FRIDAY, Nov. 12, 2021 (HealthDay News) -- For patients with large vessel occlusion (LVO) stroke not treated with reperfusion, symmetric collateral pattern at computed tomography angiography (CTA) is highly specific for small 24-hour ischemic core volume, according to a study published online Nov. 2 in Radiology.
In a secondary analysis of clinical trial data, Robert W. Regenhardt, M.D., Ph.D., from Massachusetts General Hospital in Boston, and colleagues evaluated 31 patients with anterior proximal LVO stroke not treated with reperfusion therapies. Participants underwent admission CTA and at least three magnetic resonance imaging examinations at four time points during a 48-hour period.
The researchers found that collaterals were symmetric, malignant, or other in 45, 13, and 42 percent of the patients, respectively. At all time points, median ischemic core volume differed between collateral patterns. Presentations were 16, 69, and 104 cm3 for symmetric, other, and malignant patterns, respectively. At 24 hours, the corresponding median ischemic core volumes were 28, 156, and 176 cm3. The median ischemic core growth rate (IGR) also differed and was most pronounced at presentation: 4, 17, and 20 cm3 per hour for symmetric, other, and malignant, respectively. Independent determinants of higher-presentation IGR included a higher National Institutes of Health Stroke Scale score and worse collaterals (ß = 0.20 and −2.90, respectively). Worse collaterals was the only independent determinant of 24-hour IGR. Symmetric collaterals had sensitivity and specificity of 87 and 94 percent, respectively, for 24-hour ischemic core volume less than 50 cm3, with an area under the receiver operating characteristic curve of 0.92.
"Our data shows that in almost half of patients, the core grows very slowly," a coauthor said in a statement. "That's a huge number of people who are potentially treatable."
Several authors disclosed financial ties to the biopharmaceutical and medical device industries.