Prevalence, predictors and outcome of carotid stenosis: a sub study in the Preventive Antibiotics in Stroke Study (PASS)

Background: The prevalence of carotid artery stenosis (CAS) in acute ischaemic stroke (AIS) patients is historically reported at 15–20%, but an up-to-date estimate is lacking. We hypothesise it is lower than historically reported, due to better risk management to date. The study aims to study prevalence, predictors and survival of CAS in AIS patients. Methods: We included patients with AIS from the Preventive Antibiotics in Stroke Study (PASS), a large Dutch randomized, multicentre, open-label phase III trial that included 2538 patients with acute stroke and randomised between standard care or preventive ceftriaxone. Patients with stroke in the anterior circulation that underwent diagnostic testing of the internal carotid artery (ICA) were eligible for this sub study and used in these secondary analyses. Logistic regression analyses were performed to identify predictors for CAS ≥ 50%. Additionally, an ordinal regression was performed to assess the association between presence of CAS at baseline and functional outcome at three months on the modified Rankin scale (mRS). Results: 1480 patients with AIS were included; 277 had CAS (18.7%; 95%CI:17.7-19.7). Age, hypertension, smoking and male gender were found as best-fit predictors for presence of CAS. Significant shift in mRS score after 90 days for CAS ≥50% towards a higher mRS score with an OR of 1.66 (95% CI 1.30-2.10) was found. Conclusions: Current prevalence of CAS is 18.7%, which is higher than we expected. Gender, smoking and hypertension are important factors associated with CAS. Patients with CAS had a significantly higher mRs score after 90 days. Trial registration: Unique identifier:ISRCTN66140176