Remodeling pattern is related to the degree of coronary plaque regression induced by pitavastatin: a sub-analysis of the TOGETHAR trial with intravascular ultrasound and coronary angioscopy

Abstract

This study aimed to clarify the relationships between arterial remodeling patterns and plaque volume regression or stabilization. The TOGETHAR trial is a prospective open-label trial designed to assess coronary plaque regression and stabilization with multiple plaque imaging modalities following 52 weeks of pitavastatin treatment (2 mg/day). Coronary plaques were observed in 46 patients with both angioscopy and intravascular ultrasound at baseline and after 52 weeks of drug treatment. We divided these patients into three groups according to their remodeling indices (RI). Group P consisted of patients with a baseline RI >1.05, Group M of patients with a baseline RI of 0.95-1.05, and Group N of patients with a baseline RI <0.95 and then evaluated differences in coronary plaque volume changes and yellow grade among the three groups. In the positive remodeling group, whose remodeling index (RI) exceeded 1.05 at baseline, RI and percent atheroma volume (PAV) were significantly reduced (RI 1.14 ± 0.07 to 1.05 ± 0.10, p = 0.010, PAV 47.3 ± 8.3 to 45.3 ± 7.3 mm(3), p = 0.048). There was no relationship between baseline RI and the change in yellow grade of plaque. RI increased without significant change of PAV or a decrease in lumen volume in group N, with RI below 0.95 at baseline. Plaques with positive remodeling were more likely to have plaque volume regression by pitavastatin than those without in patients with coronary artery disease. Moreover, plaques with positive and negative remodeling were changed into those with intermediate remodeling by pitavastatin. Pitavastatin might induce not only plaque regression or stabilization, but also conformational normalization of vessel structure.