Summary
Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease resulting from
the thromboembolic obstruction of the segmental and/or large size pulmonary arteries,
subsequently leading to pulmonary arterial hypertension. Incomplete resolution of
acute pulmonary emboli and thrombus organization are believed to be important for
the development of the disease. Primary pulmonary hypertension (PPH) is a further
disease that at present is poorly understood but shows a clinical picture similar
to CTEPH. Since lipoprotein(a) [Lp(a)], a genetically determined risk factor for atherosclerosis
and thrombosis, has been found increased in plasma of patients with deep vein thrombosis
and pulmonary embolism, we measured plasma Lp(a) levels in 40 patients with CTEPH
and 50 patients with PPH and compared them to 50 matched controls. The median for
Lp(a) plasma levels was significantly higher in CTEPH patients (26.6 mg/dl) than in
PPH patients (9.6 mg/dl) and controls (7.2 mg/dl). Increased plasma Lp(a) could, therefore,
play a significant role in the mechanisms of ongoing thrombosis and thrombus organization
in CTEPH, while its possible role in PPH can be limited to a small number of patients.
