Division of Angiology and Hemostasis, Geneva University Hospital, Geneva, Switzerland.
Department of Vascular Medicine, Amsterdam Medical Center, Amsterdam, the Netherlands.
JAMA. 2014 Mar 19;311(11):1117-24. doi: 10.1001/jama.2014.2135.
D-dimer measurement is an important step in the diagnostic strategy of clinically suspected acute pulmonary embolism (PE), but its clinical usefulness is limited in elderly patients.
To prospectively validate whether an age-adjusted D-dimer cutoff, defined as age × 10 in patients 50 years or older, is associated with an increased diagnostic yield of D-dimer in elderly patients with suspected PE.
DESIGN, SETTINGS, AND PATIENTS: A multicenter, multinational, prospective management outcome study in 19 centers in Belgium, France, the Netherlands, and Switzerland between January 1, 2010, and February 28, 2013.
All consecutive outpatients who presented to the emergency department with clinically suspected PE were assessed by a sequential diagnostic strategy based on the clinical probability assessed using either the simplified, revised Geneva score or the 2-level Wells score for PE; highly sensitive D-dimer measurement; and computed tomography pulmonary angiography (CTPA). Patients with a D-dimer value between the conventional cutoff of 500 µg/L and their age-adjusted cutoff did not undergo CTPA and were left untreated and formally followed-up for a 3-month period.
The primary outcome was the failure rate of the diagnostic strategy, defined as adjudicated thromboembolic events during the 3-month follow-up period among patients not treated with anticoagulants on the basis of a negative age-adjusted D-dimer cutoff result.
Of the 3346 patients with suspected PE included, the prevalence of PE was 19%. Among the 2898 patients with a nonhigh or an unlikely clinical probability, 817 patients (28.2%) had a D-dimer level lower than 500 µg/L (95% CI, 26.6%-29.9%) and 337 patients (11.6%) had a D-dimer between 500 µg/L and their age-adjusted cutoff (95% CI, 10.5%-12.9%). The 3-month failure rate in patients with a D-dimer level higher than 500 µg/L but below the age-adjusted cutoff was 1 of 331 patients (0.3% [95% CI, 0.1%-1.7%]). Among the 766 patients 75 years or older, of whom 673 had a nonhigh clinical probability, using the age-adjusted cutoff instead of the 500 µg/L cutoff increased the proportion of patients in whom PE could be excluded on the basis of D-dimer from 43 of 673 patients (6.4% [95% CI, 4.8%-8.5%) to 200 of 673 patients (29.7% [95% CI, 26.4%-33.3%), without any additional false-negative findings.
Compared with a fixed D-dimer cutoff of 500 µg/L, the combination of pretest clinical probability assessment with age-adjusted D-dimer cutoff was associated with a larger number of patients in whom PE could be considered ruled out with a low likelihood of subsequent clinical venous thromboembolism.
clinicaltrials.gov Identifier: NCT01134068.
D-二聚体检测是临床疑似急性肺栓塞（PE）诊断策略中的重要步骤，但在老年患者中的临床应用价值有限。
前瞻性验证年龄校正的 D-二聚体截断值（50 岁及以上患者为年龄×10）是否与老年疑似 PE 患者 D-二聚体的诊断收益增加相关。
设计、地点和患者：2010 年 1 月 1 日至 2013 年 2 月 28 日期间，在比利时、法国、荷兰和瑞士的 19 个中心进行的一项多中心、多国前瞻性管理结局研究。
所有连续就诊的急诊科疑似 PE 患者均采用基于简化修订版日内瓦评分或 2 级 Wells 评分评估的临床可能性的序贯诊断策略；高敏 D-二聚体检测；以及计算机断层肺动脉造影（CTPA）。D-二聚体值在常规截断值 500μg/L 和年龄校正截断值之间的患者未行 CTPA，且未接受抗凝治疗，进行为期 3 个月的正式随访。
主要结局为诊断策略失败率，定义为根据阴性年龄校正 D-二聚体截断值结果未接受抗凝治疗的患者在 3 个月随访期间发生的有明确诊断的血栓栓塞事件。
3346 例疑似 PE 患者中，PE 的患病率为 19%。在 2898 例非高或不太可能有临床可能性的患者中，817 例（28.2%）D-二聚体水平低于 500μg/L（95%CI，26.6%-29.9%），337 例（11.6%）D-二聚体在 500μg/L 和年龄校正截断值之间（95%CI，10.5%-12.9%）。D-二聚体水平高于 500μg/L 但低于年龄校正截断值的患者中，3 个月失败率为 1 例（0.3%[95%CI，0.1%-1.7%]）。在 766 例 75 岁及以上的患者中，其中 673 例有非高临床可能性，使用年龄校正截断值而非 500μg/L 截断值，可排除基于 D-二聚体诊断 PE 的患者比例从 673 例中的 43 例（6.4%[95%CI，4.8%-8.5%]）增加到 673 例中的 200 例（29.7%[95%CI，26.4%-33.3%），而无任何额外的假阴性发现。
与固定的 500μg/L D-二聚体截断值相比，联合应用预测前临床概率评估和年龄校正 D-二聚体截断值可使更多的患者可以认为排除 PE，其后续发生临床静脉血栓栓塞的可能性较低。
clinicaltrials.gov 标识符：NCT01134068。
