan circulation

Total cavopulmonary connection, commonly referred to as the Fontan procedure, is the established destination therapy for univentricular hearts. While the procedure permits a longer survival of these patients, this circulation involves several compromises from normal human circulation and poses several challenges with increasing age after surgery. We present an instance of acute ST-elevation myocardial infarction with Guillain-Barre syndrome in an adult after Fontan palliation and discuss the challenges in management.

Coagulation and Anticoagulation in Fontan Patients

Patients with a Fontan circulation for single-ventricle physiology are at increased risk of developing thromboembolic events. Thromboembolic events can lead to failure of the Fontan circulation, chronic sequelae in case of stroke, and early mortality. Controversies exist regarding the substrates, risk factors, and optimal detection methods for thromboembolic events. Despite the major clinical implications, there is currently no consensus regarding the optimal antithrombotic therapy to prevent or treat thromboembolic events after the Fontan procedure. In this review we aimed to untangle the available literature regarding antithrombotic prophylaxis and treatment for pediatric and adult Fontan patients. A decision-tree algorithm for thromboprophylaxis in Fontan patients is proposed. Additionally, the current state of knowledge is reviewed with respect to the epidemiology, pathophysiology, and detection of thromboembolic events in Fontan patients, and important evidence gaps are highlighted.

Early outcomes of fenestrated intra-extracardiac Fontan procedure: Insights, experiences, and expectations

BACKGROUND

Intraextracardiac Fontan procedure (FP) aimed to combine the advantages of lateral tunnel and extracardiac conduit modifications of the original technique. Herein, we present our early outcomes in patients with intraextracardiac fenestrated FP.

METHODS

A retrospective analysis was performed to evaluate intraextracardiac fenestrated Fontan patients between 2014 and 2021. Seventeen patients were operated on with a mean age and body weight of 9.1 ± 5.5 years and 28.6 ± 14.6 kg.

RESULTS

Sixteen patients (94%) were palliated as univentricular physiology with hypoplasia of one of the ventricles. One patient (6%) with well-developed two ventricles with double outlet right ventricle and complete atrioventricular septal defect had straddling of the chordae prohibiting a biventricular repair. All of the patients had cavopulmonary anastomosis before Fontan completion, except one case. Fenestration was performed in all cases. Postoperative mean pulmonary artery pressures and arterial oxygen saturation levels at follow-up were 10 ± 2.4 mmHg and 91.3 ± 2.7%, respectively. Mean duration of pleural drainage was 5.4 ± 2.3 days. All of the fenestrations are patent at a mean follow-up period of 4.8 ± 7.7 years, except one case. Any morbidity and mortality were not encountered.

CONCLUSIONS

Early outcomes of intraextracardiac fenestrated FP are encouraging. This procedure may improve the results in a patient population who should be palliated as univentricular physiology, especially in cases with complex cardiac anatomy.

Mechanical thrombectomy of COVID-19 DVT with congenital heart disease leading to phlegmasia cerulea dolens: a case report

BACKGROUND

COVID-19 and Fontan physiology have each been associated with an elevated risk of venous thromboembolism (VTE), however little is known about the risks and potential consequences of having both.

CASE PRESENTATION

A 51 year old male with tricuspid atresia status post Fontan and extracardiac Glenn shunt, atrial flutter, and sinus sick syndrome presented with phlegmasia cerulea dolens (PCD) of the left lower extremity in spite of supratherapeutic INR in the context of symptomatic COVID-10 pneumonia. He was treated with single session, catheter directed mechanical thrombectomy that was well-tolerated.

CONCLUSIONS

This report of acute PCD despite therapeutic anticoagulation with a Vitamin K antagonist, managed with emergent mechanical thrombectomy, calls to attention the importance of altered flow dynamics in COVID positive patients with Fontan circulation that may compound these independent risk factors for developing deep venous thrombosis with the potential for even higher morbidity.

Real-World Anticoagulant Use and Incidence of Venous Thromboembolism and Major Bleeding in Children

PURPOSE

Children generally have a lower risk of venous thromboembolism (VTE) than adults, but those with acute and chronic conditions requiring hospitalization and surgical procedures are at increased risk. Anticoagulant use in children has not been systematically studied, and limited data exist. This study aimed to provide data on the conditions associated with use of anticoagulants, the type of anticoagulant used in children, and the incidence of thromboembolism and major bleeding events reported in this population.

METHODS

To increase understanding of the use of anticoagulant therapies in children with at-risk conditions, 3 health claims databases in the United States were analyzed to describe the characteristics of use of heparins, warfarin, and direct oral anticoagulants (DOACs). Cumulative drug exposure was determined for continuous exposure, defined as >30 days. Unadjusted event rates of VTE and major bleeding after exposure to these therapies were reported. The data were presented descriptively and are not intended for comparison or to imply any causation.

FINDINGS

Anticoagulants were infrequently used in the pediatric population, including at any time point after Fontan surgery for congenital heart disease. Heparins were used most frequently in the population overall and especially for patients aged <12 years. DOACs were used least often and primarily for patients ages 12 to <18 years. Among pediatric patients exposed to anticoagulants, unadjusted incidence rates of VTE per 1000 person-years of exposure ranged from 30.8 to 34.0 for all DOACs, 21.6 to 46.2 for warfarin, and 6.0 to 7.3 for heparins. Rates per 1000 person-years for major bleeding ranged from 0 to 4.9 for all DOACs, 4.3 to 6.7 for warfarin, and 3.7 to 4.6 for heparins.

IMPLICATIONS

With results from clinical trials evaluating DOACs in the pediatric population expected in the next 2 years, these descriptive real-world data may provide a baseline understanding of current prescribing patterns and outcomes associated with the use of DOACs and other anticoagulants in routine pediatric clinical practice. This information represents the use of real-world evidence and may function as the benchmark for evaluating changes in prescription practices and potential outcomes in the future.

Thromboprophylaxis for Children Post-Fontan Procedure: Insights From the UNIVERSE Study

Background Patients with single-ventricle physiology who undergo the Fontan procedure are at risk for thrombotic events associated with significant morbidity and mortality. The UNIVERSE Study evaluated the efficacy and safety of a novel liquid rivaroxaban formulation, using a body weight-adjusted dosing regimen, versus acetylsalicylic acid (ASA) in children post-Fontan. Methods and Results The UNIVERSE Study was a randomized, multicenter, 2-part, open-label study of rivaroxaban, in children who had undergone a Fontan procedure, to evaluate its dosing regimen, safety, and efficacy. Part A was the single-arm part of the study that determined the pharmacokinetics/pharmacodynamics and safety of rivaroxaban in 12 participants before proceeding to part B, whereby 100 participants were randomized 2:1 to open-label rivaroxaban versus ASA. The study period was 12 months. A total of 112 participants were enrolled across 35 sites in 10 countries. In part B, for safety outcomes, major bleeding occurred in one participant on rivaroxaban (epistaxis that required transfusion). Clinically relevant nonmajor bleeding occurred in 6% of participants on rivaroxaban versus 9% on ASA. Trivial bleeding occurred in 33% of participants on rivaroxaban versus 35% on ASA. For efficacy outcomes, 1 participant on rivaroxaban in part B had a pulmonary embolism (2% overall event rate); and for ASA, 1 participant had ischemic stroke and 2 had venous thrombosis (9% overall event rate). Conclusions In this study, participants who received rivaroxaban for thromboprophylaxis had a similar safety profile and fewer thrombotic events, albeit not statistically significant, compared with those in the ASA group. Registration URL: https://www.clinicaltrials.gov. Identifier: NCT02846532.

Early Thromboprophylaxis Initiation is Associated With Reduced Fontan Thromboses in the Early Postoperative Period

Fontan circuit thrombosis is a significant cause of early postoperative morbidity and mortality. Thrombosis incidence and relationship to thromboprophylaxis choice and timing of initiation are not well established. We sought to evaluate the incidence of Fontan circuit thrombosis in the first 30 postoperative days and its relationship to thromboprophylaxis choice and timing. Patients undergoing Fontan surgery, 2006-2016, were reviewed. Fontan circuit thrombosis was defined by sonographic detection of intracardiac or deep venous thrombi. Logistic regression was used to assess relationships between thromboprophylaxis characteristics and thrombosis. One hundred ninety-two patients underwent Fontan. Fontan thrombosis occurred in 19 (10%) patients. 54% were started on aspirin, 27% coumadin, 4% heparin, and 7% none. There was no relationship between thrombosis and baseline anatomy, Fontan type or fenestration. Median time to thromboprophylaxis initiation was 4 days (interquartile range 2-6). Patients not started on thromboprophylaxis had 44.8 times the odds of thrombosis as those on thromboprophylaxis (confidence interval 6.4-311.7, P < 0.01); no children starting thromboprophylaxis before postoperative day 2 developed thromboses. For every day that thromboprophylaxis was delayed, odds of thrombosis increased by 30% (odds ratio 1.3; CI 1.1-1.6, P < 0.01). There was no difference in the odds of thrombosis between children taking aspirin vs other thromboprophylaxis types. Odds of early postoperative Fontan circuit thrombosis are increased in patients in whom thromboprophylaxis is delayed beyond the second postoperative day, with no difference in the odds of thrombosis between patients initiated on aspirin vs other thromboprophylaxis. Early aspirin institution post Fontan is recommended to reduce morbidity. Ultra-mini-Abstract: Odds of early postoperative Fontan circuit thrombosis are increased in patients in whom thromboprophylaxis is delayed beyond the second postoperative day, with no difference in the odds of thrombosis between patients initiated on aspirin vs other thromboprophylaxis. Early aspirin institution post Fontan is recommended to reduce morbidity and resource utilization.

Direct oral anticoagulant use and outcomes in adult patients with Fontan circulation: A multicenter retrospective cohort study

BACKGROUND

Many adult patients with Fontan circulation are treated with antithrombotic agents, including direct oral anticoagulants (DOACs). However, few studies have investigated the efficacy, feasibility, and safety of DOACs in adult patients with Fontan circulation.

METHODS AND RESULTS

In this retrospective cohort study, clinical records of 139 adult patients with Fontan circulation (70 females, 50.4%) from April 2015 to March 2018 were reviewed and classified into five groups according to the therapeutic agents used: DOAC (n = 36), vitamin K antagonist (VKA; n = 41), antiplatelet drug (n = 43), combination of an antiplatelet and anticoagulant (n = 14), and no-antithrombotic prophylaxis (n = 5). In a 1114-patient-year follow-up, 28 major events occurred, including 10 thrombotic and 18 bleeding events; 11 of 18 (61%) female patients had severe menorrhagia. The incidence (% patient-years) of major events was 0.6, 1.42, 3.74, and 5.13 in the DOAC, antiplatelet, VKA, combination, and no-antithrombotic groups, respectively. The Cox proportional hazards analysis revealed that the DOAC group had a lower rate of primary endpoints than the VKA group in males.

CONCLUSIONS

DOAC may be a safe antithrombotic agent for use in adult patients with Fontan circulation, particularly in males. However, these findings should be confirmed in multi-institutional prospective studies.

Successful in vitro fertilization in women with Fontan physiology

PURPOSE

Patients with single ventricle anatomy palliated with Fontan operation are at risk for thromboembolism, arrhythmia, and heart failure rendering pregnancy high risk or even contraindicated. Infertility and high rates of first trimester miscarriage are not uncommon. In vitro fertilization (IVF) with or without gestational surrogacy can be an option, but poses risks during ovarian stimulation, oocyte retrieval, and the post-procedural period. We present six cases of women with complex congenital heart disease status post Fontan operation who underwent successful IVF.

METHODS

Case series from a single-center tertiary care setting.

RESULTS

Indications for referral were cardiac or fertility concerns for pregnancy of the congenital cardiologist. One woman had mild volume overload after oocyte retrieval requiring furosemide and one experienced post-operative colitis. There were no thrombotic complications.

CONCLUSIONS

A multidisciplinary team-based approach can result in successful oocyte retrieval and IVF in women with complex congenital heart disease and Fontan physiology.

The intra-extracardiac Fontan: preliminary results

OBJECTIVE

Since the intra-extracardiac Fontan (IECF) was popularized by Jonas in 2008, its claimed advantages over the traditional extracardiac or lateral tunnel Fontan are simplicity, suitability for nearly all subsets, flow characteristics, low risk of sinus node artery injury, and possibly, a lower incidence of arrhythmias. In this paper, we present our early experience with this modification of the Fontan operation.

METHODS

Between 2009 and 2018, 10 patients underwent IECF on cardiopulmonary bypass (CPB) and cardioplegic arrest at our institute. Analysis of preoperative, intraoperative, and early follow-up results was performed. A polytetrafluoroethylene (PTFE) graft was sutured proximally to the orifice of the inferior vena cava (IVC) and distally to the ipsilateral bidirectional superior cavopulmonary (BSCP) junction.

RESULTS

Nine patients had undergone a previous BSCP connection, and one patient had a primary IECF. Diagnoses were double outlet right ventricle (n = 2), unbalanced atrioventricular septal defect with associated atrioventricular valve regurgitation (n = 3), single ventricle with anomalies of cardiac situs (n = 2), and tricuspid atresia with borderline pulmonary arteries (n = 1) or tricuspid atresia with borderline pulmonary artery pressures (n = 2). Median aortic cross-clamp and CPB times were 42 min and 82 min respectively. There were no early or late deaths. Median intensive care stay was 3 days (1 to 23 days). There were no arrhythmias. Mean duration of pleural effusions was 9.5 (median 5.5) days. There were no arrhythmias at a median follow-up of 5 years (range 1 month to 9.3 years).

CONCLUSION

The IECF is simple, particularly at reoperations, in borderline patients and those needing concomitant intracardiac procedures. Early results are promising. These patients need constant surveillance.

Thromboembolic Events Are Independently Associated with Liver Stiffness in Patients with Fontan Circulation

Background: Thromboembolism (TE) and Fontan-associated liver disease (FALD) are common and lead to significant morbidity in Fontan circulations. Risk factors for TE and the potential link between TE and FALD are not well understood. The objective of this study was to evaluate the association between TE and the severity of FALD based on radiologic liver stiffness. Methods: Using a retrospective cohort study design, 85 Fontan patients (aged 27.7 ± 8.2 years) who had liver stiffness measurement were included. Multivariable logistic regression was used to determine independent associations with TE. Results: Sixteen patients (19%) had a history of TE after the Fontan procedure at a mean age of 21.4 ± 15.0 years. Patients with TE were significantly older at the time of the last evaluation (33.8 ± 11.7 vs. 26.3 ± 6.5 years, p = 0.03). Liver stiffness by MRI and ultrasound was higher in the TE group (5.1 ± 1.4 vs. 4.3 ± 1.2 kPa, p = 0.04 and 2.8 ± 0.4 vs. 2.4 ± 0.5 m/s, p = 0.04, respectively). On multivariable analysis, higher liver stiffness (odds ratio (OR): 2.12, p = 0.03) and older age (OR: 1.11, p = 0.03) were associated with TE. Conclusions: This study found an association between TE, age, and radiologic liver stiffness.

Clinical Importance of Fontan Circuit Thrombus in the Adult Population: Significant Association With Increased Risk of Cardiovascular Events

BACKGROUND

The impact of Fontan circuit thrombus is poorly understood. The objectives of this study were to determine (1) the incidence of Fontan circuit thrombus and proportion of silent thrombus; (2) any association between Fontan circuit thrombus and markers of Fontan circulatory dysfunction; and (3) the association of Fontan circuit thrombus with adverse cardiac outcomes.

METHODS

We conducted a retrospective review of adult patients who underwent the Fontan procedure (aged > 18 years) followed at St. Paul's Hospital who underwent cardiac computed tomography or magnetic resonance imaging assessment (n = 67). Fontan circulatory dysfunction markers included clinical heart failure, N-terminal pro-brain natriuretic peptide, ventricular dysfunction, atrioventricular valvular regurgitation, refractory arrhythmias, declining exercise capacity, and hepatic/renal dysfunction. Adverse cardiac outcomes were death, heart transplantation, or surgery for Fontan revision or atrioventricular valve replacement.

RESULTS

Fontan circuit thrombus was present in 15 of 67 patients (22%): 41% (7/17) classic/modified Fontan and 16% (8/50) total cavopulmonary connection. Incidence was 36% among those suspected to have Fontan circuit thrombus; 14% in those with no clinical/echocardiographic suspicion; and clinically silent in 40% diagnosed with Fontan thrombus. The time from Fontan surgery to Fontan circuit thrombus diagnosis was 22 ± 6 years in the classic/modified group vs 14 ± 8 years in the total cavopulmonary connection group (P = 0.03. Fontan circuit thrombus was associated with adverse cardiac outcomes (27% [4/15] vs 8% [4/52], P = 0.02), but there was no difference in Fontan circulatory dysfunction markers.

CONCLUSION

Given the incidence of Fontan circuit thrombus and association with adverse cardiac outcomes, routine surveillance of the Fontan circuit should strongly be considered. The identification of thrombus should lead to anticoagulation implementation/optimization, along with screening/intervention for reversible Fontan circulatory issues in an attempt to prevent adverse cardiac outcomes.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Thromboprophylaxis strategies for children with single-ventricle circulations (superior or total cavo-pulmonary connections) after stent implantation

OBJECTIVE

To define optimal thromboprophylaxis strategy after stent implantation in superior or total cavopulmonary connections.

BACKGROUND

Stent thrombosis is a rare complication of intravascular stenting, with a perceived higher risk in single-ventricle patients.

METHODS

All patients who underwent stent implantation within superior or total cavopulmonary connections (caval vein, innominate vein, Fontan, or branch pulmonary arteries) were included. Cohort was divided into aspirin therapy alone versus advanced anticoagulation, including warfarin, enoxaparin, heparin, or clopidogrel. Primary endpoint was in-stent or downstream thrombus, and secondary endpoints included bleeding complications.

RESULTS

A total of 58 patients with single-ventricle circulation underwent 72 stent implantations. Of them 14 stents (19%) were implanted post-superior cavopulmonary connection and 58 (81%) post-total cavopulmonary connection. Indications for stenting included vessel/conduit stenosis (67%), external compression (18%), and thrombotic occlusion (15%). Advanced anticoagulation was prescribed for 32 (44%) patients and aspirin for 40 (56%) patients. Median follow up was 1.1 (25th-75th percentile, 0.5-2.6) years. Echocardiograms were available in 71 patients (99%), and advanced imaging in 44 patients (61%). Thrombosis was present in two patients on advanced anticoagulation (6.3%) and none noted in patients on aspirin (p = 0.187). Both patients with in-stent thrombus underwent initial stenting due to occlusive left pulmonary artery thrombus acutely post-superior cavopulmonary connection. There were seven (22%) significant bleeding complications for advanced anticoagulation and none for aspirin (p < 0.001).

CONCLUSIONS

Antithrombotic strategy does not appear to affect rates of in-stent thrombus in single-ventricle circulations. Aspirin alone may be sufficient for most patients undergoing stent implantation, while pre-existing thrombus may warrant advanced anticoagulation.

Rivaroxaban, a direct Factor Xa inhibitor, versus acetylsalicylic acid as thromboprophylaxis in children post-Fontan procedure: Rationale and design of a prospective, randomized trial (the UNIVERSE study)

BACKGROUND

The Fontan procedure is the final step of the 3-stage palliative procedure commonly performed in children with single ventricle physiology. Thrombosis remains an important complication in children after this procedure. To date, guideline recommendations for the type and duration of thromboprophylaxis after Fontan surgery are mainly based on extrapolation of knowledge gained from adults at risk for thrombosis in other clinical settings. Warfarin is being used off-label, and because of its multiple interactions with other drugs and food, a new alternative is highly desirable. Rivaroxaban, a direct Factor Xa inhibitor with a predictable pharmacokinetic profile, is a candidate to address this medical need.

STUDY DESIGN

The UNIVERSE study is a prospective, open-label, active-controlled, multicenter study in children 2 to 8 years of age who have single ventricle physiology and had the Fontan procedure within the 4 months preceding enrollment. This study consists of 2 parts. In Part A, rivaroxaban pharmacokinetics, pharmacodynamics, safety, and tolerability are assessed to validate the pediatric dosing selected. In Part B, safety and efficacy of rivaroxaban versus acetylsalicylic acid are evaluated for thromboprophylaxis in children post-Fontan procedure. Children in each part will receive study drug for 12 months. Part A has been completed with 12 children enrolled. Enrollment into Part B is currently ongoing.

CONCLUSIONS

The UNIVERSE study aims to provide dosing, pharmacokinetics/pharmacodynamics, safety, and efficacy information on the use of rivaroxaban, an oral anticoagulant, versus acetylsalicylic acid, an antiplatelet agent, in children with single ventricle physiology after the Fontan procedure.

Non-vitamin K antagonist oral anticoagulants in adults with a Fontan circulation: are they safe

Background

In Fontan patients with atrial arrhythmias (AA), non-vitamin K antagonist oral anticoagulants(NOACs) have a class III recommendation according to the Pediatric & Congenital Electrophysiology Society (PACES)/Heart Rhythm Society (HRS) guideline in 2014, due to lack of data on outcomes as opposed to evidence of harm. To address this gap in data, we investigated the safety and efficacy of NOACs in adults with a Fontan circulation in a worldwide study.

Methods

This is an international multicentre prospective cohort study, using data from the NOTE (non-vitamin K antagonist oral anticoagulants for thromboembolic prevention in patients with congenital heart disease) registry. The study population comprised consecutive adults with a Fontan circulation using NOACs. Follow-up took place at 6 months and yearly thereafter. The primary endpoints were thromboembolism and major bleeding. Secondary endpoint was minor bleeding.

Results

From April 2014 onward, 74 patients (mean age 32±10 years (range 18–68), 54% male) with a Fontan circulation using NOACs were included. During a median follow-up of 1.2 (IQR 0.8–2.0) years, three thromboembolic events (2.9 per 100 patient-years (95% CI 0.7 to 7.6)) and three major bleedings (2.9 per 100 patient-years (95% CI 0.7 to 7.6)) occurred in five atriopulmonary Fontan and one total cavopulmonary connection Fontan patients with AA. Fifteen patients experienced minor bleeding episodes (15.8 per 100 patient-years (95% CI 9.1 to 25.2)). In patients (n=37) using vitamin K antagonists (VKAs) prior to the initiation of NOAC, annual incidence of historical thromboembolic events and major bleeding were 2.4% (95% CI 0.4% to 7.4%) (n = 2) and 1.2% (95% CI 0.7% to 5.1%) (n = 1), respectively.

Conclusions

In this review of the largest Fontan cohort using NOACs with prospective follow-up, NOACs appear to be well tolerated and their efficacy and safety during short-term follow-up seem comparable to VKAs. Longer term data are required to confirm these promising short-term results.

Assessment of Late Thromboembolic Complications Post-Fontan Procedure in Relation to Different Antithrombotic Regimens: 30-Years' Follow-up Experience

Background: The current CHEST guidelines recommend the use of antithrombotic therapy, either aspirin or warfarin, as a primary thromboembolic complications (TECs) prophylaxis in patients who undergo Fontan procedure, without specification on drug selection or duration of therapy. Objective: To investigate the incidence rate of late TECs, occurring after 1-year post-Fontan procedure and to assess the difference in rate of late TECs between warfarin and aspirin. Methods: A retrospective cohort study included patients who had Fontan procedures between 1985-2010 at our institution. Patients were stratified according to the antithrombotic regimen-warfarin, aspirin, or no therapy-at the time of TECs. Results: We screened 499 patients who underwent Fontan procedures; 431 procedures met the inclusion criteria. Over a median follow-up of 13.6 years (IQR= 8.7), freedom from late TECs at 5, 10, 15, and 20 years was 97.54%, 96.90%, 90.78%, and 88.07%, respectively. There was no difference in late TEC incidence rates per 1000 patient-years between warfarin and aspirin: 7.82 and 5.83 events, respectively; rate ratio= 1.34 (95% CI= 0.68-2.60). Warfarin was associated with a higher major bleeding incidence rate per 1000 patient-years: 3.70 versus 2.91 events with aspirin; rate ratio= 1.27 (95% CI= 0.49 to 3.29). Conclusion and Relevance: The incidence rate of late clinical TECs post-Fontan procedure in our population is low. Warfarin was not superior to aspirin for prevention of late TECs. Yet warfarin was associated with a higher rate of bleeding. This finding suggests a simpler antithrombotic regimen for prevention of TEC after 1-year post-Fontan procedure.

Immediate and early post-operative sequelae of off-pump total cavopulmonary connection

Background

Extracardiac Fontan (ECF) is currently the final operation of choice for patients with a univentricular heart. Performing this procedure without cardiopulmonary bypass (CPB) carries potential benefits. In this study, we report the early results of ECF without CPB.

Patients and methods

Between 2012 and 2015, 72 consecutive patients underwent Fontan without CPB. Their medical records were examined in detail.

Results

Mean age was 11.8 ± 5.2 (range 5 to 23, median 10) years. Intraoperative mean superior vena cava clamp time was 15.19 ± 3.8 min, and the inferior vena cava clamp time was 16.93 ± 3.31 min. There were three early deaths. No patient required conversion from off-CPB to CPB. Mean inotropic score was 4.73 ± 5.9 (range 0 to 25, median 2.5). Mean time to extubation was 9.5 ± 5.82 (range 3 to 29, median 8) hours. Pleural drainage in intensive care unit (ICU) was 551.57 ± 452.77 (median 470) ml, and mean ICU stay was 2.27 ± 3.09 (median 1.5) days. Mean daily pleural drainage after discharge from the ICU was 163.7 ± 88.01 (median 140) ml, and mean time to removal of pleural tubes was 15.76 ± 8.4 (median 14) days. Total hospital stay was 17.03 ± 8.62 (median 15) days. At an early follow-up of 2-40 (median 25) months, all survivors (n = 69) had a patent Fontan circuit with normal ventricular function on echocardiography. There were no late deaths or thromboembolic complications.

Conclusions

Off-pump ECF is a low-risk procedure that avoids the harmful effects of CPB. Post-operative course of these patients is predictable with substantial savings in costs.

Conduit Route Selection for Total Cavopulmonary Connection in Patients With Apicocaval Juxtaposition

Apicocaval juxtaposition (ACJ) may complicate the selection of conduit route in patients with single ventricles when total cavopulmonary connection (TCPC) is performed. We reviewed our experience of pathway selection and evaluated the clinical results. Of 128 patients who underwent TCPC at our hospital between January 2009 and April 2016, 31 with ACJ were included in this study. In 24 patients, the conduit was placed between the inferior vena cava (IVC) and the ipsilateral pulmonary artery. To avoid compression of the conduit and pulmonary veins in 5 patients, the conduit was placed between the IVC and the contralateral pulmonary artery. In 2 patients, the tube graft was anastomosed with the IVC orifice within the atrium, then guided through the atrial free wall and anastomosed with the contralateral pulmonary artery outside the heart (intra/extracardiac Fontan). Patient demographics were compared with those of patients without ACJ. The mean age and body weight at surgery were 58.5 ± 32.4 months and 16.2 ± 6.0 kg, respectively. The mean postoperative pulmonary artery pressure was 15 ± 3 mm Hg. The postoperative data did not differ significantly from that of patients without ACJ who underwent extracardiac TCPC. One patient died of overwhelming infection. The mean follow-up was 17.5 ± 15.4 months (range, 1-65 months). There were no conduit-related early or late complications. TCPC in patients with ACJ can be performed with excellent early and midterm results. The route between the IVC and the ipsilateral pulmonary artery is our preference.

Late Follow-up of Patients Submitted to Total Cavopulmonary Derivation: Clinical Aspects, Reinterventions, and Complications Interfering in Morbidity and Mortality

Objective

To identify main complications in outpatient follow-up, as well as factors before or during operation that may interfere in patient's evolution.

Methods

Retrospective study of patients submitted to total cavopulmonary shunt with extracardiac conduit from 2000 to 2014 at the Hospital do Coração (São Paulo, Brazil) and who underwent clinical follow-up at this institution.

Results

One hundred and fifty surgeries were performed and 59 patients maintained outpatient follow-up. The mean age of these patients at the time of surgery was 4.45 years (median of 45 months) and 70.2% of them were males. Among the patients undergoing outpatient follow-up, postoperative time at evaluation ranged from 10 days to 145 months; 30 (50.8%) patients had single left ventricle and 29 (49.2%) had single right ventricle (48.2% of these presented with hypoplastic left heart syndrome [HLHS]). Patients with single left ventricle had a higher percentage of reintervention-free survival, but without statistically significant difference. 40% of the patients had no complications and 35% of them presented with thrombosis at some point in the follow-up period, with ventricular dysfunction being the second most frequently found complication (15% of cases), mainly among patients with single right ventricle morphology (P=0.04). Between the patients currently under follow-up, 20 (35%) of them had been evaluated by ultrasonography and had some degree of hepatic congestion and/or hepatomegaly. 16.7% of the patients with such alteration had HLHS (P=0.057).

Conclusion

Except for the right ventricular morphology, no other factor has been shown to interfere in late evolution after total cavopulmonary shunt.

Diagnosis and Management of Noncardiac Complications in Adults With Congenital Heart Disease: A Scientific Statement From the American Heart Association

Life expectancy and quality of life for those born with congenital heart disease (CHD) have greatly improved over the past 3 decades. While representing a great advance for these patients, who have been able to move from childhood to successful adult lives in increasing numbers, this development has resulted in an epidemiological shift and a generation of patients who are at risk of developing chronic multisystem disease in adulthood. Noncardiac complications significantly contribute to the morbidity and mortality of adults with CHD. Reduced survival has been documented in patients with CHD with renal dysfunction, restrictive lung disease, anemia, and cirrhosis. Furthermore, as this population ages, atherosclerotic cardiovascular disease and its risk factors are becoming increasingly prevalent. Disorders of psychosocial and cognitive development are key factors affecting the quality of life of these individuals. It is incumbent on physicians who care for patients with CHD to be mindful of the effects that disease of organs other than the heart may have on the well-being of adults with CHD. Further research is needed to understand how these noncardiac complications may affect the long-term outcome in these patients and what modifiable factors can be targeted for preventive intervention.

Prevalence and outcome of thrombotic and embolic complications in adults after Fontan operation

There are limited studies of thrombotic and embolic complications (TEC) in the adult Fontan population. The purpose of the study was to determine the prevalence, risk factors, and outcomes of TECs in this population.

METHODS

Retrospective review of adults with a previous Fontan operation, with follow-up at Mayo Clinic, 1994-2014. Systemic TEC was defined as intracardiac thrombus, ischemic stroke, or systemic arterial embolus. Nonsystemic TEC was defined as Fontan conduit/right atrial thrombus or pulmonary embolus.

RESULTS

We identified 387 patients with a mean (SD) age of 28 (7) years and a mean follow-up of 8 (2) years. An atriopulmonary connection (APC) was done for 286 patients (74%). Atrial arrhythmias were present in 278 (72%). There were 121 TECs (systemic n=36, nonsystemic n=85) in 98 patients (25%). Risk factors for systemic TEC were atrial arrhythmia (hazard ratio 2.28, P=.001) and APC (hazard ratio 1.98, P=.02); nonsystemic TEC also had similar risk factors. All 98 patients received warfarin. Warfarin was discontinued in 10 of 98 because of bleeding, and 8 of these 10 subsequently had a second TEC. Among the 82 patients who had follow-up imaging, 16 (20%) had resolution of thrombus. In total, 24 of 98 patients had a second TEC, most of whom had inadequate anticoagulation.

CONCLUSIONS

Thrombotic and embolic complication was not uncommon; risk factors for TEC were APC and atrial arrhythmias. Most patients were treated successfully with warfarin alone. A second TEC occurred in most patients whose anticoagulation was discontinued because of bleeding events.

No difference between aspirin and warfarin after extracardiac Fontan in a propensity score analysis of 475 patients

OBJECTIVES

The most effective method of long-term thromboprophylaxis after the Fontan procedure is not clear. We compared the rates of thromboembolic events between patients receiving aspirin and warfarin after an extracardiac conduit Fontan procedure in a bi-national registry.

METHODS

All patients who underwent an extracardiac conduit Fontan procedure from 1997 to 2010 in Australia and New Zealand were identified. Medication status and routine follow-up and echocardiographic data were obtained from all patients. Survival analysis with propensity score matching and adjustment was performed to determine the treatment effect of warfarin compared with that of aspirin beyond the first year of follow-up, after which time patients had settled on their long-term thromboprophylaxis strategy.

RESULTS

Of 570 eligible patients, the data of 475 patients who were regularly followed up without mechanical valve replacement were available for analysis. Long-term thromboprophylaxis consisted of warfarin in 301 patients (63%), aspirin in 157 (33%) and none in 17 (4%). The 10-year rate of freedom from all thromboembolic events was 91% [95% confidence interval (CI) 88-94%]. Thromboembolic events beyond the first year of follow-up occurred in 18 patients (6 on aspirin and 12 on warfarin). After (i) propensity score adjustment and (ii) matching yielding 164 pairs, the hazard rates of thromboembolic events beyond the first year were not statistically different between the warfarin and aspirin groups [(i) hazard ratio (HR) 2.3, 95% CI 0.7-7.4, P = 0.2 and (ii) HR 1.5, 95% CI 0.5-4.7, P = 0.5, respectively].

CONCLUSIONS

No difference in the hazard rates of late thromboembolic events was observed between aspirin and warfarin beyond the first year after the extracardiac conduit Fontan procedure.

Strategies for thromboprophylaxis in Fontan circulation: a meta-analysis

BACKGROUND

The Fontan circulation is associated with an increased risk of thromboembolic events (TEs). As many as 25% of these thrombotic events result in fatality. More subtle adverse effects on the pulmonary circulation from embolic thrombi may further impair adequate functioning of the circuit. Despite these well-documented phenomena, the most optimal approaches to thromboprophylaxis are still not clearly defined.

OBJECTIVE

A meta-analysis of published trials in English on PubMed and Cochrane libraries that evaluated the role of using TE prophylaxis in patients who underwent the Fontan procedure was conducted.

METHODS

10 studies with a total number of 1200 patients with an average follow-up time of 7.1 years were identified. A random effect model was used.

RESULTS

The incidence of TE was significantly less in patients who received TE prophylaxis (using either aspirin or warfarin) compared with patients who did not receive TE prophylaxis (OR 0.425, 95% CI 0.194 to 0.929, p<0.01, I(2)=37%). The incidence of TE was significantly lower in patients who received aspirin compared with no TE prophylaxis (OR 0.363, 95% CI 0.177 to 0.744, p<0.01, I(2)=0%) and who received warfarin compared with no TE prophylaxis (OR 0.327, 95% CI 0.168 to 0.634, p<0.01, I(2)=2.5%). There was no significant difference in incidence of TE between warfarin and aspirin (OR 0.936, 95% CI 0.609 to 1.438, p=0.54, I(2)=0%). Furthermore, there was no significant difference in incidence of early TE (within 6 months of the operation) or late TE (>6 months) between patients receiving warfarin and aspirin (OR 0.784, 95% CI 0.310 to 1.982, p=0.37, I(2)=8%) and (OR 0.776, 95% CI 0.249 to 2.42, p=0.3, I(2)=45%), respectively. When only total cavopulmonary connection patients were included, there was again no difference between warfarin and aspirin in the incidence of TE (OR 0.813, 95% CI 0.471 to 1.401, p=0.34, I(2)=11%).

CONCLUSIONS

This study shows a significantly lower incidence of TE after Fontan procedure if either aspirin or warfarin is used. This meta-analysis suggests no significant difference in incidence of early or late TE in patients receiving aspirin compared with warfarin.

Incidence of Venous Thromboembolism and Benefits and Risks of Thromboprophylaxis After Cardiac Surgery: A Systematic Review and Meta-Analysis

Background

Optimal thromboprophylaxis after cardiac surgery is uncertain. This systematic review aimed to define the incidence and risk factors for deep vein thrombosis (DVT), fatal and nonfatal pulmonary embolism (PE), and assess whether venous thromboembolism (VTE) prophylaxis was effective in reducing VTE without complications after cardiac surgery.

Methods and Results

Two reviewers independently searched and assessed the quality and outcomes of randomized, controlled trials (RCTs) and observational studies on VTE after cardiac surgery in the MEDLINE, EMBASE, and Cochrane controlled trial register (1966 to December 2014). Sixty‐eight studies provided data on VTE outcomes or complications related to thromboprophylaxis after cardiac surgery. The majority of the studies were observational studies (n=49), 16 studies were RCTs, and 3 were meta‐analyses. VTE prophylaxis was associated with a reduced risk of PE (relative risk [RR], 0.45; 95% confidence interval [CI], 0.28–0.72; P=0.0008) or symptomatic VTE (RR, 0.44; 95% CI, 0.28–0.71; P=0.0006) compared to the control without significant heterogeneity. Median incidence (interquartile range) of symptomatic DVT, PE, and fatal PE were 3.2% (0.6–8.1), 0.6% (0.3–2.9), and 0.3% (0.08–1.7), respectively. Previous history of VTE, obesity, left or right ventricular failure, and prolonged bed rest, mechanical ventilation, or use of a central venous catheter were common risk factors for VTE. Bleeding or cardiac tamponade requiring reoperation owing to pharmacological VTE prophylaxis alone, without systemic anticoagulation, was not observed.

Conclusions

Unless proven otherwise by adequately powered RCTs, initiating pharmacological VTE prophylaxis as soon as possible after cardiac surgery for patients who have no active bleeding is highly recommended.

Comparative trial of the use of antiplatelet and oral anticoagulant in thrombosis prophylaxis in patients undergoing total cavopulmonary operation with extracardiac conduit: echocardiographic, tomographic, scintigraphic, clinical and laboratory analysis

OBJECTIVE

To compare the efficacy of aspirin and warfarin for prophylaxis of thrombosis in patients undergoing total cavopulmonary anastomosis. Evaluate whether coagulation factors (VII, VIII and protein C), clinical data, fenestration or hemodynamic factors, interfere with postoperative thrombosis.

METHODS

A prospective, randomized study of 30 patients, randomized into Group I (Warfarin) and Group II (AAS), underwent total cavopulmonary shunt with extracardiac conduit, between 2008 and 2011, with follow-up by clinical visits to evaluate side effects and adhesion. Performed transesophageal echocardiography in post operatory time, 3, 6,12 and 24 months; angiotomography at 6, 12 and 24 months to evaluate changes in the internal tube wall or thrombi and pulmonary scintigraphy to evaluate possible PTE.

RESULTS

Two deaths in group I; 33.3% of patients had thrombus (46.7% in Group II). The previous occurrence of thrombus and low levels of coagulation protein C were the only factors that influenced the time free of thrombus (P=0.035 and 0.047). Angiotomographic evaluation: 35.7% in group II presented material accumulation greater than 2 mm (P=0.082). Scintigraphy: two patients had PTE in group II. Five patients had difficulty to comply with the treatment, 4 in group I with INR ranging from 1 to 6.4.

CONCLUSION

The previous occurrence of thrombus is a risk factor for thrombosis in the postoperative period. Patients using AAS tend to deposit material in the tube wall. The small sample size did not allow to conclude which is the most effective drug in the prevention of thrombosis in this population.

Long-term outcome and anaesthetic management for non-cardiac surgery after Fontan palliation: a single-centre retrospective analysis

OBJECTIVES

The improved management of Fontan patients has resulted in good outcome. As such, these patients may necessitate care for non-cardiac surgery. We sought to determine the long-term outcome of our Fontan series palliated with the most recent surgical techniques. Our second objective was to report the incidence and the perioperative course after non-cardiac procedures. We reviewed the records of all patients with either a lateral tunnel or an extracardiac conduit Fontan between 1996 and 2008. Follow-up was recorded until June, 2013, including records regarding non-cardiac interventions.

RESULTS

Overall, 58 patients were included. Of them, one patient underwent a takedown of his Fontan, and five patients died in the immediate postoperative course. The cumulative survival of the remaining 52 patients was 81%. There was no significant difference in survival between right and left ventricle morphologies (p=0.56), nor between both types of Fontan (p=0.9). Chronic arrhythmias (25%), fatigue/dyspnoea (40%), thrombotic complications (19%), and embolic events (10%) were among the most recurrent comorbidities. In total, 45 non-cardiac interventions were performed on 26 patients, with three bleeding complications and one death.

CONCLUSIONS

This study shows excellent long-term survival after both lateral tunnel and extracardiac conduit Fontan. The incidence of cardiovascular morbidity remains high, however. We also report a high number of non-cardiac interventions. Thorough understanding of the Fontan physiology is mandatory when non-cardiac anaesthesiologists are in charge of these patients.

Decision-Making for Surgery in the Management of Patients with Univentricular Heart

A series of technical refinements over the past 30 years, in combination with advances in perioperative management, have resulted in dramatic improvements in the survival of patients with univentricular heart. While the goal of single-ventricle palliation remains unchanged - normalization of the pressure and volume loads on the systemic ventricle, the strategies to achieve that goal have become more diverse. Optimal palliation relies on a thorough understanding of the changing physiology over the first years of life and the risks and consequences of each palliative strategy. This review describes how to optimize surgical decision-making in univentricular patients based on a current understanding of anatomy, physiology, and surgical palliation.

Inhaled iloprost for the treatment of patient with Fontan circulation

Decreased exercise capacity after Fontan surgery is relatively common and the failure of the Fontan state gradually increases with age. However, there is no further treatment for patients with Fontan circulation. Pulmonary vasodilation therapy is an effective method to solve this problem because pulmonary vascular resistance is a major factor of the Fontan problem. Inhaled iloprost is a chemically stable prostacyclin analogue and a potent pulmonary vasodilator. We experienced two cases of Fontan patients treated with inhaled iloprost for 12 weeks. The first patient was an 18-year-old female with pulmonary atresia with an intact ventricular septum, and the second patient was a 22-year-old male with a double outlet right ventricle. Fifteen years have passed since both patients received Fontan surgery. While the pulmonary pressure was not decreased significantly, improved exercise capacity and cardiac output were observed without any major side effects in both patients. The iloprost inhalation therapy was well tolerated and effective for the symptomatic treatment of Fontan patients.

Prevalence and predictors of haemostatic complications in 412 Fontan patients: their relation to anticoagulation and haemodynamics

OBJECTIVES

Our aim in the present study was to determine the prevalence of haemostatic events in our Fontan patients, to identify predictive factors and to determine their association with haemodynamics and anticoagulant therapy.

METHODS

We retrospectively evaluated 424 Fontan patients and examined correlations between postoperative haemodynamics and anticoagulant regimens with haemostatic events.

RESULTS

After exclusion of 12 patients with a mechanical valve at the time of Fontan operation, our 412 patients were sub-divided into 21 groups based on the therapeutic duration of warfarin and antiplatelet agent therapy. During the early 5- to 10-year postoperative period, patients receiving warfarin showed higher central venous pressure and lower arterial oxygen saturation (Sat) (P < 0.05-0.001). During a mean follow-up of 11.2 years, 29 (7.0%) haemostatic events occurred. With regard to haemorrhagic events, haemoptysis was most common (n = 13, 45%), followed by cerebral bleeds in 3 (10%). Of thrombo-embolic events, thrombosis in the Fontan pathway was the most common (n = 7, 24%), followed by cerebral infarction in 3. Early haemorrhagic events were associated with late Fontan operation and use of preoperative renin-angiotensin system blockers, while late events were related to heterotaxy syndrome, male gender and low Sat (P < 0.05-0.01). A low Sat was the only predictor of early postoperative thrombo-embolic events (P = 0.0192). Among the three subgroup analyses of fixed anticoagulant regimens, the most frequent haemorrhagic events were associated with long-term use of warfarin (P = 0.0033). None of the anticoagulant regimens that included warfarin and/or antiplatelet agents were independently associated with haemostatic events throughout the follow-up.

CONCLUSIONS

Anticoagulant regimens in Fontan patients varied widely with a significant trend for warfarin use in patients with impaired haemodynamics. Low arterial oxygenation may predict haemostatic events. The relatively high prevalence of haemorrhagic complications indicates the need for individualized anticoagulant administration throughout the follow-up.

Anti-platelet agents in pediatric cardiac practice

Pediatric patients with a variety of congenital and acquired cardiac conditions receive antithrombotic therapy. Many of the indications are empirical, and have either not been proven in controlled studies or are extrapolated from adult studies. This article reviews the current available literature regarding the use of anti-platelet drugs in the pediatric cardiac population.