Abstract:  Objective　To explore the risk factors of secondary pulmonary embolism (PE) in patients with chronic obstructive pulmonary disease (COPD) by Cox risk ratio model, and to provide references for early clinical identification of high-risk patients and early intervention. Methods　A total of 245 COPD patients were chosen from Chenzhou First People's Hospital from January 2019 to January 2021, including 143 males and 102 females, with an age of (58.6±10.3) years old. The follow-up time was 11.0-22.5 months. A total of 29 cases (11.84%) of secondary PE were diagnosed by CT pulmonary angiography, and the diagnosis time was recorded. The general clinical data, coagulation indicators, inflammatory markers, and CT pulmonary artery quantitative parameters of the PE group and the non-PE group were compared. The risk factors of secondary PE were analyzed by Cox risk analysis. χ² test was used for the count data and independent sample t test was used for the measurement data. Results　Comparison of the general clinical data showed that the PE group had higher proportions of severe pneumonia and heart failure, a lower proportion of prophylactic anticoagulant therapy, and a higher COPD severity grade, with statistically significant differences (all P<0.05). Comparison of the coagulation indicators found that the activated partial thromboplastin time (APTT) in the PE group decreased [(34.3±4.5) s vs. (41.6±4.8) s], the levels of D-dimer [(0.5±0.1) mg/L vs. (0.2±0.1) mg/L] and fibrinogen (FIB) [(4.2±0.4) g/L vs. (3.3±0.2) g/L] increased (all P<0.05). Comparison of the inflammatory markers found that the serum levels of high-sensitivity C-reactive protein (hs-CRP) [(9.8±1.3) mg/L vs. (6.5±1.1) mg/L], interleukin-6 (IL-6) [(56.5±12.3) mg/L vs.(42.2±9.6) mg/L], and tumor necrosis factor -α (TNF-α) [(35.6±8.7) mg/L vs. (22.4±6.5) mg/L] in the PE group increased (all P<0.05). Comparison of the CT pulmonary artery quantitative parameters found that the pulmonary artery pressure increased in the PE group [(45.6±6.3) mmHg vs. (38.9±5.4) mmHg (1 mmHg=0.133 kPa)], the blood perfusion velocity decreased [(21.8±4.7) cm/s vs. (32.4±5.2) cm/s], and the emphysema score increased [(8.6±2.4) points vs. (4.5±1.3) points] (all P<0.05). Cox analysis showed that no prophylactic anticoagulant therapy, higher COPD severity grade, high D-dimer level, high hs-CRP level, and low blood perfusion velocity were the main risk factors for secondary PE (all P<0.05). Conclusion　Patients with COPD who have not been treated with prophylactic anticoagulant therapy and have high COPD severity, high D-dimer level, high hs-CRP level, and low blood perfusion velocity should be paid more attention of secondary PE risk.

Key words: Cox risk ratio model, Chronic obstructive pulmonary disease, Pulmonary embolism

摘要： 目的　采用Cox风险比例模型探讨慢性阻塞性肺疾病（COPD）患者继发肺动脉栓塞（PE）的主要危险因素，为提高临床早期识别高危患者和早期干预提供参考依据。方法　选择2019年1月至2021年1月郴州市第一人民医院诊断COPD患者共245例，其中男143例，女102例，年龄（58.6±10.3）岁，随访时间11.0～22.5个月。采用CT肺动脉造影确诊继发PE共29例（11.84%），记录确诊PE的时间；比较PE组和非PE组患者的一般临床资料、凝血指标、炎症指标和CT肺动脉定量参数，采用Cox分析影响继发PE的主要危险因素。计数资料采用χ²检验，计量资料采用独立样本t检验。结果　一般临床资料比较发现，PE组重症肺炎和心力衰竭比例升高、预防性抗凝治疗比例较低、COPD严重分级较高，差异均有统计学意义（均P<0.05）；凝血指标比较发现，PE组活化部分凝血活酶时间（APTT）缩短［（34.3±4.5）s比（41.6±4.8）s］、D-二聚体［（0.5±0.1）mg/L比（0.2±0.1）mg/L］和纤维蛋白原（FIB）［（4.2±0.4）g/L比（3.3±0.2）g/L］水平均升高（均P<0.05）；炎症指标比较发现，PE组血清高敏C反应蛋白（hs-CRP）［（9.8±1.3）mg/L比（6.5±1.1）mg/L］、白介素-6（IL-6）［（56.5±12.3）mg/L比（42.2±9.6）mg/L］和肿瘤坏死因子-α（TNF-α）［（35.6±8.7）mg/L比（22.4±6.5）mg/L］水平均升高（均P<0.05）；CT肺动脉定量参数比较，PE组肺动脉压力升高［（45.6±6.3）mmHg比（38.9±5.4）mmHg（1 mmHg=0.133 kPa）］、血流灌注速度降低［（21.8±4.7）cm/s比（32.4±5.2）cm/s］、肺气肿评分增加［（8.6±2.4）分比（4.5±1.3）分］（均P<0.05）。经Cox分析发现，未进行预防性抗凝治疗、COPD严重分级较高、D-二聚体水平升高、hs-CRP水平升高、血流灌注速度降低均是继发PE的主要危险因素（均P<0.05）。结论　临床中针对未进行预防性抗凝治疗、COPD严重分级较高、D-二聚体水平升高、hs-CRP水平升高、血流灌注速度降低的COPD患者应高度警惕继发PE的风险。

关键词: Cox风险比例模型, 慢性阻塞性肺疾病, 肺动脉栓塞