Periprocedural Interruption of Anticoagulation in Patients with Cancer-Associated VTE: An Analysis of Thrombotic and Bleeding Outcomes
Authors: Shaw Joseph R. , Douketis James , Le Gal Gregoire , Carrier Marc 
Published: October 2019

Abstract
Background: Approximately 10-20% of patients with venous thromboembolic events (VTE) have underlying malignancy. VTE is considered the second leading cause of death in patients with cancer, and patients with cancer-associated VTE are at higher risk of anticoagulant-related bleeding. Although patients with cancer often undergo diagnostic or therapeutic invasive procedures, there is a paucity of data on adverse outcomes following the periprocedural interruption of anticoagulation in this patient population.
Methods: We did a single-center, retrospective chart review of consecutive patients with cancer-associated VTE who had periprocedural interruption of anticoagulation for invasive procedures between November 2015 and March 2018. Perioperative interruption of warfarin/low-molecular-weight heparin was done as per CHEST guidelines (Douketis et al. Chest 141(2 Suppl). Heparin bridging anticoagulation was used only for patients with recent (< 3 months) VTE. Perioperative interruption of direct oral anticoagulants (DOACs) was done as per Thrombosis Canada guidelines, with anticoagulation held for 3 half-lives prior to low bleeding risk procedures and 5 half-lives for high bleeding risk procedures. Active cancer was defined as per the HOKUSAI VTE CANCER trial (Raskob et al. NEJM 378(7)). Primary outcomes were 30-day post-operative rates of VTE and major bleeding. Secondary outcomes were 30-day post-operative rates of clinically relevant non-major bleeding (CRNMB) and mortality. Major bleeding and CRNMB were defined according to ISTH definitions. Data are reported on a per-interruption basis. Herein, we present an interim analysis of results.
Results: To date, 82 perioperative interruptions are included, of whom 69.5% were receiving a DOAC. Mean age of the cohort was 65.8 years, 62.2% were male, 92.6% had active cancer and 41.5% had metastatic cancer. Thrombocytopenia (platelet count < 100 x 106/L) was present in 12.2% of interruptions. Procedures were stratified as high bleeding risk in 65.9% of cases. The 30-day rates of thromboembolism and major bleeding were both 3.70 % (95% confidence interval [CI] 1.25 to 10.2%), as was the 30-day rate of CRNMB. There were no deaths during the 30-day follow-up period.
Conclusions: The periprocedural interruption of anticoagulation in patients with cancer-associated VTE appears to be associated with high rates of post-operative thrombotic and bleeding complications. Prospective studies are required to better quantify the risks of periprocedural anticoagulation interruption in this patient population.

Disclosures
Shaw: Portola Pharmaceuticals: Research Funding. Douketis:BMS: Other: Advisory Board; Janssen: Consultancy; Bayer: Other: Advisory Board; Pfizer: Other: Advisory Board; Daiichi-Sankyo: Other: Advisory Board; Portola: Other: Advisory Board; Astra-Zeneca: Other: Advisory Board; Sanofi: Consultancy, Other: Advisory Board; Biotie: Other: Advisory Board; Boehringer-Ingelheim: Consultancy, Other: Advisory Board, Research Funding; The Medicines Company: Other: Advisory Board. Carrier:Pfizer: Honoraria; Bayer: Honoraria; BMS: Honoraria, Research Funding; Leo Pharma: Research Funding.