Abciximab attenuates coronary microvascular endothelial dysfunction after coronary stenting.

BACKGROUND Platelet glycoprotein IIb/IIIa receptor blockade with abciximab decreases ischemic events after percutaneous coronary intervention (PCI); however, the mechanism of this benefit has not been fully elucidated. The present study was designed to assess endothelium-dependent vasomotion after coronary stenting and to determine if abciximab alters this response. METHODS AND RESULTS The study group consisted of 48 patients (59+/-10 years of age) with discrete coronary stenoses who underwent stenting alone (n=28) or stenting plus abciximab (n=20). A control group consisted of 31 additional patients who had vasomotor testing on a non-PCI vessel. Coronary blood flow (CBF) was measured (0.014-inch Doppler wire) 30 minutes after uncomplicated PCI and in response to the intracoronary infusion of acetylcholine (Ach) (10(-7), 10(-6) mol/L Ach) and adenosine (24 microg). Ach-mediated increase in CBF was impaired after stent insertion when compared with the control group (41+/-52% versus 70+/-48%; P<0.05). The stenting plus abciximab group demonstrated a superior CBF response to Ach compared with the stenting alone group (83+/-93% versus 41+/-52%; P<0.05), with no difference between groups in the peak flow or percent change in flow to adenosine. By multivariate analysis, concomitant administration of abciximab was strongly predictive of the change in CBF to Ach (P<0.005). CONCLUSIONS Abciximab preserves the CBF response to Ach after coronary stenting. The preservation of microvascular endothelial function may help explain the beneficial clinical effect of this agent in patients undergoing PCI.