Quantitative Evaluation of Pelvic Ultrasound to Predict Deep Vein Thrombosis in Patients With Nonthrombotic Iliac Vein Lesions

Methods: All patients with IF-DVT treated with MT using the ClotTriever System in the CLOUT registry or AC alone in the ATTRACT trial were included.Patients with incomplete case data, symptoms >4 weeks, or bilateral DVT were excluded.Propensity score matching was performed between MT and AC patients using nine baseline characteristics: age, sex, body mass index, leg treated, race, symptom duration, provoked DVT, prior history of DVT/pulmonary embolism, and Villalta score.Villalta scores and the incidence of any PTS (post thrombotic syndrome, Villalta score $5) or moderate-to-severe PTS (Villalta score $10) through 24 months were assessed.Additionally, logistic regression was used to estimate the likelihood of developing any PTS or moderate-to-severe PTS at 24 months by baseline Villalta score and treatment.Results: A total of 164 patient pairs with no significant differences in baseline characteristics were identified using propensity score matching (standardized mean differences <0.10 for all variables in the propensity score model).Fig 1 shows that mean follow-up Villalta scores from 6 to 24 months were lower in matched patients treated with MT compared with AC (2.3-3.3 vs 4.9-6.3;P < .001for all time points) and that fewer had any PTS (17%-19% vs 38%-46%; P < .01 for all time points) or moderate-to-severe PTS (4%-6% vs 18%-19%; P < .05for all time points).Predictive modeling showed that patients who were treated with AC had significantly higher odds of developing any PTS (OR, 3.2; 95% CI, 1.6-6.5;P < .01)or moderate-to-severe PTS (OR, 6.7; 95% CI, 2.1-29.9;P < .01)at 24 months than those with the same baseline Villalta scores treated with MT (Fig 2).Conclusions: This updated analysis strengthens previous findings that MT treatment of IF-DVT in CLOUT resulted in significantly lower Villalta scores and odds of developing PTS through 24 months than treatment with AC of matched patients in ATTRACT.Results from ongoing randomized trials will further clarify optimal use of these treatments in patients with IF-DVT.