Review of: Smalling RW, Giesler GM, Julapalli VR, et al: "Pre-hospital reduced-dose fibrinolysis coupled with urgent percutaneous coronary intervention reduces time to reperfusion and improves angiographic perfusion score compared with prehospital fibrinolysis alone or primary percutaneous coronary intervention: Results of the PATCAR pilot trial." Journal of the American College of Cardiology. 50(16):1612-1614, 2007.
I don't usually comment on science reported only in editorial remarks. However, this correspondence in the Journal of the American College of Cardiology caught my attention because it was only this past year that I and several other experts were asked whether we believed in any benefit from reduced dose fibrinolytics being administered by EMS.
The data presented was from a pilot trial of an on-going wider study. The question is, "Does the administration of a half-dose of retaplase by EMS significantly affect the time to reperfusion and subsequent angiographic perfusion scores when compared to fibrinolysis alone, primary coronary intervention (PCI) instead of EMS retaplase, or in combination with PCI?"
The study identified 60 ST-segment Elevation Myocardial Infarction (STEMI) patients. Of these 60, 46 were determined to be candidates for fibrinolytic therapy. All were given 10 units of retaplase, IV heparin and oral aspirin. They were then randomized to either receive a second, 10-unit does of retaplase (Group A) or urgent catheterization with PCI (Group B). The remaining 14 non-fibrinolytic eligible patients (Group C) along with an additional 13 patients who arrived by EMS agencies not participating in the study were taken immediately to PCI.
A summary of their findings shows that Group B patients were significantly more likely to have good to excellent perfusion by the time of catheterization, less ischemia as indicated by shorter times to reperfusion, and improved survival.
Interestingly, 68% of patients crossed over from Group A to rescue PCI for persistent symptoms, ST-segment elevation or hemodynamic instability. Less than 50% of these had good to excellent perfusion at catheterization. This suggests that routine PCI immediately after prehospital fibrinolysis, irrespective of clinical setting, should be the standard of care.
I stand corrected on the opinions I voiced this past year at EMS Expo. The findings of this pilot study will need to be verified with the full trial, but if they hold up I believe we ll have sufficient evidence to support the administration of fibrinolytics by EMS.
This study underscores the importance of beginning the process now to develop STEMI programs to ensure that EMS can acquire 12-leads, either interpret them or have them interpreted remotely, and deliver the patient to the nearest PCI-capable center.
Additionally, a vital component will be the ability of EMS providers to determine which patients are eligible for fibrinolytics by obtaining an accurate history and using stringent protocols to drive quality patient care. Each of these components must be in place before you launch your STEMI program. The ultimate goal is improved patient outcomes, but the process of getting there will require education, funding and cooperation of all interested stakeholders.
I'm excited about the future of STEMI research. This is the kind of study that truly measures the potential impact of EMS.