New Class of Medication Yields Better Outcomes: Direct Oral Anticoagulants Improve Treatment Success for Lower Extremity Acute Deep Vein Thrombosis

Optimal therapy for acute lower extremity deep venous thrombosis (DVT) remains an enigma. While clinical trials demonstrate noninferiority with an oral anti-Xa inhibitor, or direct oral anticoagulant (DOAC), versus combined low-molecular-weight heparin and oral vitamin K agonist (VKA), the most effective regimen remains to be determined. This study is a single-center retrospective review conducted from October 2014 to December 2015 of patients with a diagnosis of acute DVT and subsequent serial lower extremity venous duplex. Demographics, medical history, medications, and serial ultrasound findings, as well as the primary anticoagulant used for treatment were collected and analyzed by two independent data extractors. Successful treatment was defined as no new DVT or progression of existing DVT within 3 months of diagnosis of the index clot. Risk factors for treatment failure were assessed using standard odds ratios and Fischer’s exact test. Among 496 patients with acute DVT, 54% (n = 266) were men, the mean age was 61 years, 35% (n = 174) were popliteal or more proximal clots, and 445 had documentation of the primary treatment for DVT: 21% (n = 93) received nothing, 20% (n = 91) received an oral VKA, 34% (n = 150) received a DOAC, 20% (n = 88) received low-molecular-weight heparin, and 5% (n = 21) received another class of anticoagulant. Within 3 months, 21% (n = 90 of 427) had treatment failure defined as any new DVT or progression of prior DVT. Patients treated with a DOAC were less likely to experience treatment failure when compared with any other treatment (odds ratio, 0.43; 95% confidence interval, 0.23-0.78; P = .005), and when compared with traditional oral VKA (odds ratio, 0.44; 95% confidence interval, 0.21-0.92; P = .029). A prior history of DVT, pulmonary embolism, thrombophilia, renal insufficiency, hepatic insufficiency, cancer, or antiplatelet therapy did not correlate with treatment failure. Neither the number of anticoagulants (0-2 vs >2) nor the duration of treatment (<3 months vs ≥3 months) correlated with treatment failure (P = .12 and P = .41, respectively). Proximal and distal DVTs showed no difference in treatment failure (19% vs 22%, respectively; P = .43). The use of a DOAC for acute lower extremity DVT yielded better overall outcomes and fewer treatment failures at 3 months as compared to traditional oral VKA therapy based on serial duplex imaging.