GRANULOCYTE ACTIVATION AFTER CORONARY ANGIOPLASTY IN HUMANS

To determine whether percutaneous transluminal coronary angioplasty (PTCA) would lead to neutrophil activation with subsequent discharge of proteolytic enzymes, like elastase, and oxygen free radicals, like superoxide anion, blood samples were taken from the coronary sinus and aorta in 14 patients with stable angina and one-vessel disease who underwent PTCA. Neutrophils were separated by means of the Ficoll-Hypaque system and were stimulated to detect release of elastase and generation of superoxide anion. Plasma levels of elastase were also measured by an immunoenzymatic method. PTCA was successful in all patients. Plasma elastase levels increased significantly at the end of the procedure compared with pre-PTCA values both in the coronary sinus (from 129.2 ± 16.6 to 286.6 ± 39.7 μg/l, p < 0.0005) and in the aorta (from 117.4 ± 13.6 to 258.1 ± 41.3 μg/l, p < 0.0005). On the other hand, superoxide anion released in the supernatants after neutrophil stimulation by phorbol-myristate-acetate decreased after PTCA in the coronary sinus (before PTCA, 60.1 · 7.1; after PTCA, 40.7 ± 6.8 nmol 1 x 107 granulocytes/ml/15 min, p < 0.05), whereas a mild but not significant decrease was observed in the aorta (from 58.3 ± 10.9 to 55.3 ± 8.6 nmol 1 x 107 granulocytes/ml/15 min, p = NS). Similarly, elastase release in the supernatants after neutrophil stimulation by Ca2+ ionophore A23187 decreased after PTCA in the coronary sinus (from 226.1 ± 26.5 to 159.2 ± 27.8 μg 4 x 106 granulocytes/ml, p < 0.05), whereas no change was observed in aorta (from 233.5 ± 47.3 to 188.7 ± 31.3 μg 4 x 106 granulocytes/ml, p = NS). These results suggest that neutrophil activation occurs during PTCA and leads to higher plasma elastase levels and to a decreased ability of stimulated granulocytes to release their toxic compounds at the end of the procedure. Activation of neutrophils may have potential implications regarding the occurrence of the pathophysiological processes occurring after balloon angioplasty in humans.