D-Dimer Enhances Risk-Targeted Thromboprophylaxis in Ambulatory Patients with Cancer

The oncologist

article

Vaibhav Kumar¹  Joseph R. Shaw³  Nigel S. Key¹  Anton Ilich¹  Ranjeeta Mallick³  Philip S. Wells³  Marc Carrier³ 

[1] Division of Hematology and Oncology, University of North Carolina at Chapel Hill;UNC Blood Research Center, University of North Carolina at Chapel Hill;Department of Medicine, Ottawa Hospital Research Institute at the University of Ottawa

关键词: Venous thromboembolism;    Cancer-associated thrombosis;    Thromboprophylaxis;    Apixaban;    D-dimer;   

DOI  :  10.1002/onco.13540

学科分类：地质学

来源: AlphaMed Press Incorporated

【 摘 要 】

Background Thromboprophylaxis for ambulatory patients with cancer is effective, although uncertainties remain on who should be targeted. Using D-dimer values from individuals enrolled to the AVERT trial, we sought to identify and validate a more efficient venous thromboembolism (VTE) risk threshold for thromboprophylaxis. Materials and Methods The AVERT trial compared thromboprophylaxis with apixaban with placebo among patients with cancer with a Khorana Risk Score ≥2. The D-dimer measured at randomization was used to calculate an individualized 6-month VTE risk using the validated CATScore. A modified intention-to-treat analysis was used to assess efficacy (VTE) and safety (major and overall bleeding) in the (a) complete cohort and (b) ≥8% and < 8% 6-month VTE risk thresholds. Results Five hundred seventy-four patients were randomized in the AVERT trial; 466 (81%) with baseline D-dimer were included in the study. Two hundred thirty-seven subjects received apixaban; 229 received placebo. In the complete cohort, there were 13 (5.5%) VTE events in the apixaban arm compared with 26 (11.4%) events in the placebo arm (adjusted hazard ratio [aHR] 0.49 [0.25–0.95], p < .05). Number needed to treat (NNT) to prevent one VTE = 17. Eighty-two (35%) and 72 (31%) patients in the apixaban and placebo arms, respectively, had a 6-month VTE risk ≥8%. In this subgroup, 7 (8.4%) VTE events occurred with apixaban and 19 (26.3%) events with placebo (aHR 0.33 [0.14-0.81], p < .05), NNT = 6. Individuals with a VTE risk <8% derived no benefit from apixaban thromboprophylaxis (aHR 0.89 [0.30–2.65), p = .84). Increased rates of overall bleeding were observed with apixaban in both the complete (aHR 2.11 [1.09–4.09], p < .05) and ≥ 8% predicted risk cohorts (aHR 2.87 [0.91–9.13], p = .07). Conclusion A 6-month VTE risk threshold of ≥8% increases the efficiency of risk-targeted thromboprophylaxis in ambulatory patients with cancer. Implications for Practice Ambulatory patients with cancer receiving chemotherapy have an increased risk of venous thromboembolism (VTE). A Khorana Risk Score (KRS) ≥2 is currently the suggested threshold for thromboprophylaxis. Using baseline D-dimer values from individuals enrolled to the AVERT trial, this retrospective validation study identifies a 6-month VTE risk of ≥8% as a more efficient threshold for thromboprophylaxis. At this threshold, the number needed to treat to prevent one VTE is 6, compared with 17 when using a KRS ≥2. Conversely, individuals with a predicted risk of <8% derive no clinical benefit from thromboprophylaxis. Future prospective studies should validate this threshold for outpatient thromboprophylaxis.

【 授权许可】

CC BY|CC BY-NC