Recanalization of chronically occluded iliac veins with stent can restore blood flow and improve functional outcomes in patients with post-thrombotic syndrome (PTS). The ARIVA trial tested whether aspirin 100mg plus rivaroxaban 20mg is superior to rivaroxaban 20mg alone to prevent stent occlusion within 6 months after stent placement for PTS.

The ARIVA trial was a multinational, academic, open-label, multi-center, independently adjudicated, randomized trial. Eligible patients were aged between 18 and 75 with Villalta score >4 and a confirmed stenosis of the inferior vena cava, iliac vein, or common femoral vein after successful venous stent placement. Key exclusion criteria included contraindications to anticoagulant use, acute venous thrombosis, or any condition preventing study participation. The primary efficacy outcome was the composite of no occlusion in the treated segment or no re-intervention needed to maintain patency (primary patency rate) within 6 months. Secondary outcomes included secondary patency rates, functional outcomes, and quality of life at 6 months. The primary safety outcome included major bleeding (ISTH criteria).

From 2020 through 2022, a total of 172 patients were screened for randomization at six centers in three countries. Ultimately, 169 patients were randomized and a total of 162 patients were included in the full set analysis: those received either rivaroxaban plus aspirin (N = 80) or rivaroxaban monotherapy (N = 82). Mean age was 42.8 (standard deviation 14.7) years; 103 (60.9%) patients were women. The vast majority of patients were Caucasian (97.5%) and leg ulcerations were present in 7% of patients. The primary patency rate was 94.8% in the aspirin-rivaroxaban group and 92.4% in the rivaroxaban group (+2.4%; 95%CI -13.6%; +18.0%); Figure 1. There was no difference between groups concerning functional outcomes and quality of life 6 months after randomization. The Villalta score reduced of 6 points (Q1, Q3: -3, -10) in both groups. No major bleeding occurred.

We found no evidence for the superiority of aspirin-rivaroxaban over rivaroxaban alone to prevent stent-thrombosis over the first 6 months after intervention. The primary patency rate was higher than expected, confirming the feasibility, effectiveness, and safety of endovascular procedures for PTS.