# Pre-procedural C-reactive protein levels and carotid or intracranial artery restenosis: A systematic review and meta-analysis

## TL;DR

This study finds that higher pre-procedure C-reactive protein levels are linked to a higher risk of artery restenosis after revascularization.

## Contribution

This is the first meta-analysis to show a significant association between pre-procedural CRP levels and carotid or intracranial artery restenosis.

## Key findings

- Pre-procedural CRP levels were significantly higher in patients who developed restenosis.
- The association remained significant after sensitivity analysis and showed no publication bias.
- Elevated CRP is suggested as a risk factor for carotid or intracranial artery restenosis.

## Abstract

Restenosis of the carotid or intracranial (IC) arteries, shown to be associated with increased risk of ischemic stroke, represents an unresolved clinical issue. Residual local and systemic inflammation at the time of the index revascularization, of which C-reactive protein (CRP) is a marker of, has been associated with coronary restenosis. Its association with carotid or IC restenosis post revascularization, however, remains uncertain. We therefore conducted a systematic review and a study-level meta-analysis investigating the association of pre-procedural CRP levels and the subsequent incidence of carotid and IC restenosis.

Online databases of PubMed, EMBASE, MEDLINE, Scopus, and Web of Science were systematically searched for articles published until August 31st, 2025. Pooled effect sizes were obtained from study-level standard mean differences (SMD) and their 95% confidence intervals (CI), employing a Z-test, with random effects for analysis.

Out of 175 unique articles screened, 12 case-control studies, with a total sample of 2040 (325 restenosis cases/1715 no-restenosis controls), were included for quantitative synthesis. The pooled results demonstrated that pre-procedural CRP levels were associated with carotid or IC restenosis, with significantly higher pre-procedural CRP levels amongst the restenosis group in comparison to the no-restenosis group (SMD = 0.50, 95% CI = 0.11–0.89, p = 0.01). No apparent publication bias was detected either visually by Begg's funnel plot or Egger's test (p = 0.51). Leave-one-out sensitivity analysis supported the robustness of the results.

This meta-analysis suggests a significant association between pre-procedural CRP levels and the subsequent incidence of carotid and intracranial artery restenosis.

•Restenosis of the carotid or intracranial (IC) arteries is associated with stroke.•Elevated C-reactive protein (CRP) levels suggest local and systemic inflammation.•CRPs association with carotid or IC restenosis was investigated via a meta-analysis.•We demonstrate a significant association, suggesting elevated CRP as a risk factor.

Restenosis of the carotid or intracranial (IC) arteries is associated with stroke.

Elevated C-reactive protein (CRP) levels suggest local and systemic inflammation.

CRPs association with carotid or IC restenosis was investigated via a meta-analysis.

We demonstrate a significant association, suggesting elevated CRP as a risk factor.