Histopathologic comparison of human coronary instent and post-balloon angioplasty restenotic tissue

Recent postmortem histopathologic studies of patients dying after coronary stenting have shown that in-stent restenosis results from smooth muscle cell proliferation and extracellular matrix formation.(1,2) Conversely, restenosis after percutaneous transluminal coronary angioplasty (PTCA) is considered to be a combination of negative vascular remodeling and intimal hyperplasia.(3) Nevertheless, detailed, systematic histopathologic analysis comparing coronary in-stent and post-balloon PTCA restenosis in living patients are limited. This study analyzes the cellular and extracellular composition of in-stent restenotic lesions in vivo and establishes histopathologic differences between in-stent and post-balloon PTCA restenotic tissue in patients with symptomatic restenosis after percutaneous revascularization.