Short Door-to-Needle Times in Acute Ischemic Stroke and Prospective Identification of Its Delaying Factors.

Background: The clinical benefit of intravenous thrombolysis (IVT) in acute ischemic stroke is time dependent. Several studies report a short median door-to-needle time (DNT; 20 min), mainly in large tertiary referral hospitals equipped with a level 1 emergency department, a dedicated stroke team available 24/7, and on-site neuroimaging facilities. Meanwhile, in daily practice, the majority of stroke patients are admitted to secondary care hospitals, and in practice, even the generous benchmark of the American Heart Association (a DNT of 60 min in >80% of the cases) is met for a minority of patients treated with IVT. The first objective of our study was to investigate if, in a secondary care teaching hospital rather than a tertiary referral hospital, similar short DNTs can be accomplished with an optimized IVT protocol. Our second objective was to prospectively identify factors that delay the DNT in this setting.

Methods: A multicenter, consecutive cohort study of patients treated with IVT in one of two secondary care teaching hospitals. In both hospitals, data of consecutive stroke patients as well as median DNTs and factors delaying this were prospectively assessed for each patient. Multivariable logistic regression analysis was used to evaluate associations between patient-related and logistic factors with a delayed (i.e. exceeding 30 min) DNT.

Results: In total, 1,756 patients were admitted for ischemic stroke during the study period. Out of these, 334 (19.0%) patients were treated with IVT. The median DNT was 25 min (interquartile range: 20-35). A total of 71% (n = 238) had a DNT below 30 min. In 63% of the patients treated with IVT the DNT was delayed by at least one factor. Patients without any delaying factor had a 10 min shorter median DNT compared to patients with at least one delaying factor (p < 0.001). The following factors were independently associated with a delayed DNT: uncertainty about symptom onset, uncontrolled blood pressure, fluctuating neurological deficit, other treatment before IVT, uncertainty about (anti-)coagulation status, other patient-related factors, and incorrect triage.

Conclusions: Short median DNTs can also be accomplished in secondary care. Despite the short DNTs, several delaying factors were identified that could direct future improvement measures. This study supports the view that as a performance measure, the current DNT targets are no longer ambitious enough and it adds to the knowledge of factors delaying the DNT.