Abstract P416: Remote Ischemic Conditioning Reduces Perihematomal Edema After Intracerebral Hemorrhage: First Proof-Of-Concept Randomized Controlled Trial

Introduction: The prognosis of intracerebral hemorrhage (ICH) is poor because of the mass effect arising from the hematoma and the associated perihematomal edema (PHE). Remote ischemic conditioning (RIC) has been shown to promote hematoma clearance and reduce PHE in animal models, however it remains unknown whether RIC is safe and effective in reducing PHE in ICH patients. Objective: To evaluate the safety and efficacy of RIC in reducing PHE after ICH. Methods: In this open-label, rater-blind, randomized control trial, 40 subjects with supratentorial ICH (hematoma volume:10-30 ml) diagnosed between 24 to 48 hours of onset were assigned to the RIC group or control group. All subjects received standard background medical therapy. Subjects in the RIC group underwent repeated daily RIC (4 cycles of 5 minutes inflation [200 mmHg] /deflation [0 mmHg] of cuff on one arm) for 7 consecutive days. The primary efficacy outcome was PHE volume at 7 days, and both absolute PHE volume and relative PHE volume (defined as absolute PHE volume divided by hematoma volume) were measured. Safety outcome included death, neurological deterioration, hematoma expansion, and any other severe adverse events. Results: All 40 subjects completed this study. Mean age was 59.3±11.7 years, and 57.5% were male. At baseline, the median National Institutes of Health Stroke Scale score was 9.5 (range 1-28), median Glasgow Come Score was 15 (range 10-15), and mean ICH volume was 13.9±4.5 ml. The mean relative PHE volume was 1.11±0.26 in the control group and 1.05±0.23 in the RIC group at baseline; and 1.49±0.30 vs. 1.33 ±0.32 at Day 3 (p>0.05 each) respectively. After 7 days of treatment, RIC significantly reduced the relative PHE volume as compared to the control (1.77±0.39 vs. 2.02±0.27, p=0.02). The absolute PHE volume and hematoma volume at Day 3 and Day 7 had no significant difference between groups (p>0.05 each). No subject died or suffered from neurological deterioration or hematoma expansion and no adverse event was associated with RIC. Conclusion: RIC seemed to be safe in patients with ICH and induced a significant reduction in the relative PHE volume after 7 day of treatment. These results warrant a further study with large sample to examine the effect of RIC on functional outcome after ICH.