Patients with moderate to severe strokes (NIHSS score >10) undergoing urgent carotid interventions within 48 hours have worse functional outcomes

Abstract

Objective: Increasing evidence suggests that urgent carotid intervention after a nondisabling stroke is safe. However, the functional outcome of such patients has not been quantified for various degrees of stroke. We aimed to determine whether increased presenting stroke severity and timing to intervention are associated with poor functional outcomes in patients undergoing urgent carotid endarterectomy (CEA) or carotid artery stenting (CAS) after an acute transient ischemic attack or stroke.

Methods: We reviewed all urgent carotid interventions from January 2013 through April 2017 at a single tertiary referral center. Preoperative variables analyzed included admission stroke severity, calculated by National Institutes of Health Stroke Scale (NIHSS). The primary end point was the patient's neurologic functional independence at discharge, quantified by the modified Rankin scale (mRS) score (≤2, functionally independent; ≥3, dependent). Primary complications were defined as new or worsened stroke, intracranial hemorrhage, and death.

Results: A total of 120 urgent carotid interventions (CEA, n = 96; CAS, n = 22; 1 CEA with middle cerebral artery aspiration thrombectomy and 1 carotid embolectomy) were performed. Bivariate analysis demonstrated a correlation between admission NIHSS score and mRS score when patients were divided into groups with an admission NIHSS score ≤10 and >10 (P = .0029). Patients presenting with larger strokes (NIHSS score >10) were 3.4 times more likely (95% confidence interval [CI], 1.2-9.6; P = .024) to have functional dependence (mRS score ≥3) at discharge than patients presenting with minor to moderate strokes (NIHSS score ≤10). Patients undergoing CEA or CAS before 48 hours were also associated with a worse discharge mRS score compared with those undergoing carotid interventions after 48 hours (odds ratio, 3.5; 95% CI, 1.4-8.7; P = .007). Even when emergent carotid interventions were excluded from the subgroup of patients undergoing CEA or CAS within 48 hours, discharge mRS correlated with time to procedure (days 1- 2 compared with >2 days). The odds of having discharge functional dependence (mRS score ≥3) were 3.4 times more likely for patients with the procedure performed at 1 to 2 days compared with >2 days (95% CI, 1.3-9.1; P = .014).

Conclusions: Urgent carotid intervention performed in patients with moderate or severe strokes (NIHSS score >10) and before 48 hours is associated with functional dependence (mRS score ≥3) on hospital discharge. By demonstrating a clear correlation between admission NIHSS score and interval time to procedure with independent neurologic functional outcomes, these data aid in clinical decision-making for this high-risk subpopulation of patients who present with acute symptomatic carotid lesions.

Keywords: Carotid; Functional independence; Modified Rankin scale; NIHSS; Stroke; Urgent.