Thrombolysis Road Test.
That proposition is now undergoing definitive testing in the Early Reteplase Thrombolysis in Myocardial Infarction-19 (ER TIMI-19) trial.
If this study demonstrates that prehospital thrombolysis is advantageous--as seems likely based upon the strong supporting evidence--American medicine will surely undergo a paradigm shift in the management of acute MI, Dr. Ron M. Walls predicted at the annual scientific sessions of the American Heart Association.
Pooled data from 8,318 U.S. patients in published series showed that prehospital thrombolysis was associated with a 17% relative reduction in mortality, compared with in-hospital thrombolysis. In Miami and a few other areas, prehospital thrombolysis is already routine. But national health care policy is unlikely to embrace prehospital intervention without evidence.
In ER TIMI-19, 1,000 MI patients under age 75 in several regions of the United States will receive 10 U of rereplase in the ambulance, with a second bolus to be administered in the vehicle if the transport time exceeds 30 minutes. The decision to treat will be in the hands of a medical control physician at the hospital, who will have examined a 12-lead ECG obtained in the field and transmitted by paramedics.
Paramedics will be responsible for the initial ECG interpretation and deciding whether to send the results to the hospital. One of the likely advantages of prehospital thrombolysis is that emergency medical services personnel, far more than physicians, are amenable to being told exactly what to do via strict management protocols, Dr. Walls said.
Patient outcomes will be compared with those of an historical control group, which consists of MI patients who dialed 911 and received in-hospital thrombolytic therapy during the 6 months preceding the study ER TIMI-19 should be completed by the end of 2000.