Changes in baroreceptor sensitivity after eversion carotid endarterectomy

Abstract

Objective: Posteversion carotid endarterectomy hypertension has been suggested to be associated with impaired baroreceptor sensitivity (BRS), which has been identified as a factor of prognostic relevance in patients with cardiovascular disease. The aim of this prospective single-center nonrandomized study was to describe the changes of BRS in the early postoperative period after eversion carotid endarterectomy (E-CEA).

Methods: Spontaneous BRS and hemodynamic parameters such as blood pressure (BP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR) were evaluated preoperatively as well as postoperatively after 1 and 3 days using a noninvasive sequential cross-correlation method. Additionally, any modification in vasoactive medication due to BP derangement in the postoperative period was noted. Due to non-normal distribution of BRS, HR, and TPR samples, all measured values were expressed as medians with interquartile range (IQR), and a nonparametric test (Friedman) was performed. After adjustment for multiple testing, differences were considered statistically significant when the two-tailed P value was less than .0036.

Results: Thirty-five patients (mean age, 71 years) with symptomatic or asymptomatic internal carotid artery stenosis were included. The BRS significantly decreased to a lower level 24 hours after surgery (4.71 ms/mm Hg [3.02-6.1]) than preoperatively (5.95 ms/mm Hg [4.68-10.86]; P < .0001), resulting in a within-patient difference of -2.46 ms/mm Hg (95% confidence interval [CI], -8.38 - -1.52). This difference (95% CI, [- 1.58 (-8.24 - -0.80)]) persisted at the 72-hour measurements (5.63 ms/mm Hg [3.23-7.69]; P = .0005). The HR, reflecting the sympathetic activity, increased 24 hours after the operation (69 bpm [61.3-77.7]) compared with preoperative values (63 bpm [57.9-73.2]; P = .005) (within-patient difference [95% CI] 3.7 [1.5-8.5]), and this increase reached significance at 72 hours (69 bpm [65.4-77.5]; P = .001) (within-patient difference [95% CI] 5.5 [2.3-8.8]). Values of systolic pressure, diastolic pressure, mean arterial pressure, CO, and TPR were not significantly different between pre- and postoperative measurements. Overall, 23 (66%) patients developed significant postoperative hypertension requiring aggressive management with additional medications.

Conclusions: E-CEA might have a decreasing influence on BRS, leading to increased sympathetic activity. Investigations of the longer-term effects of impaired BRS are warranted. These findings should be interpreted with caution, noting the limitation of an absent control group.