Central venous thrombosis and thrombophilia in cystic fibrosis: A prospective study

Venous thromboembolism management in people with cystic fibrosis

BACKGROUND

Rates of venous thromboembolism (VTE) are increasing in people with cystic fibrosis (PwCF). Providers treating VTE in PwCF have reported low confidence concerning anticoagulant drug selection, dose, duration, and drug-drug interactions. As there are currently no published reports regarding management of VTE in PwCF, our objective was to describe the management of VTE in PwCF.

METHODS

PwCF and VTE at the University of Utah Health were identified through electronic medical record searches. Patients were categorized into one of three treatment groups: warfarin, direct oral anticoagulant (DOAC), and low molecular weight heparin (LMWH). The primary outcome was episodes of major bleeding. Secondary outcomes included clinically relevant nonmajor (CRNM) bleeding.

RESULTS

Nine PwCF with a total of 12 unique VTE episodes were included in the study, with all but one episode associated with a peripherally inserted central catheter (PICC). Of the 12 VTE cases, 25% were treated with warfarin, 50% with a DOAC, and 25% with LMWH. There were no episodes of major bleeding and only one episode of CRNM bleeding (Hemoptysis) in the LMWH group. All anticoagulant doses and durations generally followed guidelines for persons without CF. DOACs were the most common VTE treatment, at doses and duration consistent with guidelines for persons without CF, with no major or CRNM bleeding.

CONCLUSION

VTE treatment in PwCF is generally consistent with guidelines for persons without CF with low rates of bleeding. DOACs are a potential option for treatment of VTE in PwCF, but more research is needed.

Yield of chest computed tomography angiogram in cystic fibrosis patients with suspected pulmonary embolism

Introduction

Individuals with cystic fibrosis (CF) may be at increased risk of pulmonary embolism (PE). Symptoms of PE overlap substantially with those of CF respiratory exacerbations. CF patients commonly undergo chest computed tomography (CT) angiograms (CTPA) to evaluate for PE, but little is known about the clinical presentation and diagnosis of PE in this population.

Objectives

The objectives of this study are to determine the diagnostic yield of CTPA for PE in adult patients with CF and assess the utility of the Revised Geneva Score (RGS) in this population.

Methods

Retrospective review of all CTPA results was performed on CF patients with suspected PE at a large CF center from 1 January 2011 through 31 March 2017. Patient demographics, medical history, and presenting signs and symptoms were abstracted by chart review.

Results

A total of 103 unique CTPA studies were performed in 68 patients. Most were hospitalized at the time of CTPA, predominantly for respiratory manifestations of CF. CTPA identified four patients with PE. The small number of positive studies precluded analysis of predictors of PE. Fewer PE were diagnosed than predicted by the Revised Geneva Score, which was intermediate probability in 77/103 (75%) patients.

Conclusion

The prevalence of PE in CF patients undergoing CTPA for suspected PE was 4%, which is lower than predicted by the Revised Geneva Score. This may be due to a large overlap in the signs and symptoms of PE and exacerbations of CF lung disease.

Safety and effectiveness of a risk-stratified venous thromboembolism prophylaxis algorithm in young people with cystic fibrosis

BACKGROUND

People with cystic fibrosis (CF) have an increased risk of thrombosis due to acquired thrombophilia secondary to chronic systemic inflammation and central venous catheter use for treatment of pulmonary infections. The objective of this study is to determine the safety and effectiveness of a risk-stratified, venous thromboembolism (VTE) prophylaxis intervention.

METHODS

This single-center, IRB-approved, retrospective study assessed patients with CF admitted to our institution for treatment of a pulmonary exacerbation from 2017 to 2019. Data and outcomes were manually extracted from the electronic medical record and internal CF clinical database. Subject characteristics, calculated VTE risk, prophylaxis interventions prescribed, VTE incidence, and adverse events were captured.

RESULTS

A total of 135 CF patients had 354 admissions for pulmonary exacerbations in the time frame of the study. The majority of admissions (88.7%) were classified as moderate or high risk for VTE using the algorithm. Overall, VTE prophylaxis intervention determined by the algorithm was initiated in 36.2% of admissions. During the study period, no VTE events occurred. Four minor bleeding adverse effects were reported in patients receiving VTE chemical prophylaxis with enoxaparin (4.2%).

CONCLUSIONS

This study provides the first reported outcomes following implementation of a risk-stratified VTE prophylaxis algorithm in hospitalized young people with CF. In this population at increased risk, use of risk-stratified prophylaxis was safe and effective in preventing VTE. Additional work to improve and maintain adherence to the algorithm and VTE prophylaxis interventions at our institution is planned and similar care should be considered at other pediatric CF care centers.

Venous Thromboembolism among Noncritically Ill Hospitalized Children: Key Considerations for the Pediatric Hospital Medicine Specialist

Venous thromboembolism (VTE) is a leading cause of morbidity and preventable harm among noncritically ill hospitalized children. Several clinical factors relevant to the noncritically ill hospitalized child significantly increase the risk of VTE including the presence of central venous catheters, systemic inflammation, and prolonged immobilization. Although risk mitigation strategies have been described, the diagnosis, treatment, and prevention of VTE require standardization of institutional practices combined with multidisciplinary collaboration among pediatric hospitalists, hematologists, and other care providers. In this narrative review, we summarize the epidemiology of VTE, risk models identifying high-risk conditions associated with VTE, and prevention and treatment strategies. We further describe successful quality improvement efforts implementing institutional VTE risk stratification and thromboprophylaxis procedures. Finally, we highlight unique challenges facing pediatric hospital medicine specialists in the era of the COVID-19 pandemic, including caring for adults admitted to pediatric hospital units, and describe future research opportunities for VTE in the noncritically ill hospitalized child.

Female reproductive health in cystic fibrosis

Women with cystic fibrosis (CF) are living longer and healthier lives, and opportunities for childbearing are increasingly promising. However, this population can also face sexual and reproductive health concerns, including menstrual irregularities, unplanned pregnancies, infertility and pregnancy complications. Additionally, more women are entering menopause and are at risk for the consequences of estrogen deficiency. The exact mechanisms involved in female reproductive health conditions in CF are not clearly understood, but are thought to include cystic fibrosis transmembrane regulator (CFTR)-mediated abnormalities, changes in female sex hormones, and other CF health-related factors. In the era of CFTR modulator therapy, new data are necessary to understand the impact of CFTR modulation on contraceptive effectiveness, fertility, and pregnancy outcomes to help guide future clinical care. This article reviews the current scientific knowledge of major reproductive health issues for women with CF.

Survey of current treatment practices for venous thromboembolism in patients with cystic fibrosis

BACKGROUND

Patients with cystic fibrosis (CF) and venous thromboembolism (VTE) pose therapeutic challenges including potential drug interactions between CF-related therapies and anticoagulants. Despite these challenges, there are no recommendations for VTE management specific to patients with CF. Our objective was to describe VTE treatment practices among Cystic Fibrosis Foundation (CFF)-accredited care centers and affiliate programs in the United States.

METHODS

An online survey was distributed to CF center directors. The survey included questions regarding centers' demographics and posed a series of hypothetical clinical scenarios to gather centers' VTE treatment practices including choice of anticoagulant, dosing practices, duration decisions, and monitoring efforts. Descriptive statistics were utilized to summarize the survey results.

RESULTS

The survey response rate was 56.3%. Most centers reported treating zero to five VTE episodes per year. The following anticoagulants were used most often for VTE treatment: low-molecular-weight heparin (LMWH) (73.2%), apixaban (36.6%), warfarin (35.2%), rivaroxaban (33.8%), and unfractionated heparin (18.3%). On a scale of 0 to 100, the median confidence level in managing anticoagulant therapy was 50. Many centers expressed a desire for a CF-specific VTE treatment guideline. The most commonly cited challenging clinical situations were managing anticoagulant therapy complications (26.5%) and drug-drug interactions (21.3%). For common VTE scenarios, pediatric patients were most often treated with LMWH and warfarin, whereas adult patients were more often treated with apixaban or rivaroxaban.

CONCLUSIONS

Survey results indicated CF care centers find managing VTE in patients with CF challenging and indicated that a CF-specific VTE treatment guideline would be helpful.

Vitamin K and cystic fibrosis: A gordian knot that deserves our attention

Cystic fibrosis (CF) is an inherited genetic disorder with multiorgan involvement. Gastrointestinal tract dysfunction leads to fat and fat-soluble vitamins (A,D,E,K) malabsorption and deficiency of these vitamins. Subclinical vitamin K (VK) deficiency seems to be a common problem in CF patients. However, despite the rest of fat-soluble vitamins being routinely supplemented, this is not a universal clinical practice for VK. Inefficient levels of VK may have significant effects on blood coagulation and bone formation. There are also some data indicating that VK may play a key role on regulation of inflammation. Supplementing CF patients with VK seems rational, but the appropriate dosing regimens are still a matter of debate. This review will try to delineate the problem and communicate the latest opinions on this controversial issue.

ECFS best practice guidelines: the 2018 revision

Developments in managing CF continue to drive dramatic improvements in survival. As newborn screening rolls-out across Europe, CF centres are increasingly caring for cohorts of patients who have minimal lung disease on diagnosis. With the introduction of mutation-specific therapies and the prospect of truly personalised medicine, patients have the potential to enjoy good quality of life in adulthood with ever-increasing life expectancy. The landmark Standards of Care published in 2005 set out what high quality CF care is and how it can be delivered throughout Europe. This underwent a fundamental re-write in 2014, resulting in three documents; center framework, quality management and best practice guidelines. This document is a revision of the latter, updating standards for best practice in key aspects of CF care, in the context of a fast-moving and dynamic field. In continuing to give a broad overview of the standards expected for newborn screening, diagnosis, preventative treatment of lung disease, nutrition, complications, transplant/end of life care and psychological support, this consensus on best practice is expected to prove useful to clinical teams both in countries where CF care is developing and those with established CF centres. The document is an ECFS product and endorsed by the CF Network in ERN LUNG and CF Europe.

The Role of Inflammation in Venous Thromboembolism

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT), and pulmonary embolism (PE), is becoming increasingly recognized as a cause of morbidity and mortality in pediatrics, particularly among hospitalized children. Furthermore, evidence is accumulating that suggests the inflammatory response may be a cause, as well as consequence, of VTE, but current anticoagulation treatment regimens are not designed to inhibit inflammation. In fact, many established clinical VTE risk factors such as surgery, obesity, cystic fibrosis, sepsis, systemic infection, cancer, inflammatory bowel disease, and lupus likely modulate thrombosis through inflammatory mediators. Unlike other traumatic mechanisms of thrombosis involving vascular transection and subsequent exposure of subendothelial collagen and other procoagulant extracellular matrix materials, inflammation of the vessel wall may initiate thrombosis on an intact vein. Activation of endothelial cells, platelets, and leukocytes with subsequent formation of microparticles can trigger the coagulation system through the induction of tissue factor (TF). Identification of biomarkers to evaluate VTE risk could be of great use to the clinician caring for a patient with inflammatory disease to guide decisions regarding the risk:benefit ratio of various types of potential thromboprophylaxis strategies, or suggest a role for anti-inflammatory therapy. Unfortunately, no such validated inflammatory scoring system yet exists, though research in this area is ongoing. Elevation of C-reactive protein, IL-6, IL-8, and TNF-alpha during a response to systemic inflammation have been associated with increased VTE risk. Consequent platelet activation enhances the prothrombotic state, leading to VTE development, particularly in patients with other risk factors, most notably central venous catheters.

Acute chest pain in an adolescent with cystic fibrosis in September: Would you have thought about this?

Acute chest pain is common in patients with cystic fibrosis (CF). Here we report the case of an adolescent who suffered acute chest pain in September after an history of acute abdominal pain and fever. The reason for this clinical sceneriao was found to be Coxsackievirus B3, known to be responsible of Bornholm disease, a frequent but under recognized viral myositis. The diagnosis is mainly clinical, but evocating this diagnosis may avoid unnecessary exam.

Venous thromboembolism in children with cystic fibrosis: Retrospective incidence and intrapopulation risk factors

INTRODUCTION

Pediatric venous thromboembolism (VTE) is a rare but serious medical condition. Cystic fibrosis (CF) is a risk for recurrent pediatric VTE and has potential thrombophilic tendency. However, much remains unknown, including incidence and intrapopulation risk factors.

METHODS

A retrospective cohort of pediatric CF patients followed at Children's Hospital Colorado from January 1st 2003 through May 20th 2016 was examined. Cases were identified by informatics and validated manually. Data on CF severity, co-morbidities and treatment, central venous catheter (CVC) use, and thrombophilia were obtained from an institutional CF database and chart review.

RESULTS

Nineteen VTE occurred in 458 participants followed for 3595 person-years, yielding an incidence rate of 53 VTE per 10,000 children with CF. VTE cases had additional co-morbidities including CF-related diabetes (p=0.002) and sinus disease (p=0.04), more total admissions (p<0.001), admit days (p<0.001), positive respiratory cultures (p<0.001), pseudomonas infections (p<0.001), steroid courses (p=0.001), and total CVC days (PICC p=0.03, port p=0.007). On univariate analysis, older age (RR 1.162, p=0.007), sinus disease (RR 2.62, p=0.05), longer hospital stay (RR 1.03, p<0.001), higher ESR (RR 1.02, p=0.03) and CRP (RR 1.07, p=0.007), and an absence of systemic steroids (RR 0.19, p=0.004) increased the risk of VTE.

CONCLUSIONS

In this cohort, children with CF had a higher incidence of VTE when compared to the previously reported incidence in the overall pediatric population at Children's Hospital Colorado. Overall, those with VTE had a greater disease burden and older age, sinus disease, longer hospitalization and increased inflammation were VTE risk factors.

Thromboelastogram as a Tool to Predict Hypercoagulability in Children With Cystic Fibrosis

Increased thrombophilic tendency in patients with cystic fibrosis (CF) has recently been reported. The determinants of thrombosis in children with CF remain largely unknown. Our aim in this study was to evaluate the thromboelastography (TEG) profile of children with CF through ROTEM (whole blood rotation thromboelastometry). Nineteen patients with CF and 20 controls were included in the study. Whole blood count, prothrombin time, activated prothrombin time, fibrinogen, d-dimer levels, and ROTEM assays (INTEM, EXTEM) were performed. Clotting time, clot formation time (CFT), and maximum clot firmness (MCF) were determined by INTEM and EXTEM analysis. In INTEM assay, MCF ( P = .001) value was significantly increased and CFT ( P = .031) value was decreased in patients with CF compared with those of the control group. In the EXTEM assay, there was a similar significant increase in MCF ( P = .023) value in patients with CF compared with that of the control group. There was a significant positive correlation between fibrinogen levels and MCF in EXTEM ( r = .72) and INTEM ( r = .76) assays, whereas there was a negative correlation with CFT in EXTEM ( r = -.61) and INTEM ( r = -.67). The results of our study indicated that TEG profiles in patients with CF were more hypercoagulable compared with those of the control group.

Association of thrombophilia and catheter-associated thrombosis in children: a systematic review and meta-analysis

Essentials It is unclear if thrombophilia increases the risk of catheter-associated thrombosis in children. We conducted a meta-analysis on thrombophilia and pediatric catheter-associated thrombosis. Presence of ≥1 trait confers additional risk of venous thrombosis in children with catheters. Limitations of included studies preclude us from recommending routine thrombophilia testing.

SUMMARY

Background The association between thrombophilia and deep vein thrombosis (DVT) associated with central venous catheter (CVC) use, the most important pediatric risk factor for thrombosis, is unclear in children. Pediatric studies with small sample sizes have reported conflicting results. We sought to evaluate whether, among children with CVCs, thrombophilia increases the risk of CVC-associated DVT (CADVT). Materials and methods We systematically searched MEDLINE, EMBASE, the Web of Science, the Cochrane Central Register for Controlled Trials, PubMed and reference lists for controlled studies published from the inception of the database until September 2015. Included were studies of children aged <21 years with CVCs who were systematically tested for thrombophilic traits that are commonly screened for in clinical practice. Pooled prevalence rates and pooled odds ratios (pORs) of CADVT with thrombophilia were estimated by use of a random effects model. Results We analyzed 16 cohort studies with 1279 children, 277 of whom had CADVT, and with 12 traits tested. There was significant heterogeneity in the included studies. The presence of one or more traits was associated with CADVT (pOR 3.20; 95% confidence interval [CI] 1.56-6.54). Although the prevalence of most traits was < 0.10, children with protein C deficiency, elevated factor VIII levels and the FV Leiden mutation had an increased prevalence of CADVT. The association with thrombophilia seemed to be stronger for symptomatic CADVT (pOR 6.71; 95% CI 1.93-23.37) than for asymptomatic CADVT (pOR 2.14; 95% CI 1.10-4.18). Conclusions On the basis of the low prevalence of specific traits, the relatively weak association with CADVT, and the limitations of the included studies, we cannot recommend routine testing of thrombophilias in children with CADVT.

Pediatric Pulmonology year in review 2015: Part 4

In this article, we highlight cystic fibrosis (CF) research published in Pediatric Pulmonology during 2015. Articles from other journals that reflect similar themes, and those of special importance, are also included. Pediatr Pulmonol. 2016;51:754-765. © 2016 Wiley Periodicals, Inc.