SAN DIEGO – Acute ischemic stroke patients who didn’t meet criteria for endovascular intervention were significantly less likely than treated patients to be discharged to home and half as likely to achieve good functional outcomes at 90 days, according to a retrospective study.
More than one-third of the patients excluded from endovascular intervention, however, went on to achieve functional independence at 3 months.
The results suggest that endovascular intervention selection strategies may need to be revamped and made more inclusive, Dr. Ali Shaibani said at the annual meeting of the American Society of Neuroradiology.
"While a good number of studies have been dedicated to investigating the outcomes of AIS patients who undergo endovascular intervention, outcomes have not been well studied in those who are deemed ineligible for endovascular intervention," said Dr. Shaibani, associate professor in radiology and neurological surgery at Northwestern University, Chicago.
In the retrospective study, investigators reviewed the charts of all 110 acute ischemic stroke (AIS) patients who underwent perfusion imaging from February 2010 to August 2012. The inclusion criteria were symptom onset-to-presentation time of 8 hours or less, anterior circulation large-vessel occlusion (either of the middle cerebral artery (MCA) or internal carotid artery (ICA)) as determined by CT/MR angiography, and a baseline National Institutes of Health Stroke Scale (NIHSS) score of at least 8.
Patients who were selected for endovascular treatment had the following perfusion imaging profiles: cerebral blood volume/diffusion weighted imaging (CBV/DWI) infarct core less than 1/3 MCA territory and mismatch of the ischemic penumbra more than 20% of the infarct core.
"While a good number of studies have been dedicated to investigating the outcomes of AIS patients who undergo endovascular intervention, outcomes have not been well studied in those who are deemed ineligible for endovascular intervention."
Less than half (43.6%) of the patients were found to be eligible for endovascular treatment. Patients who were not selected were significantly older (81 years vs. 74 years, P = .04) and had more risk factors (53.2% vs. 29.2%, P = .04), such as hyperlipidemia (83.9% vs. 25.0%, P = .03), than those selected for treatment. Patients not selected for treatment were less likely to be hypertensive (3.2% vs. 14.6%, P = .05). No significant differences between groups were found for atrial fibrillation or diabetes mellitus.
Patients not selected for endovascular therapy also were more likely to have received intravenous tissue plasminogen activator (TPA) than those selected (64.5% vs. 41.7%, P = .04), and they presented to the hospital significantly earlier (166 min. vs. 250 min., P = .03). That may reflect the finding that 20% of those selected for endovascular therapy transferred from other medical facilities, while none of the nonselected patients were transfers (P = .03).
Despite earlier time to presentation and greater receipt of intravenous TPA, patients who weren’t selected for endovascular intervention were discharged to home at almost one-sixth the rate of selected patients (3.2% vs. 18.8%, P = .001). There were no significant differences in baseline NIHSS scores between nonselected and selected groups (19.35 vs. 18.67), but selected patients had better NIHSS scores at discharge (13.43 vs. 9.8, P = .02).
Although selected patients were also twice as likely (66.7% vs. 35.7%) to have good functional outcomes at 90 days (as defined by modified Rankin Scale scores of 0-2), Dr. Shaibani pointed out that nearly one-third of nonintervention patients did achieve functional independence.
"This suggests the need to refine patient selection strategies for [intra-arterial] intervention and to be more inclusive," said Dr. Shaibani. He suggested reconsidering the importance of other factors besides perfusion imaging criteria, such as the location of the occlusion in the MCA and pre-existing modified Rankin Scale scores.
Dr. Shaibani had no relevant financial relationships.