Objectives: The B cell activating factor (BAFF) is a B cell survival factor involved in atherosclerosis and ischemia-reperfusion (IR) injury. This study sought to investigate whether BAFF is a potential predictor of poor outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Methods: We prospectively enrolled 299 patients with STEMI, and serum levels of BAFF were measured. All subjects were followed for three years. The primary endpoint was major adverse cardiovascular events (MACEs), including cardiovascular death, nonfatal reinfarction, hospitalization for heart failure (HF), and stroke. Multivariable Cox proportional hazards models were constructed to analyze the predictive value of BAFF for MACEs. Results: In multivariate analysis, BAFF was independently associated with risk of MACEs (adjusted HR 1.525, 95% CI 1.085–2.145; p = 0.015) and cardiovascular death (adjusted hazard ratio [HR] 3.632, 95% confidence interval [CI] 1.132–11.650, p = 0.030) after adjustment for traditional risk factors. Kaplan-Meier survival curves demonstrated that patients with BAFF levels above the cut-off value (1.46 ng/mL) were more likely to have MACEs (log-rank p < 0.0001) and cardiovascular death (log-rank p < 0.0001). In subgroup analysis, the impact of high BAFF on MACEs development was stronger in patients without dyslipidemia. Furthermore, the C-statistic and Integrated Discrimination Improvement (IDI) values for MACEs were improved with BAFF as an independent risk factor or when combined with cardiac troponin I. Conclusions: This study suggests that higher BAFF levels in the acute phase are an independent predictor of the incidence of MACEs in patients with STEMI.

The aim of this study was to investigate the relationship between circulating levels of B cell activating factor (BAFF) and the presence and severity of coronary artery disease (CAD) and acute myocardial infarction (AMI) in humans, as its biological functions in this context remain unclear. Serum BAFF levels were measured in a cohort of 723 patients undergoing angiography, including 204 patients without CAD (control group), 220 patients with stable CAD (CAD group), and 299 patients with AMI (AMI group). Logistic regression analyses were used to assess the association between BAFF and CAD or AMI. Significantly elevated levels of BAFF were observed in patients with CAD and AMI compared to the control group. Furthermore, BAFF levels exhibited a positive correlation with the SYNTAX score (r = 0.3002, P < 0.0001) and the GRACE score (r = 0.5684, P < 0.0001). Logistic regression analysis demonstrated that increased BAFF levels were an independent risk factor for CAD (adjusted OR 1.305, 95% CI 1.078–1.580) and AMI (adjusted OR 2.874, 95% CI 1.708–4.838) after adjusting for confounding variables. Additionally, elevated BAFF levels were significantly associated with a high GRACE score (GRACE score 155 to 319, adjusted OR 4.297, 95% CI 1.841–10.030). BAFF exhibited a sensitivity of 75.0% and specificity of 71.4% in differentiating CAD patients with a high SYNTAX score, and a sensitivity of 75.5% and specificity of 72.8% in identifying AMI patients with a high GRACE score. Circulating BAFF levels serve as a valuable diagnostic marker for CAD and AMI. Elevated BAFF levels are associated with the presence and severity of these conditions, suggesting its potential as a clinically relevant biomarker in cardiovascular disease.