SAN DIEGO – Acute ischemic stroke patients who required transfer to a comprehensive stroke center in order to receive intra-arterial therapy were significantly more likely to have worse functional outcomes at 90 days than were patients who presented directly to such centers in a retrospective analysis of 116 patients.
The poor outcome of the transferred patients was independent of baseline risk factors, stroke severity, time to intra-arterial therapy, and whether the process was a success or the patient had complications, according to Dr. Ali Shaibani, who presented the findings at the annual meeting of the American Society of Neuroradiology.
"The time to intervention is critical for AIS [acute ischemic stroke] patients who are candidates for intra-arterial therapy. Access to endovascular therapy is often limited to comprehensive stroke centers. An increasing number of institutions are transferring AIS patients for therapy. The outcome for this subset of patients who are being transferred has not been studied well," said Dr. Shaibani of the departments of radiology and neurologic surgery at Northwestern University, Chicago.
This retrospective analysis analyzed 116 AIS patients deemed eligible for intra-arterial therapy who were seen at four Chicago-area medical centers. More than half (58.6%) were transferred from outside institutions.
Dr. Shaibani and his colleagues found that transfer patients tended to be younger than nontransfers (59 years vs. 69 years, P = .002) and were less likely to have had a history of prior stroke (3% vs. 22%, P = .002) or cardiac problems (18% vs. 37%, P = .040). Transfer patients had worse National Institutes of Health Stroke Scale scores at baseline (20 vs. 17, P = .005) and were more likely to have internal carotid artery occlusions (45.6% vs. 22.9%, P = .012). No differences between groups were found for THRIVE (Totaled Health Risks in Vascular Events) scores, a clinical scoring system designed to help clinicians predict a patient’s chances of achieving a good outcome after AIS.
At 90 days after intra-arterial therapy, only 16% of transfer patients had a good functional outcome, as defined by a modified Rankin Scale score of 0-2. Significantly more nontransferred patients (60%) had a good outcome (P less than .001). In a multivariate analysis, transfer status was an independent predictor of poor functional outcome (adjusted odds ratio = 0.05; 95% confidence interval, 0.011-0.222), after the findings were adjusted for relevant covariates such as baseline risk factors, stroke severity, time to intra-arterial therapy, or procedural success or complications. No differences between groups were found for median symptom onset to groin puncture times, rates of successful recanalization (defined as thrombolysis in cerebral infarction grade 2b or higher), or the presence of symptomatic intracranial hemorrhage.
Dr. Shaibani said it was not clear what factors were contributing to the findings. He said future work should explore the influence of baseline/final infarct volume, premorbid functional status, and poststroke care.
Dr. Shaibani reported that he had no relevant financial disclosures.