Predictors, Incidence, and Proximal Extension Rate of Distal Deep Vein Thrombosis in Internal Medicine Wards: Insights from the AURELIO Study

Abstract Distal deep venous thrombosis (DDVT) is a clinical condition that can affect patients hospitalized in internal medicine wards and may result in pulmonary embolism. However, many aspects of distal thrombosis in hospitalized medical patients remain poorly understood. This study aimed to evaluate the rate of asymptomatic DDVT at admission, the occurrence of DDVT during hospitalization, and to analyze the factors associated with thrombotic events. A multicenter, prospective observational study (AURELIO) was conducted across eight centers affiliated with the Ultrasound Study Group of the Italian Society of Internal Medicine. Venous ultrasound of the lower limb veins was performed within 48 hours of admission and at discharge to diagnose distal deep vein thrombosis. Among 1,458 patients (721 males and 737 females; mean age 71 ± 16 years), asymptomatic distal thrombosis was detected in 59 patients (4%) upon admission. Of these, 47% (n = 28) were classified as isolated DDVT, while 31 cases involved DDVT that extended to the proximal tract. At discharge, 9 additional cases of distal thrombosis were identified, bringing the total to 68 cases. Of these, 46% were DDVT, while 54% DDVT extended to the proximal venous system. Multivariate analysis identified reduced mobility (p = 0.036) and active malignancy (p = 0.02) as independent risk factors for DDVT extending to the proximal tract. Additionally, pneumonia (p = 0.043) and active malignancy (p = 0.008) were associated with DDVT. The study emphasizes the high prevalence of DDVT in hospitalized patients and the risk of proximal extension. Ultrasound screening should be considered for oncology patients and those with pneumonia to ensure early diagnosis and timely anticoagulant therapy.