Risk Factors for Pulmonary Embolism in Patients with Acute Exacerbation of COPD: A Systematic Review and Meta-analysis

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and acute exacerbation of COPD significantly impact both patients and healthcare systems. Patients with acute exacerbation of COPD are at a well-documented increased risk of pulmonary embolism (PE). However, the clinical manifestations of PE in these patients are frequently nonspecific, resulting in a significant risk of underdiagnosis. The primary objective of this study was to perform a systematic meta-analysis to identify potential risk factors for PE in patients with acute exacerbation of COPD. A systematic literature search was performed in PubMed, Web of Science, EMBASE, and the Cochrane Library from inception to November 2024. Two independent reviewers screened studies, reviewed full texts, and extracted data. Risk factors were identified, and odds ratio (OR) with 95% confidence interval (CI) were calculated. All statistical analyses were conducted using Review Manager 5.2. From the 7,440 articles identified, 14 studies met the predefined inclusion criteria and were included in the final analysis. The pooled analysis revealed that the following factors were significantly associated with an elevated risk of PE in patients experiencing acute exacerbation of COPD: deep vein thrombosis (DVT; OR = 5.32, 95% CI: 2.83–10.00, p < 0.001), elevated D-dimer levels (OR = 2.01, 95% CI: 1.47–2.73, p < 0.001), immobilization for >3 to 7 days (OR = 6.21, 95% CI: 2.57–15.01, p < 0.001), elevated lactate dehydrogenase (LDH) levels (OR = 1.01, 95% CI: 1.00–1.01, p < 0.001), lower limb asymmetry (OR = 2.51, 95% CI: 1.63–3.86, p = 0.040), PaCO2 < 36 mm Hg (OR = 1.73, 95% CI: 1.24–2.40, p = 0.001), and PaO2 < 80 mm Hg (OR = 1.03, 95% CI: 1.01–1.05, p = 0.0008). The following factors are identified as risk factors for PE in patients with acute exacerbation of COPD: DVT, elevated D-dimer levels, immobilization for >3 to 7 days, elevated LDH levels, lower limb asymmetry, PaCO2 < 36 mm Hg, and PaO2 <80 mm Hg. Our findings help to refine risk prediction and improve risk stratification for PE in patients with acute exacerbation of COPD in clinical practice.