Endovascular treatment of acute ischemic stroke in nonagenarians compared with younger patients in a multicenter cohort

Abstract

Background: Recent studies have demonstrated the superiority of endovascular therapy (EVT) for emergent large vessel occlusion.

Objective: To determine the effectiveness of EVT in nonagenarians, for whom data are limited.

Methods: We retrospectively reviewed clinical and imaging data of all patients who underwent EVT at two stroke centers between January 2012 and August 2014. The 90-day functional outcome (modified Rankin Scale (mRS) score) was compared between younger patients (age 18-89 years; n=175) and nonagenarians (n=18). The relationship between pre-stroke and 90-day post-stroke mRS was analyzed in these two groups. Multivariable analysis of age, recanalization grade, and admission National Institutes of Health Stroke Scale (NIHSS) for predicting outcome was performed.

Results: Age ≥90 years was associated with a poor (mRS >2) 90-day outcome relative to those under 90 (89% vs 52%, OR=8, 95% CI 1.7 to 35.0; p=0.0081). Nonagenarians had a higher pre-stroke mRS score (0.77; 95% CI 0.44 to 1.30) than younger patients (0.24; 95% CI 0.17 to 0.35; p=0.005). No difference was observed between nonagenarians and younger patients in the rate of mRS change from pre-stroke to 90 days (p=0.540). On multivariable regression, age (OR=1.05, 95% CI 1.03 to 1.08; p<0.0001), recanalization grade (OR=0.62 95% CI 0.42 to 0.91; p=0.015), and admission NIHSS (OR=1.07 95% CI 1.02 to 1.13; p=0.01) were associated with a poor 90-day outcome.

Conclusions: Nonagenarians are at a substantially higher risk of a poor 90-day outcome after EVT than younger patients. However, a small subset of nonagenarians may benefit from EVT, particularly if they have a good pre-stroke functional status. Further research is needed to identify factors associated with favorable outcome in this age cohort.

Keywords: Angiography; Intervention; Stroke; Thrombectomy.

Figure 1. Distribution of 90 day Modified Rankin Scale in nonagenarians and younger patients

Nonagenarians had worse 90 day mRS as compared to younger patients with a high mortality after endovascular therapy (P=0.006).

Figure 2. Association between pre-stroke and 90 day modified Rankin Scale (mRS) scores of nonagenarians and younger patients

(A) Nonagenarians had higher pre-stroke as well as 90 day mRS scores as compared to younger patient. However, there was no difference in the rate of magnitude of mRS worsening between the two groups (data are mean ± 95% confidence intervals). (B) Nonagenarians had an overall similar 90 day mRS compared to younger patients when stratified by the pre stroke mRS category (P>0.05; data are mean±s.e.m.). Analysis of the 90 day mRS score distribution according to the pre stroke mRS score categories shows that (C) patients under the age of ninety achieved a favorable outcome even when having a pre stroke mRS of 3. (D) Conversely, among nonagenarians essentially only those achieved a favorable outcome who had no or only mild pre stroke functional deficits.

Figure 3. Comparison of 90 day modified Rankin Scale score between octogenarians and nonagenarians

Octogenarians and nonagenarians had similar 90 day mRS after endovascular therapy.