Pre-Hospital Remote Ischemic Perconditioning - A Promising Neuroprotective Therapy.

Pre-hospital remote ischemic perconditioning (rPerC) is a potential neuroprotective therapy to patients with suspected acute stroke. We tested the effect of pre-hospital rPerC as an adjunct treatment to intravenous alteplase (rtPA) in patients suspected of acute stroke. The study was conducted as a single-blinded randomized study of rPerC in a 1:1 ratio in 298 consecutive patients with acute ischemic stroke or TIA of whom 184 were subsequently treated with rtPA and 149 had a 1 month MRI follow-up (81 rPerC, 68 controls). TIA was more frequent (p=0.006) in the intervention group (n=42) than in the control group (n=16). NIHSS on admission was significantly lower (p=0.016) in the intervention group (median 4, IQR 2-7) than in the control group (5, IQR 3-11). Accordingly there was a trend towards smaller volumes of tissue hypoperfusion (PWI 17.35 (1.01-87.18) vs. 16.55 (1.71-170.16), p=0.26) at the time of the initial MRI. Tissue voxels in the volume difference between PWI and DWI at baseline which did not proceed to infarction on follow-up T2-FLAIR MRI were identified and adjusted for baseline values of PWI and DWI. This voxel based logistic regression analysis takes any imbalance in baseline severity of DWI and PWI and any patient-specific effects into account to determine tissue-level infarct risks. The results were analysed according to baseline vessel status and recanalisation at 24 h. The likelihood ratio test for effect of rPerC in the whole group was p=0.0003. In the subgroups not changing vessel status (occlusion without recanalization and the group without observed occlusion) the tests for effect of rPerC yielded p<0.0001. For the recanalizer subgroup p=0.0002. . The neuroprotective effect of rPerC may have worked already prior to admission.