The standard diagnostic approach of patients with clinically suspected acute pulmonary embolism (PE) relies on sequential diagnostic tests, such as clinical probability assessment, plasma D-dimer measurement, compression ultrasonography, computed tomography pulmonary angiography (CTPA), or ventilation-perfusion lung scan.^1,2

Summary. Background: Pretest probability assessment is necessary to identify patients in whom pulmonary embolism (PE) can be safely ruled out by a negative D‐dimer without further investigations. Objective: Review and compare the performance of available clinical prediction rules (CPRs) for PE probability assessment. Patients/methods: We identified studies that evaluated a CPR in patients with suspected PE from Embase, Medline and the Cochrane database. We determined the 95% confidence intervals (CIs) of prevalence of PE in the various clinical probability categories of each CPR. Statistical heterogeneity was tested. Results: We identified 9 CPR and included 29 studies representing 31215 patients. Pooled prevalence of PE for three‐level scores (low, intermediate or high clinical probability) was: low, 6% (95% CI, 4–8), intermediate, 23% (95% CI, 18–28) and high, 49% (95% CI, 43–56) for the Wells score; low, 13% (95% CI, 8–19), intermediate, 35% (95% CI, 31–38) and high, 71% (95% CI, 50–89) for the Geneva score; low, 9% (95% CI, 8–11), intermediate, 26% (95% CI, 24–28) and high, 76% (95% CI, 69–82) for the revised Geneva score. Pooled prevalence for two‐level scores (PE likely or PE unlikely) was 8% (95% CI,6–11) and 34% (95% CI,29–40) for the Wells score, and 6% (95% CI, 3–9) and 23% (95% CI, 11–36) for the Charlotte rule. Conclusion: Available CPR for assessing clinical probability of PE show similar accuracy. Existing scores are, however, not equivalent and the choice among various prediction rules and classification schemes (three‐ versus two‐level) must be guided by local prevalence of PE, type of patients considered (outpatients or inpatients) and type of D‐dimer assay applied.

Data on the optimal diagnostic management of pregnant women with suspected pulmonary embolism (PE) are limited, and guidelines provide inconsistent recommendations on use of diagnostic tests. To prospectively validate a diagnostic strategy in pregnant women with suspected PE. Multicenter, multinational, prospective diagnostic management outcome study involving pretest clinical probability assessment, high-sensitivity D-dimer testing, bilateral lower limb compression ultrasonography (CUS), and computed tomography pulmonary angiography (CTPA). (ClinicalTrials.gov: NCT00740454) 11 centers in France and Switzerland between August 2008 and July 2016. Pregnant women with clinically suspected PE in emergency departments. Pulmonary embolism was excluded in patients with a low or intermediate pretest clinical probability and a negative D-dimer result. All others underwent lower limb CUS and, if results were negative, CTPA. A ventilation–perfusion (V/Q) scan was done if CTPA results were inconclusive. Pulmonary embolism was excluded if results of the diagnostic work-up were negative, and untreated pregnant women had clinical follow-up at 3 months. The primary outcome was the rate of adjudicated venous thromboembolic events during the 3-month follow-up. 441 women were assessed for eligibility, and 395 were included in the study. Among these, PE was diagnosed in 28 (7.1%) (proximal deep venous thrombosis found on ultrasound [n = 7], positive CTPA result [n = 19], and high-probability V/Q scan [n = 2]) and excluded in 367 (clinical probability and negative D-dimer result [n = 46], negative CTPA result [n = 290], normal or low-probability V/Q scan [n = 17], and other reason [n = 14]). Twenty-two women received extended anticoagulation during follow-up, mainly for previous venous thromboembolic disease. The rate of symptomatic venous thromboembolic events was 0.0% (95% CI, 0.0% to 1.0%) among untreated women after exclusion of PE on the basis of negative results on the diagnostic work-up. There were several protocol deviations, reflecting the difficulty of performing studies in pregnant women with suspected PE. A diagnostic strategy based on assessment of clinical probability, D-dimer measurement, CUS, and CTPA can safely rule out PE in pregnant women. Swiss National Foundation for Scientific Research, Groupe d'Etude de la Thrombose de Bretagne Occidentale, and International Society on Thrombosis and Haemostasis.

Summary: The standard diagnostic approach of suspected deep vein thrombosis (DVT) is serial lower limb compression ultrasound (CUS) of proximal veins. Although it only assesses the proximal veins, withholding anticoagulant treatment in patients with a negative CUS on day one and after one week has been proven to be safe. However, in many centres, distal DVT is systematically screened for and treated by anticoagulants. The objectives of the review were 1) to evaluate the rate of extension of distal DVTs to proximal veins 2) to compare the safety of proximal limited CUS versus single complete CUS. We performed a MEDLINE search covering the period from January 1983 to January 2005 by using the key-words “calf vein thrombosis”, “distal thrombosis” and “compression ultrasonography”. English, German and French language original studies were retrieved. Moreover, references of retrieved articles were screened in order to detect missed pertinent articles. We pooled data of management studies where proximal or complete (i. e. proximal and distal) CUS were used, respectively. Studies evaluating CUS limited to the proximal veins showed a good safety profile with a pooled estimate of the 3-month thromboembolic rate of 0.6% (95% CI: 0.4–0.9%) in patients in whom anticoagulation was withheld. Studies using proximal and distal CUS showed a similar pooled estimate of the 3-month thromboembolic rate (0.4%, 95% CI: 0.1–0.6%) but distal DVT accounted for as many as 50% of all diagnosed DVTs in those series. Therefore, searching for distal DVT potentially doubles the number of patients given anticoagulant therapy and entails a risk of over-treatment. Data suggesting that anticoagulation is indicated for distal DVT are limited, and realizing distal CUS entails a risk of over-treatment. There is an urgent need for randomised trials assessing the usefulness of anticoagulant treatment in distal DVT.