Time to individualize duration of parenteral anticoagulation in pulmonary thromboembolism?

[...]giving oral anticoagulant (OAC) from the first day may be somewhat counterproductive (at least theoretically) because of well-known prothrombotic action of warfarin in the first days of administration. Namely, heparin not only acts more rapidly than OAC, but it also has a better antithrombotic effect [12-14]. [...]low-molecular-weight heparin (LMWH) is preferred to unfractionated heparin (UFH) for the initial treatment of acute nonmassive PTE Antithrombotic Therapy for Venous Thromboembolic Disease- American College of Chest Physicians Guidelines (8th Edition) recommendation grade 1A) [15].