Predictive Value of Cystatin C for Stroke Recurrence in Patients With Acute Ischemic Stroke.

Background: This study explored the value of cystatin C (CysC) in predicting stroke recurrence in patients with acute ischemic stroke.

Methods and results: This was a post hoc analysis of the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS) on 3,474 acute ischemic stroke patients with documented serum CysC and high-sensitivity C-reactive protein (hsCRP) concentrations. Study outcomes included stroke recurrence and combined vascular events within 2 years after stroke. In stroke patients with higher (i.e., ≥4.8ng/mL), but not lower, hsCRP concentrations, a higher CysC concentration (i.e., ≥0.78 mg/L) was associated with a 2.48-fold increase in the risk of recurrent stroke (95% confidence interval [CI] 1.37-4.51; P=0.003) and a 2.04-fold increase in the risk of vascular events (95% CI 1.27-3.28; P=0.003). Serum hsCRP concentrations significantly modified the association of serum CysC with recurrent stroke (P=0.001) and vascular events (P=0.007). Moreover, CysC may improve reclassification of stroke recurrence (net reclassification improvement [NRI] 42.9%, P=0.001; integrated discrimination improvement [IDI] 1.2%, P=0.001) and vascular events (NRI 35.8%, P=0.001; IDI 1.1%, P=0.004).

Conclusions: In ischemic stroke patients with high hsCRP concentrations, higher CysC concentrations increased the risk of stroke recurrence and vascular events. This indicates that the predictive value of CysC on stroke recurrence may depend on the inflammation status of patients.