Incidence and characteristics of asymptomatic distal deep vein thrombosis unexpectedly found at admission in an Internal Medicine setting

Introduction

Lower limb deep vein thrombosis (DVT) is the most frequent clinical manifestation of venous thromboembolism (VTE) and can involve proximal or distal veins. Distal DVT (dDVT) is often asymptomatic and data about its incidence and prognosis are scanty, especially in high risk medical inpatients. Therefore, no consensus exists on the value of detecting and treating dDVTs. Aim of study was to evaluate incidence and characteristics of asymptomatic isolated dDVT at admission in an Internal Medicine department.

Materials and methods

Consecutive patients hospitalized for acute medical illnesses, in whom VTE was not the admission diagnosis, underwent Doppler Ultrasonography. For all patients with dDVT standard treatment with therapeutic doses of low molecular weight heparin or fondaparinux was proposed. Follow-up visits were scheduled at 1, 6 and 12 weeks.

Results

One-hundred-fifty-four patients were enrolled. In 4.5% a proximal DVT and in 16.2% an asymptomatic dDVT were found. Female sex, elevated age and renal and electrolyte abnormalities were significantly associated to dDVT (p = 0.014, p = 0.009 and p = 0.046, respectively). Only low degree of mobility (LDM) was independently associated to dDVT OR 7.97 (95%CI 2.42-26.27), p = 0.001)]. A high mortality rate, not for VTE-related causes, was found, especially in the first week, among dDVT patients.

Conclusions

We found a high incidence of clinically silent dDVTs. LDM evaluation could be useful to select patients at high risk in whom to perform a search for dDVT.