Successful recanalization is significantly associated with higher rates of good outcomes when selection of patients is based on imaging.
SEATTLE—Intraarterial recanalization therapies are safe beyond eight hours of stroke onset in patients who are selected based on CT perfusion imaging or MRI, according to a study presented at the 61st Annual Meeting of the American Academy of Neurology.
Tudor G. Jovin, MD, Assistant Professor of Neurology at the University of Pittsburgh, and colleagues identified 133 patients (51% male; median age, 65) with a mean NIH Stroke Scale Score of 15 for a retrospective, multicenter study. The mean time from stroke symptom onset to treatment was 17 hours (range, 8 to 110 hours). Occlusion sites were M1 middle cerebral artery (MCA) (57/43%), M2 MCA (13/10%), internal cerebral artery (ICA) terminus (29/22%), tandem ICA origin/MCA (23/17%), and tandem ICA origin/ICA terminus (11/8%). Treatment included intraarterial thrombolytics (55/133, 42%), MERCI device (87/133, 67%), and other mechanical modalities (34/133, 49%).
Dr. Jovin noted that modern neuroimaging techniques often identify patients with large penumbral volumes beyond the eight-hour time frame and that such patients may be appropriate candidates for revascularization therapies.
Defined by independent level of functioning, good outcomes were achieved by 47.5% of patients (modified Rankin Scale [mRS] score, 0 to 2). “This sounds very promising, but we don’t know the natural history of this group of patients,” Dr. Jovin commented to Neurology Reviews. “The treatment group needs to be compared to a control group treated with conventional therapy,” Dr. Jovin continued. “I personally don’t think that aspirin or heparin is going to be significantly different with regard to outcomes.”
Acceptable outcomes (mRS scores, 0 to 3) were achieved by 62% of patients. “The rate of symptomatic intracranial hemorrhage (9.6%) was encouraging,” said Dr. Jovin, adding that the rate compared favorably to that in patients who were treated within six to eight hours from symptom onset. In addition, inpatient mortality was 20%.
Seventy-two percent of patients achieved successful recanalization, defined as Thrombolysis in Myocardial Infarction (TIMI) scores of 2 to 3. The proportion of good outcomes in patients who achieved successful recanalization was 55%, versus 25.6% in those who did not achieve recanalization. “Patients who recanalized were more likely to achieve a good outcome and confirms results from other trials showing that successful recanalization increases the chance of a good clinical outcome,” Dr. Jovin commented. In addition, mortality rates were 16% in those who underwent recanalization, versus 35.9% who did not.
“In univariate and multivariate analyses, age (odds ratio [OR], .96), time to treatment (OR, 1.11), and successful recanalization (OR, 3.21) were significantly associated with favorable outcomes,” Dr. Jovin stated. “[We did not find] an inverse relation between time to treatment and chances of a good outcome. People who presented very late were likely to have a larger mismatch and a smaller ischemic core. [However], we are not implying that people who present later do better.”