Adjunctive pharmacotherapy for coronary interventions-time to read the writing on the wall

The Role of Glycoprotein IIb/IIIa Inhibitors- A Promise Not Kept?

For over one decade Glycoproteins IIb/IIIa inhibitors (GPI) have been administered to prevent coronary artery thrombosis. Initially these agents were used for acute coronary syndromes and subsequently as adjunctive pharmacotherapy for percutaneous coronary interventions (PCIs).

Most benefit of GPI emerged from reduction of ischemic events: mostly non-q-wave myocardial infarctions (NQWMIs) during PCI. However, individual randomized clinical trials could not demonstrate that any of these agents could significantly reduce mortality in any clinical subset of patients. Studies of employing prolonged oral GPI administration resulted in excessive death. The non-homogenous statistically-significant reduction of ischemic endpoints was accompanied by an excess of bleeding, vascular complications, and thrombocytopenia. The clinical and ecomomic burden of major bleeding and thrombocytopenia is substantial. The ACUITY trial has initiate a new debate regarding the efficacy and safety of GPI.

Selective “patient-tailored” use of GPI limited to moderate-high risk PCI patients with low bleeding propensity is suggested. Research of new algorithms emphasizing abbreviated GPI administration, careful access site and bleeding surveillance, in conjunction with lower doses of unfractionated heparin or new and safer anti-thrombins may further enhance patient safety.

Glycoprotein IIb/IIIa inhibitors: questioning indications and treatment algorithms

Glycoprotein inhibitors (GPI) are viewed as beneficial adjunctive pharmacotherapy agents for percutaneous coronary interventions (PCIs). The major benefit of GPI is derived from the reduction of ischemic events (mostly non-Q-wave myocardial infarctions) during PCI. There is no single randomized clinical trial demonstrating that any of these agents significantly reduces mortality in any clinical subset of patients. Studies of sustained oral GPI resulted in excessive death and myocardial infarctions. Reduction of ischemic end points was counteracted by excessive bleeding, vascular complications, and thrombocytopenia. These complications bear considerable medical and economic impact. The Acute Catheterization and Early Intervention Triage Strategy trial demonstrated that GPI, when added to heparin, enoxaparine, or bivalirudin, do not reduce mortality or ischemic events but significantly increase bleeding complications. Major bleeding resulted in threefold mortality at 1 year. In view of available data, the use of GPI should be limited to moderate-risk to high-risk PCI patients with low bleeding propensity. Protocols of abbreviated GPI administration and careful bleeding surveillance, in conjunction with lower doses of unfractionated heparin or new and possibly safer antithrombins, can potentially improve patient safety.