ORLANDO — High-density lipoproteins, which are known protectors against arterial atherothrombosis, may also protect against recurrent venous thrombosis, Dr. Sabine Eichinger reported at the annual meeting of the American Society of Hematology.
In a prospective study of 772 patients with a first episode of spontaneous venous thromboembolism, the relationship between plasma lipoprotein parameters and recurrence of venous thrombosis was evaluated. Of the 772 patients, 100 (13%) had recurrent venous thromboembolism during an average follow-up of 4 years. Patients who had a recurrence had significantly lower mean plasma levels of apolipoprotein A-I, a major component of HDL (1.12 vs. 1.23 mg/mL), compared with those who had no recurrence, said Dr. Eichinger of the Medical University of Vienna.
The relative risk of recurrence in this study population was 0.87 for each increase of 0.1 mg/mL in plasma apolipoprotein A-I; for those patients with apolipoprotein A-I levels above the 67th percentile of the study population, compared with those with lower levels, the relative risk of recurrence was 0.51.
In addition, the HDL cholesterol levels and HDL particle concentrations in the plasma of patients with recurrence were lower, compared with those patients without recurrence, Dr. Eichinger noted.
Although HDL is known to protect against arterial atherothrombosis, venous thrombosis is a clinically distinct entity, particularly with regard to thrombus appearance, pathogenic mechanisms, and therapeutic approaches. Although it was believed that HDL is protective against recurrent venous thrombosis as a result of its multiple antithrombotic and anti-inflammatory actions, this had not been previously shown, she explained.