HTRS TE Registry (ThromboEmbolism Registry)

Hereditary defects that predispose to thromboembolism (TE) and its complications afflict
5-8% of the U.S population. Annually, ~60,000 Americans die from TE and half of the
survivors suffer long-term morbidity. Despite these staggering statistics, little is known
about the clinical characteristics or epidemiology of the inherited risk factors for TE.
Less is known regarding the acquired risk factors or the phenotype of TE in persons with
multiple risk factors, yet preliminary data suggest that as many as 10% of patients may have
multiple risk factors.

Data from several studies, primarily involving adult subjects, shows that in a population of
consecutively studied thrombosis patients, that one of the five most common inherited
predispositions will occur in ~33.8%. Antithrombin (AT) is the least common (~1.9%) of
these, while Factor V Leiden (FVL) is the most common (~18.8%). Most children who suffer
from TE have indwelling catheters to assist therapy of underlying medical conditions, or are
sick neonates. Thus, the contribution of molecular risk factors in children is largely
unknown, with the exception of sparse retrospective data.

The TE Registry may help clearly define the clinical phenotype, epidemiology, and
complications seen in patients with TE associated with known molecular risk factors.

Inclusion Criteria:

- Patients should be enrolled at the time of their FIRST thromboembolic event.
Ideally, patients should be enrolled within three months of the diagnosis of an
eligible event.

- Deep Venous, Arterial, or Intra-Cardiac Thrombosis

- Pulmonary Thromboembolism AND:

- Must have evidence of Venous Thrombosis on imaging studies -OR-

- Must have elevated Quantitative or Semi-Quantitative D-dimer level (as defined
by local laboratory technology/normal ranges)

- Arterial Thromboembolism (with imaging evidence of thrombus source)

- Stroke (Cerebral Vascular Accident) AND age < 20 years. Stroke is defined as a
completed stroke with symptoms persisting for > 24 hours and radiographic evidence of
infarction by Computed Tomography or Magnetic Resonance Imaging. Transient Ischemic
Attacks (TIA) are NOT eligible for this registry.

- Myocardial Infarction AND age <20 years. Must have elevated cardiac enzymes (CK
and/or Troponin) and Electrocardiographic (EKG) evidence meeting the local standard
for diagnosis. Angina is NOT eligible for this registry.

Exclusion Criteria:

- Bleeding disorders

- Transient Ischemic Attack(s) (TIA)

- Sickle Cell Disease

- Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS)

- Ornithine Transcarbamylase Deficiency

- Homocystinuria

- Other metabolic disorders known to be associated with Stroke

- Hemorrhagic Stroke

- Bacterial Endocarditis

- Microangiopathic Hemolytic Anemias (Thrombotic Thrombocytopenic Purpura or Hemolytic
Uremic Syndrome)

- Patients greater than or equal to 20 years of age with Stroke or Myocardial
Infarction (in order to limit confounding cardiovascular risk factors)

- Angina