The efficacy of remote ischemic conditioning for outcomes in ischemic stroke patients with or without prior stroke: A post hoc analysis of the RICAMIS trial

Abstract Background and Purpose To investigate the impact of a history of ischemic stroke or transient ischemic attack (TIA) on the effectiveness of remote ischemic conditioning (RIC) for outcomes in acute ischemic stroke patients. Methods We conducted a post hoc analysis of the Remote Ischaemic Conditioning for Acute Moderate Ischaemic Stroke (RICAMIS) trial. Patients in RICAMIS were categorized into two groups according to a history of stroke. The primary outcome was an excellent functional outcome, defined as a modified Rankin Scale (mRS) score of 0–1 at 90 days. Instead of comparing patients receiving usual care alone, we investigated the association of the RIC effect with functional outcomes in each group and the interaction between the RIC effect and a history of ischemic stroke or TIA. Results We included a total of 1695 patients, of whom 562 patients had a history of ischemic stroke or TIA and 1133 patients without prior ischemic stroke or TIA. In the Never Stroke or TIA group, a higher proportion of excellent functional outcomes was found in the RIC subgroup compared to the control subgroup (adjusted OR = 1.557 [95% CI 1.187–2.043], p = 0.001) but not in Prior Stroke or TIA group (adjusted OR = 1.299 [95% CI 0.893–1.888], p = 0.171). However, no significant interaction between the RIC effect and a history of ischemic stroke or TIA was found among the groups. Conclusion This is the first report suggesting that the RIC effect may be influenced by the history of ischemic stroke or TIA for patients with acute ischemic stroke.