Risk Factors for Postoperative Hypotension and Hypertension following Carotid Endarterectomy

Abstract

Patients undergoing carotid endarterectomy (CEA) often experience postoperative hemodynamic changes that require intravenous medications for hypo- and hypertension. Prior studies have found these changes to be associated with increased risks of 30-day mortality, stroke, myocardial infarction (MI), and length of stay (LOS). Our aim is to investigate preoperative risk factors associated with the need for postoperative intravenous medications for blood pressure control. A retrospective review of an internally maintained prospective database of patients undergoing carotid interventions between January 2014 and March 2019 was performed. Demographic data, clinical history, and perioperative data were recorded. Carotid artery stents and reinterventions were excluded. Our primary end points were the need to intervene with intravenous medication for either postoperative hypotension [systolic blood pressure (SBP) <100mm Hg] or postoperative hypertension (SBP >160mm Hg). A total of 221 patients were included in the study after excluding those with a prior ipsilateral CEA or carotid artery stent. The mean age was 72.3 (±8.9) years, 157 (71%) patients were male, and 78 (35.3%) were Caucasian. Following CEA, 151 (68.3%) patients were normotensive, while 33 (14.9%) and 37 (16.7%) required medication for hypotension and hypertension, respectively. A univariate logistic regression identified 5 variables as being associated with postoperative blood pressure including race, history of MI, prior percutaneous transluminal coronary angioplasty (PTCA), statin use, and angiotensin-converting enzyme-inhibitor/angiotensin-receptor blocker (ARB) use. A stepwise regression selection found race, prior MI, and statin use to be associated with our primary end points. The hypertensive group was more likely to have a history of MI compared to the hypotensive and normotensive groups (40.5% vs. 27.3% vs. 18.5%, P=0.02), PTCA (43.2% vs. 39.4% vs. 23.8%, P=0.03), and statin use (94.6% vs. 93.9% vs. 78.8%, P=0.01). Mean LOS was also the highest for the hypertensive group, followed by hypotensive and normotensive patients [2.0 (±1.6) vs. 1.8 (±2.4) vs. 1.3 (±0.8), P=0.002]. Multivariable logistic regression demonstrated that non-Caucasian patients [odds ratio (OR) 2.72, 95% confidence interval (CI) 1.26-5.86, P=0.01] and those with a history of MI (OR 2.98, 95% CI 1.33-6.67) were more likely to have postoperative hypertension compared to patients who were Caucasian or had no history of MI. Postoperative hypertension is associated with non-Caucasian race and a history of MI. Given the potential implications for adverse perioperative outcomes including MI, mortality, and LOS, it is important to continue to elucidate potential risk factors in order to further tailor the perioperative management of patients undergoing CEA.