Impact of presenting stroke severity and thrombolysis on outcomes following urgent carotid interventions

Background: Carotid interventions are increasingly performed in select patients following acute stroke. We aimed to determine the effects of presenting stroke severity (National Institutes of Health Stroke Scale [NIHSS]) and use of systemic thrombolysis (tissue plasminogen activator [tPA]) on discharge neurological outcomes (modified Rankin scale [mRS]) after urgent carotid endarterectomy (uCEA) and urgent carotid artery stenting (uCAS).

Methods: Patients undergoing uCEA/uCAS at a tertiary Comprehensive Stroke Center (January 2015 to May 2022) were divided into two cohorts: (1) no thrombolysis (uCEA/uCAS only) and (2) use of thrombolysis before the carotid intervention (tPA + uCEA/uCAS). Outcomes were discharge mRS and 30-day complications. Regression models were used to determine an association between tPA use and presenting stroke severity (NIHSS) and discharge neurological outcomes (mRS).

Results: Two hundred thirty-eight patients underwent uCEA/uCAS (uCEA/uCAS only, n = 186; tPA + uCEA/uCAS, n = 52) over 7 years. In the thrombolysis cohort compared with the uCEA/uCAS only cohort, the mean presenting stroke severity was higher (NIHSS = 7.6 vs 3.8; P = .001), and more patients presented with moderate to severe strokes (57.7% vs 30.2% with NIHSS >4). The 30-day stroke, death, and myocardial infarction rates in the uCEA/uCAS only vs tPA + uCEA/uCAS were 8.1% vs 11.5% (P = .416), 0% vs 9.6% (P < .001), and 0.5% vs 1.9% (P = .39), respectively. The 30-day stroke/hemorrhagic conversion and myocardial infarction rates did not differ with tPA use; however, the difference in deaths was significantly higher in the tPA + uCEA/uCAS cohort (P < .001). There was no difference in neurological functional outcome with or without thrombolysis use (mean mRS, 2.1 vs 1.7; P = .061). For both minor strokes (NIHSS ≤4 vs NIHSS >4: relative risk, 1.58 vs 1.58, tPA vs no tPA, respectively, P = .997) and moderate strokes (NIHSS ≤10 vs NIHSS >10: relative risk, 1.94 vs 2.08, tPA vs no tPA, respectively; P = .891), the likelihood of discharge functional independence (mRS score of ≤2) was not influenced by tPA.

Conclusions: Patients with a higher presenting stroke severity (NIHSS) had worse neurological functional outcomes (mRS). Patients presenting with minor and moderate strokes were more likely to have discharge neurological functional independence (mRS of ≤2), regardless of whether they received tPA or not. Overall, presenting NIHSS is predictive of discharge neurological functional autonomy and is not influenced by the use of thrombolysis.