Effect of atorvastatin therapy on fibrous cap thickness in coronary atherosclerotic plaque as assessed by optical coherence tomography: the EASY-FIT study.

BACKGROUND: The detailed mechanism of plaque stabilization by statin therapy is not fully understood. OBJECTIVES: The aim of this study was to assess the effect of lipid-lowering therapy with 20 mg/day of atorvastatin versus 5 mg/day of atorvastatin on fibrous cap thickness in coronary atherosclerotic plaques by using optical coherence tomography (OCT). METHODS: Seventy patients with unstable angina pectoris and untreated dyslipidemia were randomized to either 20 mg/day or 5 mg/day of atorvastatin therapy. OCT was performed to assess intermediate nonculprit lesions at baseline and 12-month follow-up. RESULTS: Serum low-density lipoprotein cholesterol level was significantly lower during therapy with 20 mg/day compared with 5 mg/day of atorvastatin (69 mg/dl vs. 78 mg/dl; p = 0.039). The increase in fibrous cap thickness was significantly greater with 20 mg/day compared with 5 mg/day of atorvastatin (69% vs. 17%; p < 0.001). The increase in fibrous cap thickness correlated with the decrease in serum levels of low-density lipoprotein cholesterol (R = -0.450; p < 0.001), malondialdehyde-modified low-density lipoprotein (R = -0.283; p = 0.029), high-sensitivity C-reactive protein (R = -0.276; p = 0.033), and matrix metalloproteinase-9 (R = -0.502; p < 0.001), and the decrease in grade of OCT-derived macrophages (R = -0.415; p = 0.003). CONCLUSIONS: Atorvastatin therapy at 20 mg/day provided a greater increase in fibrous cap thickness in coronary plaques compared with 5 mg/day of atorvastatin. The increase of fibrous cap was associated with the decrease in serum atherogenic lipoproteins and inflammatory biomarkers during atorvastatin therapy. (Effect of Atorvastatin Therapy on Fibrous Cap Thickness in Coronary Atherosclerotic Plaque as Assessed by Optical Coherence Tomography: The EASY-FIT Study; NCT00700037).

Circulating malondialdehyde-modified low-density lipoprotein levels are associated with the presence of thin-cap fibroatheromas determined by optical coherence tomography in coronary artery disease.

AIMS: The importance of oxidized low-density lipoprotein (oxLDL) has been implicated in the process of plaque rupture. However, few previous studies demonstrated the relationship between plaque morphology and oxLDL. We evaluated the relationship between coronary plaque vulnerability assessed by optical coherence tomography (OCT) and circulating malondialdehyde-modified low-density lipoprotein (MDA-LDL). METHODS AND RESULTS: OCT was used to determine plaque vulnerability in 102 patients with acute coronary syndrome (ACS; n = 53) and stable angina pectoris (SAP; n = 49). Circulating levels of MDA-LDL were measured by using enzyme-linked immunosorbent assay. Thin-cap fibroatheromas (TCFAs; defined as lipid-rich with plaque cap thickness <65 µm) were detected more frequently in ACS than in SAP (83% vs. 16%, P < 0.001). The circulating levels of MDA-LDL were significantly higher in patients with ACS compared with SAP (P = 0.008). The levels of MDA-LDL were significantly higher in SAP patients with TCFA than those with non-TCFA (P < 0.001). Although the levels of MDA-LDL were not significant between ACS patients with TCFA and those with non-TCFA, patients with ruptured TCFA had higher levels of MDA-LDL compared with those with morphologically intact TCFA (P = 0.023). MDA-LDL levels were associated with the presence of TCFA (odds ratio, 1.45 per 10-unit increment of MDA-LDL; 95% CI, 1.24-1.68; P< 0.001) in multivariable logistic regression analysis. CONCLUSION: Circulating MDA-LDL levels might be associated with the presence of TCFA in the culprit lesion.

Virtual histology intravascular ultrasound compared with optical coherence tomography for identification of thin-cap fibroatheroma.

Virtual histology intravascular ultrasound (VH-IVUS) allows detailed assessment of plaque composition in the clinical setting. Optical coherence tomography (OCT) has been developed as a high-resolution imaging method, which might be a promising technique to identify thin-cap fibroatheroma (TCFA) in vivo. The purpose of the present study was to evaluate the diagnostic accuracy of VH-IVUS to identify TCFA as determined by OCT.We examined 96 target lesions in patients with stable angina pectoris by using VH-IVUS and OCT. VH-IVUS derived TCFA was defined as a focal necrotic core-rich lesion without evident overlying fibrous tissue. OCT derived TCFA was defined as a plaque with a fibrous cap of < 65 µm. VH-IVUS correctly identified 16 TCFA and 67 non-TCFA but misclassified 2 TCFA and 11 non-TCFA as determined by OCT. The sensitivity, specificity, and positive and negative predictive values of VH-IVUS to identify TCFA as determined by OCT were 89%, 86%, 59%, and 97%, respectively.VH-IVUS showed an acceptable sensitivity and specificity to identify TCFA as determined by OCT. Although the positive predictive value was low reflecting a high number of false positives, the negative predictive value was notably high. Our results suggest a potential role for VH-IVUS to exclude high risk lesions for future coronary events.