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

OBJECTIVES The purposes of this study were to analyze coronary specimens from patients with diabetes mellitus (DM) and to compare them with specimens from patients without DM. BACKGROUND Diabetes mellitus is associated with an increased incidence of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Increased hypercellular smooth muscle cell proliferation with exaggerated intimal hyperplasi formation may be responsible for this predisposition. METHODS Eighteen coronary atherectomy specimens with restenosis after PTC from patients with DM were compared with 18 coronary atherectomy specimens with restenosis after PTC from patients without DM. Total and segmental areas were quantified on trichrome-stained tissue of hypercellular tissue, collagen-rich sclerotic tissue, atherom and thrombus. Demographic and angiographic dat were similar in both groups. RESULTS The percentage of total plaque are composed of hypercellular tissue was lower in restenotic specimens from patients with DM than in restenotic specimens from patients without DM (19 ± 6% vs. 44 ± 5%; p = 0.003). The percentage of collagen-rich sclerotic tissue are was larger in restenotic specimens from patients with DM than in restenotic specimens from patients without DM (77 ± 9% vs. 53 ± 4%; p = 0.004). The percentages of atherom and thrombus were similar in both groups. CONCLUSIONS Intimal hypercellular tissue content is reduced in restenotic tissue from patients with DM. Collagen-rich sclerotic content is increased in restenotic lesions from patients with DM. These results suggest an accelerated fibrotic rather than proliferative response in diabetic lesions from patients with restenosis after PTCA.