Effect of pravastatin on malondialdehyde-modified low-density lipoprotein levels and coronary plaque regression as determined by three-dimensional intravascular ultrasound

Atherogenic Lipoproteins for the Statin Residual Cardiovascular Disease Risk

Randomized controlled trials (RCTs) show that decreases in low-density lipoprotein cholesterol (LDL-C) by the use of statins cause a significant reduction in the development of cardiovascular disease (CVD). However, one of our previous studies showed that, among eight RCTs that investigated the effect of statins vs. a placebo on CVD development, 56–79% of patients had residual CVD risk after the trials. In three RCTs that investigated the effect of a high dose vs. a usual dose of statins on CVD development, 78–87% of patients in the high-dose statin arms still had residual CVD risk. The risk of CVD development remains even when statins are used to strongly reduce LDL-C, and this type of risk is now regarded as statin residual CVD risk. Our study shows that elevated triglyceride (TG) levels, reduced high-density lipoprotein cholesterol (HDL-C), and the existence of obesity/insulin resistance and diabetes may be important metabolic factors that determine statin residual CVD risk. Here, we discuss atherogenic lipoproteins that were not investigated in such RCTs, such as lipoprotein (a) (Lp(a)), remnant lipoproteins, malondialdehyde-modified LDL (MDA-LDL), and small-dense LDL (Sd-LDL). Lp(a) is under strong genetic control by apolipoprotein (a), which is an LPA gene locus. Variations in the LPA gene account for 91% of the variability in the plasma concentration of Lp(a). A meta-analysis showed that genetic variations at the LPA locus are associated with CVD events during statin therapy, independent of the extent of LDL lowering, providing support for exploring strategies targeting circulating concentrations of Lp(a) to reduce CVD events in patients receiving statins. Remnant lipoproteins and small-dense LDL are highly associated with high TG levels, low HDL-C, and obesity/insulin resistance. MDA-LDL is a representative form of oxidized LDL and plays important roles in the formation and development of the primary lesions of atherosclerosis. MDA-LDL levels were higher in CVD patients and diabetic patients than in the control subjects. Furthermore, we demonstrated the atherogenic properties of such lipoproteins and their association with CVD as well as therapeutic approaches.

The Effects of Statin Therapy on Oxidized LDL and Its Antibodies: A Systematic Review and Meta-Analysis

Background

Elevated serum low-density lipoproteins (LDL), the substrate for the formation of atherogenic oxidized LDLs (oxLDL), are a causal factor for atherosclerotic cardiovascular disease (ASCVD). Statins are well known to decrease LDL particle concentration and reduce ASCVD morbidity and mortality.

Objective

To perform a meta-analysis of the effects of statins (i.e., type, dose, and duration of treatment) on serum levels of oxLDL and on immunoglobulin M (IgM) and immunoglobulin G (IgG) antibody levels against oxLDL.

Methods

PubMed, Scopus, Embase, and Web of Science were searched up to February 5th, 2021, for randomized controlled trials (RCT) evaluating the effect of statins on oxLDL and anti-oxLDL antibody levels. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. To evaluate the influence of each study on the overall effect size, a sensitivity analysis was performed using the leave-one-out method. Evaluation of the funnel plot, Begg's rank correlation, and Egger's weighted regression tests was used to assess the presence of publication bias in the meta-analysis.

Results

A total of 28 RCTs including 4019 subjects were finally included in the meta-analysis. The results indicated a significant decrease in circulating concentrations of oxLDL after treatment with statins (SMD: -2.150, 95% CI: -2.640, -1.697, p < 0.001). Subgroup analysis found no significant effect of the intensity of statin treatment or statin lipophilicity on the reduction of circulating concentrations of oxLDL. An additional meta-analysis of 3 trials showed that statins did not change the serum levels of IgM and IgG antibodies to oxLDL.

Conclusion

Statin therapy decreases serum oxLDL concentrations but does not affect circulating levels of anti-oxLDL antibodies.

Serum Sulfhydryl Groups, Malondialdehyde, Uric Acid, and Bilirubin as Predictors of Adverse Outcome in Heart Failure Patients due to Ischemic or Nonischemic Cardiomyopathy

Oxidative stress plays a significant role in the pathogenesis of heart failure (HF). The aim of the study was to investigate the prognostic value of oxidation-reduction (redox) markers in patients with HF due to ischemic and nonischemic cardiomyopathy. The study included 707 patients of HF allocated into two groups depending on ethology: ischemic cardiomyopathy (ICM) (n = 435) and nonischemic cardiomyopathy (nICM) (n = 272), who were followed up for one year. The endpoint occurrence (mortality or heart transplantation) in a 1-year follow-up was similar in the ICM and nICM group. The predictive value of endpoint occurrence of oxidative stress biomarkers such as the serum protein sulfhydryl groups (PSH), malondialdehyde (MDA), uric acid (UA), bilirubin, and MDA/PSH ratio and other clinical and laboratory data were assessed in both groups (ICM and nICM) separately using univariate and multivariate Cox regression analyses. In multivariate analysis, the higher concentrations of UA (p = 0.015, HR = 1.024, 95% CI (1.005-1.044)) and MDA (p = 0.004, HR = 2.202, 95% CI (1.296-3.741)) were significantly associated with adverse prognosis in patients with ICM. Contrastingly, in patients with nICM, we observed that higher bilirubin concentration (p = 0.026, HR = 1.034, 95% CI (1.004-1.064)) and MDA/PSH ratio (p = 0.034, HR = 3.360, 95% CI (1.096-10.302)) were significantly associated with increased risk of death or HT. The results showed the association of different oxidative biomarkers on the unfavorable course of heart failure depending on etiology.

The effects of lipid-lowering therapy on coronary plaque regression: a systematic review and meta-analysis

To assess the influence of lipid-lowering therapy on coronary plaque volume, and to identify the LDL and HDL targets for plaque regression to provide a comprehensive overview. The databases searched (from inception to 15 July 2020) to identify prospective studies investigating the impact of lipid-lowering therapy on coronary plaque volume and including quantitative measurement of plaque volume by intravascular ultrasound after treatment. Thirty-one studies that included 4997 patients were selected in the final analysis. Patients had significantly lower TAV (SMD: 0.123 mm³; 95% CI 0.059, 0.187; P = 0.000) and PAV (SMD: 0.123%; 95% CI 0.035, 0.212; P = 0.006) at follow-up. According to the subgroup analyses, TAV was significantly reduced in the LDL < 80 mg/dL and HDL > 45 mg/dL group (SMD: 0.163 mm³; 95% CI 0.092, 0.234; P = 0.000), and PAV was significantly reduced in the LDL < 90 mg/dL and HDL > 45 mg/dL group (SMD: 0.186%; 95% CI 0.081, 0.291; P = 0.001).Thirty-one studies that included 4997 patients were selected in the final analysis. Patients had significantly lower TAV (SMD: 0.123 mm³; 95% CI 0.059, 0.187; P = 0.000) and PAV (SMD: 0.123%; 95% CI 0.035, 0.212; P = 0.006) at follow-up. According to the subgroup analyses, TAV was significantly reduced in the LDL < 80 mg/dL and HDL > 45 mg/dL group (SMD: 0.163 mm³; 95% CI 0.092, 0.234; P = 0.000), and PAV was significantly reduced in the LDL < 90 mg/dL and HDL > 45 mg/dL group (SMD: 0.186%; 95% CI 0.081, 0.291; P = 0.001). Our meta-analysis suggests that not only should LDL be reduced to a target level of < 80 mg/dL, but HDL should be increased to a target level of > 45 mg/dL to regress coronary plaques.

Trial Registration PROSPERO identifier: CRD42019146170.

Lipid Peroxidation in Atherosclerotic Cardiovascular Diseases

Significance: Atherosclerotic cardiovascular diseases (ACVDs) continue to be a primary cause of mortality worldwide in adults aged 35-70 years, occurring more often in countries with lower economic development, and they constitute an ever-growing global burden that has a considerable socioeconomic impact on society. The ACVDs encompass diverse pathologies such as coronary artery disease and heart failure (HF), among others. Recent Advances: It is known that oxidative stress plays a relevant role in ACVDs and some of its effects are mediated by lipid oxidation. In particular, lipid peroxidation (LPO) is a process under which oxidants such as reactive oxygen species attack unsaturated lipids, generating a wide array of oxidation products. These molecules can interact with circulating lipoproteins, to diffuse inside the cell and even to cross biological membranes, modifying target nucleophilic sites within biomolecules such as DNA, lipids, and proteins, and resulting in a plethora of biological effects. Critical Issues: This review summarizes the evidence of the effect of LPO in the development and progression of atherosclerosis-based diseases, HF, and other cardiovascular diseases, highlighting the role of protein adduct formation. Moreover, potential therapeutic strategies targeted at lipoxidation in ACVDs are also discussed. Future Directions: The identification of valid biomarkers for the detection of lipoxidation products and adducts may provide insights into the improvement of the cardiovascular risk stratification of patients and the development of therapeutic strategies against the oxidative effects that can then be applied within a clinical setting.

Association of plasminogen activator inhibitor-1 and low-density lipoprotein heterogeneity as a risk factor of atherosclerotic cardiovascular disease with triglyceride metabolic disorder: a pilot cross-sectional study

BACKGROUND

We hypothesized that an increase in plasminogen activator inhibitor 1 (PAI-1) might reduce low-density lipoprotein (LDL) particle size in conjunction with triglyceride (TG) metabolism disorder, resulting in an increased risk of atherosclerotic cardiovascular disease (ASCVD).

METHODS

This study was carried out as a hospital-based cross-sectional study in 537 consecutive outpatients (mean age: 64 years; men: 71%) with one or more risk factors for ASCVD from April 2014 to October 2014 at the Cardiovascular Center of Nihon University Surugadai Hospital. The estimated LDL-particle size was measured as relative LDL migration using polyacrylamide gel electrophoresis with the LipoPhor system.The plasma PAI-1 level, including the tissue PA/PAI-1 complex and the active and latent forms of PAI-1, was determined using a latex photometric immunoassay method.

RESULTS

A multivariate regression analysis after adjustments for ASCVD risk factors showed that an elevated PAI-1 level was an independent predictor of smaller-sized LDL-particle in both the overall patients population (β=0.209, P<0.0001) and a subset of patients with a serum low-density lipoprotein cholesterol (LDL-C) level lower than 100 mg/dl (β=0.276, P<0.0001). Furthermore, an increased BMI and TG-rich lipoprotein related markers [TG, remnant-like particle cholesterol, apolipoprotein (apo) B, apo C-II, and apo C-III] were found to be independent variables associated with an increased PAI-1 level in multivariate regression models. A statistical analysis of data from nondiabetic patients with well-controlled serum LDL-C levels yielded similar findings. Furthermore, in the 310 patients followed up for at least 6 months, a multiple-logistic regression analysis after adjustments for ASCVD risk factors identified the percent changes of the plasma PAI-1 level in the third tertile compared with those in the first tertile as being independently predictive of decreased LDL-particle size [odds ratio (95% confidence interval): 2.11 (1.12/3.40), P=0.02].

CONCLUSION

The plasma PAI-1 levels may be determined by the degree of obesity and TG metabolic disorders. These factors were also shown to be correlated with a decreased LDL-particle size, increasing the risk of ASCVD, even in nondiabetic patients with well-controlled serum LDL-C levels.

Investigation of MDA-LDL (malondialdehyde-modified low-density lipoprotein) as a prognostic marker for coronary artery disease in patients with type 2 diabetes mellitus

BACKGROUND

Although increased circulating levels of malondialdehyde-modified low-density lipoprotein (MDA-LDL) are associated with coronary artery disease (CAD), there is no direct evidence that increased MDA-LDL is a prognostic factor for CAD.

METHODS

Forty-two patients (20 diabetic and 22 non-diabetic patients) who underwent percutaneous coronary intervention (PCI) were enrolled, and their baseline MDA-LDL levels were determined by immunoassay. Follow-up coronary angiography was performed at 2 to 7 months post-PCI. The patients were then divided into 2 groups, with in-stent restenosis (ISR) (n=13) and without ISR (n=29), and the baseline MDA-LDL levels were compared. We also studied 34 diabetics with CAD for up to 57 months until the onset of the next coronary event.

RESULTS

In the diabetic patients, the mean MDA-LDL level was significantly higher in those with ISR than in those without ISR (151+/-61 vs. 90+/-26 U/l, p=0.010). A baseline MDA-LDL value of 110 U/l for differentiating between diabetics with and without ISR was defined as the cut-off value. Kaplan-Meier analysis demonstrated that a circulating MDA-LDL of ≥ 110 U/l correlated significantly with a higher prevalence of cardiac events than MDA-LDL <110 U/l (p=0.032).

CONCLUSIONS

Circulating MDA-LDL is a useful prognostic marker for future cardiac event in diabetic patients with CAD.

Association between LDL-C, Non HDL-C, and Apolipoprotein B Levels with Coronary Plaque Regression

BACKGROUND

Previous reports have inferred a linear relationship between LDL-C and changes in coronary plaque volume (CPV) measured by intravascular ultrasound. However, these publications included a small number of studies and did not explore other lipid markers.

OBJECTIVE

To assess the association between changes in lipid markers and regression of CPV using published data.

METHODS

We collected data from the control, placebo and intervention arms in studies that compared the effect of lipidlowering treatments on CPV, and from the placebo and control arms in studies that tested drugs that did not affect lipids. Baseline and final measurements of plaque volume, expressed in mm3, were extracted and the percentage changes after the interventions were calculated. Performing three linear regression analyses, we assessed the relationship between percentage and absolute changes in lipid markers and percentage variations in CPV.

RESULTS

Twenty-seven studies were selected. Correlations between percentage changes in LDL-C, non-HDL-C, and apolipoprotein B (ApoB) and percentage changes in CPV were moderate (r = 0.48, r = 0.47, and r = 0.44, respectively). Correlations between absolute differences in LDL-C, non‑HDL-C, and ApoB with percentage differences in CPV were stronger (r = 0.57, r = 0.52, and r = 0.79). The linear regression model showed a statistically significant association between a reduction in lipid markers and regression of plaque volume.

CONCLUSION

A significant association between changes in different atherogenic particles and regression of CPV was observed. The absolute reduction in ApoB showed the strongest correlation with coronary plaque regression.

The difference between Asian and Western in the effect of LDL-C lowering therapy on coronary atherosclerotic plaque: a meta-analysis report

Background

The different effects of LDL-C levels and statins therapy on coronary atherosclerotic plaque between Western and Asian remain to be settled.

Methods

PubMed, EMBASE, and Cochrane databases were searched from Jan. 2000 to Sep. 2014 for randomized controlled or blinded end-points trials assessing the effects of LDL-C lowering therapy on regression of coronary atherosclerotic plaque (CAP) in patients with coronary heart disease by intravascular ultrasound. The significance of plaques regression was assessed by computing standardized mean difference (SMD) of the volume of CAP between the baseline and follow-up.

Results

Twenty trials (ten in the West and ten in Asia) were identified. For Westerns, Mean lowering LDL-C by 49.4% and/or to level 61.9 mg/dL in the group of patients with baseline mean LDL-C 123.2 mg/dL could significantly reduce the volume of CAP at follow up (SMD −0.156 mm³, 95% CI −0.248 ~ −0.064, p = 0.001). LDL-C lowering by rosuvastatin (mean 40 mg daily) could significantly decrease the volumes of CAP at follow up. For Asians, Mean lowering LDL-C by 36.1% and/or to level 84.0 mg/dL with baseline mean LDL-C 134.2 mg/dL could significantly reduce the volume of CAP at follow up (SMD −0.211 mm³, 95% CI −0.331 ~ −0.092, p = 0.001). LDL-C lowering by rosuvastatin (mean 14.1 mg daily) and atorvastatin (mean 18.9 mg daily) could significantly decrease the volumes of CAP at follow up.

Conclusions

There was a different effect of LDL-C lowering on CAP between Westerns and Asians. For regressing CAP, Asians need lower dosage of statins or lower intensity LDL-C lowering therapy than Westerns.

Systematic study of the effects of lowering low-density lipoprotein-cholesterol on regression of coronary atherosclerotic plaques using intravascular ultrasound

BACKGROUND

Conflicting results currently exist on the effects of LDL-C levels and statins therapy on coronary atherosclerotic plaque, and the target level of LDL-C resulting in the regression of the coronary atherosclerotic plaques has not been settled.

METHODS

PubMed, EMBASE, and Cochrane databases were searched from Jan. 2000 to Jan. 2014 for randomized controlled or blinded end-points trials assessing the effects of LDL-C lowering therapy on regression of coronary atherosclerotic plaque (CAP) in patients with coronary heart disease by intravascular ultrasound. Data concerning the study design, patient characteristics, and outcomes were extracted. The significance of plaques regression was assessed by computing standardized mean difference (SMD) of the volume of CAP between the baseline and follow-up. SMD were calculated using fixed or random effects models.

RESULTS

Twenty trials including 5910 patients with coronary heart disease were identified. Mean lowering LDL-C by 45.4% and to level 66.8 mg/dL in the group of patients with baseline mean LDL-C 123.7 mg/dL, mean lowering LDL-C by 48.8% and to level 60.6 mg/dL in the group of patients with baseline mean LDL-C 120 mg/dL, and mean lowering LDL-C by 40.4% and to level 77.8 mg/dL in the group of patients with baseline mean LDL-C 132.4 mg/dL could significantly reduce the volume of CAP at follow up (SMD -0.108 mm3, 95% CI -0.176 ~ -0.040, p = 0.002; SMD -0.156 mm3, 95% CI -0.235 ~ -0.078, p = 0.000; SMD -0.123 mm3, 95% CI -0.199 ~ -0.048, p = 0.001; respectively). LDL-C lowering by rosuvastatin (mean 33 mg daily) and atorvastatin (mean 60 mg daily) could significantly decrease the volumes of CAP at follow up (SMD -0.162 mm3, 95% CI: -0.234 ~ -0.081, p = 0.000; SMD -0.101, 95% CI: -0.184 ~ -0.019, p = 0.016; respectively). The mean duration of follow up was from 17 ~ 21 months.

CONCLUSIONS

Intensive lowering LDL-C (rosuvastatin mean 33 mg daily and atorvastatin mean 60 mg daily) with >17 months of duration could lead to the regression of CAP, LDL-C level should be reduced by >40% or to a target level <78 mg/dL for regressing CAP.

A systematic review of the time course of atherosclerotic plaque regression

OBJECTIVE

We sought to determine the time required for lipid treatment to produce regression of atherosclerotic plaques.

BACKGROUND

The cholesterol content of atherosclerotic plaques contributes to their instability, and most acute cardiac events including myocardial infarction and sudden death are produced by coronary plaque disruption. We systematically reviewed the literature on atherosclerosis regression to identify the time required for cholesterol egress, plaque regression, and possible plaque stabilization. Such information may help decide when patients with statin side effects or other reasons for statin discontinuation could consider a reduction in the intensity of treatment.

METHODS

We performed a PubMed search to identify English language articles reporting atherosclerotic regression. Articles pertinent to the topic were reviewed in detail.

RESULTS

We identified 189 articles, 50 of which provided sufficient information to establish a rate of regression and 31 of which demonstrated plaque regression with statin therapy in the carotid (n = 11), coronary (n = 16), and aortic (n = 4) vascular beds. Plaque regression occurred after an average of 19.7 months of treatment.

CONCLUSION

Regression of atherosclerotic plaque using statin therapy in those studies documenting regression occurred after an average time of 19.7 months. This suggests that patients should undergo approximately two years of aggressive lipid reduction before considering a reduction of statin therapy.

Effect of statin therapy on the progression of coronary atherosclerosis

BACKGROUND

An increasing number of authors employing intravascular ultrasound (IVUS) and virtual histology (VH-IVUS) have investigated the effect of statin use on plaque volume (PV) and plaque composition. However, inconsistent results have been reported. Therefore, we conducted a meta-analysis to determine the appropriate regimen of statins to effectively stabilize vulnerable coronary plaques.

METHODS

Online electronic databases were carefully searched for all relevant studies. We compared mean values of PV and plaque composition between baseline and follow-up in patients receiving statin therapy. We pooled treatment effects and calculated mean differences (MD) with the 95% confidence interval (CI) using a random-effects model. By stratified analyses, we explored the influence of clinical presentation, dose and duration of statin treatment, and low-density lipoprotein-cholesterol (LDL-C) levels on the effects of statins.

RESULTS

Seventeen studies involving 2,171 patients were analyzed. Statin therapy significantly decreased PV (-5.3 mm(3); 95% CI: -3.3 mm(3) to -7.2 mm(3) P < 0.001), without heterogeneity. When considering the dose and duration of statins used, only subgroups employing a high dose and long duration demonstrated a significant reduction in PV (p < 0.001). A significant decrease in PV was noted if achieved LDL-C levels were <100 mg/dL (p < 0.001). Statin treatment could induce a twofold decrease in PV in patients with acute coronary syndrome (ACS) compared with that observed in patients with stable angina pectoris (SAP). A regressive trend was seen for necrotic core volume (MD: -2.1 mm(3); 95% CI: -4.7 mm(3) to 0.5 mm(3), P = 0.11). However, statin use did not induce a significant change for fibrotic, fibro-fatty, or dense calcium compositions.

CONCLUSIONS

Our meta-analysis demonstrated that statin therapy (especially that involving a high dose and long duration and achieving <100 mg/dL LDL-C levels) can significantly decrease PV in patients with SAP or ACS. These data suggested that statins can be used to reduce the atheroma burden for secondary prevention by appropriately selecting the statin regimen. No significant change in plaque composition was seen after statin therapy.

Association of the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio and body mass index with coronary plaque regression

BACKGROUND

The change (Δ) in the low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio (ΔLDL-C/HDL-C) and obesity are known to play important roles in the progression of coronary atherosclerosis. We hypothesized that a reasonable predictive model of coronary plaque regression could be constructed using ΔLDL-C/HDL-C and the body mass index (BMI).

OBJECTIVE

The purpose of this study was to establish a predictive model of coronary plaque regression using ΔLDL-C/HDL-C and BMI.

METHODS AND RESULTS

A 6-month prospective observational study was conducted among 114 patients with coronary artery disease (CAD) who were treated with pravastatin. The plaque volume, as assessed using volumetric intravascular ultrasound, decreased significantly by 9.9% (p < 0.0001 vs baseline). In a multivariate regression analysis with traditional risk factors, ΔLDL-C/HDL-C (β: 0.473, p = 0.0001) and the baseline BMI (β: 0.249, p = 0.004) were identified as independent predictors of the Δplaque volume. The patients were divided using the 50th percentile of the baseline BMI and the 50th percentile of the ΔLDL-C/HDL-C ratio as cutoffs, and a model for predicting coronary atherosclerotic regression was prepared using a combination of the two variables. The Δplaque volumes were -18.3%, -14.1%, -4.8%, and -2.2% for the groups with ΔLDL-C/HDL-C ≤ -22.2% and a BMI ≤ 24.1 kg/m(2), ΔLDL-C/HDL-C ≤ -22.2% and ΔBMI >24.1 kg/m(2), ΔLDL-C/HDL-C > -22.2% and BMI ≤ 24.1 kg/m(2), and ΔLDL-C/HDL-C > -22.2% and BMI >24.1 kg/m(2), respectively (p = 0.003).

CONCLUSION

A predictive model for coronary plaque regression based on a combination of ΔLDL-C/HDL-C and the baseline BMI may be a useful clinical tool in patients with CAD.

Antiatherosclerotic Effect of an Antibody That Binds to Extracellular Matrix Glycosaminoglycans

Objective—

Subendothelial retention of proatherogenic lipoproteins by proteoglycans is critical in atherosclerosis. The aim of this study was to characterize the recognition and antiatherogenic properties of a chimeric monoclonal antibody (mAb) that reacts with sulfated molecules.

Methods and Results—

chP3R99 mAb recognized sulfated glycosaminoglycans, mainly chondroitin sulfate (CS), by ELISA. This mAb blocked ≈70% of low-density lipoprotein (LDL)–CS association and ≈80% of LDL oxidation in vitro, and when intravenously injected to Sprague-Dawley rats (n=6, 1 mg/animal), it inhibited LDL (4 mg/kg intraperitoneally, 1 hour later) retention and oxidation in the artery wall. Moreover, subcutaneous immunization of New Zealand White rabbits (n=19) with chP3R99 mAb (100 μg, 3 doses at weekly intervals) prevented Lipofundin-induced atherosclerosis (2 mL/kg, 8 days) with a 22-fold reduction in the intima-media ratio ( P <0.01). Histopathologic and ultrastructural studies showed no intimal alterations or slight thickening, with preserved junctions between endothelial cells and scarce collagen fibers and glycosaminoglycans. In addition, immunization with chP3R99 mAb suppressed macrophage infiltration in aorta and preserved redox status. The atheroprotective effect was associated with the induction of anti-CS antibodies in chP3R99-immunized rabbits, capable of blocking CS-LDL binding and LDL oxidation.

Conclusion—

These results support the use of anti-sulfated glycosaminoglycan antibody–based immunotherapy as a potential tool to prevent atherosclerosis.

Comparison of preventive effect on cardiovascular events with different statins. -The CIRCLE study-

BACKGROUND

Although statins vary in their effectiveness in lowering low-density lipoprotein cholesterol (LDL-C) and increasing high-density lipoprotein cholesterol (HDL-C) levels, there is little evidence that the degree of these changes can explain cardiac risk reduction in Japan. Our objective was to compare the efficacy of statins on serum lipid levels and to explore the association between those changes and cardiac events in patients after percutaneous coronary intervention (PCI).

METHODS AND RESULTS

The 743 consecutive patients who underwent PCI from 2001 to 2008 were retrospectively investigated. Treatment with either atorvastatin or pitavastatin significantly reduced LDL-C compared with pravastatin or no statin. In contrast, only pitavastatin treatment significantly increased HDL-C (13.4 ± 22.9%, P=0.01 vs. no statin). Each statin significantly prevented major adverse cardiac events (MACE) compared with no statin, and pitavastatin was the most effective of all. Multivariate-adjusted analysis revealed that percent changes of both LDL-C and HDL-C independently predicted the incidence of MACE (hazard ratio [HR]: 1.015; 95% confidence interval [CI]: 1.010-1.020, HR: 0.988; 95%CI: 0.981-0.996, respectively). This relationship was preserved in patients with a baseline HDL-C level ≤ 45 mg/dl, but not HDL-C level > 45 mg/ml.

CONCLUSIONS

The extent of changes in LDL-C and HDL-C with statin treatment would independently alter the risk of cardiac events in Japanese patients for secondary prevention. Statins with varying lipid-modifying ability might provide differing prognosis in patients after PCI.

Development of a model for prediction of coronary atherosclerotic regression: evaluation of high-density lipoprotein cholesterol level and peripheral blood monocyte count

Monocytes and high-density lipoprotein cholesterol (HDL-C) play important roles in the process of coronary atherosclerosis. We hypothesized that a reasonable predictive model of coronary plaque regression might be constructed using the change in the peripheral monocyte count and the serum HDL-C level. The plaque volume, as assessed by volumetric intravascular ultrasound, was measured at the baseline and after 6 months of pravastatin therapy in 114 patients with coronary artery disease. After 6 months of pravastatin therapy, a significant decrease of the plaque volume by 9.9% (p < 0.0001, vs. baseline) was observed; furthermore, a corresponding increase of the serum HDL-C level and decrease of the peripheral blood monocyte count were also seen (12.5%, p < 0.01 and -7.3%, p < 0.0001). In a multivariate regression analysis using the serum lipids and traditional risk factors as the covariates, the increase in the serum HDL-C (β -0.56, p < 0.0001) and the decrease in monocyte count (β 0.23, p = 0.03) were identified as independent predictors of the plaque regression. A model for the prediction of plaque regression according to whether the achieved the change in (Δ) monocyte count and ΔHDL-C were above or below the median values was prepared. Among the four groups, the group with ΔHDL-C ≥8.8% and Δmonocyte count ≤-8.6% showed the largest plaque regression (-20.4%), and the group with ΔHDL-C <8.8% and Δmonocyte count >-8.6% showed the increase of the plaque volume (2.6%). In view of the inflammatory nature of atherosclerosis, the model constructed using the two predictors may be a useful model for the prediction of plaque regression.

Assessment of coronary atherosclerosis by IVUS and IVUS-based imaging modalities: progression and regression studies, tissue composition and beyond

Cardiovascular disease remains the leading cause of mortality, morbidity and disability in the developed world, predominantly affecting the adult population. In the early 1990s coronary heart disease (CHD) was established as affecting one in two men and one in three women by the age of forty. Despite the dramatic progress in the field of cardiovascular medicine in terms of diagnosis and treatment of heart disease, modest improvements have only been achieved when the reduction of cardiovascular mortality and morbidity indices are assessed. To better understand coronary atherosclerosis, new imaging modalities have been introduced. These novel imaging modalities have been used in two ways: (1) for the characterization of plaque types; (2) for the assessment of the progression and regression of tissue types. These two aspects will be discussed in this review.

Intravascular ultrasound imaging for assessing regression and progression in coronary artery disease

New imaging techniques have been used as surrogate markers of atherosclerotic burden to determine the effects of pharmacologic intervention. The aim of this study was to better determine potential utility and limitations of intravascular ultrasound (IVUS) imaging for assessing regression and progression in coronary artery disease. Medline was searched for randomized trials using IVUS for assessing regression and progression in coronary artery disease (through September 2009). A comparison of IVUS studies with large trials evaluating the same issue with clinical end points was performed. A total of 26 relevant reports (8,631 patients randomized [median 207.5], 5,794 patients analyzed [median 152], duration 2 weeks to 3.4 years [median 12 months]) were identified. Three frequently used IVUS variables were the focus of the analysis: (1) nominal change in plaque volume, (2) percentage change in plaque volume, and (3) nominal change in percentage plaque volume. These variables were presented in 21, 12, and 11 studies, respectively. The variables were the primary end points in 4, 5, and 4 studies, respectively. Large variance with a relatively small difference was noticed in all 3 variables. Fewer than half of the variables showed statistically significant differences in comparing groups. Comparison of IVUS studies with large trials evaluating the same issue with clinical end points showed consistent and inconsistent results. In conclusion, the current method of calculating plaque volume using IVUS seems logical, and some clinical outcomes trials have yielded some evidence. Future studies are needed to determine which IVUS variable is the best surrogate to determine the effects of pharmacologic intervention in patients with coronary artery disease.

Impact of olmesartan on progression of coronary atherosclerosis a serial volumetric intravascular ultrasound analysis from the OLIVUS (impact of OLmesarten on progression of coronary atherosclerosis: evaluation by intravascular ultrasound) trial

OBJECTIVES

The aim of this study was to evaluate the impact of olmesartan on progression of coronary atherosclerosis.

BACKGROUND

Prior intravascular ultrasound (IVUS) trial results suggest slowing of coronary atheroma progression with some medicines but have not shown convincing evidence of regression with angiotension-II receptor blocking agents.

METHODS

A prospective, randomized, multicenter trial-OLIVUS (Impact of OLmesartan on progression of coronary atherosclerosis: evaluation by IntraVascular UltraSound)-was performed in 247 stable angina pectoris patients with native coronary artery disease. When these patients underwent percutaneous coronary intervention for culprit lesions, IVUS was performed in their nonculprit vessels (without angiographically documented coronary stenosis [<50%]). Patients were randomly assigned to receive 10 to 40 mg of olmesartan or control and treated with a combination of beta-blockers, calcium channel blockers, diuretics, nitrates, glycemic control agents, and/or statins per physician's guidance. Serial IVUS examinations (baseline and 14-month follow-up) were performed to assess coronary atheroma volume. Volumetric IVUS analyses included lumen, plaque, vessel volume, percent atheroma volume (PAV), percent change in total atheroma volume (TAV) and PAV.

RESULTS

Patient characteristics and blood pressure control were identical between the 2 groups. However, follow-up IVUS showed significantly decreased TAV and percent change in PAV in the olmesartan group (5.4% vs. 0.6 % for TAV and 3.1% vs. -0.7% for percent change in PAV, control vs. olmesartan, p < 0.05 for all).

CONCLUSIONS

These observations suggest a positive role in a potentially lower rate of coronary atheroma progression through the administration of olmesartan, an angiotension-II receptor blocking agent, for patients with stable angina pectoris.

Relation of change in apolipoprotein B/apolipoprotein A-I ratio to coronary plaque regression after Pravastatin treatment in patients with coronary artery disease

Some investigations have looked into the ability of measurements of apolipoprotein B/apolipoprotein A-I (apoB/apoA-I) ratio to predict cardiovascular events. We hypothesized that a decrease in the apoB/apoA-1 ratio by statin therapy would act on suppression of coronary plaque progression. A 6-month prospective study was conducted of 64 patients with coronary artery disease treated with pravastatin. The plaque volume, assessed by volumetric intravascular ultrasonography, had decreased significantly by 12.6% (p <0.0001 vs baseline). Although a significant decrease of 6.4% and 14.6% was found in the serum level of apoB and the apoB/apoA-1 ratio (p = 0.0001 and p <0.0001, respectively, vs baseline), a significant increase of 14.0% of and 12.0% in the level of apoA-I and apoA-II (both p <0.0001 vs baseline). No significant changes were found in the level of apoC-II or apoE. A stepwise regression analysis revealed that the change in the apoB/apoA-1 ratio was an independent predictor of the change in coronary plaque volume (beta coefficient 0.386; p = 0.0023). In conclusion, our results have indicated that the decrease in the apoB/apoA-I ratio is a simple predictor for coronary atherosclerotic regression: the lower the apoB/apoA-I ratio, the lower the risk of coronary atherosclerosis.

Association of leukocyte subtype counts with coronary atherosclerotic regression following pravastatin treatment

The purpose of this study was to clarify the relation between differential leukocyte counts and inhibition of the development of coronary atherosclerosis in patients with coronary artery disease. A 6-month prospective study was conducted in 84 patients treated with pravastatin. Plaque volume, as assessed by volumetric analysis using intravascular ultrasound, decreased significantly by 12.6% (p <0.0001 vs baseline) after treatment; furthermore, a corresponding decrease of total leukocyte count (8.9%, p <0.01 vs baseline) was seen. Change in plaque volume was correlated with changes in monocyte (r = 0.35, p = 0.002) and lymphocyte (r = 0.25, p = 0.03) counts but not with changes in neutrophil, eosinophil, or basophil counts. In a multivariate regression analysis with changes in serum lipids, traditional risk factors, and medications as covariates, the decrease in monocyte count was identified as an independent predictor of coronary plaque regression (beta coefficient 0.313, 95% confidence interval 0.089 to 0.353, p = 0.0014). No correlation was found between change in monocyte count and changes in any other lipid levels. This study demonstrated that monocyte count was the only leukocyte type significantly and independently associated with coronary atherosclerotic regression, even after adjustment for changes in any lipid levels. In conclusion, the decrease in monocyte count as a nonlipid-lowering effect of statins may be used as a novel marker of coronary atherosclerotic regression.

Association of body mass index with coronary plaque regression: 6-month prospective study

AIM

Obesity is a well known strong risk factor for coronary artery disease (CAD). We prospectively investigated the influence of body mass index (BMI) on the inhibitory effects of pravastatin against the development of coronary atherosclerosis.

METHODS

In 56 patients with stable CAD, 3-dimensional intravascular ultrasound was performed in matched coronary segments at the baseline and after 6-month treatment with pravastatin.

RESULTS

The plaque volume was significantly reduced by 11% after treatment (p<0.001 vs. baseline). The percent plaque volume was positively correlated with the baseline BMI (r=0.37, p<0.001), and negatively correlated with the serum total cholesterol / high-density lipoprotein cholesterol ratio (r=0.27, p<0.05) and total leukocyte count (r=0.27, p<0.05). Multivariate regression analysis showed that BMI was an independent predictor of the change in plaque volume (beta coefficient: 0.326; 95% CI: 0.003 to 0.037; p<0.05). No correlations were found between BMI and changes in the serum levels of any other lipids, apolipoproteins, or hs-CRP.

CONCLUSION

The present study demonstrated that an increase in BMI attenuated pravastatin-induced coronary atherosclerosis regression. The results may provide new insight into the framework for the treatment of obese patients with CAD.

Qualitative and quantitative changes in coronary plaque associated with atorvastatin therapy

BACKGROUND

The aim of this study was to elucidate the time course of atorvastatin-induced changes in vulnerable plaque using angioscopy and intravascular ultrasound (IVUS).

METHODS AND RESULTS

Fifty-seven hypercholesterolemic patients with coronary artery disease (CAD) were treated with atorvastatin (10-20 mg/day) for 80 weeks and then coronary plaques were evaluated with angioscopy and IVUS. Angioscopic images were classified into 6 grades (0-5) based on yellow color intensity. A 20-mm segment containing angioscopically-identified yellow plaque was also examined by IVUS to measure atheroma volume. The mean angioscopic grade of 58 yellow plaques significantly decreased from 1.5 (95% confidence interval [CI] 1.2 to 1.8) to 1.1 (95%CI 0.9 to 1.3, P=0.012) at week 28 and 1.2 (95%CI 0.9 to 1.4, P=0.024) at week 80. Mean volume of 30 lesions, including the 58 yellow plaques, significantly reduced -8.3% (95%CI -11.5 to -5.2) at week 28 (P<0.001 for baseline vs week 28) and -17.8% (95%CI -23.9 to -11.8) at week 80 (P<0.001 for baseline vs week 80).

CONCLUSIONS

In patients with CAD treated with atorvastatin, serial analysis with angioscopy demonstrated early loss of yellow color in plaques, and IVUS volumetric analysis showed subsequent plaque regression. Both changes possibly indicate reduction of plaque vulnerability in an additive manner.

A case of vasospastic angina showing resolution of coronary vasospasm in acetylcholine provocation test corresponding to regression of coronary atherosclerosis

We experienced a case of vasospastic angina showing resolution of vasospasm in the acetylcholine provocation test corresponding to regression of coronary atherosclerotic plaque following treatment with a combination of benidipine and pravastatin.

Association of circulating leukocyte count with coronary atherosclerosis regression after pravastatin treatment

Epidemiological studies have demonstrated that the peripheral blood leukocyte count could be used as a marker of the progression of atherosclerosis. Few data exist regarding the relationship between inhibition of the progression of coronary atherosclerosis and the anti-inflammatory effects of statins, especially the drugs' effects on the leukocyte count in patients with coronary artery disease. A 6-month prospective study was, therefore, conducted in 50 patients treated with pravastatin. The plaque volume, as assessed by volumetric analysis using intravascular ultrasound, reduced significantly by 14% (p<0.0001, vs. baseline) following the treatment, furthermore, a corresponding decrease of the leukocyte count (8.9%, p<0.01, vs. baseline) was also seen. No correlation was found between the change in the leukocyte count and any of the changes in the lipid levels; changes in either of these are known to be associated with the rate of progression of atherosclerosis. A multivariate regression analysis using other traditional risk factors and medications as covariates revealed that the decrease in the leukocyte count was an independent predictor of inhibition of the progression of coronary atherosclerosis. In conclusion, a reduction of the leukocyte count as one of the non-lipid-lowering effects of pravastatin may be a novel marker of regression of coronary atherosclerosis.

Impact of lipid-lowering therapy with pitavastatin, a new HMG-CoA reductase inhibitor, on regression of coronary atherosclerotic plaque

BACKGROUND

Recent lipid-lowering trials have reported that statin therapy may retard progression or stimulate regression of human coronary plaque. In the present study volumetric intravascular ultrasound (IVUS) analyses were performed to investigate the effect of pitavastatin, a newly developed statin, on regression of human coronary plaque.

METHODS AND RESULTS

Eighty-two patients matched for age and gender from 870 consecutive patients undergoing IVUS guided percutaneous coronary intervention were retrospectively assigned to either lipid-lowering therapy (n=41; pitavastatin 2 mg/day) or control group (n=41; diet only). Serial volumetric IVUS analyses of a matched left main coronary arterial site were performed. A significant reduction in low-density lipoprotein-cholesterol (LDL-C) level of 33.2% (p<0.001) was observed in the pitavastatin group. Plaque volume index (PVI) was significantly reduced in the pitavastatin group (10.6+/-9.4% decrease) compared with the control group (8.1+/-14.0% increase, p<0.001). There were positive correlations between the percent change in the PVI and follow-up LDL-C level (r=0.500, p<0.001) and the percent change in LDL-C level (r=0.479, p<0.001).

CONCLUSION

Lipid-lowering therapy with pitavastatin induced significant coronary plaque regression, associated with a significant reduction in the LDL-C level. The percent change in the PVI showed a significant positive correlation with the percent change in LDL-C level.

Meta-analysis of the studies assessing temporal changes in coronary plaque volume using intravascular ultrasound

To assess the temporal effect of statin therapy on coronary atherosclerotic plaque volume measured by intravascular ultrasound (IVUS), we searched PubMed for eligible studies published between 1990 and January 2006. Inclusion criteria for retrieved studies were (1) IVUS volume analysis at baseline and follow-up and (2) statin therapy in > or =1 group of patients. All data of interest were abstracted in prespecified structured collection forms. Statistical analysis was performed with Review Manager 4.2. Random-effect weighted mean difference (WMD) was used as summary statistics for comparison of continuous variables. Nine studies of 985 patients (with 11 statin treatment arms) were selected. After a mean follow-up of 9.8 +/- 4.9 months, we found a significant decrease in coronary plaque volume (WMD -5.77 mm(3), 95% confidence interval -10.36 to -1.17, p = 0.01), with no significant heterogeneity across studies (p = 0.47). Prespecified subgroup analyses showed similar trends. Studies in which the achieved low-density lipoprotein (LDL) cholesterol level was <100 mg/dl showed a trend for plaque regression (WMD -7.88 mm(3), 95% confidence interval -16.31 to 0.55, p = 0.07), whereas studies in which the achieved level of LDL cholesterol was > or =100 mg/dl, the trend was less evident (WMD -4.22 mm(3), 95% confidence interval -10.27 to 1.82, p = 0.17). Plaque volume remained essentially unchanged in patients not treated with statins (WMD 0.13 mm(3), 95% confidence interval -4.42 to 4.68, p = 0.96). In conclusion, statin therapy, particularly when achieving the target LDL level, appears to promote a significant regression of coronary plaque volume as measured by IVUS.

Japan Assessment of Pitavastatin and Atorvastatin in Acute Coronary Syndrome (JAPAN-ACS) Rationale and Design

BACKGROUND

Many trials have shown that 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors reduce the incidence of cardiovascular events and mortality. One method of decreasing the incidence of cardiovascular events could be to reduce the progression of coronary atherosclerosis, and a recent study found that atorvastatin can cause coronary plaque to regress. To generalize this finding, using conventional HMG-CoA reductase inhibitors at many Japanese centers, randomized trials of pitavastatin and atorvastatin will be conducted with patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

Patients with ACS who have undergone successful percutaneous coronary intervention under intravascular ultrasound guidance will be studied. They will be randomly allocated to pitavastatin or atorvastatin groups and followed up for 8-12 months. The primary endpoint will be the percent change in coronary plaque volume, and secondary endpoints will include absolute changes in coronary plaque volume, serum lipid levels and inflammatory markers. The safety profile will also be evaluated.

CONCLUSIONS

This study will examine the ability of HMG-CoA reductase inhibitors to regress coronary plaque in Japanese patients with ACS and the findings should help to improve the prognosis of such patients and clarify the involved mechanisms.