Oct. 20 (HealthDay News) -- Tissue plasminogen activator (tPA) treatment benefits stroke patients when used up to 4.5 hours after a stroke, according to German researchers who said their findings provide further evidence to increase the tPA treatment window from the current three hours to 4.5 hours.

Previously published findings from the ECASS III study indicated that tPA treatment led to better outcomes than placebo in stroke patients treated from three hours to 4.5 hours post-stroke.

In this new study, Dr. Werner Hacke, of the University of Heidelberg, and colleagues conducted a secondary analysis of ECASS III data using different endpoints. They focused on the efficacy and safety of tPA treatment (using alteplase) and also looked for any factors or patient subgroups that might affect treatment outcome.

The study included 418 patients who received alteplase from three hours to 4.5 hours after a stroke, and 403 patients who received a placebo. The results showed a clear benefit from treatment with alteplase in all types of patients, including those younger and older than 65 years, men and women, and those with or without a history of diabetes, stroke or high blood pressure.

The researchers also found that alteplase was beneficial, regardless of the severity of the stroke.

"Our results support the use of this thrombolytic drug in the extended period across a broad range of patient subgroups who meet the requirements of the European product label but miss the approved treatment window of 0-3 hours," Hacke and colleagues wrote. "Even with these encouraging findings, the most important principle of acute stroke intervention should, however, not be lost -- i.e., time remains critical and fast treatment still provides the greatest chance of recovery."

The study was released online Oct. 20 in advance of publication in the December print issue of The Lancet.

"Thrombolytic therapy benefits patients, should be given as early as possible, offers sustained benefit, and is cost-effective," Dr. Patrick Lyden, of Cedars-Sinai Medical Center in Los Angeles, wrote in an accompanying editorial.

"The physician must, as always, diligently undertake a careful history and physical examination, look at the non-contrast brain CT scan carefully, and follow the appropriate protocol. All of these steps will result in substantial benefit to public health and will safely benefit many patients. But 'time is brain,' and therapy must be given as soon as possible after the patient arrives -- there is indeed not a moment to lose."

SOURCE: The Lancet, news release, Oct. 20, 2009