Coronary artery calcium and cystatin C for risk stratification of MACCEs and all-cause death in symptomatic patients.

Objectives: The aim of this study was to examine the independent and joint associations of baseline coronary artery calcium score (CACS) and cystatin C (Cys-C) with the risk of major adverse cardiac and cerebrovascular events (MACCEs) and all-cause death in symptomatic populations.

Methods: The study included 7140 patients with symptom of chest pain who underwent cardiac computerized tomography examinations to measure CACS. All of them had serum Cys-C results. Endpoints were set for MACCEs and all-cause death events.

Results: A total of 7140 participants were followed for a median of 1106 days. A total of 305 patients had experienced MACCEs and 191 patients had experienced all-cause death. CACS ≥ 100 and Cys-C ≥ 0.995 mg/L were independently associated with an increased risk of MACCEs (adjusted hazard ratio [HR]: 1.46; 95% confidence interval [CI]: 1.15-1.85; p = .002 and adjusted HR: 1.57; 95% CI: 1.24-2.00; p < .001, respectively). Compared with CACS < 100 and Cys-C < 0.995 mg/L patients, CACS ≥ 100 and Cys-C ≥ 0.995 mg/L patients had the highest risk of MACCEs and all-cause death (adjusted HR: 2.33; 95% CI: 1.64-3.29; p < .001 and adjusted HR: 2.85; 95% CI: 1.79-4.55; p < .001, respectively). Even in patients with CACS < 100, Cys-C ≥ 0.995 mg/L was also associated with a higher risk of MACCEs and all-cause death than Cys-C < 0.995 mg/L (adjusted HR: 1.76; p = .003 and adjusted HR: 2.02; p = .007, respectively).

Conclusions: The combined stratification of CACS and Cys-C showed an incremental risk of MACCEs and all-cause death, reflecting complementary prognostic value. Our results support the combination of the two indicators for risk stratification and event prediction.