P690Incidence of events between vitamin K antagonists and direct oral anticoagulants in patients with cancer

Background

Balance between embolic and bleeding risk is challenging in patients with cancer. There is a lack of specific recommendations for the use of antithrombotic therapy in oncologic patients with atrial fibrillation (AF).

We aimed to evaluate the effectiveness and safety of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) within patients with breast cancer. We also compared the embolic and bleeding risk, the preventive management and the incidence of events between patients with and without cancer.

Methods

It is an ambispective observational multicentric study that analysed patients with non-valvular AF treated in Oncology and Cardiology Departments in Spain in the period 2011–2018. A total of 1237 female patients with AF were enrolled: 637 with breast cancer and 599 without cancer. The incidence of thromboembolic and major bleeding events according to the antithrombotic strategy with VKAs or DOACs was evaluated in the cohort of 637 patients with cancer. Analysis were conducted using SPSS software V.22.0 and R V.3.5.1, with a two-tailed significance value of 0.05.

Results

Mean follow-up was 3.1 years. Both groups were similar in age, CHA2DS2-VASc and HASB-LED scores. There was no evidence that the incidence of ischemic stroke/systemic embolism differed between patients with cancer treated with AVK and DOAC after CHA2DS2-VASc adjustment: HR 0.91 (95% CI, 0.42–1.99). In addition, no significant differences in the incidence of major bleeding events were found between DOACs and VKA after adjustment for HAS-BLED score: HR 1.53 (95% CI, 0.93–2.53) (Figure 3). Gastrointestinal bleeding was the main source of haemorrhages in both groups (45% of bleedings among patients treated with DOACs and, 37% in VKAs group). Metastatic disease or active chemotherapy were studied as potential covariates but none of them posed any relevant change in the result.

Kaplan-Meier analysis

Conclusions

Cancer patients treated with DOACs did not differ versus those treated with VKAs with regards to stroke or systemic embolism in a model adjusted for CHA2DS2-VASc. Neither significant differences were found for bleeding events in a model adjusted for baseline HASBLED.