NEW YORK (Reuters Health) – Some stroke patients with a large ischemic core and large mismatch imaging profile appear to benefit from endovascular treatment (ET), according to new findings.

Patients with large ischemic cores have typically been excluded from clinical trials of ET, Dr. Raul Nogueira of Emory University School of Medicine in Atlanta and his colleagues note.

“We hypothesized that CTP (computed tomographic perfusion) imaging may identify a subset of patients with high ischemic core volumes on presentation who remain at high risk for significant infarct expansion and thus could still benefit from endovascular reperfusion as a strategy to reduce their degree of disability,” the team writes in JAMA Neurology.

To investigate, they conducted a case-control study of 56 patients with a baseline ischemic core greater than 50 mL on CTP at their tertiary care center. Patients treated with ET were matched to those who received medical treatment alone based on age, baseline ischemic core volume and glucose levels.

Ninety-day modified Rankin Scale (mRS) scores had a significantly more favorable overall distribution in patients who underwent ET, the researchers found. While a quarter of the ET group were independent at 90 days, none of the patients in the control group were. Final infarct volumes were 87 mL in the ET group compared to 242 mL in the controls (P<0.001). One patient in the control group and two in the ET group developed parenchyma hematoma type 2.

Rates of hemicraniectomy and 90-day mortality were numerically lower with ET, but not significantly different. The 11 patients who were over 75 all had poor outcomes (mRS above 3). “In properly selected patients, ET appears to benefit patients with large core and large mismatch profiles,” Dr. Nogueira and colleagues write. “Future prospective studies are warranted.”

Dr. David S. Liebeskind of the University of California, Los Angeles, wrote an editorial accompanying the study. “Most of the prior studies and trials have focused in on ideally predicting exactly who will benefit the most,” he told Reuters Health by phone. “But this recent study raises a different question.”

“Even when patients present with more extensive ischemia on their scan, it may be worthwhile proceeding with revascularization although we know the outcome may not be as good as we would have hoped in another situation if there was less ischemia, but it doesn’t mean we should forego treatment,” he said.

“What remains unclear and must be defined from a practical standpoint is that we often have discordance or different perspectives on the specific extent of early ischemia on both CT and MRI,” Dr. Liebeskind added. “There is some discrepancy in assessing the degree of early ischemia depending on who reviews the scan and in what context and moreover to what purpose.”