“GP IIb/IIIa blockers, if indicated (high risk patients, early phase of infarction) are still of value, especially if given well before the intervention,” Dr. Paul W. Armstrong from the University of Alberta in Edmonton (Canada) told Reuters Health by e-mail. “However, this strategy would have to be tested again by a prospective randomized investigation before this strategy might become routine.”
But, he adds, “Keep your eyes open in this specific field of antiplatelet therapy in acute coronary syndromes, because historic treatment options are going to be changed rapidly.”
European guidelines for ST-elevation myocardial infarction (STEMI) have come out against GPI pretreatment of STEMI patients – largely because previous studies have yielded contradictory results.
Using data from 5707 participants in the APEX-AMI trial, Dr. Armstrong and colleagues compared the effects of pre-sheath, in-lab, or non-use of GPIs on 90-day clinical outcomes. (The original goal of APEX-AMI was to compare pexelizumab to placebo for preventing reperfusion injury.)
Overall, 3969 patients received GPIs: 1125 (28.3%) pre-sheath and 2844 (72.7%) in the lab.
Rates of 90-day mortality were 3.2% with pre-sheath GPI, 4.8% with in-lab GPI, and 5.5% with no GPI at all (p = 0.015). Patients in the pre-sheath GPI group also had a lower rate (p = 0.018) of the combined endpoint of death, congestive heart failure, or shock within 90 days (8.4%), compared to the in-lab group (10.0%) and the no-GPI group (11.6%).
In subgroup analyses, there was lower mortality with abciximab use and pre-sheath administration versus no/in-lab use and in-lab use, but there was no such relationship in patients who received small-molecule GPIs. There was a trend towards a lower composite endpoint with pre-sheath versus in-lab abciximab, but again small-molecule GPIs were not associated with event-free survival regardless of timing of administration.
In-hospital severe and moderate bleeding rates were low and did not differ significantly between treatment groups.
In-hospital stroke rates were significantly lower in GPI-treated patients (0.6%) than in those not treated with GPIs (1.2%; p = 0.02).
“In primary PCI (patients with acute STEMI) the GP IIb/IIIa blockers are frequently used as ‘downstream’ therapy,” Dr. Armstrong said. “To use them as early as possible (as shown in our posthoc analysis of the APEX-AMI trial) is still (considered) controversial. Current guidelines believe more in outcome data of prospective randomized trials and such trials did not show the same evidence for an early use.”
Eur Heart J 2010.