Use of ICHOR-platelet works to assess platelet function in patients treated with GP IIb/IIIa inhibitors

Platelet glycoprotein GP IIb/IIIa inhibitors have been recently approved fo r use in treating patients with acute coronary syndromes and those undergoi ng PCI. The purpose of this study was to assess the feasibility of using a new device, the ICHOR platelet works, to detect platelet inhibition in pati ents undergoing PCI and treated with abciximab or tirofiban, The study was conducted at Baylor College of Medicine, Houston, Texas. Thirty patients un dergoing PCI and treated with abciximab (n = 10) or tirofiban (n = 20) are included. Blood samples were obtained before, at 30 min, at 4 hr, and at 12 hr after starting the GP IIb/IIIa inhibitors and 2 hr after discontinuatio n. Baseline studies revealed > 95% platelet aggregability in all patients a fter exposure to ADP (20 muM). After starting tirofiban, 82%, 83%, and 82% of platelets were inhibited at 30 min, 4 hr, and 12 hr. Platelet inhibition decreased to 43% 2 hr after discontinuation of tirofiban. Similarly, ICHOR platelet works detected 91%, 92%, and 85% platelet inhibition at 30 min, 4 hr, and 12 hr after starting abciximab, respectively. Platelet inhibition decreased to 73% 2 hr after discontinuation. The ICHOR platelet works is a promising, simple, and rapid bedside method that may have clinical utility in assessing platelet inhibition in patients treated with GP IIb/IIIa inhib itors. (C) 2001 Wiley-Liss, Inc.