Is Distal (aka Calf Vein) DVT as Dangerous as Proximal DVT?
October 12, 2021
Written by Seth Walsh-Blackmore
Spoon Feed
Patients treated with anticoagulation for isolated distal deep vein thrombosis (IDDVT) vs. proximal deep vein thrombosis (PDVT) did not experience significant differences in overall mortality, VTE recurrence, major or minor bleeding within 12-months. Subgroup analysis found lower recurrence rates, major bleed, and death in those treated with DOACs vs. UFH/LMWH/warfarin.
Why this does this matter?
CHEST guidelines recommend serial imaging without anticoagulation in select patients with IDDVT, and ACEP has B level evidence for anticoagulation. Both CHEST and ACEP recommend DOACs as the first-line therapy in uncomplicated patients who undergo anticoagulation. Understanding outcomes for patients with IDDVT vs PDVT could sway our decision to anticoagulate or not, what anticoagulant to use, and help us provide appropriate shared decision making and education for our patients.
Continued stasis in ED management
This was a single-center retrospective study of 1922 consecutive LE DVT patients diagnosed with ultrasound who were treated with anticoagulation. 746 had IDDVT, defined by isolation to the posterior tibial, peroneal, soleal, or gastrocnemius venous segments. 1176 had PDVT, defined by any involvement of the popliteal femoral or iliac veins, including those with coexisting distal involvement. IDDVT was more often related to recent surgery, immobilization, or trauma, while PDVT was more often unprovoked or in the setting of active malignancy. A larger majority of PDVT patients had a history of VTE.
Within 12 months, 2.3% of IDDVT and 3.1% of PDVT (p=.217) experienced recurrent VTE, which manifested as PE in 60% of IDDVT and 39.5% of PDVT. 7.2% of IDDVT vs 3.9% of PDVT (p =0.001) had died at 3 months, but death at 12 months was similar at 14.6% in IDDVT and 13.4% in PDVT (p=.468). Major bleeding within 12 months occurred in 3.2% of IDDVT and 4.3% of PDVT (p=.217). In both IDDVT and PDVT, a statistically significant lower proportion of VTE recurrence, major bleeding, and death was observed in those treated with DOACs vs. LMWH/UFH/warfarin; however, results may have been confounded.
This study excluded IDDVT patients managed without anticoagulation and serial observation, was not limited to those diagnosed in the emergency department, and did not compare those managed solely outpatient versus those admitted. For this reason, the findings are not as informing for ED management. However, this study makes me more apt to treat IDDVT and use a DOAC. If a patient can’t afford or obtain a DOAC, it makes me nervous considering them for outpatient treatment.
Source
Outcome of anticoagulation in isolated distal deep vein thrombosis compared to proximal deep venous thrombosis. J Thromb Haemost. 2021 Sep;19(9):2206-2215. doi: 10.1111/jth.15416. Epub 2021 Jul 21.
Peer reviewed by Aaron Lacy and Clay Smith