Qualitative and Quantitative Changes in Coronary Plaque Associated With Atorvastatin Therapy

Abstract

Circ J 2009; 73: 718 -725 here have been many reports that intensive lowering of low-density lipoprotein-cholesterol (LDL-C) with 3-hydroxy-3-methylglutaryl-coenzyme A (HMGCoA) reductase inhibitors (statins) is effective in preventing cardiovascular events. [1][2][3] Although the mechanism by which statins confer cardiovascular benefit is not precisely understood, regression of coronary plaque volume and reduction of plaque vulnerability are presumed to play important roles. Angioscopic observations have shown that the presence of yellow plaque is associated with unstable symptoms, which suggests that as plaques become more yellow in appearance, they also become more prone to rupture. [4][5][6] Editorial p 628Angioscopy is used to assess plaque vulnerability on the basis of its color and the presence of thrombi. 7,8 Angioscopy gives a full-color, 3-dimensional perspective of the intracoronary surface morphology, and reasonably accurate information regarding a specific lesion, if performed by trained technicians. Intravascular ultrasound (IVUS) is an alternative imaging modality that provides real-time tomographic images of blood vessels on a monitor. It generates information on vessel wall structure, atheroma volume, and the echogenicity of plaque, which is amenable to qualitative and quantitative analysis and can be used to evaluate plaque regression. 9 The effects of statins on coronary plaque have been evaluated by angioscopy, as well as IVUS, in patients with hypercholesterolemia. Using angioscopy, Takano et al demonstrated that the grade of yellow color decreased during statin therapy, 10 and Nissen et al 11 and Okazaki et al 12 used IVUS to investigate the effects of statins on atheroma volume. However, because no study has serially monitored the coronary plaques of patients receiving statin therapy using both angioscopy and IVUS, the relationship between changes in plaque color and changes in atheroma volume has not been elucidated. Therefore, we used both imaging modalities concurrently to investigate the qualitative and quantitative changes over time in coronary plaques in patients receiving atorvastatin therapy to reduce LDL-C levels to ≤100 mg/dl. Methods Study PopulationPatients with coronary artery disease (CAD) complicated by hypercholesterolemia, with a fasting LDL-C level (Received August 10, 2008; accepted December 2, 2008; released online February 18, 2009

Plaque-Stabilizing Effect of Atorvastatin Is Stronger for Plaques Evaluated as More Unstable by Angioscopy and Intravenous Ultrasound

“…The details of this procedure and its reproducibility were previously described. 5 IUVS measurements were performed with a 2.6F, 40-MHz Atlantis Pro IVUS catheter (Boston Scientific Corporation, Natick, MA, USA). IVUS volumetric analysis of the target lesions was conducted by using a 20-mm segment at the lesion site for analysis.…”

“…The details of IVUS volumetric analysis have been also described previously. 5 Data for plaques that underwent angioscopic color assessment and IVUS volumetric analysis at baseline, week 28, and week 80 were defined as "matched data". When multiple yellow plaques were included in a single 20-mm IVUS analysis segment, the mean color grade was used.…”

“…We previously conducted the TWINS (evaluation with simultaneous angioscopy and intravascular ultrasound study) study, which revealed that the angioscopic plaque color grade showed a significant decrease by week 28 and was maintained until week 80, while a significant decrease of plaque volume on IVUS was also seen by week 28 and there was a further decrease by week 80. 5 The angioscopic plaque color grade has been reported to show a good correlation with plaque stability. It has also been reported that the vulnerability of yellow plaques is greater than that of white to light-yellow plaques.…”

Acute Coronary Syndrome from Angioscopic Viewpoint

“…Statin treatment is known to reduce both plaque volume evaluated by IVUS and yellow color evaluated by angioscopy 20,21 . However, it has not been clarified which of plaque volume and plaque color is more directly associated with the risk of plaque disruption or the risk of ACS.…”

Chronic Kidney Disease and Coronary Artery Vulnerable Plaques

“…Subanalysis in our previous study (6) revealed that statin treatment was effective to reduce ACS events in the patients with multiple yellow plaques but not in the patients with fewer yellow plaques. Therefore, it is reasonable that statin treatment is more effective in CKD patients than in non-CKD patients (15) because it may reduce cardiac events by the regression and stabilization of vulnerable plaques (16).…”