SAN DIEGO – An approach that uses CT perfusion findings to select patients for mechanical thrombectomy resulted in effective, safe treatment of stroke patients beyond the traditional 7- to 8-hour treatment window, results from a single-center study demonstrated.
"CT perfusion–based patient selection for endovascular therapy enables us to treat patients who would otherwise have not received such therapy based on time criteria," Jordan Magarik said at the annual meeting of the Society of Neurointerventional Surgery. "We have seen improved outcomes over historical controls and improved safety as well. The bottom line is that patient selection is paramount. When patients are selected based solely on CT perfusion imaging, we are finding very similar rates of good functional outcome regardless of when they were treated, whether it’s 8 or 18 hours after symptom onset."
When the Medical University of South Carolina (MUSC) in Charleston launched its Comprehensive Stroke Center in 2008, clinicians there devised an alternate method of selecting patients solely based on the CT perfusion findings, regardless of their time from symptom onset. For the current study, Mr. Magarik, who is a medical student at MUSC, and his associates reviewed the records of 140 stroke patients who were treated at the stroke center from 2008 to 2011. The mean age of the patients was 67 years. Data of interest included age, concurrent administration of IV tissue plasminogen activator (TPA), time to treatment, presenting National Institutes of Health Stroke Scale (NIHSS) score, 90-day modified Rankin score (mRS), and angiographic recanalization rates. The primary intra-arterial device used was the Penumbra System.
All 140 patients underwent mechanical thrombectomy; 54 received IV TPA in addition to mechanical thrombectomy and 86 only underwent mechanical thrombectomy. The mean NIHSS score was 16.2, and the mean time to treatment was 11.3 hours, which is well beyond the traditional 7- to 8-hour time window used in mechanical device trials, said Mr. Magarik.
The majority of patients (87%) achieved a partial or full recanalization and 10% of patients suffered symptomatic intracranial hemorrhage, which is consistent with previous trials.
More than one-third of patients (38%) achieved a 90-day mRS of 0-2, and 53% achieved a 90-day mRS of 0-3. The mortality rate was 25%, which is consistent with previous trials.
When the researchers divided patients on the basis of mean time from symptom onset to treatment, they observed no statistically significant differences in the rates of patients with mRS of 0-2 (31% among those treated within a 7-hour window vs. 42% among those treated beyond a 7-hour window) or mRS of 0-3 (49% among those treated within a 7-hour window vs. 55% among those treated beyond a 7-hour window).
"Many patients in the later time group are presenting 15 or 18 hours out from symptom onset, yet they are still achieving a very similar rate of good functional outcome," Mr. Magarik said. "We believe this is because they were selected based on their CT perfusion findings."
Mr. Magarik said that he had no relevant financial disclosures to make.