Association Between High‐Sensitivity C‐Reactive Protein and Prognosis in Different Periods After Ischemic Stroke or Transient Ischemic Attack

BACKGROUND: The aim of this study was to investigate the association between hsCRP (high‐sensitivity C‐reactive protein) and prognosis over time after stroke onset. METHODS AND RESULTS: In this prespecified prospective substudy of the Third China National Stroke Registry, a total of 9438 patients with acute ischemic stroke or transient ischemic attack and measured hsCRP were included. Patients were categorized into 3 groups according to the sampling time after index onset (<24 hours, 24–72 hours, 72 hours–8 days). The outcomes consisted of stroke recurrence and combined vascular events within 1 year, and dependence or death defined as modified Rankin Scale score of 3 to 6 at 1 year. The associations between hsCRP and outcomes in different groups were analyzed by using Cox proportional hazards and logistic regression models. The median levels of hsCRP within 24 hours, between 24 and 72 hours and between 72 hours and 8 days were 2.01, 1.72, and 1.72 mg/L, respectively (P < 0.05). Compared with the bottom quartile, patients in the top quartile measured within 72 hours were at increased risk of recurrent stroke (<24 hours: adjusted hazard ratio [HR], 1.57 [95% CI, 1.05–2.35], P = 0.03; 24–72 hours: adjusted HR, 1.60 [95% CI, 1.18–2.17], P = 0.003). Association was attenuated after further adjusting for the Org 10 172 test in the Treatment of Acute Stroke classification (<24 hours: adjusted HR, 1.51 [95% CI, 1.01–2.27]; P = 0.05; 24–72 hours: adjusted HR, 1.55 [95% CI, 1.14–2.10]; P = 0.01). The association only existed in patients with large‐artery atherosclerosis (adjusted HR, 1.68 [95% CI, 1.06–2.64]; P = 0.03). However, the association was not found in the hsCRP level measured between 72 hours and 8 days. Similar results were found for the outcome of combined vascular events. Additionally, hsCRP levels measured between 24 and 72 hours were associated with an increased risk of poor functional outcomes. CONCLUSIONS: Elevated levels of hsCRP measured in the first 72 hours after ischemic stroke or transient ischemic attack but not 72 hours to 8 days, were associated with an increased risk of 1‐year stroke recurrence.