Effects of Carotid Endarterectomy or Stenting on Blood Pressure in the International Carotid Stenting Study (ICSS)

Abstract

Arterial hypotension is more frequently observed early after carotid artery stenting (CAS) than after carotid endarterectomy (CEA), but their long-term effects on blood pressure (BP) are unclear. We compared the effects of CAS and CEA on BP up to 1 year after treatment in the International Carotid Stenting Study. Patients with symptomatic carotid stenosis were randomly allocated to CAS or CEA. Systolic and diastolic BP were recorded at baseline, at discharge, and at 1, 6, and 12 months. Antihypertensive medication use was recorded. A per-protocol analysis was performed. Patients with missing BP records were excluded. Between-group BP changes were compared and adjusted for baseline covariates with linear regression. Within-group BP changes were compared with the paired t test. CAS (N=587) and CEA (N=637) were both associated with a decrease in BP at discharge, which was greater after CAS (mean difference in systolic BP between groups, 10.3 mm Hg; 95% CI, 7.3-13.3; P<0.0001; in diastolic BP, 4.1 mm Hg; 95% CI, 2.4-5.7; P<0.0001). During follow-up, BP changes were not different between groups. Adjustment for differences in baseline characteristics did not change the results. Fewer patients undergoing CAS used antihypertensive medication during follow-up than patients undergoing CEA (relative risk at 12 months, 0.91; 95% CI, 0.85-0.97; P=0.0073). CAS leads to a larger early decrease in BP than CEA, but this effect does not persist over time. CAS may lessen the requirement for antihypertensive medication more than CEA. Clinical Trial Registration- URL: www.controlled-trials.com. Unique identifier: ISRCTN25337470.