Effects of administration of glycoprotein IIb/IIIa receptor antagonists inpatients with failed thrombolysis - A pilot study

Aim: To evaluate the effectiveness of glycoprotein (GP) IIb/IIIa receptor a ntagonists in patients with acute myocardial infarction (AMI) who have unde rgone unsuccessful thrombolysis. Design: Randomised, prospective, single-blind trial. Patients and Participants: 84 patients (62 males, 22 females, aged 40 to 80 years) in whom thrombolysis had failed out of a total of 225 consecutive p atients admitted to hospital with suspected AMI. Methods: In suitable patients, thrombolysis with 'accelerated' recombinant tissue-type plasminogen activator (rtPA) was initiated. Patients in whom th rombolysis was unsuccessful were randomised within 4 hours of onset of symp toms into two groups, Unsuccessful thrombolysis was defined as failure to s how any sign of reperfusion after administration of the first 65mg of rtPA, or as recurrence of pain and ST-segment elevation within 30 to 60 minutes of the end of full thrombolysis (100mg of rtPA). The 42 patients in group 1 (GPIIb/IIIa) stopped thrombolysis (if still being administered) and receiv ed treatment with an intravenous bolus plus infusion of GPIIb/IIIa antagoni sts (abciximab or tirofiban or eptifibatide) plus heparin according to the Thrombolysis in Myocardial Infarction (TIMI)- 14 schedule and aspirin. The 42 patients in group 2 (placebo) received the full dose of rtPA, even if th ere was no sign of reperfusion, and placebo together with standard heparin and aspirin. Patients without signs of reperfusion were immediately referre d for rescue revascularisation. Results: In group I (GPIIb/IIIa), 22 patients received rtPA 65mg and 20 pat ients received rtPA 100mg. 39 patients showed rapid reperfusion (4 +/- 3 mi n) on treatment with GPIIb/IIIa antagonists, and only one required rescue p ercutaneous transluminal coronary angioplasty (PTCA). Coronarography after 12 to 72 hours demonstrated patency of the infarct-related artery in the 39 patients who showed rapid reperfusion. In group 2 (placebo), no patients s howed reperfusion and all received rescue PTCA. Three patients in the GPIIb /IIIa group and two in the placebo group experienced bleeding-related adver se effects. Patients receiving GPIIb/IIIa antagonists showed a nonsignifica ntly reduced requirement for stent treatment and a reduction of angina at 3 0 days after treatment compared with the placebo group. Conclusion: These preliminary data suggest the possibility of using GPIIb/I IIa receptor antagonists in patients with failed thrombolysis after AMI, wi th an acceptable increase in bleeding risk. We consider the demonstration o f the safety of this combination as the most important result of this study .