Time courses of apoptosis and cell proliferation and their relationship to arterial remodeling and restenosis after angioplasty in an atherosclerotic rabbit model

OBJECTIVES We sought to evaluate whether cellular mass changes (including apoptosis and proliferation) after arterial injury could interact with restenosis and arterial remodeling. BACKGROUND The mechanisms controlling arterial remodeling after angioplasty, remain poorly, understood. Apoptosis and cell proliferation have been previously, described after balloon angioplasty. However, their importance in the occurrence of arterial remodeling and restenosis is unknown. METHODS Atherosclerosis was induced in 48 femoral arteries of New Zealand White rabbits by air-desiccation and a high-cholesterol diet. One month later, angioplasty was per-formed in 46 arteries. Apoptosis, cell proliferation, residual stenosis and arterial remodeling were evaluated at 2 h and 3, 7, 14, 21 and 28 days after angioplasty. RESULTS Cell proliferation and apoptosis profiles were similar, but the peak in cell proliferation occurred approximately four days earlier than the peak in apoptosis in the neointima and media. Apoptosis density was positively correlated with arterial remodeling in the neointima and media (r = 0.69, p = 0.005 and r = 0.50, p = 0.05, respectively). Moreover, residual stenosis was inversely correlated with apoptosis density in the neointima and media (r = -0.62, p = 0.008 and r = -0.52, p = 0.04, respectively). In contrast, cell proliferation was independent of restenosis and arterial remodeling. CONCLUSIONS In this model, cell proliferation preceded apoptosis throughout the four weeks after angioplasty. Apoptosis was inversely, correlated with restenosis. Interestingly, apoptosis was also related to enlargement remodeling after balloon angioplasty. (J Am Coll Cardiol 2002; 39:1680-5) (C) 2002 by the American College of Cardiology, Foundation.