Defining the Risk: Benefit Ratio of Venous Thromboembolism (VTE) Prophylaxis in Hospitalized Cancer Patients

Introduction: VTE affects 1.6-1.8/1000 hospitalized patients per year; active cancer increases the rate of VTE 6-fold. Despite the high risk of VTE, studies show cancer patients receive inpatient VTE prophylaxis at a lower rate than general medical patients. In addition, VTE prophylaxis is often held for a platelet value of 9 /L, despite a lack of evidence. Current recommendations for all inpatients with cancer (and no contraindication to blood thinners) are to receive prophylactic anticoagulation, regardless of an increased bleeding tendency in this population. A formal risk:benefit ratio of inpatient VTE prophylaxis for cancer patients has not been evaluated to date. Methods: The Michigan Hospital Medicine Safety Consortium, a 49 hospital quality collaborative, has prospectively collected data on VTE risk factors and outcomes in medical patients > 18 years of age. Exclusion criteria include surgical patients, pregnancy, admission to the ICU or for palliative care, therapeutic anticoagulation, diagnosis of acute thrombus, history of VTE within 6 months, and length of stay Results: Between 7/2012-7/2015, 86,634 admissions were captured in the cohort; 70,086 were eligible for VTE prophylaxis and included in this analysis. 22% of cases had a diagnosis of cancer. Of cancer admissions, 89.5% had solid tumors, 13.5% hematologic malignancies, 3.4% both and 20% metastatic disease. Active treatment for cancer was delivered 12 mo in 44.4% and no treatment or unknown in 20.3%. When compared to general medical admissions, cancer admissions were more likely to receive VTE prophylaxis (72.16% vs 69.21%, p Conclusions: In this prospective inpatient cohort, we compared general medicine to cancer cases and found cancer admissions received VTE prophylaxis at a higher rate. This is different than previously reported data, likely due to the exclusion of patients with contraindications to prophylaxis. However, despite prophylaxis, cancer patients had a higher rate of VTE during admission and 90 days post discharge as well as more bleeding complications. The risk:benefit ratio of VTE prophylaxis is 6 times worse in cancer patients due to bleeding. While bleeding occurs more frequently in cancer patients with platelet count 9 /L, VTE occurs at a similar rate regardless of platelet count, meaning that cancer patients are at high risk of both clotting and bleeding. Recommendations for inpatient VTE prophylaxis for cancer patients require a targeted approach to identify a subset who would most benefit from VTE prophylaxis. Disclosures Flanders: Institute for Healthcare Improvement and the Society of Hospital Medicine: Consultancy; Wiley Publishing: Patents & Royalties; CDC Foundation: Research Funding; Blue Cross Blue Shield of Michigan: Research Funding; Michigan Hospital Association: Research Funding. Sood: Bayer: Research Funding.