Prevention of thromboembolism in adults with congenital heart disease

This thesis discusses the indications and treatment of clot formation using blood thinners in adults with congenital heart disease (ACHD). Clot formation is one of the most common and life-threating complications in this population. Recently, new types of blood thinners called ‘non-vitamin K antagonists’ (NOACs) have appeared in the market. NOACs were specially developed to eliminate an important disadvantage when using the prevailing blood thinners called vitamin K antagonists (VKA). For example, patients using VKAs must regularly take blood tests for continuous monitoring of the medication effect while with NOACs this is not necessary. In line with the new upcoming types of blood thinners, new insight in indication and type of appropriate blood thinners is important and highly relevant for safe and effective prevention of clot formation in ACHD patients. The key findings of this thesis are as follows. 1. The prevailing guidelines on the indication of blood thinners are discrepant and confusing, and probably therefore, the implementation of the guidelines seems to be random and suboptimal in daily practice. 2. Use of NOACs seems to be safe in patients with a Fontan circulation, who are at exceptionally high risk for clot formation and bleeding, on a short-term observation. 3. NOACs appear to be safe in a heterogeneous group of ACHD patients, mostly with an indication of atrial arrhythmias, on a short-term observation. 4. With growing evidence, NOACs may be a great alternative to VKA in ACHD patients.