Do glycoprotein IIb/IIIa inhibitors interact with assays for myocardial necrosis?

Objectives To determine whether glycoprotein (GP) IIb/IIIa inhibitors interact with cardiac marker assays: total creatine kinase (CK), CK-MB, and troponin-I (TnI). Design and methods Two blood samples were collected during coronary angiography or angioplasty and analyzed for cardiac markers: one after arterial sheath insertion and the second 10 mins later. In the first phase (n = 101), heparin and GP IIb/IIIa inhibitors were given between samples, in the second phase (n = 45) only heparin was given, and in the third phase (n = 54) neither drug was given. Results In each phase, there was a significant decline in total CK over the 10 min period. There were no consistent significant changes in CK-MB or TnI. Conclusions Neither GP IIb/IIIa inhibitors nor IV heparin interact with cardiac marker assays. There is a small but significant decline in total CK levels within 10 mins of arterial puncture that is unrelated to administration of these drugs.