Abstract P637: Blood Pressure Stability Has a Closer Relationship With Atherosclerosis Burden of Carotid Sinuses Than Atherosclerosis Burden of Aortic Arch

Abstract

Background: Instable blood pressure (BP) increased vascular risk independently of high BP level, which might be partially attributed to impaired arterial baroreflex. The receptors of baroreflex mainly distributed at carotid sinuses and aortic arch, where atherosclerosis (AS) is common in patients with ischemic stroke (IS) and potentially blunts the baroreflex. We aimed to test whether AS conditions of carotid sinuses and aortic arch would equally indicate BP instability in IS patients. Methods: The daytime and nighttime standard derivations (SDs) of systolic BP (SBP) and diastolic BP (DBP) were recorded by ambulatory BP monitoring on the sixth day after IS to measure BP stability (higher SD indicates less stability). Using computed tomography angiography, AS conditions of carotid sinuses (6 segments) and aortic arch (4 segments) were scored based on AS percentage of each segment circumference (0, none; 1, <25%; 2, 25%~49%; 3, 50%~74%; 4, ≥75%) and summed into “carotid sinuses AS burden (CSAB)” and “aortic arch AS burden (AAAB)”. AS conditions of cervicocephalic arteries were also scored. Results: Of the 245 patients with IS, 65.7% had carotid sinuses AS and 69.4% had aortic arch AS. Daytime SBP SD was positively correlated with CSAB ( r =0.230; P <0.001) rather than AAAB ( P =0.103). Patients with CSAB above the median had significantly higher daytime SBP SD than those with less CSAB (median 14 mmHg vs. 12 mmHg, P =0.001). CSAB remained related to ln- transformed daytime SBP SD after adjusting for age, sex, vascular risk factors, weighted 24-hour means of SBP and DBP, and cervicocephalic AS score (adjusted B =0.012; 95% CI, 0.004-0.020). In contrast, DBP SD and nighttime SBP SD had no statistically significant association with both CSAB and AAAB. Conclusions: Higher CSAB was independently associated with SBP instability during the daytime, while AAAB was less relevant to BP stability. Compared with AAAB, evaluating CSAB might be more important in the prediction of BP instability.