As discussed in"Prehospital Fibrinolysis in Concert with Rapid PCI" inMarch 2008 JEMS, acute myocardial infarction (AMI) remains a leading cause of death in the U.S. despite the many recent advances in cardiac care. Re-establishing blood flow through the infarct-related coronary artery using lytic agents or balloon angioplasty with or without stent placement, also known as percutaneous coronary intervention (PCI), as early as possible, has been the main focus of STEMI care.
But there's controversy over which therapy is superior -- IV lytic therapy that could be administered quickly in the emergency department, or PCI, which would take longer but potentially be more definitive and theoretically have less associated risk of hemorrhage.
In an effort to contribute to knowledge that could resolve this controversy, Houston Fire Department (HFD) EMS began a pilot study on reduced-dose prehospital fibrinolysis used with urgent PCI to assess the effects on STEMI patients. The pilot study is known as PATCAR (Prehospital Administration of Thrombolytic Therapy with Urgent Culprit Artery Revascularization) and was undertaken through a partnership with the University of Texas Health Science Center at Houston Medical School and the university's teaching institution, Memorial Hermann Hospital.
One of the initial purposes of this pilot trial is to demonstrate the feasibility of urban paramedics to accurately and safely identify fibrinolytic-eligible STEMI patients and initiate therapy appropriately.
When an HFD paramedic arrives on scene and identifies a patient as experiencing a STEMI and a potential candidate for the administration of a fibrinolytic, the paramedic reviews the HFD Acute Myocardial Infarction Therapy Inclusion and Exclusion Criteria and enrolls the patient into the program. (Download the PDF at the bottom of the page to review the criteria.)
Four STEMI patient groups are being evaluated:
- Group A: Full-dose, prehospital initiated fibrinolysis (given half-dose in the ambulance and half-dose 30 minutes later) followed by treatment in the coronary-care unit;
- Group B: Half-dose prehospital fibrinolysis followed by urgent PCI;
- Group C: Patients who are ineligible for fibrinolysis; and
- Group D: Patients not transported by participating EMS units.