Aim: Several clinical trials using intravascular ultrasound (IVUS) evaluation have demonstrated that intensive lipid-lowering therapy by statin or a combination therapy with statin and ezetimibe results in significant regression of coronary plaque volume. However, it remains unclear whether adding ezetimibe to statin therapy affects coronary plaque composition and the molecular mechanisms of plaque regression. We conducted this prospective IVUS analysis in a subgroup from the CuVIC trial.
Methods: The CuVIC trial was a prospective randomized, open, blinded-endpoint trial conducted among 11 cardiovascular centers, where 260 patients with coronary artery disease who received coronary stenting were randomly allocated into either the statin group (S) or the combined statin and ezetimibe group (S＋E). We enrolled 79 patients (S group, 39 patients; S＋E group, 40 patients) in this substudy, for whom serial IVUS images of nonculprit lesion were available at both baseline and after 6-8 months of follow-up.
Results: After the treatment period, the S＋E group had significantly lower level of low-density lipoprotein cholesterol (LDL-C; 80.9±3.7 vs. 67.7±3.8 mg/dL, p=0.0143). Campesterol, a marker of cholesterol absorption, and oxysterols (β-epoxycholesterol, 4β-hydroxycholesterol, and 27-hydroxycholesterol) were also lower in the S＋E group. IVUS analyses revealed greater plaque regression in the S＋E group than in the S group (-6.14% vs. -1.18% for each group, p=0.042). It was noteworthy that the lowering of campesterol and 27-hydroxycholesterol, but not LDL-C, had a significant positive correlation with plaque regression.
Conclusions: Compared with statin monotherapy, ezetimibe in combination with statin achieved significantly lower LDL-C, campesterol, and 27-hydroxycholesterol, which resulted in greater coronary plaque regression.
Keywords: Coronary plaque; Ezetimibe; Intravascular ultrasound; Oxysterols; Statin.