Needle Before Door Safe for STEMI Patients
By Chris Kaiser, Cardiology Editor, August 16, 2011
Note that this report summarizes a survey of programs worldwide that have successfully used pre-hospital fibrinolysis as a reperfusion strategy and suggests that this stategy is safe and can improve survival compared with in-hospital administration.
Note that whether a pre-hospital fibrinolytic strategy would be appropriate in the United States is unclear. Point out that the editorialist suggests that the major challenge to successful implementation of such a strategy is the regional variations in EMS resources in the United States.
Review
It's widely recognized that shortening "door-to-needle" time improves outcomes for STEMI patients, but starting lysis before the patient reaches the hospital may give an added edge.
An analysis of seven pre-hospital fibrinolysis programs confirmed a low reinfarction rate -- ranging from 2.4% (France) to 5.8% (England/Wales) -- reported Thao Huynh, MD, MSc, from McGill Health University Center in Montreal, Quebec, and colleagues.
Rates of in-hospital stroke also were low -- less than 2% of pre-hospital fibrinolysis patients (≤0.6% in most programs), according to the study in the August JACC: Cardiovascular Interventions.
But despite those benefits, pre-hospital fibrinolysis is the exception rather than the rule in the United States.
"The major challenge to successful implementation of a pre-hospital fibrinolytic strategy is the regional variations in EMS resources. The EMS system in the United States is particularly fractionated with a wide range of both funding and available services," wrote Timothy D. Henry, MD, from the Minneapolis Heart Institute Foundation, and Bernard J. Gersh, MB, CHB, DPhil, from the Mayo Clinic College of Medicine, Rochester, Minn., in an accompanying editorial.
The Minneapolis Heart Institute's regional STEMI system, for example, includes 33 hospitals and 10 clinics throughout Minnesota and Wisconsin and "requires integration with nearly 50 different EMS agencies and a wide spectrum of resource availability."
While it may be more difficult to enact STEMI programs (with fibrinolysis) in the U.S., "the most important insight from the survey is that fibrinolytic and PCI reperfusion strategies should no longer be considered mutually exclusive," Henry and Gersh wrote.
In the current study, researchers examined STEMI programs that included pre-hospital fibrinolysis in Sweden; France; England/Wales; Vienna, Austria; Edmonton in Alberta, Canada; Houston; and Nova Scotia.
Pre-hospital fibrinolysis is recommended by the European Society of Cardiology and has been in use in Europe for more than two decades, the researchers wrote.
While pre-hospital fibrinolysis is not as widespread in the U.S. or (Canada), pre-hospital ECGs are endorsed by the American Heart Association and the American College of Cardiology. Pre-hospital ECG is a crucial step for early lysis.
In the study, most ambulance personnel were trained to interpret ECGs, and only two programs – Vienna and France -- staffed their ambulances with physicians (95% and 100%, respectively).
In Vienna and Sweden, all STEMI patients were transported directly to a PCI hospital for primary PCI. In the other programs, direct transport varied.
In England/Wales, paramedics could initiate fibrinolysis. In the other programs, paramedics had to send the ECG to the hospital and wait for authorization from a physician.
Pre-hospital fibrinolysis was administered by paramedics in Houston, Nova Scotia and Edmonton; by nurses in Sweden; and by physicians in France and Vienna.
The mortality rate was generally low for those receiving pre-hospital fibrinolysis.
France had the lowest mortality at 2.7% in-hospital and 4.5% at one year, whereas Sweden had the highest in-hospital mortality at 6.5% and 10.7% at 1 year.
Pre-hospital fibrinolysis should be seen as a complement to PCI, said Huynh and colleagues. Ideally, these programs should have formal protocols that help to identify patients that would benefit from either direct transport to a PCI hospital or pre-hospital lysis.
The authors acknowledge that the study was limited by the lack of a comparison of morbidity and mortality data across programs. Also, the program descriptions relied on self-administered surveys. Finally, there were no economic or quality assurance data.