Sequential Use of the LEFt Rule, D-dimer Measurement and Complete Ultrasonography to Rule Out Deep Vein Thrombosis During Pregnancy: a Prospective Outcome Study.
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 300
- 试验地点
- 1
- 主要终点
- The main outcome will be the number of thromboembolic recurrent events (DVT, PE, death attributable to venous thromboembolic disease) documented during the three-month follow-up in the patients left untreated on the basis of a normal diagnostic strategy.
研究概览
简要总结
In pregnant women with suspected DVT, a sure diagnosis is mandatory. In non-pregnant patients, sequential diagnostic strategies based on 1) the assessment of clinical probability, 2) D-dimer measurement and 3) compression ultrasonography (CUS) have been well validated.
Clinical probability assessment by clinical prediction rules (CPRs) is a crucial step in the management of suspected DVT. However, the most commonly used CPR for DVT, the Wells' score, has never been validated in pregnant women. Recently, the 'LEFt' clinical prediction rule was derived and internally validated. A prospective validation of this rule is now warranted, and we plan to use it in our prospective study.
The second step used in the diagnostic strategy including non-pregnant patients is D-dimer measurement. The test has been widely validated in non-pregnant patients and, in association with a non-high clinical probability, it allows to safely rule out DVT.
As D-dimer level raise steadily during pregnancy, the specificity of the test decreases and it is less useful in pregnant women. Data from the literature clearly suggest that the usual cut-off set a 500 ng/ml would safely rule out DVT in pregnant women [6]. As the usual cut-off has never been prospectively validated in pregnant women with suspected DVT, we would like to use it in our study.
Some studies suggested that complete CUS is safe to rule out DVT in pregnant women. However, this test is not always available. Therefore, a strategy in which the association of clinical probability assessment and D-dimer measurement would allow to safely rule out DVT in a significant proportion of patients without performing a complete CUS, would be of great help in everyday clinical practice and would probably be cost-effective.
Therefore, we plan a prospective study to assess the safety of a sequential diagnostic strategy based on the assessment of clinical probability with the LEFt rule, D-dimer measurement and complete CUS in pregnant women with suspected DVT.
详细描述
In pregnant women with suspected DVT, a sure diagnosis is mandatory. Indeed, false positive tests lead to inappropriate anticoagulant treatment, which increases the risk of bleeding. Conversely, false negative tests might lead to a life-threatening thromboembolic event. Thus, accuracy of diagnostic methods used in pregnant women is crucial [1].
In non-pregnant patients, sequential diagnostic strategies based on 1) the assessment of clinical probability, 2) D-dimer measurement and 3) compression ultrasonography (CUS) have been widely validated [2, 3].
Clinical probability assessment by clinical prediction rules (CPRs) is a crucial step in the management of suspected DVT. However, the most commonly used CPR for DVT, the Wells' score, has never been validated in pregnant women [3]. Recently, the 'LEFt' clinical prediction rule was derived and internally validated by Chan et al. among 194 pregnant women investigated for suspected DVT[4]. This rule combines three variables: symptoms in the left leg ("L"), calf circumference difference equal or greater than 2 centimeters ("E" for edema) and first trimester presentation ("Ft") [4].
We performed an external validation of this rule on a recently published prospective cohort of pregnant patients with suspected DVT (submitted to JTH). This external validation showed that a negative "LEFt" rule accurately identified pregnant women in whom the proportion of confirmed DVT appears to be very low. A prospective validation of this rule is now warranted, and we plan to use it in our prospective study.
The second step used in the diagnostic strategy including non-pregnant patients is D-dimer measurement. The test has been widely validated in non-pregnant patients and, in association with a non-high clinical probability, it allows to safely rule out DVT [5].
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 否
入选标准
- •Pregnant women with clinically suspected DVT
排除标准
- •Age less than 18
- •No available informed consent
- •Associated suspicion of pulmonary embolism
- •Ongoing anticoagulant treatment
- •Planned anticoagulant treatment at therapeutic dosage during pregnancy
结局指标
主要结局
The main outcome will be the number of thromboembolic recurrent events (DVT, PE, death attributable to venous thromboembolic disease) documented during the three-month follow-up in the patients left untreated on the basis of a normal diagnostic strategy.
时间窗: 3 years
Rate of thromboembolic events after a normal diagnostic strategy.
次要结局
- Prospective evaluation of the diagnostic performances of the LEFt rule.(3 years)
- Prospective evaluation of D-dimer measurement to rule out DVT in pregnant women.(3 years)
研究者
Marc Righini
Principal investigator
University Hospital, Geneva