Few predictors of massive deep vein thrombosis.

Factors that predispose to thrombus propagation from the femoropopliteal veins to the pelvic veins are poorly understood. Our goal was to determine whether there are characteristics that identify patients with massive deep vein thrombosis (DVT). We compared the 122 (2.5%) patients presenting with massive DVT (pelvic plus lower-extremity DVT) to the 4,674 (97.5%) patients with isolated lower-extremity DVT from a prospective United States multicenter DVT registry. Patients with massive DVT were younger (59.4+/-18.9 years vs. 64.3+/-16.8 years; p<0.01), less likely to have hypertension (40% vs. 51%; p=0.02), and more likely to smoke (21% vs. 13%; p=0.02) and have ongoing radiation therapy (7% vs. 3%; p=0.02). The massive DVT group more commonly presented with extremity edema (80% vs. 69%; p<0.01) and erythema (21% vs. 12%; p<0.01) than the isolated lower-extremity DVT group. However, after multivariable logistic regression analysis, extremity erythema (adjusted odds ratio 1.86; 95% CI 1.13-3.04) was the only independent sequela of massive DVT and younger age (adjusted odds ratio 1.17 per decreasing decade of age; 95% confidence interval: 1.02-1.34) was the only independent predictor of massive DVT. Thrombus propagation from the femoropopliteal system cannot be reliably predicted using demographic or clinical characteristics.