Abstract WP5: Collaterals in the Interventional Management of Stroke (IMS) III Trial
Background: Collateral circulation may exert an influential effect on arterial recanalization, downstream angiographic and tissue reperfusion and ensuing clinical outcomes after revascularization for acute ischemic stroke. Endovascular strategies provide unique opportunity to correlate definitive angiographic measures of collaterals at the time of interventional therapy. We conducted a systematic analysis of collaterals on conventional angiography in the endovascular treatment arm of the Interventional Management of Stroke (IMS) III trial.
Methods: Prospective evaluation of angiographic collaterals was conducted via central review of all cases enrolled and treated in the endovascular arm of IMS III. Collateral grade was assessed with the ASITN/SIR scale on angiography at procedure start and immediately prior to intra-arterial treatment (time 0), blind to all other data. Statistical analyses investigated the association between collateral grade with baseline clinical data, angiographic measures of recanalization (AOL), angiographic reperfusion (TICI), and clinical outcomes.
Results: From 2006-2012, 380 cases were prospectively evaluated for collateral grade at start of procedure and time 0 prior to treatment. Adequate collateral views were available in 283/380 (75%) cases at baseline, and 277/380 (73%) cases at time 0 and after subsequent treatment with intra-arterial tPA, EKOS, MERCI, Penumbra, and Solitaire devices. Detailed results will be presented at ISC in coordination with release of the primary trial results. The relationships between collateral flow grade and baseline clinical features (NIHSS and age), location of vascular occlusion at cerebral angiography, AOL recanalization and TICI reperfusion, and mROS of 0-2 at 90 days will be presented. Analyses will explore potential interactions between collateral flow grade with recanalization, angiographic reperfusion, and clinical outcome.
Conclusions: Collateral circulation was available and prospectively evaluated in the largest endovascular therapy trial for stroke conducted to date. The role of collaterals may be an important consideration in the design of future endovascular trials.
- © 2012 by American Heart Association, Inc.