The value of four-detector row spiral computed tomography for the diagnosis of pulmonary embolism.

Although spiral computed tomography (CT) is being used increasingly as the first-line imaging procedure in the diagnostic workup of patients with clinically suspected pulmonary embolism (PE), the diagnostic value of negative findings, at least when using the four-detector row scanners, is still controversial. A total of 702 consecutive patients with clinical symptoms suggestive of PE underwent four-slice CT. Patients with negative findings received the determination of D-dimer. Those with positive D-dimer underwent further diagnostic workup to confirm or rule out the diagnosis of PE. Those with negative D-dimer were followed-up to 6 months to detect the development of symptomatic venous thromboembolism (VTE). The CT test was interpreted as negative in 536 patients (76.3%). These patients had the D-dimer determination, which was positive in 279 and negative in the remaining 257 patients. Of the former, PE subsequently was documented in 55 patients (19.7%). Of the latter, symptomatic VTE in the follow-up period developed in three patients (1.17%; 95% confidence interval, 0.24 to 3.38%). In conclusion, when using the four-detector row, the negative predictive value of CT findings in patients with clinically suspected PE and positive D-dimer is low. In contrast, it is safe to withhold anticoagulation from patients with negative findings and negative D-dimer.

Below-knee elastic compression stockings to prevent the post-thrombotic syndrome: a randomized, controlled trial.

BACKGROUND: Because only limited evidence suggests that elastic stockings prevent the post-thrombotic syndrome in patients with symptomatic deep venous thrombosis (DVT), these stockings are not widely used. OBJECTIVE: To evaluate the efficacy of compression elastic stockings for prevention of the post-thrombotic syndrome in patients with proximal DVT. DESIGN: Randomized, controlled clinical trial. SETTING: University hospital. PATIENTS: 180 consecutive patients with a first episode of symptomatic proximal DVT who received conventional anticoagulant treatment. INTERVENTIONS: Before discharge, patients were randomly assigned to wear or not wear below-knee compression elastic stockings (30 to 40 mm Hg at the ankle) for 2 years. Follow-up was performed for up to 5 years. MEASUREMENTS: The presence and severity of the post-thrombotic syndrome were scored by using a standardized scale. RESULTS: Post-thrombotic sequelae developed in 44 of 90 controls (severe in 10) and in 23 of 90 patients wearing elastic stockings (severe in 3). All but 1 event developed in the first 2 years. The cumulative incidence of the post-thrombotic syndrome in the control group versus the elastic stockings group was 40.0% (95% CI, 29.9% to 50.1%) versus 21.1% (CI, 12.7% to 29.5%) after 6 months, 46.7% (CI, 36.4% to 57.0%) versus 22.2% (CI, 13.8% to 30.7%) after 1 year, and 49.1% (CI, 38.7% to 59.4%) versus 24.5% (CI, 15.6% to 33.4%) after 2 years. After adjustment for baseline characteristics, the hazard ratio for the post-thrombotic syndrome in the elastic stockings group compared with controls was 0.49 (CI, 0.29 to 0.84; P = 0.011). LIMITATIONS: This study lacked a double-blind design. CONCLUSIONS: Post-thrombotic sequelae develop in almost half of patients with proximal DVT. Below-knee compression elastic stockings reduce this rate by approximately 50%.

Residual venous thrombosis as a predictive factor of recurrent venous thromboembolism.

BACKGROUND: The optimum duration of anticoagulant therapy after an episode of deep venous thrombosis (DVT) is controversial. Contributing to the controversy is uncertainty about whether residual venous thrombosis, as assessed by repeated ultrasonography over time, increases the risk for recurrent thromboembolism. OBJECTIVE: To determine the risk for recurrent thromboembolism in patients who have persistent residual thrombosis compared with patients who have early vein recanalization. DESIGN: Prospective cohort study. SETTING: A university hospital in Padua, Italy. PATIENTS: 313 consecutive symptomatic outpatients with proximal DVT who received conventional short-term anticoagulation. MEASUREMENTS: Ultrasonographic assessment of the common femoral and popliteal veins was performed 3 months after acute DVT in all patients and at 6, 12, 24, and 36 months in patients found to have residual venous thrombosis. Veins were considered recanalized if they were 2.0 mm or less in diameter on a single test or 3.0 mm or less in diameter on two consecutive tests. Recurrent thromboembolism was assessed during a 6-year period. RESULTS: The cumulative incidence of normal results on ultrasonography was 38.8% at 6 months, 58.1% at 12 months, 69.3% at 24 months, and 73.8% at 36 months. Of 58 recurrent episodes, 41 occurred while the patient had residual thrombosis. The hazard ratio for recurrent thromboembolism was 2.4 (95% CI, 1.3 to 4.4; P = 0.004) for patients with persistent residual thrombosis versus those with early vein recanalization. CONCLUSIONS: Residual venous thrombosis is an important risk factor for recurrent thromboembolism. Ultrasonographic assessment of residual venous thrombosis may help clinicians modify the duration of anticoagulation in patients with DVT.