A “CTA-for-All” stroke imaging policy improved large vessel occlusion (LVO) detection, fast-tracked intervention and improved outcomes in a recent study of patients with acute ischemic stroke (AIS), researchers reported in Stroke.
Right now, the standard of care for patients who present to the hospital within 6 to 24 hours of experiencing AIS with LVO is mechanical thrombectomy (MT), lead author Stephan A. Mayer, MD, and colleagues said. But thrombectomy is a time-sensitive procedure, and we’re struggling to identify patients best suited for MT within what’s typically a limited time frame.
"Combined noncontrast computed tomography (NCCT) and CT angiography (CTA) have been championed as the new minimum standard for initial imaging of disabling stroke,” Mayer, a neurologist at Henry Ford Hospital in Detroit, and co-authors wrote in their paper. “Patient selection criteria that impose arbitrary limits on time from last known well (LKW) or baseline National Institutes of Health Stroke Scale (NIHSS) score may delay CTA and the diagnosis of LVO.”
For their study, Mayer et al. assessed the efficacy of a CTA-for-All stroke imaging protocol—something Michigan’s Henry Ford Health System had recently implemented. CTA was previously reserved for patients presenting within 6 hours of LKW with an NIHSS score of 6 or greater; under CTA-for-All, all potential stroke patients who present to the hospital within 24 hours of LKW, regardless of their baseline NIHSS score, undergo both NCCT and CTA.
The researchers compared treatment processes and outcomes between patients with AIS admitted one year before (388 patients) and one year after (515 patients) the health system implemented the new policy. After the protocol was implemented, more AIS patients underwent CTA (91% vs. 61% of patients before the new policy) and had CTA performed at the same time as initial NCCT (78% vs. 35%).
Average time from emergency department arrival to CTA was also shorter after the hospital implemented the new protocol, dropping from a mean 43 minutes to 29 minutes. Physicians detected more cases of LVO (166 vs. 96; 32% vs. 25% of all AIS) and performed more MT procedures (108 vs. 68; 21% vs. 18% of all AIS) under the new policy, and LVO patients who presented within six hours of LKW saw speedier MTs and more favorable outcomes.
Though patients with LVO were more likely to be discharged with better outcomes after the policy was implemented, Mayer and colleagues said the odds of a favorable outcome after protocol implementation were insignificant after adjusting for age and baseline NIHSS scores.
“These findings suggest that a uniform CTA-for-All imaging policy for stroke patients presenting within 24 hours is feasible and safe, improves LVO detection, speeds intervention and can improve outcomes,” the authors wrote. “The benefit appears to primarily affect patients presenting within six hours of symptom onset."