The utility of the Wells clinical prediction model and ventilation-perfusion scanning for pulmonary embolism diagnosis in pregnancy

Abstract

Pulmonary embolism is one of the leading causes of mortality in pregnancy in the Western world. No clinical prediction models have been validated in pregnancy. As a result, any pregnant woman presenting with signs possibly consistent with pulmonary embolism is investigated radiologically. This study investigates whether using clinical prediction models for pulmonary embolism in pregnancy should be pursued in future prospective trials. The aim of this study was to retrospectively evaluate the Wells clinical prediction model and ventilation-perfusion scanning for pulmonary embolism in pregnancy. A retrospective study was performed on consecutive pregnant women who presented with suspected pulmonary emboli and underwent ventilation perfusion scanning at two tertiary institutions from 2007 until 2010. The clinical pretest probability was determined as likely or unlikely by two independent clinicians retrospectively using Wells-modified criteria. Scans were determined as normal, nondiagnostic or high probability for pulmonary emboli independently by two experienced radiologists. Disagreements were resolved by a third assessor independently. In 183 pregnant women, the pretest probability was determined as 'pulmonary emboli likely' in 76 (42%) and 'pulmonary emboli unlikely' in 107 (58%) of women. Scans were of high probability in four (2%), nondiagnostic in six (3%) and normal in 173 (95%) of women. This gives the pretest probability using Wells-modified criteria a sensitivity of 100% [95% confidence interval (CI) 0.4-1.0] and a negative predictive value of 100% (95% CI 0.96-1.0). A structured clinical model such as modified Wells criteria may be useful in pregnancy, but further prospective evaluation is required.

Selecting pregnant or postpartum women with suspected pulmonary embolism for diagnostic imaging: the DiPEP diagnostic study with decision-analysis modelling

“…O'Connor et al 17 reported that a modified Wells's score of ≥ 6 units (meaning that PE is likely) has a sensitivity of 100% and a specificity of 90% for PE, whereas Cutts et al 8 reported a sensitivity of 100% (95% CI 40% to 100%) and a specificity of 60% (52% to 67%). The wide CIs for sensitivity mean that further research is required.…”

“…We have since updated the literature searches and have identified an additional four papers, along with the published version of the paper in press. 8 These are outlined in Table 1.…”

Treatment and diagnosis of pulmonary embolism in pregnancy

“…Klinik skorlama yöntemlerinden Wells kriterlerinin gebelikte kullanımıyla ilgili prospektif olarak kullanılmamıştır (9). Yüz seksen üç hastayı içeren retrospektif bir çalışma-da ise modifiye Wells kriterlerinin (PE olası ve PE olası değil) sensitivite ve negatif prediktif değeri %100 olarak bulunmuştur (10).…”

Diagnosis of pregnancy-associated venous thromboembolism - position paper of the Working Group in Women’s Health of the Society of Thrombosis and Haemostasis (GTH)

“…O'Connor et al published a retrospective analysis of 125 pregnant women who were referred for CT angiography [107], whereas Cutts et al retrospectively investigated 183 pregnant patients who underwent ventilation perfusion scanning for suspected PE [108]. In both studies, no patients with a Wells score of less than 6 points had confi rmed PE, corresponding to sensitivity and an NPV of 100 % [107,108]. Further prospective evaluation of this clinical prediction model is required.…”

“…Because pregnant women frequently develop leg swelling or dyspnoea unrelated to DVT or PE, and are less likely to have comorbidities included as risk factors in these models, these scores might not be applicable during pregnancy and cannot be recommended [50]. O'Connor et al published a retrospective analysis of 125 pregnant women who were referred for CT angiography [107], whereas Cutts et al retrospectively investigated 183 pregnant patients who underwent ventilation perfusion scanning for suspected PE [108]. In both studies, no patients with a Wells score of less than 6 points had confi rmed PE, corresponding to sensitivity and an NPV of 100 % [107,108].…”