Inhibitory efficacy of pitavastatin on the early inflammatory response and neointimal thickening in a porcine coronary after stenting

Abstract

Neointimal hyperplasia plays a crucial role in restenosis after stenting. The severity of neointimal thickness correlates with inflammatory reactions in the injured vessel and statins can inhibit inflammation. Pitavastatin has favorable effects on plasma lipoproteins and inflammation. Thus, we hypothesized that pitavastatin might inhibit the early inflammatory response, resulting in prevention of neointimal hyperplasia in porcine coronary arteries after stenting. Pitavastatin (18 coronaries, 40 mg per day) or placebo (20 coronaries) was administered orally from 7 days before stenting until the time of euthanasia at 3 or 28 days after stenting. The coronary artery of the animals was injured with an oversized metallic coil stent. Inflammatory cell infiltration was evaluated by scanning electron microscopy and was significantly reduced in the treated vessels compared to controls. On Day 28, intravascular ultrasound analysis revealed the neointimal area was significantly less at the stent site in the pitavastatin group than in the placebo. Histopathologic assessment showed significantly decreased in neointimal area in the pitavastatin group compared to the placebo (2.16±0.13 mm 2 versus 2.88±0.25 mm 2, P=0.029), whereas the mean injury score in the pitavastatin group was larger than in the placebo group. In conclusion, Pitavastatin inhibited neointimal hyperplasia after stenting through a reduction of inflammatory reactions.