ISC: Less than one-third of stroke patients receive timely thrombolysis
Less than one-third of acute stroke patients treated with intravenous tissue plasminogen activator (tPA) receive the thrombolytic drug within 60 minutes of their hospital arrival, according to research presented at the American Stroke Association's International Stroke Conference (ISC) 2011 in Los Angeles. The research is simultaneously published Feb. 10 in Circulation.

While there was a modest improvement in delivery of tPA within 60 minutes or less among hospitals participating in American Heart Association/American Stroke Associtation Get With The Guidelines (GWTG)–Stroke quality improvement program, the researchers suggested that more needs to be done to highlight the program, such as disseminating best practice strategies for its achievement that include:
  • Pre-arrival notification by EMS providers;
  • Written protocols for acute triage and patient flow;
  • Single call systems to activate all stroke team members;
  • CT or MRI scanner clearance as soon as the center is made aware of an incoming patient;
  • Locating the CT scanner in the emergency department (ED);
  • Storage and rapid access to thrombolytic drug in the ED;
  • Collaboration in developing treatment pathways among physicians, nurses, pharmacists and technologists from emergency medicine, neurology and radiology; and
  • Continuous data collection to drive iterative system improvement

Tissue plasminogen activator is a proven intervention for acute ischemic stroke patients, but can only be given within 4.5 hours after stroke onset and has the greatest benefits when given earlier in that timeframe, according to researchers.

To better understand the timely delivery of tPA, Gregg C. Fonarow, MD, a professor of cardiovascular medicine at the University of California, Los Angeles, and colleagues analyzed data from 1,082 hospitals involved in the GWTG–Stroke program between April 2003 and September 2009. Specifically, the researchers assessed 25,504 acute ischemic stroke patients treated with tPA within three hours of symptom onset.

The mean door-to-needle time for intravenous tPA administration for the 25,504 patient cohort was 79 minutes.

Only 26.6 percent of patients received tPA in 60 minutes or less—"with only modest improvement over the past 6.5 years"—from 19 percent in 2003 to 29 percent in 2009, Fonarow said.

Patients who were younger, male, white and had no prior stroke were most likely to receive the therapy within the 60-minute window.

"It is a concern that older patients, women and black patients were less likely to receive timely tPA administration," he said.

Patients in whom door-to-needle times were 60 minutes or less were more likely to arrive during on-hours (Monday through Friday, 7 a.m. to 5 p.m.) and by EMS transport. In addition, symptom onset-to-arrival times were shorter in patients with door-to-needle times greater than 60 minutes, "suggesting that hospitals were taking a more relaxed approach to the administration of tPA in earlier arriving patients," Fonarow said.

Among those with door-to-needle times within 60 minutes for tPA, the median time from door-to-imaging was 18 minutes, whereas it was significantly longer at 24 minutes in those patients with door-to-needle times greater than 60 minutes, Fonarow said. While 68.5 percent of those with door-to-needle times within 60 minutes had door-to-imaging times within 25 minutes, it was only 53 percent for those with door-to-needle times greater than 60 minutes. The difference was significant.

"Thus, delays in imaging are playing some component in longer door-to-needle times for tPA in acute ischemic stroke," Fonarow said. "We did not however analyze the data by type of brain imaging, so this study cannot address any comparison between CT versus MRI and door-to-needle times."

Hospitals that had greater annual volumes of tPA-treated stroke patients were more likely to administer the therapy within 60 minutes of hospital arrival.

"This suggests that greater hospital team experience translates into improved performance," said Fonarow, immediate-past chair of the GWTG steering committee.

The proportion of patients with door-to-needle times of 60 minutes or less varied widely by hospital. Some hospitals did not achieve tPA administration within the ideal time frame for any patient. Other hospitals achieved door-to-needle times of 60 minutes or less in 80 percent or more of patients.

Hospital size, academic or nonacademic status, primary stroke center certification and geographic region were not independently associated with door-to-needle times within 60 minutes.

There also was an unadjusted relationship of modest improvement of door-to-needle times of less than 60 minutes with the duration of hospital participation in the GWTG-Stroke Program.

"Given the slow progress in achieving faster door-to-needle times and the large remaining 'gap,' we believe these data support the need for a collaborative national campaign to improve timely treatment with intravenous tPA," the authors wrote.

Overall, the most powerful patient characteristics independently associated with door-to-
needle time in less than 60 minutes were:
  • More severe neurologic deficits
  • Arrival on-hours rather than off-hours, and
  • Longer onset to arrival times.

Other patient factors independently associated with decreased odds of door-to-needle times in less than 60 minutes included:
  • Older age
  • Female sex
  • Black race, and
  • Medical history of atrial fibrillation, diabetes and prior stroke/transient ischemic attack.

In another study presented at the ISC, Fonarow and colleagues found that in-hospital mortality was significantly lower among patients treated more timely with tPA, and there were fewer complications with more timely treatment.

"These findings demonstrate for the first time that shorter door-to-needle times improve the likelihood that acute ischemic stroke patients will survive," Fonarow said.

The study identifies substantial opportunities nationally for improving the speed of tPA therapy initiation in acute ischemic stroke patients, he said.

"These findings suggest there is a critical need for a targeted campaign tailored to increase the portion of patients with door-to-needle times 60 minutes or less, such as the recently launched American Stroke Association Target: Stroke initiative," Fonarow said. "Nearly 1,000 hospitals across the country are now registered to use Target: Stroke information and tools to improve their door-to-needle time for administering tPA to appropriate stroke patients."