Outcomes during anticoagulation in patients with symptomatic vs. incidental splanchnic vein thrombosis

Introduction: Current guidelines recommend the use of anticoagulant therapy in patients with symptomatic splanchnic vein thrombosis (SVT) and suggest no routine anticoagulation in those with incidental SVT. Methods: We used the RIETE (Registro Informatizado Enfermedad Trombo Embólica) registry to assess the rate and severity of symptomatic venous thromboembolism (VTE) recurrences and major bleeding events appearing during the course of anticoagulation in patients with symptomatic or incidental SVT. Results: In March 2017, 521 patients with SVT were recruited. Of them, 212 (41%) presented with symptomatic SVT and 309 had incidental SVT. Most (93%) patients received anticoagulant therapy (median, 147 days). During the course of anticoagulation, 20 patients developed symptomatic VTE recurrences (none died) and 26 had major bleeding (fatal bleeding, 5). On multivariable analysis, patients with incidental SVT had a non-significantly higher risk for symptomatic VTE recurrences (adjusted hazard ratio [HR]: 2.04; 95%CI: 0.71–5.88) and a similar risk for major bleeding (HR: 1.12; 95%CI: 0.47–2.63) than those with symptomatic SVT. Active cancer was associated with at increased risk for VTE recurrences (HR: 3.06; 95%CI: 1.14–8.17) and anaemia (HR: 4.11; 95%CI: 1.45–11.6) or abnormal prothrombin time (HR: 4.10; 95%CI: 1.68–10.1) were associated with at increased risk for major bleeding. Conclusions: The rates of recurrent SVT and major bleeding were similar between patients with incidental or symptomatic SVT. Because the severity of bleeding complications during anticoagulation may outweigh the severity of VTE recurrences in both groups, further studies should identify those SVT patients who benefit from anticoagulant therapy.