Improving Door To Needle Time In Stroke Patients

One year after their thrombotic episode, ischemic stroke patients who were treated with intravenous tissue plasminogen activator who experienced door to needle times that were longer than 45 minutes had higher all cause mortality and higher all cause hospital readmission than those with shorter times to treatment, according to Gress Fonarow, MD., of the University of California Los Angeles. 

After arrival at the hospital within a 90 minute window, every 15 minute increase in door to needle time increased the risk of a 1 year all cause case of death or readmission. "Faster treatment translates into better long-term outcomes in patients with stroke," Fonarow said. “For every 15 minutes improvement in treatment time, improvements in 1-year outcomes were observed.”

Quicker tPA treatment is associated with better short term outcomes, but it is less clear whether faster treatment also has long term benefits, notes Christopher Muth, MD, of Rush University Medical Center in Chicago and senior editor of JAMA, in an accompanying commentary.

"Clinical trial data have not demonstrated a long-term mortality benefit with thrombolytic therapy, perhaps because trials were underpowered for this outcome," Muth wrote. Observational studies have shown better long-term survival in tPA-treated than untreated patients, but have not matched granular treatment data with long-term outcomes, he added.

In this study detailed information about time to treatment from hospitals participating in the Get With The Guidelines - Stroke Registry were linked with long term clinical outcomes from Medicare claim data, and the associations between door to needle times and 1 year outcomes were evaluated for 61,416 patients with acute ischemic stroke who were treated with intravenous tPA from 2006-2016 within 4.5 hours from the time they were last known to be well. 

The median age was 80 years old, 82% were white, and 43.5% were men, with the median door to needle time being 65 minutes. 48,666 patients had a door to needle time longer than 45 minutes and they were found to have a significantly higher 1 year all cause mortality rate and a higher all cause hospital readmission rate than those who were treated within 45 minutes. However, they did not have significantly higher recurrent stroke readmission at 1 year. 

34,367 patients had door to needle times longer than 60 minutes, these patients also had significantly increased all cause mortality and all cause readmission rates than those treated within 60 minutes. 

Door to needle times that were within 30 minutes were not associated with better 1 year outcomes, but the analysis may have been underpowered for this small group of patients that was only 5.6% of the group, according to the researchers. 

Although the large sample size of the group is advantageous it also has limitations that may affect the generalizability of the findings such as only older adults being included and over 41,000 participants in the registry were excluded because their records could not be linked to Medicare claims which included a higher proportion of racial and ethnic minorities. Additionally those who were treated with concomitant therapy with intra-arterial reperfusion techniques were not included in this study.