Lidwine W. Tick

Further validation and simplification of the Wells clinical decision rule in pulmonary embolism

The Wells rule is a widely applied clinical decision rule in the diagnostic work-up of patients with suspected pulmonary embolism (PE). The objective of this study was to replicate, validate and possibly simplify this rule. We used data collected in 3,306 consecutive patients with clinically suspected PE to recalculate the odds ratios for the variables in the rule, to calculate the proportion of patients with PE in the probability categories, the area under the ROC curve and the incidence of venous thromboembolism during follow-up. We compared these measures with those for a modified and a simplified version of the decision rule. In the replication, the odds ratios in the logistic regression model were found to be lower for each of the seven individual variables (p = 0.02) but the proportion of patients with PE in the probability categories in our study group were comparable to those in the original derivation and validation groups. The area under the ROC of the original, modified and simplified decision rule was similar: 0.74 (p = 0.99; p = 0.07). The venous thromboembolism incidence at three months in the group of patients with a Wells score < or = 4 and a normal D-dimer was 0.5%, versus 0.3% with a modified rule and 0.5% with a simplified rule. The proportion of patients safely excluded for PE was 32%, versus 31% and 30%, respectively. This study further validates the diagnostic utility of the Wells rule and indicates that the scoring system can be simplified to one point for each variable.

Practical Diagnostic Management of Patients with Clinically Suspected Deep Vein Thrombosis by Clinical Probability Test, Compression Ultrasonography, and D-dimer Test

PURPOSE To evaluate a new noninvasive diagnostic strategy for ruling out deep vein thrombosis consisting of either a combination of low clinical probability and normal ultrasonography or a combination of moderate-to-high clinical probability, normal ultrasonography, and a normal D-dimer test. SUBJECTS AND METHODS We studied 811 patients with clinically suspected deep vein thrombosis using a diagnostic management strategy that combined clinical probability, ultrasonography, and measurement of D-dimers. The primary endpoint was venous thromboembolism occurring during a 3-month follow-up. RESULTS Of the 280 patients (35%) with a low clinical probability, 30 (11%) had an abnormal initial ultrasonography and were treated. Of the other 250 untreated patients with low clinical probability and a normal ultrasonography, 5 (2%; 95% confidence interval [CI]: 1% to 5%) developed a nonfatal venous thromboembolism during follow-up. Of the 531 patients (65%) with a moderate-to-high clinical probability, 300 (56%) had an abnormal ultrasonography. Of the remaining 231 patients with a normal ultrasonography, 148 had a normal D-dimer test; none of these patients developed deep vein thrombosis during follow-up (0%; 95% CI: 0% to 3%). Of the 83 patients with an abnormal D-dimer test, 77 underwent repeat ultrasonography about 1 week later; none of the 64 patients with a second normal ultrasound developed symptomatic deep vein thrombosis during follow-up (0%; 95% CI: 0% to 6%). CONCLUSIONS This management strategy, which combines clinical probability, ultrasonography, and D-dimer measurements, is practical and safe in ruling out deep vein thrombosis in patients with clinically suspected thrombosis and reduces the need for repeat ultrasonography.

Accuracy of clinical decision rule, D‐dimer and spiral computed tomography in patients with malignancy, previous venous thromboembolism, COPD or heart failure and in older patients with suspected pulmonary embolism

Summary.  Background: The diagnostic work‐up of patients with suspected pulmonary embolism (PE) has been optimized and simplified by the use of clinical decision rules (CDR), D‐dimer (DD) testing and spiral computed tomography (s‐CT). Whether this strategy is equally safe and efficient in specific subgroups of patients is evaluated in this study. Methods: A diagnostic strategy including a CDR, DD test and s‐CT was evaluated in patients with malignancy, previous venous thromboembolism (VTE), chronic obstructive pulmonary disease or heart failure and in older patients. PE was ruled out by either an unlikely CDR and a normal DD or a s‐CT negative for PE. The safety of these tests was assessed by the 3‐month incidence rate of symptomatic VTE in those without PE at baseline. The efficiency was evaluated by calculating the numbers needed to test for the different subgroups. Results: The venous thromboembolic incidence rate after the combination of an unlikely CDR and a normal DD varied from 0% (95% CI: 0–7.9%) in the 482 patients older than 75 years of age to 2% (95% CI: 0.05–10.9%) in the 474 patients with a malignancy. For s‐CT these incidences varied from 0.3% to 1.8%. The number needed to test in order to rule out one patient from PE with the studied strategy was highest in cancer patients and in the elderly patients (approximately 10). Conclusion: It appears to be safe to rule out PE by either the combination of an unlikely CDR and a normal DD or by a negative s‐CT in various subgroups of patients with suspected PE. However, the clinical usefulness of the CDR in combination with the DD as the initial step in the diagnostic process varied among these patient groups.

A simple diagnostic strategy in hospitalized patients with clinically suspected pulmonary embolism

Objectives.  Diagnostic strategies in patients with suspected pulmonary embolism have been extensively studied in outpatients; their value in hospitalized patients has not been well established. Our aim was to determine the safety and clinical utility of a simple diagnostic strategy in hospitalized patients with suspected pulmonary embolism.

High D-dimer levels increase the likelihood of pulmonary embolism.

Objective.  To determine the utility of high quantitative D‐dimer levels in the diagnosis of pulmonary embolism.

Clinically suspected acute recurrent pulmonary embolism: A diagnostic challenge

It is unknown whether strategies validated for diagnosing pulmonary embolism (PE) are valid in patients with a history of PE. It was the objective of this study to investigate whether a diagnostic algorithm consisting of sequential application of a clinical decision rule (CDR), a quantitative D-dimer test and computed tomography (CT) safely ruled out a clinical suspicion of acute recurrent PE. Data were obtained from a diagnostic outcome study of patients suspected of PE. Acute recurrent PE was ruled out by an unlikely probability of PE (CDR score </= 4 points) combined with a normal D-dimer test (</= 500 ng/ml) or by a normal CT in all other patients. The primary outcome was the incidence of acute recurrent venous thromboembolism during three months of follow-up in patients with normal tests and not treated with anticoagulants. Of 3,306 patients suspected of acute PE, 259 patients (7.8%) had a history of PE of whom 234 were not treated with anticoagulants. The probability of PE was unlikely in 82 of 234 patients (35%), and 42 had a normal D-dimer test (18%), excluding recurrent PE. None of these patients had a thrombotic event during follow-up (0%, 95%CI: 0-6.9). A CT was indicated in all other patients (192) and ruled out recurrent PE in 127 patients (54%). Only one patient with a negative CT had a fatal recurrent PE during follow-up (0.8%; 95%CI: 0.02-4.3). In conclusion, this prospective study demonstrates the safety of ruling out a clinical suspicion of acute recurrent PE by a simple diagnostic algorithm in patients with a history of PE.

Excluding pulmonary embolism without imaging tests – Can our diagnostic algorithm be optimized?

Excluding pulmonary embolism without imaging tests – Can our diagnostic algorithm be optimized? -

Clinical and economic impact of compression in the acute phase of deep vein thrombosis

Essentials The value of compression therapy in acute phase of deep vein thrombosis is still unclear. Patients with deep vein thrombosis received acute compression hosiery, bandaging, or none. Acute compression reduces irreversible skin signs related to post thrombotic syndrome. Compression hosiery may be the preferred choice for the acute phase

Residual vein occlusion in relation to immediate compression and postthrombotic syndrome in deep vein thrombosis

Thus far, the association between residual vein occlusion and immediate compression therapy and postthrombotic syndrome is undetermined. Therefore, we investigated whether compression therapy immediately after diagnosis of deep vein thrombosis affects the occurrence of residual vein obstruction (RVO), and whether the presence of RVO is associated with postthrombotic syndrome and recurrent venous thromboembolism. In a prespecified substudy within the IDEAL (individualized duration of elastic compression therapy against long-term duration of therapy for prevention of postthrombotic syndrome) deep vein thrombosis (DVT) study, 592 adult patients from 10 academic and nonacademic centers across The Netherlands, with objectively confirmed proximal DVT of the leg, received no compression or acute compression within 24 hours of diagnosis of DVT with either multilayer bandaging or compression hosiery (pressure, 35 mm Hg). Presence of RVO and recurrent venous thromboembolism was confirmed with compression ultrasonography and incidence of postthrombotic syndrome as a Villalta score of at least 5 at 6 and 24 months. The average time from diagnosis until assessment of RVO was 5.3 (standard deviation, 1.9) months. A significantly lower percentage of patients who did receive compression therapy immediately after DVT had RVO (46.3% vs 66.7%; odds ratio, 0.46; 95% confidence interval, 0.27-0.80; P = .005). Postthrombotic syndrome was less prevalent in patients without RVO (46.0% vs 54.0%; odds ratio, 0.65; 95% confidence interval, 0.46-0.92; P = .013). Recurrent venous thrombosis showed no significant association with RVO. Immediate compression should therefore be offered to all patients with acute DVT of the leg, irrespective of severity of complaints. This study was registered at ClinicalTrials.gov (NCT01429714) and the Dutch Trial registry in November 2010 (NTR2597).