Blood fibrinogen level as a biomarker of adverse outcomes in patients with coronary artery disease: A systematic review and meta-analysis

BACKGROUND: The association between elevated fibrinogen level and adverse outcomes in patients with coronary artery disease (CAD) remains conflicting. This systematic review and meta-analysis aims to evaluate the association between fibrinogen level and adverse outcomes in CAD patients. METHODS: Relevant studies were identified by searching PubMed, Web of Science, and Embase databases from their inception to September 30, 2021. Observational studies that investigated the association of blood fibrinogen level with cardiovascular death, all-cause mortality, and major adverse cardiovascular events were eligible. RESULTS: A total of 20,395 CAD patients from 15 articles (13 studies) were included. Comparison with the highest and the lowest fibrinogen level indicated that elevated fibrinogen level was associated with higher risk of cardiovascular death (risk ratio [RR] 2.24; 95% confidence interval [CI] 1.69–2.98), all-cause mortality (RR 1.88; 95% CI 1.50–2.36), and major adverse cardiovascular events (RR 1.46; 95% CI 1.18–1.81). CONCLUSION: Elevated fibrinogen level is significantly associated with an increased risk of cardiovascular and all-cause mortality in patients with CAD. Baseline fibrinogen level can serve as a promising biomarker for risk stratification of CAD.