Ruling Out Pulmonary Embolism During Pregnancy:a Multicenter Outcome Study
Condition: Pulmonary Embolism; Deep Vein Thrombosis
MeSH terms: Pulmonary Embolism; Thrombosis; Embolism; Venous Thrombosis
Study type: Observational

Summary: 
      Venous thromboembolism (VTE) remains a major cause of maternal morbidity and mortality in
      developed countries. Objective diagnosis of pulmonary embolism (PE) and/or deep vein
      thrombosis (DVT) in pregnancy is crucial. Failure to identify PE or/or DVT will place the
      mother's life at risk, and unnecessary treatment will not only expose her to anticoagulants
      but will also label her as having had VTE. Thus, this diagnosis has serious implications for
      the management of her present pregnancy, and for other aspects of her life ranging from
      contraception to thromboprophylaxis in future pregnancies and hormone replacement therapy in
      later life. It is therefore critical that all women with symptoms or signs that suggest
      venous thromboembolism have appropriate investigation and diagnosis based on objective
      diagnostic tests.

      The current diagnostic approach in suspected PE is based on sequential diagnostic tests: 1)
      assessment of clinical probability, 2) fibrin D-dimer measurement, 3) compression
      ultrasonography of lower limb veins and 4) multi-slice computed tomography (MSCT). However,
      physicians are reluctant to perform MSCT in pregnant women because of potential adverse
      effect of radiation exposure to the fetus. For this reason, ventilation/perfusion or
      perfusion-only lung scan has been the cornerstone of PE diagnosis in pregnant women. Indeed,
      perfusion lung scan was assumed to be associated with less radiation than computed tomography
      (CT). However, this technique is now widely abandoned in the usual diagnostic strategy of PE
      for the following reasons: it is not widely available; its interpretation may be difficult
      and the test may be inconclusive in the presence of other chest abnormalities. Moreover,
      recent data convincingly show that the radiation exposure associated with single-slice or
      multi-slice CT exposes the fetus to less radiation than perfusion lung scan.

      However, the use of CT has never been adequately validated in pregnant women with clinically
      suspected PE. The investigators, therefore, plan to set up a prospective management study in
      which pregnant women with suspected PE will undergo a sequential diagnostic strategy based on
      1) assessment of clinical probability 2) D-dimer measurement 3) compression ultrasonography,
      and 4) MSCT.

      Nowadays, the overestimated fear of radiation exposure for the fetus leads to an irrational
      attitude and inadequate investigations in pregnant women with suspected PE, even though both
      European [3, 4] and North-American guidelines [5] suggest that only objective testing may
      accurately rule out the disease. The proposed study should lead to an increased awareness of
      the risks and benefits of appropriate imaging in pregnant women suspected of PE and should
      result in a more rational management of this under-studied patient group.
    

Detailed description: 
      Venous thromboembolism (VTE) remains a major cause of maternal morbidity and mortality in
      developed countries. Objective diagnosis of pulmonary embolism (PE) and/or deep vein
      thrombosis (DVT) in pregnancy is crucial. Failure to identify PE or/or DVT will place the
      mother's life at risk, and unnecessary treatment will not only expose her to anticoagulants
      but will also label her as having had VTE. Thus, this diagnosis has serious implications for
      the management of her present pregnancy, and for other aspects of her life ranging from
      contraception to thromboprophylaxis in future pregnancies and hormone replacement therapy in
      later life. It is therefore critical that all women with symptoms or signs that suggest
      venous thromboembolism have appropriate investigation and diagnosis based on objective
      diagnostic tests.

      Diagnosis of VTE on a clinical basis is unreliable, especially during pregnancy because leg
      swelling and mild dyspnea are frequent during normal pregnancy.

      The current diagnostic approach in suspected PE is based on sequential diagnostic tests: 1)
      assessment of clinical probability, 2) fibrin D-dimer measurement, 3) compression
      ultrasonography of lower limb veins and 4) multi-slice computed tomography (MSCT). However,
      physicians are reluctant to perform MSCT in pregnant women because of potential adverse
      effect of radiation exposure to the fetus. For this reason, ventilation/perfusion or
      perfusion-only lung scan has been the cornerstone of PE diagnosis in pregnant women. Indeed,
      perfusion lung scan was assumed to be associated with less radiation than computed tomography
      (CT). However, this technique is now widely abandoned in the usual diagnostic strategy of PE
      for the following reasons: it is not widely available; its interpretation may be difficult
      and the test may be inconclusive in the presence of other chest abnormalities. Moreover,
      recent data convincingly show that the radiation exposure associated with single-slice or
      multi-slice CT exposes the fetus to less radiation than perfusion lung scan.

      However, the use of CT has never been adequately validated in pregnant women with clinically
      suspected PE. We, therefore, plan to set up a prospective management study in which pregnant
      women with suspected PE will undergo a sequential diagnostic strategy based on 1) assessment
      of clinical probability 2) D-dimer measurement 3) compression ultrasonography, and 4) MSCT.

      Nowadays, the overestimated fear of radiation exposure for the fetus leads to an irrational
      attitude and inadequate investigations in pregnant women with suspected PE, even though both
      European and North-American guidelines suggest that only objective testing may accurately
      rule out the disease. The proposed study should lead to an increased awareness of the risks
      and benefits of appropriate imaging in pregnant women suspected of PE and should result in a
      more rational management of this under-studied patient group.
    

Intervention name(s): Pregnant patients with suspected PE will undergo a strategy based on clinical probability assessment, D-dimer, lower limb vein ultrasonography and MSCT.
Intervention type(s): Other
Intervention MeSH terms: Fibrin fragment D
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Pregnant women with suspected PE.
      
Biospecimen description: 
      Nt-pro BNP measurement
    
Keywords: Pregnancy; Pulmonary embolism; MSCT