Upper Extremity Blood Pressure Difference in Patients Undergoing Carotid Revascularisation

Abstract

Blood pressure (BP) regulation is important in patients with carotid artery atherosclerotic disease. Concomitant subclavian artery stenosis (SAS) might lead to an underestimation of the true systemic BP in the monitoring of these patients. This study aimed to assess the prevalence of the inter-arm BP difference in patients undergoing carotid intervention and its association with ipsilateral significant subclavian stenosis and clinical outcome. Bilateral BP measurements and vascular imaging (CTA and MRA) of both subclavian arteries and the innominate artery were assessed in 182 symptomatic patients with carotid artery stenosis undergoing revascularisation in the International Carotid Stenting Study (ICSS). Data were separately analysed according to previously described cutoff values for systolic BP (SBP) differences of ≥10 and <15mmHg, ≥15 and <20mmHg, or ≥20mmHg. Significant SAS was defined as a >50% diameter reduction. Of the 182 patients, 39 (21%) showed an inter-arm difference in SBP >15mmHg. The mean inter-arm SBP difference associated with ipsilateral SAS was 14mmHg. SAS was present in 21/182 (12%) patients. Only two patients (1%) had bilateral stenotic disease. An inter-arm SBP difference of ≥20mmHg was associated with unilateral SAS (RR 11.8; 95% CI 3.2-43.1) with a sensitivity of 23% and a specificity of 98%. Patients were followed up for a median of 4.0 years (IQR 3.0-6.0; maximum 7.5). Risk of stroke or death during follow-up was 20.0% (95% CI 11.1-28.9) in patients with, and 15.1% (95% CI 12.3-17.9) in patients without SAS (p=.561). The hospital stay was longer in patients with significant SAS (5.0 days, SD 4.9 vs. 2.7 days, SD 4.3, p=.035). The present study is the first to affirm the clinical need for the measurement of inter-arm BP differences in patients undergoing carotid revascularisation, especially in the post-operative phase in the prevention of cerebral hyperperfusion.