Release of TNF-α during stent implantation into saphenous vein aortocoronary bypass grafts and its relation to plaque extrusion and restenosis

Abstract
The reduction in plaque volume during stent implantation is associated with the release of particulate debris and plaque-derived soluble substances. We studied the potential release of the proinflammatory cytokine TNF-α into the coronary circulation and whether such release is related to the reduction in plaque volume and, possibly, a predictor for restenosis. In 18 male patients ( n = 24 stents) with severe stenosis in a saphenous vein aortocoronary bypass graft (SVG), we used a distal balloon occlusion-aspiration device during stent implantation. The aspirate TNF-α levels were determined before and after stent implantation and related to the angiographic and intravascular ultrasound-assessed severity of stenosis and restenosis. We found that TNF-α is, indeed, released into the aspirate of stented SVG (9 ± 1 and 28 ± 3 pg/ml before and after stent implantation, respectively, P < 0.0001) and that such release is related to the reduction in plaque volume ( r = 0.88, P < 0.0001) and associated with restenosis after 5 mo ( r = 0.71, P = 0.001). The periprocedural release of plaque-derived TNF-α possibly represents the amount and activity of the atherosclerotic process and might be a predictor for restenosis.