LAUSR

OBJECTIVE Hypotension is a frequent complication of carotid artery stenting (CAS). Though common, its occurrence is unpredictable and association with adverse events has not been well defined. The aim of this study is to identify predictors of postoperative hypotension following CAS and the association with stroke/TIA, major adverse cardiac events (MACE), increased length of stay (LOS) and in-hospital mortality. METHODS This is a retrospective analysis of all CAS including transfemoral (tf-CAS) and transcarotid (TCAR), performed in the VQI between 2003-2018. The primary study endpoint was postoperative hypotension defined as hypotension treated with continuous infusion of vasoactive agent for > 15 minutes. Secondary endpoints include any postoperative neurologic events (stroke/TIA), MACE (MI, CHF and dysrhythmias), prolonged LOS (>1-day) and in-hospital mortality. Patient demographics predictive of hypotension were determined by multivariable logistic regression and a risk score was developed for correlation with outcomes. RESULTS During the time period of study, 24,699 patients underwent CAS, 19,716 (80%) were transfemoral, 3,879 (16%) TCAR and 1,104 (4%) were not defined. Fifty-six percent were for symptomatic disease, 75% were for a primary atherosclerotic lesion, and 72% under local or regional anesthesia. Postoperative hypotension occurred in 15% of tf-CAS and 14% of TCAR (p=0.50). Patients with hypotension (vs no hypotension) had higher rates of stroke/TIA (7.3% vs 2.6%, p<0.001), MACE (9.6% vs 2.1%, p<0.001), prolonged LOS (65% vs 28%, p<0.001) and in-hospital mortality (2.9% vs 0.7%, p<0.001). By multivariable analysis, risk factors associated with hypotension included: an atherosclerotic (vs restenotic) lesion, (O.R. 2.2, 95% C.I. 2.0-2.4, p=0.001), female gender (1.3, 1.2-1.4, 0.001), positive stress test (1.3, 1.2-1.4, 0.001), age 70-79 (1.1, 1.1-1.3, 0.002), age > 80, (1.2, 1.1-1.4, 0.001), history of MI or angina (1.3, 1.2-1.4, 0.001), and an urgent (vs elective) procedure (1.1, 1.0-1.2, 0.01). A history of hypertension was protective (0.9, 0.8-0.9, 0.02). A normalized risk score for hypotension was created from the multivariable model. Increasing risk scores correlated directly with rates of adverse events, including postoperative stroke/TIA, MACE, increased LOS and increased in-hospital mortality. CONCLUSION Hypotension after CAS is associated with adverse neurologic and cardiac events as well as prolonged length of stay and in-hospital mortality after carotid stenting. A scoring tool may be valuable in stratifying patients at risk. Interventions aimed at preventing postoperative hypotension may improve outcomes with CAS.