近日，加拿大朱拉文斯基医院Clive Kearon团队研究了临床概率与D-二聚体对肺栓塞的诊断。这一研究成果发表在2019年11月28日出版的国际学术期刊《新英格兰医学杂志》上。

回顾性分析表明，低临床验前概率（C-PTP）患者D-二聚体水平低于1000 ng/mL，中C-PTP患者D-二聚体水平低于500 ng/mL时，即可排除肺栓塞。

研究组进行了一项前瞻性研究，招募了2017名参与者，并采用上述标准进行评估，无法排除肺栓塞的患者则接受胸部成像。未诊断出肺栓塞的患者不进行抗凝治疗。

7.4%的患者在最初的诊断测试中确诊肺栓塞。在1285例低C-PTP和40例中C-PTP且D-二聚体阴性（分别低于1000或500 ng/mL）的患者中，没有一例在3个月的随访期间发生静脉血栓栓塞。包括315名低C-PTP且D-二聚体水平为500-999 ng/mL的患者。

在1863名未接受初始肺栓塞诊断也未接受抗凝治疗的患者中，有1例（0.05%）患者发生静脉血栓栓塞。研究组的诊断策略导致34.3%的患者使用胸部成像，而如果采用低C-PTP且D-二聚体水平低于500 ng/mL来排除肺栓塞，则胸部成像的使用率为51.9%。

综上，低C-PTP和D-二聚体水平低于1000 ng/mL的患者在随访期间发生肺栓塞的风险较低。

附：英文原文

Title: Diagnosis of Pulmonary Embolism with d-Dimer Adjusted to Clinical Probability

Author: Clive Kearon, M.B., Ph.D.,, Kerstin de Wit, M.B.,, Sameer Parpia, Ph.D.,, Sam Schulman, M.D., Ph.D.,, Marc Afilalo, M.D.,, Andrew Hirsch, M.D.,, Frederick A. Spencer, M.D.,, Sangita Sharma, M.D.,, Frédérick D’Aragon, M.D.,, Jean-Franois Deshaies, M.D.,, Gregoire Le Gal, M.D., Ph.D.,, Alejandro Lazo-Langner, M.D.,, Cynthia Wu, M.D.,, Lisa Rudd-Scott, R.N.,, Shannon M. Bates, M.D.,, and Jim A. Julian, M.Math.

Issue&Volume: 2019-11-27

Abstract: 

BACKGROUND
Retrospective analyses suggest that pulmonary embolism is ruled out by a d-dimer level of less than 1000 ng per milliliter in patients with a low clinical pretest probability (C-PTP) and by a d-dimer level of less than 500 ng per milliliter in patients with a moderate C-PTP.

METHODS
We performed a prospective study in which pulmonary embolism was considered to be ruled out without further testing in outpatients with a low C-PTP and a d-dimer level of less than 1000 ng per milliliter or with a moderate C-PTP and a d-dimer level of less than 500 ng per milliliter. All other patients underwent chest imaging (usually computed tomographic pulmonary angiography). If pulmonary embolism was not diagnosed, patients did not receive anticoagulant therapy. All patients were followed for 3 months to detect venous thromboembolism.

RESULTS
A total of 2017 patients were enrolled and evaluated, of whom 7.4% had pulmonary embolism on initial diagnostic testing. Of the 1325 patients who had a low C-PTP (1285 patients) or moderate C-PTP (40 patients) and a negative d-dimer test (i.e., <1000 or <500 ng per milliliter, respectively), none had venous thromboembolism during follow-up (95% confidence interval [CI], 0.00 to 0.29%). These included 315 patients who had a low C-PTP and a d-dimer level of 500 to 999 ng per milliliter (95% CI, 0.00 to 1.20%). Of all 1863 patients who did not receive a diagnosis of pulmonary embolism initially and did not receive anticoagulant therapy, 1 patient (0.05%; 95% CI, 0.01 to 0.30) had venous thromboembolism. Our diagnostic strategy resulted in the use of chest imaging in 34.3% of patients, whereas a strategy in which pulmonary embolism is considered to be ruled out with a low C-PTP and a d-dimer level of less than 500 ng per milliliter would result in the use of chest imaging in 51.9% (difference, −17.6 percentage points; 95% CI, −19.2 to −15.9).

CONCLUSIONS
A combination of a low C-PTP and a d-dimer level of less than 1000 ng per milliliter identified a group of patients at low risk for pulmonary embolism during follow-up. (Funded by the Canadian Institutes of Health Research and others; PEGeD ClinicalTrials.gov number, NCT02483442. opens in new tab.)

DOI: 10.1056/NEJMoa1909159

Source: https://www.nejm.org/doi/full/10.1056/NEJMoa1909159