Plasminogen activator inhibitor-1 4G/5G genotype and residual venous occlusion following acute unprovoked deep vein thrombosis of the lower limb: A prospective cohort study.

BACKGROUND

A recent study suggested that the plasminogen activator inhibitor (PAI)-1 4G/5G genotype may play a role in the resolution of deep vein thrombosis (DVT) after surgery. In the present study, we investigated the association between PAI-1 4G/5G genotype and the persistence of venous occlusion after acute idiopathic DVT of the lower limb.

METHODS

The PAI-1 4G/5G genotype was determined by real-Time PCR in 43 patients with unprovoked DVT of the lower limb. Residual venous occlusion was assessed by duplex sonography 1, 3, 6, 12 and 24months after the acute event. The PAI-1 Activity was determined by ELISA.

RESULTS

Ten patients (23%) were homozygous for 4G (4G/4G), 27 patients (63%) were heterozygous 4G/5G and 6 patients (14%) were homozygous for 5G (5G/5G). Residual venous occlusion (RVO) was found in 77%, 65%, 58%, 56% and 37% of the overall study population, at 1, 3, 6, 12 and 24months after acute DVT, respectively. The presence of residual venous occlusion at 1, 3, 6, 12 and 24months after acute unprovoked DVT did not differ significantly between genotypes, but age was associated with RVO. Plasma levels of PAI-1 activity correlated with body mass index but was not associated with genotypes in our study.

CONCLUSION

The PAI-1 4G/5G genotype was not a relevant predictor of persistent residual venous occlusion after idiopathic DVT, which however was associated with age.