Tissue characteristics of restenosis after percutaneous transluminal coronary angioplasty in diabetic patients

The purposes of this study were to analyze coronary specimens from patients with diabetes mellitus (DM) and to compare them with specimens from patien ts without DM. BACKGROUND Diabetes mellitus is associated with an increased incidence of r estenosis after percutaneous transluminal coronary angioplasty (PTCA). Incr eased hypercellular smooth muscle cell proliferation with exaggerated intim al hyperplasia formation may be responsible for this predisposition. METHODS Eighteen coronary atherectomy specimens with restenosis after PTCA from patients with DM were compared with 18 coronary atherectomy specimens with restenosis after PTCA from patients without DMI. Total and segmental a reas were quantified on trichrome-stained tissue of hypercellular tissue, c ollagen-rich sclerotic tissue, atheroma and thrombus. Demographic and angio graphic data were similar in both groups. RESULTS The percentage of total plaque area composed of hypercellular tissu e was lower in restenotic specimens from patients with DM than in restenoti c specimens from patients without DM (19 +/- 6% vs. 44 +/- 5%; p = 0.003). The percentage of collagen-rich sclerotic tissue area was larger in resteno tic specimens from patients with DM than in restenotic specimens from patie nts without DM (77 +/- 9% vs. 53 +/- 4%; p = 0.004). The percentages of ath eroma and thrombus were similar in both groups. CONLUSIONS Intimal hypercellular tissue content is reduced in restenotic ti ssue from patients with DM. Collagen-rich sclerotic content is increased in restenotic lesions from patients with DM. These results suggest an acceler ated fibrotic rather than a proliferative response in diabetic lesions from patients with restenosis after PTCA.. (J Am Cell Cardiol 1999;34:1045-9) ( C) 1999 by the American College of Cardiology.