Prognostic value of fibrinogen in patients with coronary artery disease and prediabetes or diabetes following percutaneous coronary intervention: 5-year findings from a large cohort study

BACKGROUND: Fibrinogen (FIB) is an independent risk factor for mortality and cardiovascular events in the general population. However, the relationship between FIB and long-term mortality among CAD patients undergoing PCI remains unclear, especially in individuals complicated with diabetes mellitus (DM) or prediabetes (Pre-DM). METHODS: 6,140 patients with CAD undergoing PCI were included in the study and subsequently divided into three groups according to FIB levels (FIB-L, FIB-M, FIB-H). These patients were further grouped by glycemic status [normoglycemia (NG), Pre-DM, DM]. The primary endpoint was all-cause mortality. The secondary endpoint was cardiac mortality. RESULTS: FIB was positively associated with hemoglobin A1c (HbA1c) and fasting blood glucose (FBG) in CAD patients with and without DM (P < 0.001). During a median follow-up of 5.1 years (interquartile range 5.0–5.2 years), elevated FIB was significantly associated with long-term all-cause mortality (adjusted HR: 1.86; 95% CI 1.28–2.69; P = 0.001) and cardiac mortality (adjusted HR: 1.82; 95% CI 1.15–2.89; P = 0.011). Similarly, patients with DM, but not Pre-DM, had increased risk of all-cause and cardiac mortality compared with NG group (all P < 0.05). When grouped by both FIB levels and glycemic status, diabetic patients with medium and high FIB levels had higher risk of mortality [(adjusted HR: 2.57; 95% CI 1.12–5.89), (adjusted HR: 3.04; 95% CI 1.35–6.82), all P < 0.05]. Notably, prediabetic patients with high FIB also had higher mortality risk (adjusted HR: 2.27; 95% CI 1.01–5.12). CONCLUSIONS: FIB was independently associated with long-term all-cause and cardiac mortality among CAD patients undergoing PCI, especially in those with DM and Pre-DM. FIB test may help to identify high-risk individuals in this specific population. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12933-021-01335-1.