NEW YORK (Reuters Health) The earlier a patient with ST-segment elevation myocardial infarction (STEMI) receives clopidogrel before primary coronary intervention (PCI), the better, according to a study in the July issue of the American Heart Journal.

Earlier ìupstreamî pretreatment allows for optimal platelet inhibition and reduces ischemic complications such as reinfarction or stent thrombosis, without increased bleeding complications, the researchers say.

Clopidogrel ìshould be given in all STEMI patients either in the emergency department or perhaps even in the ambulance if pre-hospital ECGs are used to make the diagnosis,î lead author Dr. David M. Larson of Abbott Northwestern Hospital in Minneapolis, Minnesota told Reuters Health by e-mail.

He and his colleagues analyzed data from a prospective registry on 2,014 consecutive STEMI patients. All of them were treated in a regional system using rapid transfer of STEMI patients to Abbott Northwestern for primary PCI. The referring hospitals are stratified by region: zone 1 is within 60 miles, while zone 2 extends from 60 to 210 miles out.

All patients received aspirin, heparin and clopidogrel (600 mg in 92.7% of cases) in their local emergency department within 15 minutes of diagnosis.

The median door-to-balloon times were 63 minutes for patients who came directly to Abbott Northwestern, 94 minutes for zone 1 patients, and 123 minutes for zone 2 patients.

This meant that the longer the distance patients had to travel, the longer the duration of clopidogrel pretreatment before PCI ñ and the authors found that patients coming from zone 1 and 2 had significantly lower 30-day reinfarction/reischemia rates (0.85% and 0.9%, respectively) than non-transferred patients (3.2%; p = 0.001).

Zone 1 and zone 2 patients also had significantly lower stent thrombosis rates (0.6% for each versus 2.0% for nontransferred patients; p = 0.04).

There was no difference between the groups in the percentage of patients with in-hospital bleeding complications.

The exact time of clopidogrel administration was known for 1,862 patients (92%). According to the investigators, the 30-day reinfarction/reischemia rate was 1.0% with a pretreatment duration of at least 1 hour compared with 2.9% with shorter durations (p = 0.0028)

ìJust like aspirin, which is given in the ambulance or ER, clopidogrel should be given at the point of first medical contact in all patients with STEMI,î Dr. Larson told Reuters Health. ìOur study showed that this was an effective strategy without increased bleeding complications.î

Reference:

Clopidogrel pretreatment in ST-elevation myocardial infarction patients transferred for percutaneous coronary Intervention

Am Heart J 2010;160:202-207.