Ammad Mahmood, MBChB

Kaesmacher J, Maamari B, Meinel TR, Piechowiak EI, Mosimann PJ, Mordasini P, Goeldlin M, Arnold M, Dobrocky T, Boeckh-Behrens T, et al. Effect of Pre- and In-Hospital Delay on Reperfusion in Acute Ischemic Stroke Mechanical Thrombectomy. Stroke. 2020;51:2934–2942.

Following the onset of vessel occlusion, the progressive detriment in the effectiveness of therapy is known and the mantra of “time is brain” is imbedded in the delivery of stroke pathways. Reducing door-to-needle, admission-to-groin (ATG), and symptom-to-admission (STA) times requires robust public health messaging, efficient pre-hospital care, and streamlined inpatient pathways. Analysis of the HERMES data suggested that prolonged ATG times were associated with reduced chances of achieving reperfusion. However, symptom-onset-to-groin (STG) times were not found to have a significant effect on reperfusion, though this was attributed to strict inclusion criteria for the HERMES trials.

In this study, real-world data from the BEYOND-SWIFT registry studied the effect of ATG, STA and STG on the likelihood of reperfusion in 2386 patients, of whom 2008 (84%) had successful reperfusion (TICI 2b-3). There was a small reduction in chance of successful reperfusion with increasing STA (aOR 0.97 [0.94–0.99] per hour). There was a stronger relationship between increasing ATG with reduced chance of successful reperfusion, aOR, 0.87 [0.79–0.96] per hour, meaning a 13% reduced chance of successful reperfusion with each hour of increase in ATG time. STG time was also significantly related, but this effect was attributed to the ATG time period.

Factors associated with decreased ATG time included transfer admissions, use of CT rather than MRI, higher admission NIHSS, patient conforming with AHA/ASA guidelines and treatment in the most recent years of the registry. Late presentation and use of general anesthesia were associated with longer ATG times. There was a 19% relative odds reduction in achieving mRS 0-2 for each hour of in-hospital delay. When correcting for confounding factors such as treatment in later years, interventional technique, and stroke etiology, the effect of increased ATG on chance of reperfusion was maintained.

In this real-world cohort, the authors identified use of MRI or general anesthesia, late presentation, low admission NIHSS, and not meeting early time window AHA/ASA criteria as factors which prolonged ATG and reduced the chance of successful reperfusion. Points of improvement include streamlined MRI protocols and quicker decision-making for patients who are borderline for meeting conventional treatment criteria. The comparatively weaker relationship with STA times than ATG times raises a point of interest that warrants further research.