The American Heart Association has issued a scientific statement on the prevention and treatment of thrombosis in children and adults with congenital heart disease and children with acquired heart disease.
“Thrombosis has long been recognized as a potentially life-threatening complication in children with congenital heart disease, children with acquired heart disease and in adults with congenital heart disease,” statement chair Therese M. Giglia, MD, and colleagues wrote in the statement.
Among children and adults with congenital heart disease and children with acquired heart disease, those most at risk for thrombosis include patients with shunt-dependent single ventricles, postoperative central lines, Fontan circulation, arrhythmia disorders, Kawasaki disease with coronary aneurysms, and cardiomyopathy/myocarditis, according to the writing group.
Although the prevalence, risk factors and management of some of these situations have been well described (ie, Kawasaki disease), for the management of others (ie, anticoagulation after the Fontan operation), there is a paucity of data, and controversy exists even among experts,” according to the statement.
Lack of data
There was previously no document that focused solely on the issue of thrombosis in pediatric and congenital heart disease, according to the writing group.
Many of the recommendations are based on expert consensus because of a lack of randomized controlled trial data on thrombosis in this patient population.
“It is the anticipation of the writing group that this work will serve as a springboard to the medical and scientific communities for much-needed research on the causes of, risk factors for, prevention of, and treatment of thrombosis in children with heart disease and in adults with congenital heart disease,” according to the statement.
The document consists of dozens of recommendations in a variety of categories, including:
- Long-term management of children on anticoagulants.
- Incidence, treatment and prevention of stroke.
- Primary prevention and treatment of thrombi in children with arrhythmias, acquired heart disease, and that related to diagnostic and interventional cardiac catheterization.
- Thrombus prevention in systemic-to-pulmonary artery shunts.
- Prevention of thrombosis in a patient with a palliated single ventricle.
- Anticoagulation for prosthetic valves in children.
- Anticoagulation for cardiopulmonary bypass in children with congenital heart disease.
- Treatment of heparin resistance in children with congenital heart disease.
One set of recommendations focuses on agents for the treatment and prevention of thrombosis. There are a number of antithrombotic agents available for the treatment and prevention of thrombosis in this patient population, although most are used off label. A table details the properties, indications, contraindications, dose, target range, monitoring and side effects of various antithrombotic and fibrinolytic therapies, including unfractionated heparin, low-molecular–weight heparin, enoxaparin and clopidogrel, among others. The use of newer direct thrombin inhibitors is recommended only for the indication of heparin-induced thrombocytopenia and used with caution, due to few studies conducted in children.
Another set of recommendations concerns warfarin management and monitoring in children.
The writing group recommends international normalized ratio testing in infants and children a minimum of once every 4 weeks after a stable warfarin dose is achieved. If there is a change in diet or medication or an illness occurs, testing should be more frequent. The guideline states that point-of-care monitoring of warfarin therapy is reasonable in children, but at least two comparisons of point-of-care-based and laboratory-based international normalized ratio measurements should be done to evaluate the accuracy of the point-of-care device.
According to the guideline, anticoagulation education should be provided for any infant or child using warfarin, including a discussion of the indication, risks and importance of monitoring. Patients should also be counseled on nutritional sources high in vitamin K and common drugs that inhibit the effects of warfarin.
The statement also provides guidance for nurses to identify and treat thrombi in infants and children. “Because central venous lines are not without risk, especially in the neonate who has limited access sites, the nurse can be a valuable member of the team in terms of maintaining patency of the line and identifying contraindications for thrombolytic therapy such as the presence of abnormal clotting studies, presence of active bleeding or major surgery within the last 10 days. Early diagnosis of the presence of a thrombus by the nurse may be based on observations such as a sluggish or absent blood return, difficulty flushing the catheter, or the inability to infuse or withdraw fluid,” according to the statement.
For more information:
Giglia TM. Circulation. 2013;128:2622-2703.
Disclosure: See the full statement for the writing group members’ relevant financial disclosures.