Impact of Collateral Status on Neuroprotective Effect of Cyclosporine A in Acute Ischemic Stroke

Abstract

Neuroprotection for acute ischemic stroke remains an elusive goal. Intracranial collaterals may favor neuroprotective drugs delivery at the acute stage of ischemic stroke. A recent phase 2 study showed that cyclosporine A (CsA) reduced ischemic damage in patients with a proximal occlusion who experienced effective recanalization. Collateral flow may improve this benefit. Collateral supply was assessed using dynamic susceptibility contrast MRI in 47 patients among the 110 patients from the original study and were graded in two groups: good collaterals and poor collaterals. Patients with good collaterals had significantly smaller initial infarct in both CsA group (p = 0.003) and controls (p = 0.016). Similarly, the final lesion volume was significantly lower in patients with good collaterals in both groups. In patients with either good or poor collaterals CsA showed no additional benefit on ischemic lesion progression and final infarct size at day 30. We failed to demonstrate any significant additional benefit of CsA in patients with good collateral circulation.