RECAST (Remote Ischemic Conditioning After Stroke Trial) A Pilot Randomized Placebo Controlled Phase II Trial in Acute Ischemic Stroke

Background and Purpose-Repeated episodes of limb ischemia and reperfusion (remote ischemic conditioning [RIC]) may improve outcome after acute stroke. Methods-We performed a pilot blinded placebo-controlled trial in patients with acute ischemic stroke, randomized 1:1 to receive 4 cycles of RIC within 24 hours of ictus. The primary outcome was tolerability and feasibility. Secondary outcomes included safety, clinical efficacy (day 90), putative biomarkers (pre-and post-intervention, day 4), and exploratory hemodynamic measures. Results-Twenty-six patients (13 RIC and 13 sham) were recruited 15.8 hours (SD 6.2) post-onset, age 76.2 years (SD 10.5), blood pressure 159/83 mm Hg (SD 25/11), and National Institutes of Health Stroke Scale (NIHSS) score 5 (interquartile range, 3.75-9.25). RIC was well tolerated with 49 out of 52 cycles completed in full. Three patients experienced vascular events in the sham group: 2 ischemic strokes and 2 myocardial infarcts versus none in the RIC group (P=0.076, log-rank test). Compared with sham, there was a significant decrease in day 90 NIHSS score in the RIC group, median NIHSS score 1 (interquartile range, 0.5-5) versus 3 (interquartile range, 2-9.5; P=0.04); RIC augmented plasma HSP27 (heat shock protein 27; P<0.05, repeated 2-way ANOVA) and phosphorylated HSP27 (P<0.001) but not plasma S100-beta, matrix metalloproteinase-9, endocannabinoids, or arterial compliance. Conclusions-RIC after acute stroke is well tolerated and appears safe and feasible. RIC may improve neurological outcome, and protective mechanisms may be mediated through HSP27. A larger trial is warranted.