Abstract Background and aims As EVT has become the standard treatment for large vessel occlusion (LVO), timely reperfusion is crucial for favorable outcomes. Prolonged door-in–door-out (DIDO) time during transfer from primary to comprehensive stroke centers (PSCs to CSCs) remains a major source of delay. Using data from the Tainan–Chiayi Stroke Network (TCSN) in Taiwan, this study investigated the contributors to DIDO delay and its impact on EVT outcomes. Methods The TCSN includes 6 CSCs and 13 PSCs. We retrospectively analyzed EVT transfers (2021–2025), defining delayed DIDO as 90 minutes per AHA/ASA recommendations. Causes of delay were categorized, and univariate and multivariate analyses were performed to identify predictors of prolonged DIDO. Results Among 276 patients, 156 (56.5%) had delayed DIDO. Delayed DIDO was more common among patients transferred from rural PSCs, those undergoing CTA at the PSC, and those arriving beyond 8 hours (all P 0.01). The most frequent causes of delay were necessary patient management and unrecognized LVO. In multivariable analysis, performing CTA at the PSCs independently prolonged DIDO by an estimated 38 minutes, whereas unrecognized LVO was associated with the greatest delay (approximately 168 minutes). Despite significantly longer transfer workflow intervals (PSC door-to-final EVT time 271 vs. 208.5 minutes), clinical outcomes, including sICH, mortality, and 3-month mRS, did not differ between groups. Conclusions A substantial proportion of DIDO delays persists during interhospital transfer. Targeted interventions, including optimized prehospital triage, streamlined imaging protocols, and improved early recognition of LVO, may reduce delays and expedite access to EVT for eligible patients. Conflict of interest All authors: nothing to disclose
Cheng et al. (Fri,) studied this question.