Meta-analysis on stroke treatment: 4.5-hour time window for thrombolysis confirmed

12.01.2015 22:23

In Germany, approximately 260,000 people suffer a stroke each year. Because strokes are usually painless for the affected person, many patients still arrive at a specialized stroke unit too late. Treatment must begin as quickly as possible to prevent permanent neurological damage or even death. The earlier thrombolysis is initiated, the better the treatment outcomes for patients. This is the conclusion of a meta-analysis of all major therapy studies, recently published in the medical journal The Lancet. The study confirmed that thrombolysis is effective within 4.5 hours of a stroke, even in older individuals, explain the German Stroke Society (DSG) and the German Society for Neurology (DGN).

Four out of five strokes are caused by a blood clot in a cerebral artery, which can be dissolved in some patients by an infusion of the enzyme alteplase, a procedure known as thrombolysis. "The effectiveness of thrombolysis was first demonstrated in a clinical trial almost 20 years ago, and it is now firmly established in all certified stroke units in Germany," explains Prof. Dr. Hans-Christoph Diener, Director of the Department of Neurology at Essen University Hospital. However, thrombolysis is only performed on about 10 percent of stroke patients in Germany. "This is primarily because only about 30 to 40 percent of stroke patients reach the hospital in time," adds the spokesperson for the German Society of Neurology (DGN). In some European countries, but not in Germany, treatment is also discouraged in cases of mild or particularly severe strokes, as well as in people over 80 years of age.

The „Stroke Thrombolysis Trialists’ Collaborative Group,“ an international research team led by Prof. Dr. med. Dr. hc Dipl. Psych. Werner Hacke, Senior Professor of Neurology at Heidelberg University Hospital, has therefore summarized the results from nine studies. „For the meta-analysis, we individually evaluated the data of all 6,756 study participants to obtain the most accurate picture possible of the effectiveness and potential risks,“ explains Professor Hacke.

The meta-analysis confirmed the findings of the individual studies: Thrombolysis is more successful the earlier it is initiated. A patient's chances of surviving a stroke without severe disability were 75 percent higher in the first three hours than in the control group that did not receive thrombolysis. If thrombolysis was initiated three to 4.5 hours after the stroke, the benefit was still 26 percent. "Our results confirm the effect of thrombolysis within the 4.5-hour time window," explains Professor Hacke. At a later time, the expert adds, its use always remains a case-by-case decision.

Many doctors are currently hesitant to use thrombolytic therapy in elderly patients. "The fear of complications is widespread," says Prof. Dr. Joachim Röther, press spokesperson for the German Stroke Society (DSG) and head of the Neurology Clinic at the Asklepios Clinic Altona. Since 1,729 participants in the studies were over 80 years old, the current meta-analysis provides reliable results for the first time. "The success rate of thrombolytic therapy was by no means lower in the very elderly; in fact, the results tended to be even better," reports Professor Röther. The expert also sees no problems regarding the risk of bleeding in older patients.