Fabio Verlato

D-dimer testing as an adjunct to ultrasonography in patients with clinically suspected deep vein thrombosis: prospective cohort study

Abstract Objective To investigate the efficacy of using a rapid plasma D-dimer test as an adjunct to compression ultrasound for diagnosing clinically suspected deep vein thrombosis. Design D-dimer concentrations were determined in all patients with a normal ultrasonogram at presentation. Repeat ultrasonography was performed 1 week later only in patients with abnormal D-dimer test results. Main outcome measure Patients with normal ultrasonograms were not treated with anticoagulants and were followed for 3 months for thromboembolic complications. Setting University research and affiliated centres. Subjects 946 patients with clinically suspected deep vein thrombosis. Results Ultrasonograms were abnormal at presentation in 260 (27.5%) patients. Of the remaining 686 patients tested for D-dimer, 88 (12.8%) had abnormal concentrations. During follow up venous thromboembolic complications occurred in one of the 598 patients who were not treated with anticoagulants and who had an initial normal ultrasonogram and D-dimer concentration, whereas thromboembolic complications occurred in two of the 83 untreated patients who had abnormal D-dimer concentrations but a normal repeat ultrasonogram. The cumulative incidence of venous thromboembolic complications during follow up was 0.4% (95% confidence interval 0% to 0.9%). The rapid plasma D-dimer test used as an adjunct to compression ultrasonography resulted in a reduction in the mean number of repeat ultrasound examinations and additional hospital visits from 0.7 to 0.1 per patient. Conclusions Testing for D-dimer as an adjunct to a normal baseline ultrasound examination decreased the number of subsequent ultrasound examinations considerably without any increased risk of venous thromboembolic complications in patients not receiving anticoagulants. The use of ultrasound and testing for D-dimer enabled treatment decisions to be made at the time of presentation in most patients.

Serial 2-Point Ultrasonography Plus D-Dimer vs Whole-Leg Color-Coded Doppler Ultrasonography for Diagnosing Suspected Symptomatic Deep Vein Thrombosis: A Randomized Controlled Trial

CONTEXT Patients with suspected deep vein thrombosis (DVT) of the lower extremities are usually investigated with ultrasonography either by the proximal veins (2-point ultrasonography) or the entire deep vein system (whole-leg ultrasonography). The latter approach is thought to be better based on its ability to detect isolated calf vein thrombosis; however, it requires skilled operators and is mainly available only during working hours. No randomized comparisons are yet available evaluating the relative values of these 2 strategies. OBJECTIVE To assess if the 2 diagnostic strategies are equivalent for the management of symptomatic outpatients with suspected DVT of the lower extremities. DESIGN, SETTING, AND PATIENTS A prospective, randomized, multicenter study of consecutive symptomatic outpatients (n = 2465) with a first episode of suspected DVT of the lower extremities who were randomized to undergo 2-point or whole-leg ultrasonography. Data were taken from ultrasound laboratories of 14 Italian universities or civic hospitals between January 1, 2003, and December 21, 2006. Patients with normal ultrasound findings were followed up for 3 months, with study completion on March 20, 2007. MAIN OUTCOME MEASURE Objectively confirmed 3-month incidence of symptomatic venous thromboembolism in patients with an initially normal diagnostic workup. RESULTS Of 2465 eligible patients, 345 met 1 or more exclusion criteria and 22 refused to participate; therefore, 2098 patients were randomized to either 2-point (n = 1045) or whole-leg (n = 1053) ultrasonography. Symptomatic venous thromboembolism occurred in 7 of 801 patients (incidence, 0.9%; 95% confidence interval [CI], 0.3%-1.8%) in the 2-point strategy group and in 9 of 763 patients (incidence, 1.2%; 95% CI, 0.5%-2.2%) in the whole-leg strategy group. This met the established equivalence criterion (observed difference, 0.3%;95% CI, -1.4% to 0.8%). CONCLUSION The 2 diagnostic strategies are equivalent when used for the management of symptomatic outpatients with suspected DVT of the lower extremities. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00353093.

An unexpectedly high rate of pulmonary embolism in patients with superficial thrombophlebitis of the thigh

PURPOSE The rate of objectively proven pulmonary embolism in patients with thrombophlebitis of the greater saphenous vein was studied. METHODS Consecutive ambulant patients with thrombophlebitis of the greater saphenous vein, involving the above-knee segment, underwent a complete venous echo color Doppler examination of the lower limbs, perfusion lung scanning, and chest radiography. A high probability of pulmonary embolism was defined as the presence of two or more large segmental defects, one large and two or more moderate perfusion defects, or four or more moderate perfusion defects, with no corresponding abnormality found by means of chest radiography. RESULTS Of the 21 patients included in the study, findings compatible with a high probability of pulmonary embolism were detected in seven patients (33.3%; 95% CI, 14.6 to 57. 0), although clinical symptoms of pulmonary embolism were present only in one patient. No association was found between the presence of thrombosis at the saphenofemoral junction and the risk for pulmonary embolism. CONCLUSION The rate of pulmonary embolism in patients with thrombophlebitis of the greater saphenous vein is unexpectedly high. This risk is similarly high in patients with thrombosis at the saphenofemoral junction and in patients without thrombosis at the saphenofemoral junction. Our results are consistent with those of other recent investigations and suggest that superficial thrombophlebitis of the thigh is not as benign a disease entity as previously described.