The prevalence and risk factors of pulmonary embolism in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis.

Background: An increased prevalence of PE has been found in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD). Early identification of risk factors for the development of PE in patients with AECOPD and intervention is important. Therefore, we comprehensively pool and analyze the prevalence and risk factors of PE among patients experiencing AECOPD, aiming to provide valuable insights for clinical-based diagnostic determination and prevention of PE in the AECOPD patient population.

Methods: A systematic literature search was conducted for studies reporting the incidence and risk factors for PE in patients with AECOPD. Study quality was assessed using the modified Newcastle-Ottawa Quality Assessment Scale. The degree of heterogeneity was assessed by the I² statistic. The publication bias (studies ≥ 10) was evaluated using Egger's test.

Results: Among the 1421 studies initially retrieved, 22 articles were ultimately selected and incorporated into the analysis. Based on the meta-analysis and the review's updated findings, the prevalence of PE in AECOPD is 17.82% (95% CI 12.72%-23.57%, P<0.001). The following factors were identified as risk factors for PE among patients with AECOPD: age(weighted mean difference [WMD] 2.0119, 95% CI 0.7126-3.3133, I² = 51.8%, P = 0.02), males(odds ratio [OR] 0.9528, 95% CI 0.6869-1.3216, I² = 65.0%, P<0.001), obesity(OR 1.3086, 95% CI 0.1895-9.0385, I² = 74.5%, P = 0.02), malignant disease(OR 1.5902, 95%CI 0.9689-2.6097, I² = 54.7%, P = 0.03), hypertension(OR 1.0663, 95%CI 0.7920-1.4355, I² = 57.7%, P = 0.009), immobilization ≥ 3d(OR 3.9158, 95% CI 1.0925-14.0354, I² = 91.6%, P<0.001), edema of lower limb(OR 2.1558, 95% CI 1.3365-3.4773, I² = 75.4%, P<0.001), pulmonary hypertension(OR 1.3146, 95%CI 0.7481-2.3100, I² = 70.1%, P = 0.04), cough(OR 0.7084, 95%CI 0.1304-3.8497, I² = 88.8%, P<0.001), purulent sputum(OR 0.7570, 95%CI 0.4005-1.4309, I² = 61.9%, P = 0.049), and D-dimer(WMD 0.8619, 95%CI 0.0449-1.6789, I² = 91.4%, P<0.001), C-reactive protein(CRP)(WMD 0.8852, 95%CI -4.0639-5.8344, I² = 76.4%, P = 0.005) or fibrinogen(WMD 0.8663, 95%CI -0.2572-1.9898, I² = 92.2%, P<0.001) levels. Clinical risk factors(including S1Q3 pattern on electrocardiograph(ECG), hospital stay and home oxygen therapy) showed no significant association with the occurrence of PE (P>0.05).

Conclusions: This updated meta-analysis and systematic review revealed that the prevalence of pulmonary embolism in the AECOPD was 17.82%. This figure may vary depending on how the diagnostic procedure is carried out. Age, males, obesity, malignant disease, hypertension, immobilization ≥ 3d, edema of lower limb, pulmonary hypertension, cough, purulent sputum, and D-dimer, CRP or fibrinogen level may serve as potential risk factors for PE among patients with AECOPD.