Delayed door to puncture time during off-duty hours is associated with unfavorable outcomes after mechanical thrombectomy in the early window of acute ischemic stroke.

Backgrounds: The impact of off-duty hours mechanical thrombectomy on outcomes remains a subject of controversy. The impacts of off-duty hours on procedures are influenced by various factors, but the most critical one is the time delay in initiating the procedure after the patient's arrival at the emergency room. Recently, a report suggested that the impact of time delay on post-procedural outcomes is evident in patients who arrive at the emergency room within 6 h of symptom onset, referred to as the "early window." We hypothesized that the impact of procedure delays on outcomes during off duty-hours would be most significant within this early window. This study aimed to investigate the impact of door-to-puncture time (DTPT) delays in patients who underwent mechanical thrombectomy for acute ischemic stroke (AIS) during off-duty hours in both the early and late time windows.

Methods: We investigated patients who presented to the emergency center between 2014 and 2022. Among a total of 6,496 AIS patients, we selected those who underwent mechanical thrombectomy within 24 h of the onset of acute anterior circulation occlusion. The eligible patients were divided into two groups: those who arrived within 6 h of symptom onset and received the procedure within 8 h (early window), and those who received the procedure between 8 h and 24 h after symptom onset (late window). The study assessed the association between the onset to puncture time in each group and poor outcomes, measured by the modified Rankin scores(mRs) at 90 days. Furthermore, the study analyzed the impact of receiving the procedure during off-hours in both the early and late windows on outcomes. Specifically, the analysis focused on the impact of delayed DTPT in patients during off-duty hours on outcomes measured by the 90-days mRS.

Results: Among the eligible patients, a total of 501 AIS patients underwent mechanical thrombectomy for acute anterior circulation occlusion within 24 h. Of these, 395 patients (78.8%) fell into the early window category, and 320 patients (63.9%) underwent the procedure during off-duty hours. In the early window, for every 60-minute increase in OTPT, the probability of occurrence a poor outcome at 90 days significantly increased in the fully adjusted model (OR = 1.21; 95% CI, 1.02 to 1.43; p = 0.03). In the early window, delayed procedures during off-duty hours (exceeding 103 min of DTPT) were identified as an independent predictor of poor outcomes (OR = 1.85; 95% CI, 1.05 to 3.24; p = 0.03). However, in the late window, there was no association between DTPT and outcomes at 90 days, and the impact of DTPT delays during off-hours was not observed.

Conclusions: Through this study, it became evident that the impacts of off-duty hours in mechanical thrombectomy were most pronounced in the early window, where the impact of time delay was clear. Therefore, it is believed that improvements in the treatment system are necessary to address this issue.