Collateral circulation grading
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Hilda Mahmoudi M.D., M.P.H.[2]
Overview
Collateral Circulation assessed visually using the following grading system
Grade 0: No collaterals present. Angiography fails to reveal evidence of collateral vessels.
Grade 1 (or partial): Minimal collaterals present. Evidence of minimal to partial filling of the recipient branch epicardial arteries/infarct region. It is not necessary for one to see the branches connect directly to the major epicardial artery.
Grade 2 (or complete): Well-developed collaterals. Evidence of collateral circulation with near complete to complete filling of the recipient major epicardial artery/infarct region.
Grade 3 (myocardial): Filling of the myocardium by collaterals. If the collaterals are not filling any visible arterial branch, but are only participating in the perfusion of the myocardium.