Barcelona, Spain, 31 August: The outcome of patients with acute myocardial infarction (AMI) complicated by cardiogenic shock* is generally very poor. Although early mechanical revascularisation by primary PCI has been shown as superior to medical treatment, the mortality range remains high (at about 45-60%). Registries have shown further therapeutic benefit from the administration of glycoprotein (GP) IIb/IIIa inhibitors** during PCI in AMI patients with cardiogenic shock. However, there are no randomised data to support this approach in these high risk patients. The PRAGUE-7 study was designed to determine whether the routine upfront administration of abciximab (a IIb/IIIa GP inhibitor) improves outcome when compared with conventional selective administration.
This study, which is part of a series of randomised trials in cardiology and cardiac surgery performed in the Czech Republic, enrolled 80 of these most critically ill patients (AMI complicated by cardiogenic shock) but failed to show any benefit from the routine upfront administration of abciximab to all patients (before coronary angiography) over a more conventional selective use of abciximab during subsequent primary PCI.
All 80 patients in this open-label multicentre trial received standard antithrombotic and anticoagulant treatment (either during transport or directly at the catheterisation laboratory) and coronary angiography. Patients in the upfront treatment group (group A) received a bolus of abciximab immediately after randomisation followed by an infusion for 12 hours. PCI was performed immediately after coronary angiography. Group B received standard therapy with optional abciximab administration during PCI according to the interventional cardiologist.
The study's primary endpoint was a 30-day combined outcome of death/reinfarction/stroke/new renal failure. Secondary objectives were left ventricular ejection fraction assessed by echocardiography on day 30, major bleeding complications, myocardial blush grade after PCI, and TIMI-flow (a system for measuring coronary blood flow) after PCI.
Results showed that PCI was technically successful in 90% of group A and 87.5% of group B patients. Abciximab was used in 100% of group A and 35% of group B. The primary endpoint was reached in 17 group A patients (42.5%) and 11 group B patients (27.5%) (p=0.24). Fifteen patients (37.5%) died during hospitalisation in group A and 13 patients in group B (32.5%) (p=0,82). Ejection fraction among survivors after 30 days was 44 ±11% (A) vs. 41 ±12% (B) (p=0.205). Major bleeding occurred in 17.5% (A) vs. 7.5% (B) (p=0.310) and stroke in 2.5% (A) vs. 5% (B). No differences were found in TIMI-flow and MBG after PCI.
* Cardiogenic shock is defined as a state of hypotension and poor blood flow resulting from ventricular failure.
** Glycoprotein IIb/IIIa inhibitors are potent antiplatelet drugs which are frequently used during PCI. They work by inhibition of the GPIIb/IIIa receptor on the surface of platelets, thereby preventing thrombus formation.