New guidelines cover VTE prophylaxis, diagnosis, anticoagulation, and HIT

Several guidelines related to venous thromboembolism (VTE) prevention and treatment were recently published by the American Society of Hematology, with more promised soon.


New guidelines on preventing, diagnosing, and treating venous thromboembolism (VTE) were recently released by the American Society of Hematology.

The society's new guideline on VTE prophylaxis for hospitalized and nonhospitalized medical patients includes 19 recommendations. Among other recommendations, they strongly recommend pharmacological VTE prophylaxis in acutely or critically ill inpatients who have acceptable bleeding risk and mechanical prophylaxis when bleeding risk is too high. The guideline also strongly recommends against using direct oral anticoagulants during hospitalization or extending pharmacological prophylaxis after hospital discharge. Nonhospital recommendations in the guideline address patients in long-term care facilities, outpatients with minor injuries, and long-distance travelers.

The new guideline on diagnosis of VTE includes 10 recommendations. It recommends that for patients at low VTE risk, using D-dimer as the initial test reduces the need for diagnostic imaging. For patients at high VTE risk, imaging is warranted. For pulmonary embolism diagnosis, ventilation-perfusion scanning and CT pulmonary angiography are the most validated tests, whereas lower- or upper-extremity deep venous thrombosis should be diagnosed with ultrasonography. Research is needed on new diagnostic modalities and to validate clinical decision rules for patients with suspected recurrent VTE, the guideline said.

The guideline on optimal management of anticoagulation offers 25 recommendations and two good-practice statements. They include strong recommendations in favor of patient self-management of international normalized ratio (INR) with home point-of-care INR monitoring for vitamin K antagonist therapy and against periprocedural low-molecular-weight heparin (LMWH) bridging therapy. Conditional recommendations support basing treatment dosing of LMWH on actual body weight, not using anti–factor Xa monitoring to guide LMWH dosing, using specialized anticoagulation management services, and resuming anticoagulation after episodes of life-threatening bleeding.

The guideline on heparin-induced thrombocytopenia (HIT) contains 33 recommendations. Strong recommendations support use of the 4Ts score rather than a gestalt approach for estimating the pretest probability of HIT and oppose HIT laboratory testing and empiric treatment of HIT in patients with a low-probability 4Ts score. Conditional recommendations address the choice of nonheparin anticoagulant for treatment of acute HIT.

The multidisciplinary expert panels convened by the society also issued guidelines on VTE in pregnant and pediatric patients. All of the guidelines were published online by Blood Advances on Nov. 27. Related resources, including a guideline snapshot and a list of upcoming related guidelines, are available on the American Society of Hematology's website.