Primary Stroke Centers Use More Thrombolytic Therapy Than Other Hospitals, but Overall Numbers Still Low

Alice Lium

October 14, 2009

October 14, 2009 (Baltimore, Maryland) — A new study using data from the National Inpatient Sample, a nationally representative database, shows that although thrombolytic therapy with recombinant tissue plasminogen activator (r-tPA) is used more often at primary stroke centers, only about 3% of ischemic stroke patients were treated at these centers between 2004 and 2006. At hospitals not designated stroke centers, the number was even lower, at 1.3%.

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Dr. Leslie Lee describes the nationwide study.

"Thrombolysis is administered at profoundly low rates; overall, at the rate of 2% to 3% in the United States across the board," said lead author Leslie K. Lee, a medical student at Columbia University Medical Center, New York City.

Leslie Lee explaining the poster to another neurologist.

Thrombolytic therapy is the only therapy approved by the US Food and Drug Administration for acute ischemic stroke. When the therapies were developed in the 1990s, the hope was that they would become widely used.

"We've clearly fallen short of that goal," Mr. Lee said. He presented the new findings here at the American Neurological Association's 134th Annual Meeting in Baltimore, Maryland.

Daunting Task

Providing thrombolytic therapy to patients with acute ischemic stroke is daunting. Clinton Wright, MD, MSc, from the University of Miami, who was not involved in the study noted, "This study underscores the importance of an organized stroke center network within an institution to maximize the use of thrombolytic therapy. [There's] need for further work in this field to identify the barriers to the use of thrombolytics."

Many hospitals simply do not have the infrastructure and staff to provide thrombolysis as an option, Mr. Lee explained. The major problem probably is the limited time window for the therapy.

The recommendation has been that treatment must be administered within 3 hours of the onset of stroke symptoms, although a recent American Heart Association/American Stroke Association Science Advisory now states that tPA can be safely given out to 4.5 hours in selected patients, based on results of the third European Cooperative Acute Stroke Study.

Such prompt response, though, means the community must have an emergency network that can transport patients to a stroke center quickly. In addition, a hospital must have 24-hour physicians on call who are trained and licensed to provide thrombolytics, as well as 24-hour imaging to detect whether a patient is having a hemorrhagic or an ischemic stroke. The hospital also must have neuro-intensive care backup in case of hemorrhagic conversion of an ischemic stroke.

PSC Certification Is Valid

The Joint Commission (formerly the Joint Commission on Accreditation of Healthcare Organizations) in 2004 began certifying hospitals as Primary Stroke Centers (PSCs). In general, slightly more than half of the PSCs were teaching hospitals, 58% were in the western United States, and almost all of them were urban.

The PSCs had to meet a number of criteria, one of which was delivering timely thrombolytic therapy to ischemic stroke patients. Although the Joint Commission has statistics on thrombolysis, no study had assessed the entire swath of both stroke centers and non–stroke centers across the nation.

The researchers used the National Inpatient Sample, the largest inpatient all-payer healthcare database, which comprises one fifth of all the hospitalizations in the United States. The researchers compared treatment rates for 2004 to 2006 at hospitals that were later designated PSCs in early 2009 and then extrapolated to look at ischemic stroke patients over the entire country.

Data showed that 3.0% of patients at stroke centers received thrombolysis, whereas only 1.3% of patients at non–stroke centers received it.

A multivariable logistic regression adjusted for differences in patients and hospitals, and the statistical significance of the difference between PSCs and non–stroke centers persisted. Admission to a present-day PSC almost doubled the odds of receiving thrombolysis (odds ratio, 1.96; 95% confidence interval, 1.61 – 2.38).

As would be expected, intracranial hemorrhage was also higher at PSCs, where 5.7% of patients had a diagnosis of intracranial hemorrhage in the same hospitalization vs 4.8% at non-PSC hospitals.

Mr. Lee added that the study shows that the Joint Commission PSC designation has validity. "It isn't just a piece of paper. It means that these hospitals are truly able to deliver thrombolysis at significantly higher rates," he said.

There is more work to be done. This study assessed hospitals, not patient outcome, and the National Inpatient Sample administrative data source provides no patient history, no information on whether thrombolysis was appropriate or timely, and no long term-outcomes.

Mr. Lee noted that in the current climate of healthcare cost concerns, it is important to establish whether this is an appropriate, cost-effective therapy for hospitals to provide, or whether it should be provided only at some hospitals and stroke patients should be routed there.

This work was supported by the Doris Duke Clinical Research Foundation. Mr. Lee and colleagues have disclosed no relevant financial relationships.

American Neurological Association 134th Annual Meeting: Abstract M27. Presented Monday, October 12, 2009.