Abstract
The C-reactive protein-to-albumin ratio (CAR) is an emerging biomarker linked to cardiovascular disease. However, its role in predicting outcomes among acute decompensated heart failure (ADHF) patients, particularly when stratified by glycemic status, remains poorly defined. This retrospective study included 1,494 consecutive ADHF patients admitted between 2018 and 2023, with the primary endpoint being major adverse cardiac and cerebrovascular events (MACCEs). Patients were stratified into low- and high-CAR groups using an optimal cutoff of 0.29, derived from maximally selected rank statistics. To assess the relationship between CAR and MACCEs in different glucose metabolism states, multivariable Cox proportional hazards models, restricted cubic splines (RCS), and Kaplan-Meier survival curves were used. During a median follow-up of 528 days, 565 patients (37.8%) experienced MACCEs. After adjusting for potential confounders, higher CAR levels were significantly associated with an increased risk of MACCEs (Model 3: hazard ratio [HR]: 1.45, 95% confidence interval [CI]: 1.19-1.77, p < 0.001). When stratified by glycemic status, CAR as a robust predictor in diabetic patients (Model 3 HR: 1.91, 95% CI: 1.41-2.58, p < 0.001), whereas no significant associations were observed in prediabetic or normoglycemic individuals (all p > 0.05). In conclusion, CAR demonstrates independent prognostic value in ADHF patients with concomitant diabetes, highlighting its potential as a stratification tool for personalized risk assessment and therapeutic optimization in this high-risk population.