C-reactive protein and embolization during carotid artery stenting. A serological and morphological study

High-sensitivity C-Reactive Protein (hsCRP) levels are correlated with vulnerable carotid plaques, although their impact on the outcome of carotid revascularization is unknown. The aim of our study was to investigate the correlation between hsCRP and embolization during carotid artery stenting (CAS).

Patients with symptomatic carotid stenosis were submitted to CAS with distal protection filters. Serum hsCRP was analysed prior to CAS and patients were divided into two groups: Class I, patients presenting hsCRP < 5 mg/l and, Class II, patients presenting hsCRP≥5 mg/l. Plaques were categorised by ultrasound grey scale measurement as homogenous and dishomogenous. Afterwards CAS filters were analyzed microscopically and ultrastructurally to determine the type and the amount of debris present, based on percentage of surface involvement (SI) and pore occluded (PO) by embolic material.

Fourteen patients underwent uneventful CAS, with a mean hsCRP of 11.5±18.4 mg/l. Eight patients were in Class I and six in Class II. All filters had microscopic debris. SI was 25.4% in Class I and 33.3% in Class II (p=ns), PO 22.9% and 33.3% respectively (p=0.049). Patients in Class II who also had a dishomogenous plaque showed greater SI and PO compared with patients in Class I with homogenous plaque (35.0% vs. 21.8% and 40.4% vs. 22.7% respectively, p<0.05). Microscopically embolic material was identified as atherosclerotic plaque fragments and platelet aggregates and was similar in both groups.

High hsCRP levels are associated with significantly greater embolization during CAS in symptomatic patients, particularly in dishomogenous plaque. Although these results need further investigation due to the limited number of enrolled patients, this study suggests that CAS may not be indicated as a method of carotid revascularization in this setting.