Angiographic collaterals in acute stroke - relationship to clinical presentation and outcome: The PROACT II trial
We studied the relationship between angiographic collateral flow and stroke severity and outcome in patients with MCA occlusion. Patients (180) were randomized 2:1 to 9mg IA r-proUK + subtherapeutic IV heparin or IV heparin alone; 162 were treated as randomized. Angiography at baseline assessed vascular occlusion and collateral flow (no, partial, or complete supply of the ischemic territory). CT was obtained at baseline, 24hrs and 7–10days, and hypodensity volumes were measured. Clinical outcome was assessed at 90days (modified Rankin score≤2). At baseline, collateral flow in 161 cases was: 50 no supply, 100 partial, and 11 complete supply. Patients with complete supply had significantly smaller infarct volumes (2±1cc) on baseline CT than patients with some (13±2cc, p<0.05) or no collaterals (18±4cc, p<0.05). There was a statistically significant difference in the median baseline NIHSS score among the three collateral groups (15 complete vs.16.5 partial vs.18 no). There was no overall relationship between the extent of collaterals and outcome. When considering treatment groups, the effect of r-proUK appears to be (n.s.) greater with increasing degree of collaterals (Table). An analysis of the effect of collaterals and treatment groups on the evolution of hypodensity volumes on 24hrs- and 7–10day CTs was also performed. Collaterals appear to have an effect on baseline CT infarct volume and stroke severity, and on the effect of thrombolytic treatment.