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

To determine whether glycoprotein (GP) IIB/IIIA inhibitors interact with cardiac marker assays: total creatine kinase (CK), CK-MB, and troponin-I (TnI).

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.

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.

Neither GP IIb/IIIa inhibitors nor i.v. 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.