Effectiveness and Safety of Direct Oral Anticoagulants Vs. Low Molecular Weight Heparin As Anticoagulant Therapy in Patients with Active Cancer Therapy and Non Valvular Atrial Fibrillation

BACKGROUND Non Valvular Atrial Fibrillation (NVAF) is the most common cardiac arrhythmia among patients with cancer. Anticoagulation in this setting is associated with a higher rate of clinically relevant major and non-major bleeding and therefore, can be especially challenging. Due to concerns about drug interactions in patients receiving chemo-immunoterapy, Low Molecular Weight Heparin (LMWH) has been the most commonly prescribed anticoagulant for stroke prevention as a substitute for vitamin K antagonists. Direct Oral Anticoagulants (DOAC) are an increasing alternative for anticoagulant therapy for stroke prevention in NVAF, but there are are still limited data regarding it's effectiveness and safety for cancer patients receiving active treatment. AIMS To assess the effectiveness and safety according to DOAC or LMWH treatment, and to determine the rate of anticoagulant-associated clinically relevant bleeding-free survival in a cohort of cancer patients with NVAF receiving active treatment. METHODS From April 2016 to December 2018 we consecutively included NVAF patients with active cancer therapy treated with DOAC or LMWH in a prospective multicenter registry. Patients with prosthetic valves or a life expectancy of less than one month were excluded from this study. Active cancer therapy was defined as evidence of neoplasm with ongoing antineoplastic therapy (chemo-immunotherapy or hormonal treatment). Pharmacological interactions check-up was performed prior election of treatment. Demographic, laboratory, cancer diagnosis, and antineoplastic therapy data were collected. Patients had a minimum follow-up (FU) of 6 months. In patients who received antineoplastic therapy with a potential DOAC interaction, plasma drug concentrations were measured during the FU using the Direct Thrombin Inhibitor Assay from IL (Bedford-MA-USA) for Dabigatran and the Technoclone anti-Xa assay from Technoclone (Vienna-Austria) for Rivaroxaban. Bleeding events were classified according to ISTH criteria. RESULTS A total of 302 patients with NVAF and active cancer therapy were included. Among all patients, 192 (63.5%) were treated with DOAC (20 dabigatran, 24 rivaroxaban, 80 apixaban and 68 edoxaban) and 110 with LMWH. Mean FU was 14.8 and 12.5 months (DOAC vs LMWH; p:0.53). Demographic characteristics and cancer subtypes and drugs are summarised in table 1 and 2, respectively. In LMWH group, 81.8% (n=90) of patients received full-dose of LMWH, 13.6% (n=15) intermediate dose and on