Baseline neurologic deficit and efficacy of remote ischemic conditioning after acute ischemic stroke: A post hoc analysis of RICAMIS

Abstract

RICAMIS (ClinicalTrials.gov Identifier: NCT03740971) trial has demonstrated efficacy of remote ischemic conditioning (RIC) in acute ischemic stroke, but whether baseline NIHSS score can affect outcomes in stroke remains unclear. We conducted a post hoc analysis of RICAMIS to investigate the issue. Patients included in RICAMIS were divided into three groups based on baseline NIHSS score. The primary outcome was excellent functional outcome at 90 days, defined as mRS score of 0-1. Compared with patients receiving usual care, we investigated association of RIC effect with outcomes in each group and interaction between RIC effect and stroke severity. Among 1776 patients, 1255 were assigned into NIHSS score 6-8 group, 402 into NIHSS score 9-12 group, and 119 into NIHSS score 13-16 group. A higher proportion of primary outcome was found associated with RIC in NIHSS score 9-12 group (adjusted risk difference [RD], 14.6 ​%; 95 ​% CI, 5.0 ​%-24.2 ​%; P ​= ​0.003), but no significant association was found in NIHSS score 6-8 group (adjusted RD, 2.3 ​%; 95 ​% CI, -2.5 ​%-7.2 ​%; P ​= ​0.34), or in NIHSS score 13-16 group (adjusted RD, 9.7 ​%; 95 ​% CI, -7.5 ​%-26.9 ​%; P ​= ​0.27). There was a significant interaction between RIC effect and stroke severity when analysis was performed between NIHSS score 6-8 and 9-12 groups (P ​= ​0.04), but not between NIHSS score 9-12 and 13-16 groups (P ​= ​0.57). Current study firstly reported patients with NIHSS score 9-12 may get more benefit from RIC after stroke with respect to excellent functional outcome at 90 days.

Keywords: Acute ischemic stroke; Efficacy; NIHSS score; Remote ischemic conditioning; Stroke severity.