PO-01 - Congestive heart failure is an independent risk factor for venous thromboembolism and mortality in cancer patients.

Introduction: Prediction of venous thromboembolism (VTE) occurrence in cancer patients using individual risk factors may contribute to preventing the burden of disease associated with VTE. Congestive heart failure in patients with cancer may increase the risk of VTE and worsen the prognosis.

Aim: We sought to investigate the association of congestive heart failure and occurrence of VTE in cancer patients, specifically with consideration for the poor prognosis in patients with heart failure and cancer.

Materials And Methods: Hospitalized and ambulatory cancer patients were included in the prospective Vienna Cancer and Thrombosis Study (CATS) in search of risk factors for occurrence of VTE. Cancer entities and comorbidities were recorded at baseline and verified using medical documentation including a diagnosis of congestive heart failure. The occurrence of VTE events was compiled via mail and telephone follow-ups for two years. Risk of VTE occurrence was calculated in the competing risk regression model, considering death as a competing event during follow-up.

Results: In the current analysis 1,433 patients (632 women, 44.1%) with a median age of 61 years (25th-75th percentile: 52-75) were included. During the observation period, 108 (7.5%) VTE events and 522 (36.4%) deaths occurred. The median observation time was 729 days (233-731), and 34 patients (2.3%) had diagnosed congestive heart failure at the time of study inclusion, 12 of which had NYHA II-IV and 22 unspecified congestive heart failure. In the group of heart failure patients, 6 had VTE events and 23 died. In univariate competing risk analysis, the risk of VTE occurrence was increased 2.6-fold in patients with heart failure compared to those without a diagnosis of heart failure (SHR 2.58, 95% CI 1.13-5.92, p=0.025). After multivariable adjustment for age, BMI, gender, diabetes, history of myocardial infarction or stroke, use of antiplatelet drugs, cancer site, hypertension, D-Dimer level and peripheral arterial disease, the risk of VTE in heart failure patients was 3-times the risk of patients without heart failure (HR 3.07, 95% CI 1.15-8.19, p=0.025). Further, congestive heart failure was a strong predictor of mortality (HR 1.70, 95% CI 1.10-2.65, p=0.018).

Conclusions: Congestive heart failure is not only a risk factor for mortality in cancer patients, but also an independent predictor of VTE occurrence. In order to prevent VTE and the associated burden, patients with cancer and congestive heart failure may benefit from thromboprophylaxis.