Hypercoagulability Markers Predict Thrombosis in Single Ventricle Neonates Undergoing Cardiac Surgery

Intracardiac thrombosis after congenital heart disease surgeries in neonates: a report of two cases

BACKGROUND

Intracardiac thrombosis (ICT) is a rare complication after the cardiopulmonary surgery for interrupted aortic arch (IAA) or total anomalous pulmonary venous connection (TAPVC) without previous records. There are still no general guidelines regarding as the mechanism or management of postoperative ICT in neonates and younger infants.

CASE PRESENTATION

We reported the conservative and surgical therapies in two neonates with intra-ventricular and intra-atrial thrombosis after the anatomical repair for IAA and TAPVC, respectively. There were no risk factors for ICT in both patients, except for the use of blood product and prothrombin complex concentrate. The surgery was indicated after TAPVC correction due to the worsening respiratory status and rapidly decreased mixed venous saturation. Anticoagulation combined with antiplatelet therapies was adopted in another patient. These two were both finally recovered, and three-month, six-month, and one-year follow-up echocardiography revealed no abnormality.

CONCLUSIONS

ICT is uncommon in pediatric population after the surgery for congenital heart disease. Single ventricle palliation, heart transplantation, longer central line use, post-extracorporeal membrane oxygenation, and massive blood product use are major risk factors for postcardiotomy thrombosis. The causes of postoperative ICT are multifactorial, and the immaturity of thrombolytic and fibrinolytic system in neonates may serve as a prothrombotic factor. However, no consensus reached regarding as the therapies for postoperative ICT, and the large-scale prospective cohort study or randomized clinical trial is needed.

Exploring the Role of Antithrombin in Nephrotic Syndrome-Associated Hypercoagulopathy: A Multi-Cohort Study and Meta-Analysis

BACKGROUND

Nephrotic syndrome is associated with an acquired hypercoagulopathy that is thought to drive its predisposition for venous thromboembolism. Previous studies have suggested that urinary antithrombin (AT) loss leading to acquired AT deficiency is the primary mechanism underlying this hypercoagulopathy, but this hypothesis has not been directly tested. The objectives of this study were to test the influence of AT levels on hypercoagulopathy in nephrotic syndrome patient samples and perform meta-analyses to evaluate the likelihood of AT deficiency in patients with nephrotic syndrome.

METHODS

Samples from three independent nephrotic syndrome cohorts were analyzed. AT antigen and activity assays were performed using ELISA and amidolytic assays, respectively. Plasma thrombin generation, albumin, and urine protein-to-creatinine ratios were determined using established methods. Meta-analyses were performed by combining these new data with previously published data.

RESULTS

AT levels were not consistently related to either plasma albumin or proteinuria. AT was quantitatively related to hypercoagulopathy in adult nephrotic syndrome, whereas AT activity was inconsistently associated with hypercoagulopathy in childhood nephrotic syndrome. Notably, hypercoagulopathy did not differ between patients with normal AT levels and those with levels below the threshold used to define clinical AT deficiency (<70%). Moreover, ex vivo AT supplementation did not significantly alter hypercoagulopathy in AT-deficient plasma samples. The meta-analyses demonstrated that AT deficiency was not a uniform feature of nephrotic syndrome and was more common in children than adults.

CONCLUSIONS

These data suggest that AT deficiency plays only a limited role in the mechanisms underlying the acquired hypercoagulopathy of nephrotic syndrome. Moreover, AT deficiency was not present in all patients with nephrotic syndrome and was more likely in children than adults despite the higher risk for venous thromboembolism in adults than children.

Post-operative Anticoagulation Strategy Following Comprehensive Stage 2 Procedure for Single Ventricle Physiology

Thrombosis, especially thrombosis of the pulmonary artery, is a large contributor to morbidity and mortality following comprehensive stage 2 procedure for single ventricle cardiac physiology. A peri-operative management protocol was implemented at our institution in March 2010. It includes 6 weeks of therapeutic anticoagulation post-operatively to mitigate the thrombotic risks in this patient population. This is a retrospective study of hospitalized children who received post-operative anticoagulation following a comprehensive stage 2 procedure for single ventricle cardiac physiology at a free-standing children's hospital. The primary objectives are to describe our institution's anticoagulation strategy and report on the number of thromboses and major bleeding episodes in the 6 weeks post-operatively. Secondary objectives include the dose of enoxaparin required to obtain a therapeutic low-molecular weight anti-factor-Xa (AFXaLMWH) level, and the number of patients outside of the therapeutic range. A total of 71 infants were included in the final analysis. Four patients experienced a thrombosis episode and three patients experienced clinically significant bleeding. The mean dose of enoxaparin required to obtain a therapeutic AFXaLMWH level between 0.5-1 unit/mL was 1.23 mg/kg SQ every 12 h and 37% of patients achieved goal AFXaLMWH levels with the initial starting dose of enoxaparin 1 mg/kg SQ every 12 h. We describe a 9-year experience of anticoagulation after single ventricle palliation. Anticoagulation with therapeutic AFXaLMWH goals of 0.5-1 unit/mL may reduce the rates of clinically significant thrombosis post-operatively in this population and appears safe without increase in significant bleeding episodes when compared to a historical cohort. Further studies comparing this population to those who do not receive post-operative anticoagulation are warranted.

Immuno-Thrombotic Complications of COVID-19: Implications for Timing of Surgery and Anticoagulation

Early in the coronavirus disease 2019 (COVID-19) pandemic, global governing bodies prioritized transmissibility-based precautions and hospital capacity as the foundation for delay of elective procedures. As elective surgical volumes increased, convalescent COVID-19 patients faced increased postoperative morbidity and mortality and clinicians had limited evidence for stratifying individual risk in this population. Clear evidence now demonstrates that those recovering from COVID-19 have increased postoperative morbidity and mortality. These data-in conjunction with the recent American Society of Anesthesiologists guidelines-offer the evidence necessary to expand the early pandemic guidelines and guide the surgeon's preoperative risk assessment. Here, we argue elective surgeries should still be delayed on a personalized basis to maximize postoperative outcomes. We outline a framework for stratifying the individual COVID-19 patient's fitness for surgery based on the symptoms and severity of acute or convalescent COVID-19 illness, coagulopathy assessment, and acuity of the surgical procedure. Although the most common manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is COVID-19 pneumonitis, every system in the body is potentially afflicted by an endotheliitis. This endothelial derangement most often manifests as a hypercoagulable state on admission with associated occult and symptomatic venous and arterial thromboembolisms. The delicate balance between hyper and hypocoagulable states is defined by the local immune-thrombotic crosstalk that results commonly in a hemostatic derangement known as fibrinolytic shutdown. In tandem, the hemostatic derangements that occur during acute COVID-19 infection affect not only the timing of surgical procedures, but also the incidence of postoperative hemostatic complications related to COVID-19-associated coagulopathy (CAC). Traditional methods of thromboprophylaxis and treatment of thromboses after surgery require a tailored approach guided by an understanding of the pathophysiologic underpinnings of the COVID-19 patient. Likewise, a prolonged period of risk for developing hemostatic complications following hospitalization due to COVID-19 has resulted in guidelines from differing societies that recommend varying periods of delay following SARS-CoV-2 infection. In conclusion, we propose the perioperative, personalized assessment of COVID-19 patients' CAC using viscoelastic hemostatic assays and fluorescent microclot analysis.

Plasma and Platelet Transfusions Strategies in Neonates and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass or Neonates and Children Supported by Extracorporeal Membrane Oxygenation: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the recommendations and consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children undergoing cardiac surgery with cardiopulmonary bypass or supported by extracorporeal membrane oxygenation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of nine experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement, two recommendations, and three expert consensus statements.

CONCLUSIONS

Whereas viscoelastic testing and transfusion algorithms may be considered, in general, evidence informing indications for plasma and platelet transfusions in neonatal and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass or those requiring extracorporeal membrane oxygenation support is lacking.

ENNOBLE-ATE trial: an open-label, randomised, multi-centre, observational study of edoxaban for children with cardiac diseases at risk of thromboembolism

Children with cardiac diseases suffer from significant morbidity and mortality secondary to thromboembolic complications. Anticoagulant agents currently used for thromboprophylaxis have many limitations, including subcutaneous administration (low molecular weight heparins) and requirement for frequent monitoring via venipuncture (vitamin K antagonists). Edoxaban is an oral direct factor Xa inhibitor without need of monitoring. In the treatment of venous thromboembolism in adults, edoxaban has shown to be effective and safe.This manuscript summarises the rationale and design of a phase 3, open-label, randomised controlled trial to evaluate and compare the safety and efficacy of edoxaban against standard of care (namely, vitamin K antagonist and low molecular weight heparin) in children with cardiac diseases.A goal of 150 children with cardiac diseases at risk of thromboembolic complications who need primary or secondary anticoagulant prophylaxis will be recruited. Eligible children between 6 months and <18 years of age will be randomised in a ratio of 2 to 1 for edoxaban versus standard of care. Randomisation will be stratified based on underlying cardiac disease and concomitant use of aspirin for patients other than Kawasaki disease. The primary outcome will be safety, comprised of major and clinically relevant non-major bleeding in first 3 months of treatment. Bleeding beyond 3 months, symptomatic and asymptomatic thromboembolic events, and pharmacokinetic and pharmacodynamic parameters will be evaluated as secondary outcomes.Randomised controlled anticoagulation trials are challenging in children. This study will evaluate a potentially valuable alternative of oral anticoagulant prophylactic use in children with cardiac diseases.

Nephrotic syndrome disease activity is proportional to its associated hypercoagulopathy

INTRODUCTION

Nephrotic syndrome (NS) is associated with an acquired hypercoagulopathy that drives its strong predilection for life-threatening thrombosis. We previously demonstrated that hypercoagulopathy is proportional to NS disease severity in animal models. Therefore, hypercoagulopathy and disease severity may inform thrombosis risk and better guide therapeutic decision making. The objective of this study was thus to establish the relationship between disease severity and hypercoagulopathy in human NS.

MATERIALS AND METHODS

Thrombin generation assays (TGA) were performed on biorepository plasma samples from a prospective longitudinal NS cohort study. TGA was also determined on a separate cohort of incident NS patients. Multivariable regression was used to build NS-hypercoagulopathy relationship models.

RESULTS

Endogenous thrombin potential (ETP) was the TGA parameter most strongly correlated with NS severity and was proportional to conventional measures of NS disease activity including proteinuria, hypercholesterolemia, and hypoalbuminemia. The overall disease activity model was well correlated with ETP (R² = 0.38). The relationship with disease activity was confirmed in the second cohort. These models further revealed that ETP is related to disease activity in a manner dependent on remission status.

CONCLUSION

Consistent with our previously reported animal model observations, we found that the combination of proteinuria, hypercholesterolemia, and hypoalbuminemia correlated with ETP-defined hypercoagulopathy. Hypercoagulopathy improved significantly with partial or complete NS remission. These data are expected to inform studies designed to stratify thrombotic risk for patients with NS.

Central Vascular Thrombosis in Neonates with Congenital Heart Disease Awaiting Cardiac Intervention

Central vascular thrombosis (CVT) in critically ill neonates carries significant clinical implications. Neonates with congenital heart disease (CHD) awaiting cardiac intervention might be associated with increased risk of thrombosis. Outcome analysis was undertaken. An analysis of 77 neonates with CHD who were admitted to the NICU prior to cardiac intervention between January 2015 and December 2016 was undertaken. Patients requiring extracorporeal life support prior to any cardiac intervention, or receiving prophylactic anticoagulation not related to central vascular catheter (CVC) were excluded. Diagnosis of CVT was provided based on clinical indication and verified with imaging that warranted anticoagulation therapy. Location of CVC and extent of CVT along with treatments, outcomes, and vascular access types and durations were assessed. Logistic regression multivariate analysis was used to assess predictors of outcome. Neonates with CHD were complicated with CVT in 10.4%. Longer duration of CVC was also associated with thrombosis in neonates with CHD (72.7 days vs. 29.3 days, p < 0.001). Independent predictors of outcome included lower gestational age and CHD with single-ventricle (SV) anatomy (p < 0.05). In neonates with CHD awaiting cardiac intervention risk of CVT is substantial. Duration CVC, lower gestational age and SV anatomy are risk determinants of outcome. Standardized development of customized surveillance protocols tailored to this unique subsets of neonates and adherence to quality guidelines can influence outcome.

Nephrotic syndrome-associated hypercoagulopathy is alleviated by both pioglitazone and glucocorticoid which target two different nuclear receptors

BACKGROUND

Thrombosis is a potentially life-threatening nephrotic syndrome (NS) complication. We have previously demonstrated that hypercoagulopathy is proportional to NS severity in rat models and that pioglitazone (Pio) reduces proteinuria both independently and in combination with methylprednisolone (MP), a glucocorticoid (GC). However, the effect of these treatments on NS-associated hypercoagulopathy remains unknown. We thus sought to determine the ability of Pio and GC to alleviate NS-associated hypercoagulopathy.

METHODS

Puromycin aminonucleoside-induced rat NS was treated with sham, Low- or High-dose MP, Pio, or combination (Pio + Low-MP) and plasma was collected at day 11. Plasma samples were collected from children with steroid-sensitive NS (SSNS) and steroid-resistant NS (SRNS) upon presentation and after 7 weeks of GC therapy. Plasma endogenous thrombin potential (ETP), antithrombin (AT) activity, and albumin (Alb) were measured using thrombin generation, amidolytic, and colorimetric assays, respectively.

RESULTS

In a rat model of NS, both High-MP and Pio improved proteinuria and corrected hypoalbuminemia, ETP and AT activity (p < .05). Proteinuria (p = .005) and hypoalbuminemia (p < .001) were correlated with ETP. In childhood NS, while ETP was not different at presentation, GC therapy improved proteinuria, hypoalbuminemia, and ETP in children with SSNS (p < .001) but not SRNS (p = .330).

CONCLUSIONS

Both Pio and GC diminish proteinuria and significantly alleviate hypercoagulopathy. Both Pio and MP improved hypercoagulopathy in rats, and successful GC therapy (SSNS) also improved hypercoagulopathy in childhood NS. These data suggest that even a partial reduction in proteinuria may reduce NS-associated thrombotic risk.

In silico features of ADAMTS13 contributing to plasmatic ADAMTS13 levels in neonates with congenital heart disease

INTRODUCTION

Risk factors contributing to heightened thrombosis in pediatric congenital heart disease (CHD) patients are not fully understood. Among the neonatal CHD population, those presenting with single ventricular physiology are at the highest risk for perioperative thrombosis. The von Willebrand factor and ADAMTS13 interactions have emerged as causative risk factors for pediatric stroke and could contribute to heightened thrombosis in CHD neonates.

METHODS

This study investigates a cohort of children with single ventricle physiology and undergoing cardiac surgery, during which some patients developed thrombosis. In this cohort, we analyzed the relationship of several molecular features of ADAMTS13 with the plasma and activity levels in patients at risk of thrombosis. Additionally, in light of the natural antithrombotic activity of ADAMTS13, we have sequenced the ADAMTS13 gene for each patient and evaluated the role of genetic variants in determining the plasma ADAMTS13 levels using a series of in silico tools including Hidden Markov Models, EVmutation, and Rosetta.

RESULTS

Lower ADAMTS13 levels were found in patients that developed thrombosis. A novel in silico analysis to assess haplotype effect of co-occurring variants identified alterations in relative surface area and solvation energy as important contributors. Our analysis suggested that beneficial or deleterious effect of a variant can be reasonably predicted by comprehensive analysis of in silico assessment and in vitro and/or in vivo data.

CONCLUSION

Findings from this study add to our understanding the role of genetic features of ADAMTS13 in patients at high risk of thrombosis related to an imbalanced relation between VWF and ADAMTS13.

Arterial Ischemic Stroke Secondary to Cardiac Disease in Neonates and Children

OBJECTIVE

We describe the risk factors for peri-procedural and spontaneous arterial ischemic stroke (AIS) in children with cardiac disease.

METHODS

We identified children with cardiac causes of AIS enrolled in the International Pediatric Stroke Study registry from January 2003 to July 2014. Isolated patent foramen ovale was excluded. Peri-procedural AIS (those occurring during or within 72 hours of cardiac surgery, cardiac catheterization, or mechanical circulatory support) and spontaneous AIS that occurred outside of these time periods were compared.

RESULTS

We identified 672 patients with congenital or acquired cardiac disease as the primary risk factor for AIS. Among these, 177 patients (26%) had peri-procedural AIS and 495 patients (74%) had spontaneous AIS. Among non-neonates, spontaneous AIS occurred at older ages (median 4.2 years, interquartile range 0.97 to 12.4) compared with peri-procedural AIS (median 2.4 years, interquartile range 0.35 to 6.1, P < 0.001). About a third of patients in both groups had a systemic illness at the time of AIS. Patients who had spontaneous AIS were more likely to have a preceding thrombotic event (16 % versus 9 %, P = 0.02) and to have a moderate or severe neurological deficit at discharge (67% versus 33%, P = 0.01) compared to those with peri-procedural AIS.

CONCLUSIONS

Children with cardiac disease are at risk for AIS at the time of cardiac procedures but also outside of the immediate 72 hours after procedures. Many have acute systemic illness or thrombotic event preceding AIS, suggesting that inflammatory or prothrombotic conditions could act as a stroke trigger in this susceptible population.

Standardized Approach to Intervention for Intestinal Malrotation in Single Ventricle Patients with Heterotaxy Syndrome: Impact on Interstage Attrition and Time to Superior Cavopulmonary Connection

Heterotaxy syndrome (HS) is a significant determinant of outcome in single ventricle (SV) physiology. Attrition rate and time-related events associated with intestinal malrotation (IM) are, yet, to be determined. We sought to evaluate hospital and interstage outcomes in relation with operative intervention for IM (IMO). Twelve SV/HS patients, who underwent IMO, from January 2004 to December 2016, were studied. Early shunt failure, time to superior cavopulmonary connection (SCPC) and interstage attrition were assessed. Since September 2014, based on a comprehensive standardized protocol, IMO was performed at the time of hospitalization for stage-I palliation (S1P) irrespective of clinical manifestations. Patients were assigned to Group A (n = 8): expectant /symptoms-driven versus Group B (n = 4): protocol-driven. At S1P 7 had systemic-to-pulmonary shunt (SPS), 1 SPS with anomalous pulmonary venous return (APVR) repair (Group A) compared to 2 SPS, 1 SPS with APVR repair and 1 Norwood operation (Group B). Median duration from S1P to IMO was 82 days (range 57-336; Group A) compared to 14 days (range 11-31; Group B); p < 0.05. Median age at IMO was 87 days (range 8-345) [Group A: 99 days (range 68-345) vs Group B: 25 days (range 8-39)] (p < 0.05). Early SPS failure occurred in 25% (2 of 8) for Group A compared to none in Group B (p < 0.05). Hospital mortality following IMO was 25% [Group A: 37.5% (3 of 8) vs Group B: 0; p < 0.05]. Interstage survival was 67% [Group A: 50% (4 of 8) vs Group B: 100%; p < 0.05]. Time to SCPC following S1P was 186 days (range 169-218) for Group A compared to 118 days (range 97-161) (Group B); p < 0.05. Operative intervention for IM in SV/HS is associated with significant interstage attrition and might impact the time to SCPC. SPS is at risk for early failure after IMO. A comprehensive standardized concept can mitigate detrimental implications.

Enzymatic Functional Assays of Coagulation Using Small Sample Volumes

Current laboratory methods for comprehensive thrombophilia status require large blood volumes and long turn-around times. We demonstrate the feasibility of performing thrombophilia panel testing of enzymatic functional assays on a microfluidic cartridge using low sample volume.Functional assays for Antithrombin III, Protein C, Factor VIII, and plasminogen were adapted on the digital microfluidic platform by developing novel fluorogenic substrates and establishing on-cartridge fluorescence (360/460 nm) detection. Cartridge vs. microtiter plate results were compared using samples obtained from pediatric patients. Linear regression and Bland-Altman plots were used to establish correlations. Results were not significantly different when performed on-cartridge compared to microtiter plates. Importantly, the sample volume required is significantly lower for all on-cartridge compared to microtiter plate assays (25 μL vs. 2 ml).This study demonstrates the feasibility of thrombophilia panel testing with high-fidelity using small plasma volume. The efficacy of this near-patient technology in clinical settings needs further investigation.

Increasing rates of thrombosis in children with congenital heart disease undergoing cardiac surgery

OBJECTIVE

To determine thrombosis incidence, morbidities, and mortality of children with congenital heart disease who develop thrombosis after cardiac surgery.

MATERIALS AND METHODS

This retrospective study reviewed patients <18 years old within the Pediatric Health Information System (PHIS) database who underwent cardiac surgery from 2004-2012. Thrombosis rates were compared for each procedure. Mortality was modeled using proportional hazards, adjusting for important clinical and demographic factors.

RESULTS

Of 91909 CHD patients who underwent surgery, 2655 (2.9%) developed thrombosis within the ensuing 12 months. The rate of thrombosis increased 253% (p<0.001), from 1.7% in 2004 to 4.4% in 2012. Systemic to pulmonary shunt placement (34.3%) and septostomy (26.1%) had the highest thrombosis percentages. Children <28 days had the highest prevalence (61%). Those with thrombosis had longer lengths of stay than those without [median 27 hospital days and 10 ICU days vs. 6 and 2 (p<0.001)]. Mean risk-adjusted cost was higher with thrombosis; $126,257 vs. $40,773 (p<0.001). Thrombosis was also associated with higher rates of bacteremia [8.3% vs. 3.4%, p<0.001], endocarditis [0.7% vs. 0.2%, p<0.001], and mortality [12.3% vs. 0.8%, p<0.001]. The adjusted hazard ratio for mortality in patients with thrombosis was 5.5 (95% CI: 4.6-6.5).

CONCLUSIONS

Thrombosis rates in CHD patients after cardiac surgery is increasing. Thrombosis is associated with longer hospital stay, increased ICU days, and cost. CHD patients with thrombosis also have increased bacteremia and mortality rates. More research is needed to understand contributors to thrombosis which may help develop strategies to mitigate morbidity and mortality.

Elevated preoperative von Willebrand factor is associated with perioperative thrombosis in infants and neonates with congenital heart disease

Essentials Perioperative thrombosis is a major cause of morbidity and mortality in congenital heart disease. Neonates and infants undergoing repair of congenital heart lesions were prospectively followed. Elevated von Willebrand factor (VWF) to ADAMTS-13 activity ratios typified the postoperative period. Thrombosis was associated with preoperative VWF activity and cryoprecipitate transfusion SUMMARY: Background The surgical repair of congenital heart malformations is frequently complicated by perioperative thrombosis of unclear etiology. An imbalance between von Willebrand factor (VWF) and ADAMTS-13 is an emerging variable in thrombosis. Objectives To describe perioperative changes to VWF, ADAMTS-13 and NETosis, and evaluate clinical and biochemical associations with postoperative thrombosis. Methods Neonates and infants undergoing palliation or definitive surgical repair of congenital heart malformations were recruited (n = 133). Preoperative and postoperative plasma levels of VWF, ADAMTS-13 and markers of NETosis were determined. Patients were followed for up to 30 days for the occurrence of thrombosis. Univariate and multivariate logistic regression analyses were conducted to identify variables associated with thrombosis. Results We identified significant postoperative increases in VWF activity, VWF level, DNA-histone complexes and cell-free DNA with an overall decrease in ADAMTS-13 activity. Patients experiencing postoperative thrombotic events (9%) were characterized by surgery performed at a lower intraoperative temperature, higher preoperative lactic acid levels, and higher preoperative VWF activity and level. A multivariate logistic regression model identified preoperative VWF activity (odds ratio (OR) 8.39 per IU mL-1 , 95% confidence interval [CI] 1.73-40.55) and transfusion of cryoprecipitate (OR 1.10 per mL kg-1 , 95% CI 1.03-1.17) as being associated with thrombosis. Conclusions Pediatric patients undergoing surgical repair of congenital heart malformations are exposed to high levels of VWF with diminished or minimal change to ADAMTS-13 in the immediate postoperative period. Elevated preoperative VWF activity is associated with postoperative thrombosis in pediatric congenital heart disease.

Risk Factors For Unfavorable Outcomes After Bidirectional Cavopulmonary Anastomosis

Background:

Bidirectional cavopulmonary anastomosis (BCPA) is an important preliminary step toward the Fontan procedure; thus, understanding of risk factors for morbidity and mortality after BCPA may ultimately promote improved rates of success with Fontan completion and general survival. This study evaluated survival and predictors of unfavorable outcomes in patients after BCPA.

Methods:

Clinical data of 157 patients who underwent BCPA from 2003 to 2015 at a single center were retrospectively analyzed.

Results:

Three-year and nine-year survival after BCPA were 87.1% ± 2.8% and 85.8% ± 2.9%, respectively. Freedom from unfavorable outcomes (mortality, BCPA takedown, nonsuitability for Fontan procedure) was 83.8% ± 3.1% at three years and 73.5% ± 4.8% at nine years. Multivariate proportional hazards regression analysis revealed that total anomalous pulmonary venous connection (TAPVC; hazard ratio [HR]: 3.74, 95% confidence interval [CI]: 1.35-10.36; P = .01) and increased mean pressure in BCPA circuit (HR: 1.17, 95% CI: 1.02-1.34; P = .03) were independent risk factors for unfavorable outcomes. Postoperative mean pressure in BCPA circuit in patients with poor outcomes was median 16 mm Hg (interquartile range [IQR]: 14-18 mm Hg) versus median 14 mm Hg (IQR: 12-15.5 mm Hg) in patients with favorable outcomes ( P < .01). Preoperative (HR: 1.87, 95% CI: 1.20-2.91; P < .01) and postoperative atrioventricular valve regurgitation (AVVR; HR: 2.22, 95% CI: 1.24-3.94; P < .01) were also associated with unfavorable outcome in univariate Cox regression.

Conclusions:

Elevated mean pressure in the BCPA circuit is the main predictor of unfavorable outcome; therefore, thorough preoperative examination and careful patient selection are critical points for successful intermediate-stage and later Fontan completion. Total anomalous pulmonary venous connection and insufficient correction of AVVR worsen the prognosis in this patient group.

Heterotaxy syndrome infants are at risk for early shunt failure after Ladd procedure

BACKGROUND

Cardiac-specific risks and complications after a Ladd procedure in patients with heterotaxy syndrome (HS) and intestinal rotational anomalies (IRA) are unknown. We sought to (1) describe rates of hospital mortality and early systemic-to-pulmonary (S-P) artery shunt failure after the Ladd procedure in patients with HS and (2) explore risk factors associated with early shunt failure in patients with HS with single ventricle (SV).

METHODS

This retrospective study included all Ladd procedures performed from January 1999 to December 2012 in patients with HS at a single center. Risk factors investigated for early S-P artery shunt failure included birth weight, gestational age, sex, age at and timing of Ladd procedure relative to cardiac operations, and shunt type.

RESULTS

Ladd procedure was performed on 54 infants with HS and congenital heart disease. Hospital mortality for the entire cohort was 5.6% (3 of 54 patients). Early shunt failure occurred in 19% (4 of 21) of HS infants with SV. Mean preoperative blood urea nitrogen (BUN) levels were higher in HS infants with early shunt failure (20 versus 12.5 mg/dL; p = 0.054).

CONCLUSIONS

Patients with SV and HS with S-P artery shunts are at risk for early shunt failure after a Ladd procedure. A higher mean preoperative BUN level is noted in patients with HS and early shunt failure. Careful risk-benefit analysis is indicated before recommending routine elective Ladd procedures in patients with HS.

Hypercoagulability panel testing predicts thrombosis in neonates undergoing cardiac surgery

Thrombosis contributes to morbidity and mortality in neonates following cardiac surgery. Alterations in hemostatic factors following cardiac surgery have been described, but there is no data correlating these changes with risk of thrombosis in neonates. The aim of this study is to predict thrombosis in neonates undergoing cardiac surgery by assessment of a panel of hypercoagulability markers. Neonates undergoing cardiac surgery were enrolled preoperatively and prospectively followed. Preoperative hypercoagulability panel testing included thrombin generation assay (TGA), immunoassays for antithrombin III, protein C, protein S, factor VIII, thrombin-activatable fibrinolytic inhibitor (TAFI), plasminogen activator inhibitor-1 (PAI-1), and cardiolipin antibody. Postoperative thrombosis was defined by clinical events (shunt thrombosis, limb ischemia, and stroke) or imaging (intravascular or intracardiac thrombus). Risk factors for thrombosis were assessed. One hundred neonates were enrolled in the study over a two-year period. The incidence of postoperative in-hospital thrombosis was 20%. The only significant clinical risk factor associated with thrombosis was the single ventricle physiology. Hypercoagulability factors associated with increased risk of thrombosis by univariate analysis were elevated PAI-1, TAFI, and TGA, and presence of anticardiolipin antibodies. Multivariable logistic regression analysis demonstrated that elevated PAI-1 (P = 0.015), TAFI (P = 0.028), and TGA (P = 0.007) were independent predictors of thrombosis. Hypercoagulability panel testing may help identify neonates at high risk for thrombosis following cardiac surgery. Future studies are warranted to determine if high risk patients benefit from targeted anticoagulation therapies.