[Antithrombotic therapy in deep venous thrombosis associated with port-a-cath catheter in patients with cancer: evidence in Argentina].

Introduction: Recommendations for treating catheter-associated deep vein thrombosis (DVT) and cancer are based on studies of lower extremity DVT, due to the lack of direct evidence. The aim of the study was to describe antithrombotic strategies, catheter management, and compare outcomes according to strategy and anticoagulant used, in a subanalysis of patients with port-a-cath-associated DVT from a cancer-related thrombosis cohort.

Materials and methods: Retrospective, single-center cohort study, from January 2016 to March 2022. Three strategies were evaluated after 3-6 months of full anticoagulation: A) dose reduction, B) maintenance, and C) discontinuation. Major bleeding (MB), clinically relevant non-major bleeding (CMNMB), and recurrent venous thromboembolism (rVTE) rates were compared by strategy and anticoagulant.

Results: A total of 112 patients were included, treated with rivaroxaban (48%), apixaban (2%), and enoxaparin (24%). Eighty-two patients underwent strategy A, B, or C, and 46 underwent catheter removal. The MB/CMNMB rate was 14%, and the MB/CMNMB rate was 1%. The MB/CMNMB rates were 5/42 for A, 6/36 for B, and 1/4 for C (p=0.7). One MB/CMNMB event was recorded in A and B, with no events in C (p=0.94). With apixaban, MB/CMNMB was 3/31; with enoxaparin, 6/27; and with rivaroxaban, 7/54 (p=0.36). The MS/SNMCR rate was 2/31 with apixaban, 0/54 with rivaroxaban and 0/27 with enoxaparin (p=0.06).

Discussion: No significant differences were found in ETVr, MS or SNMCR between strategies or anticoagulants.