Idiopathic/local factor NC-SVT ups risk of recurrent thrombosis

The risk of overall recurrent thrombosis (RT) is greater among individuals with idiopathic/local factor-related noncirrhotic splanchnic vein thrombosis (NC-SVT), reveals a study. Moreover, splanchnic RT can appear without symptoms and requires screening to be detected.

“Clinical guidelines do not recommend long-term anticoagulation in NC-SVT without underlying thrombophilia because it is assumed that there is a very low risk of RT,” the authors said.

In this multicentre, retrospective observational study, the authors assessed the risk factors for RT in 64 people with NC-SVT of idiopathic/local factor aetiology. They also analysed the potential value of additional thrombophilic parameters to predict RT in a subgroup of 48 individuals. Finally, the findings were validated in 70 participants with idiopathic/local factor NC-SVT.

Seventeen (26 percent) of 64 participants presented splanchnic and/or extrasplanchnic RT (overall RT) during follow-up (cumulative incidence: 2 percent at 1 year, 10 percent at 2 years, 19 percent at 5 years, and 34 percent at 10 years). Among those with splanchnic RT, 53 percent were asymptomatic.

No clinical or biochemical parameters were predictive of overall RT. In 48 individuals with an additional comprehensive thrombophilic study, however, factor VIII ≥150 percent independently predicted overall RT (hazard ratio [HR], 7.10, 95 percent confidence interval [CI], 2.17‒23.17; p<0.01).

In the validation cohort, 19 participants (27 percent) presented overall RT, which was also independently predicted by factor VIII >150 percent (HR, 3.71, 95 percent CI, 1.31‒10.5; p<0.01). Of note, the predictive value of factor VIII was confirmed in individuals with NC-SVT of idiopathic/local factor aetiology.

“People with idiopathic/isolated local factor noncirrhotic portal vein thrombosis were previously thought to be at minimal risk of rethrombosis and therefore did not receive scheduled follow-up,” the authors said.

“The results of this study are of special interest for hepatologists treating people with NC-SVT, as they show a 25-percent incidence of rethrombosis and support the close follow-up of people with factor VIII >150 percent to ensure the early identification of new thrombotic events,” they added.