Objective:

To summarize the current evidence on the prognostic value of C-reactive protein/Albumin ratio (CAR) on aneurysmal subarachnoid hemorrhage (aSAH).

Background:

Currently, CAR is a biomarker studied as a promising predictor of severy and poor outcomes in various neurologic events, including aSAH, based on the elevation of the C-reactive protein on cerebral vasospasm and the important role of albumin in modulating immune response on aSAH.

Design/Methods:

A systematic search was conducted in PubMed, Embase, Scopus, Web of Knowledge, and Google Scholar until April 2023. The risk of bias was assessed with the NewCastle-Ottawa tool. GRADE criteria was used to assess the certainty of the evidence.

Results:

We selected 3 out of 1408 articles. With moderate certainty, we found a CAR sensitivity and specificity value of 76.6% and 69.5%, respectively, for a modified Rankin Scale score >2 at 3 months. With the same level of certainty, we reported that a higher level of CAR is related to a Glasgow outcome scale score <4 at 3 months (OR: 5.23 95% CI: 1.11-24.59).  With moderate certainty, one study showed a mean difference of 0.02 (95% CI: -0.03 a 0.07) between aSAH patients that develop delayed cerebral ischemia (DCI) and those who do not.

Conclusions:

With moderate evidence, we found that CAR is a useful tool for predicting poor outcomes in aSAH patients. However, we need more studies, especially prospective ones, in order to improve the evidence regarding this index.