Peripheral vascular disease as remote ischemic preconditioning, for acute stroke

Objectives: Remote ischemic preconditioning (RIPC) is a powerful endogenous mechanism whereby a brief period of ischemia is capable of protecting remote tissues from subsequent ischemic insult. While this phenomenon has been extensively studied in the heart and brain in animal models, little work has been done to explore the effects of RIPC in human patients with acute cerebral ischemia. This study investigates whether chronic peripheral hypoperfusion, in the form of pre-existing arterial peripheral vascular disease (PVD) that has not been surgically treated, is capable of inducing neuroprotective effects for acute ischemic stroke. Methods: Individuals with PVD who had not undergone prior surgical treatment were identified from a registry of stroke patients. A control group within the same database was identified by matching patient's demographics and risk factors. The two groups were compared in terms of outcome by NIH Stroke Scale (NIHSS), modified Rankin scale (mRS), mortality, and volume of infarcted tissue at presentation and at discharge. Results: The matching algorithm identified 26 pairs of PVD-control patients (9 pairs were female and 17 pairs were male). Age range was 20-93 years (mean 73). The PVD group was found to have significantly lower NIHSS scores at admission (NIHSS <= 4: PVD 47.1%, control 4.35%, p < 0.003), significantly more favorable outcomes at discharge (mRS <= 2: PVD 30.8%, control 3.84%, p < 0.012), and a significantly lower mortality rate (PVD 26.9%, control 57.7%, p = 0.024). Mean acute stroke volume at admission and at discharge were significantly lower for the PVD group (admission: PVD 39.6 mL, control 148.3 mL, p < 0.005 and discharge: PVD 111.7 mL, control 275 mL, p < 0.001). Conclusion: Chronic limb hypoperfusion induced by PVD can potentially produce a neuroprotective effect in acute ischemic stroke. This effect resembles the neuroprotection induced by RIPC in preclinical models. (C) 2013 Elsevier B.V. All rights reserved.