Mitogenic activity in connection with coronary angioplasty

The aim of this study was to assess the plasma mitogenic activity in connection with percutaneous transluminal coronary angioplasty (PTCA) and the relation to restenosis. Plasma samples were taken on the morning before, 1 and 24 h after, 2 weeks after and 6 months after elective PTCA in 50 patients. Follow-up coronary angiography was carried out after 6 months or earlier if clinically warranted. Samples were also taken from 17 patients undergoing coronary angiography without PTCA. The mitogenic activity, expressed as the fraction of labelled nuclei after incubation of arterial smooth muscle cells with plasma in the presence of 3H-thymidine, was higher 1 h after PTCA than before (53.1 +/- 7.4 vs 26.8 +/- 7.3, P < 0.001). Later values were not elevated and no increase was seen after coronary angiography. The groups with (n = 19) and without (n = 31) restenosis did not differ in mitogenic activity. These results indicate that the plasma level of mitogenic activity increases immediately after PTCA. The pathophysiological significance of this increase for the development of restenosis is unclear, since the magnitude of the increase does not seem to be related to restenosis.