Choice of thromboprophylaxis in patients with multiple myeloma treated with immunomodulatory drugs

IMiD: immunomodulatory drug; VTE: venous thromboembolism; LMWH: low molecular weight heparin; CABG: coronary artery bypass graft surgery; GFR: glomerular filtration rate.
* For most of these patients treated with single agent lenalidomide or thalidomide, we favor low dose aspirin prophylaxis (ie, 81 to 100 mg daily) rather than no prophylaxis or the use of other agents. However, these patients are at lower risk for VTE and do not require VTE prophylaxis if the risks of daily aspirin are felt to outweigh the small absolute reduction in expected risk of thrombosis. Trials of pomalidomide have routinely incorporated some form of thromboprophylaxis.
¶ The ideal regimen in this setting is unknown and clinical practice varies widely. Prophylactic dose LMWH may be preferred over full anticoagulation in patients at higher risk for bleeding complications, whereas therapeutic doses may be preferred for those receiving intensive, anthracycline-containing therapy in conjunction with an IMiD.
Δ The impact of individual risk factors on the incidence of VTE likely differs. As examples, prior VTE and known inherited thrombophilia are stronger risk factors for VTE than obesity and chronic kidney disease. With these caveats, we apply this stratification loosely in our practices. While elevated D-dimer levels are a risk factor for VTE, we do not routinely measure D-dimer for the purpose of risk stratification. Patients may shift from one group to another if complications arise or treatment is de-escalated.