Calf deep vein thrombosis: frequency, therapeutic management, early outcomes and all-causes mortality in a cohort of hospitalized patients

BACKGROUND: Isolated distal deep vein thromboses (IDDVT) are frequent; however, their optimal management is still controversial. METHODS: We performed a retrospective study on inpatients undergoing ultrasound for suspected deep vein thrombosis (DVT) or with a particular risk profile, during 2016. This study aimed to assess the frequency of proximal deep vein thromboses (PDVT) and IDDVT; to evaluate therapeutic management and identify variables associated with early outcomes and mortality among IDDVT patients; to compare all-causes mortality between subjects with PDVT and IDDVT. RESULTS: Among 21594 patients hospitalized in the study period 251 IDDVT and 149 PDVT were diagnosed; the frequency was 1.2% and 0.7% respectively. 19% of IDDVT patients died compared to 25.5% of PDVT subjects (OR=0.72; 95% CI=0.44-1.17; P=0.19). In IDDVT patients, age ≥80, cancer and intracranial bleeding increased the risk of death (OR=2; 95% CI=1.07-3.75, P=0.001; OR=8.47; 95% CI=3.28-21.88, P=0.0000003; OR=2.33; 95% CI=1.18-4.58, P=0.0003). A significant association between intracranial hemorrhage and both proximal extension by using the Fisher's exact test (P=0.031; OR=16.11; 95% CI=0.80-321.2), and composite of propagation to popliteal or to other calf veins (OR=8.28, 95% CI=2.07-33 P=0.001) was observed. Standard anticoagulation significantly reduced the composite of propagation to popliteal or to other calf veins (OR=0.07; 95% CI=0.009-0.61, P=0.007), and all-causes mortality (OR=0.37; 95% CI=0.17-0.8; P=0.02), without a significant increase of bleeding. CONCLUSIONS: Among inpatients, IDDVT exceeded 60% of DVT. Mortality was not significantly different between IDDVT and PDVT subjects. Intracranial bleeding significantly increased the risk of propagation and death. Although standard anticoagulation decreased both these complications, further targeted studies are needed.