Collateral Circulation ("Collaterome") in Acute Ischemic Stroke With Large Vessel Occlusion: A Study of Clinical, Radiological, Plasma and Genetic Factors.

Introduction. In patients with an acute ischemic stroke due to a large-vessel intracranial occlusion (LVO), the status of the colateral circulation (CC) is related to clinical outcome and to the success of mechanical thrombectomy. However, CC is highly variable from patient to patient.

Methods. An observational, prospective, multicenter study of 700 consecutive patients with acute ischemic stroke and a LVO. Factors to be evaluated: 1) Modifiable: Vascular risk factors, blood analysis, prior medications, vital constants (with emphasis on continuous blood pressure monitoring), head position, metrics (time to admission, Computed tomography (CT), groin puncture, end of procedure), 2) Non-modifiable: age, sex, completeness of Circle of Willis, etiology, type of mechanical thrombectomy, plasma biomarkers, genetic/epigenetic factors (a discovery phase with GWAs study and a replication phase). CC grade will be assessed by the ASITN/SIR collateral score from CT-angiography (CTA) and the Digital substraction angiography (DSA, when performed). Statistics: bivariate analyses and a logistic regression to predict CC grade (poor versus good) and CC persistence comparing CTA with DSA (4 possibilities: poor-poor, poor-good, good-poor, good-good).

Expected results. Our study may find markers of the CC status, facilitate the design of clinical trials to improve CC grade, may find new therapeutic targets and new treatments to enhance the beneficial effects of mechanical thrombectomy.