Priming of neutrophils after elective percutaneous transluminal coronary angioplasty is unrelated to accompanying brief myocardial ischemia

Abstract

Objective: The purpose of this study was to investigate the effect of brief myocardial ischemia and vascular trauma induced by elective percutaneous transluminal coronary angioplasty on in vivo `priming' and activation of neutrophils. Patients and Methods: We studied 16 patients undergoing elective coronary angioplasty for symptomatic coronary artery disease and a control group of seven patients undergoing diagnostic cardiac catheterization. Free radical production from purified neutrophils (Ficoll–Hypaque density gradient method) was measured indirectly by the chemiluminescence method. Myocardial ischemia during balloon inflation was assessed by serial lactate determinations from coronary sinus and arterial blood. The degree of transient angioplasty-related myocardial ischemia was related to the oxidative response of activated neutrophils. Results: Mean (±S.E.M.) oxidative response, i.e. the lucigenin- and luminol-enhanced- chemiluminescence (counts per minute) of neutrophils sampled from the coronary sinus increased significantly after percutaneous transluminal coronary angioplasty (Lucigenin-chemiluminescence: pre-angioplasty 3.69±0.64×10 5 vs. post-angioplasty 7.08±1.2×10 5, P<0.01; Luminol-chemiluminescence: pre-angioplasty 2.81±0.67×10 6 vs. post-angioplasty 5.2±0.92×10 6, P<0.01). Twelve of 16 patients developed transient cardiac lactate production (mean coronary sinus lactate excess: +0.12 mmol/l) and three disclosed a lactate extraction ratio <10%, both suggestive of myocardial ischemia. However, there was no correlation between the cardiac lactate production and the increased oxidative response after coronary angioplasty ( r 2 (Lucigenin-chemiluminescence)=0.02, n.s.; r 2 (Luminol-chemiluminescence)=0.06, n.s.). Conclusion: `Priming' of neutrophils, as reflected by increased oxidative response, is likely to occur after coronary angioplasty, but not after the angiographic procedure itself. However, `priming' seems to be unrelated to the transient brief period of myocardial ischemia and rather depends on an alternative mechanism.