Statin treatment for coronary artery plaque composition based on intravascular ultrasound radiofrequency data analysis

Atherosclerotic Coronary Plaque Regression and Risk of Adverse Cardiovascular Events: A Systematic Review and Updated Meta-Regression Analysis

Importance

The association between changes in atherosclerotic plaque induced by lipid-lowering therapies (LLTs) and reduction in major adverse cardiovascular events (MACEs) remains controversial.

Objective

To evaluate the association between coronary plaque regression assessed by intravascular ultrasound (IVUS) and MACEs.

Data Sources

A comprehensive, systematic search of publications in PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science was performed.

Study Selection

Clinical prospective studies of LLTs reporting change in percent atheroma volume (PAV) assessed by IVUS and describing MACE components were selected.

Data Extraction and Synthesis

Reporting was performed in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The association between mean change in PAV and MACEs was analyzed by meta-regression using mixed-effects, 2-level binomial logistic regression models, unadjusted and adjusted for clinical covariates, including mean age, baseline PAV, baseline low-density lipoprotein cholesterol level, and study duration.

Main Outcome and Measures

Mean PAV change and MACE in intervention and comparator arms were assessed in an updated systematic review and meta-regression analysis of IVUS trials of LLTs that also reported MACEs.

Results

This meta-analysis included 23 studies published between July 2001 and July 2022, including 7407 patients and trial durations ranging from 11 to 104 weeks. Mean (SD) patient age ranged from 55.8 (9.8) to 70.2 (7.6) years, and the number of male patients from 245 of 507 (48.3%) to 24 of 26 (92.3%). Change in PAV across 46 study arms ranged from -5.6% to 3.1%. The number of MACEs ranged from 0 to 72 per study arm (17 groups [37%] reported no events, 9 [20%] reported 1-2 events, and 20 [43%] reported ≥3 events). In unadjusted analysis, a 1% decrease in mean PAV was associated with 17% reduced odds of MACEs (unadjusted OR, 0.83; 95% CI, 0.71-0.98; P = .03), and with a 14% reduction in MACEs in adjusted analysis (adjusted OR, 0.86; 95% CI, 0.75-1.00; P = .050). Further adjustment for cardiovascular risk factors showed a 19% reduced risk (adjusted OR, 0.81; 95% CI, 0.68-0.96; P = .01) per 1% decrease in PAV. A 1% reduction of PAV change between intervention and comparator arms within studies was also associated with a significant 25% reduction in MACEs (OR, 0.75; 95% CI, 0.56-1.00; P = .046).

Conclusions and Relevance

In this meta-analysis, regression of atherosclerotic plaque by 1% was associated with a 25% reduction in the odds of MACEs. These findings suggest that change in PAV could be a surrogate marker for MACEs, but given the heterogeneity in the outcomes, additional data are needed.

Intravascular imaging assessment of pharmacotherapies targeting atherosclerosis: advantages and limitations in predicting their prognostic implications

Intravascular imaging has been often used over the recent years to examine the efficacy of emerging therapies targeting plaque evolution. Serial intravascular ultrasound, optical coherence tomography, or near-infrared spectroscopy-intravascular ultrasound studies have allowed us to evaluate the effects of different therapies on plaque burden and morphology, providing unique mechanistic insights about the mode of action of these treatments. Plaque burden reduction, a decrease in necrotic core component or macrophage accumulation-which has been associated with inflammation-and an increase in fibrous cap thickness over fibroatheromas have been used as surrogate endpoints to assess the value of several drugs in inhibiting plaque evolution and improving clinical outcomes. However, some reports have demonstrated weak associations between the effects of novel treatments on coronary atheroma and composition and their prognostic implications. This review examines the value of invasive imaging in assessing pharmacotherapies targeting atherosclerosis. It summarizes the findings of serial intravascular imaging studies assessing the effects of different drugs on atheroma burden and morphology and compares them with the results of large-scale trials evaluating their impact on clinical outcome. Furthermore, it highlights the limited efficacy of established intravascular imaging surrogate endpoints in predicting the prognostic value of these pharmacotherapies and introduces alternative imaging endpoints based on multimodality/hybrid intravascular imaging that may enable more accurate assessment of the athero-protective and prognostic effects of emerging therapies.

Associations of pre-hospital statin treatment with in-hospital outcomes and severity of coronary artery disease in patients with first acute coronary syndrome-findings from the CCC-ACS project

Background

The current burden of dyslipidemia, the pre-hospital application of statins and the association of pre-hospital statins with the severity of coronary artery disease (CAD) and in-hospital outcomes in Chinese patients with first acute coronary syndrome (ACS) are very significant and remain unclear.

Methods

A total of 41,183 patients who underwent coronary angiography and were diagnosed with ACS for the first time from a nationwide registry study (CCC-ACS) were enrolled. The severity of CAD was assessed using the CAD prognostic index (CADPI). The patients were classified into statin and non-statin groups according to their pre-hospital statin treatment status. Clinical characteristics, CADPI and in-hospital outcomes were compared, and a logistic regression analysis was performed to determine whether pre-hospital statin therapy is associated with in-hospital outcomes and CADPI. A sensitivity analysis was used to further explore the issues above.

Results

The non-statin group had more in-hospital all-cause deaths (1.2 vs. 0.8%, P = 0.010). However, no association exists between statin pretreatment and in-hospital major adverse cardiovascular events (MACEs) or all-cause deaths in the entire population and subgroups (all P > 0.05). Surprisingly, statin pretreatment was associated with an 8.9% higher risk of severely obstructive CAD (CADPI ≥ 37) (OR, 1.089; 95% CI, 1.010-1.175, P = 0.028), and similar results were observed in subgroups of females, those aged 50 to 75 years, and patients with hypertension.

Conclusion

Statin pretreatment was not related to MACEs or all-cause death during hospital stay, but it was associated with a higher risk of increased angiographic severity in patients with first ACS.

C-reactive protein and coronary atheroma regression following statin therapy: A meta-regression of randomized controlled trials

OBJECTIVE

Several clinical trials have indicated that statins stabilize and reverse atherosclerotic plaque. However, different studies have provided inconsistent findings regarding mechanisms and influencing factors of plaque regression under statin therapy. Apart from lipid-lowering effect, statins have pleiotropic effects including anti inflammation in humans. In this study, meta-analysis and meta-regression were used to determine the effects of statin medications on coronary plaque volume. Meanwhile, to assess whether statins promote plaque regression effect was related to their anti-inflammatory ability, the impact of CRP/hsCRP reduction during statin therapy on plaque regression was investigated.

METHODS

Up to June 15, 2022, a systematic PubMed, EMBASE, and Cochrane search was performed for randomized controlled trials that assessed treatment effect using total atheroma volume (TAV), percent atheroma volume (PAV), or plaque volume (PV). Only CRP/hsCRP and LDL-C values reported before and after treatment were considered.

RESULTS

12 studies (2,812 patients with heart and/or vascular disease) fulfilled the inclusion criteria and were included in the systematic review. A meta-analysis of 15 statin-treated arms reported a significant reduction in change of TAV/PV [standardized mean difference (SMD): -0.27, 95% confidence intervals (-CI): -0.42, -0.12, p < 0.001], compared with the control arms. Another meta-analysis of 7 trials also found that patients in the intervention group had a significant reduction in change of PAV (SMD: -0.16, 95% CI: -0.29, -0.03, p = 0.019), compared with those in the control group. Meta-regressionanalysis revealed that the percent change of CRP/hsCRP was significantly associated with SMD in change of TAV/PV after adjusting for percent change of LDL-C, age, gender and study duration. Meta-regression analysis showed that percent change of CRP/hsCRP statistically influenced SMD in change of PAV, when percent change of CRP/hsCRP was included separately. However, the percent change of CRP/hsCRP was not significantly associated with SMD of PAV change after adjusting for all covariates.

CONCLUSION

In conclusion, statin therapy is beneficial for plaque regression. Statins promote plaque regression, which might be associated to their anti-inflammatory ability.

Associations between statins and adverse events in secondary prevention of cardiovascular disease: Pairwise, network, and dose-response meta-analyses of 47 randomized controlled trials

Objectives

To explore the associations between different types and doses of statins and adverse events in secondary prevention of cardiovascular disease.

Methods

We searched PubMed, Embase, and Cochrane databases for randomized controlled trials that compared statins with non-statin controls or different types or doses of statins. The primary outcomes included muscle condition, transaminase elevations, renal insufficiency, gastrointestinal discomfort, cancer, new onset or exacerbation of diabetes, cognitive impairment, and eye condition. We also analyzed myocardial infarction (MI), stroke, death from cardiovascular diseases (CVD), and all-cause death as the secondary outcomes to compare the potential harms with the benefits of statins. We conducted pairwise meta-analyses to calculate the odds ratio (OR) and 95% confidence intervals (CIs) for each outcome. Network meta-analyses were performed to compare the adverse effects of different statins. An Emax model was used to examine the dose-response relationships of the adverse effects of each statin.

Results

Forty-seven trials involving 107,752 participants were enrolled and followed up for 4.05 years. Compared with non-statin control, statins were associated with an increased risk of transaminase elevations [OR 1.62 (95% CI 1.20 to 2.18)]. Statins decreased the risk of MI [OR 0.66 (95% CI 0.61 to 0.71), P < 0.001], stroke [OR 0.78 (95% CI 0.72 to 0.84), P < 0.001], death from CVD [OR 0.77 (95% CI 0.72 to 0.83), P < 0.001] and all-cause death [OR 0.83 (95% CI 0.79 to 0.88), P < 0.001]. Atorvastatin showed a higher risk of transaminase elevations than non-statin control [OR 4.0 (95% CI 2.2 to 7.6)], pravastatin [OR 3.49 (95% CI 1.77 to 6.92)] and simvastatin [OR 2.77 (95% CI 1.31 to 5.09)], respectively. Compared with atorvastatin, simvastatin was associated with a lower risk of muscle problems [OR 0.70 (95% CI 0.55 to 0.90)], while rosuvastatin showed a higher risk [OR 1.75 (95% CI 1.17 to 2.61)]. An Emax dose-response relationship was identified for the effect of atorvastatin on transaminase elevations.

Conclusion

Statins were associated with increased risks of transaminases elevations in secondary prevention. Our study provides the ranking probabilities of statins that can help clinicians make optimal decisions when there is not enough literature to refer to.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021285161].

Impact of diabetes on coronary physiology evaluated by quantitative flow ratio in patients who underwent percutaneous coronary intervention

Aims/Introduction

There are mixed opinions on the influence of diabetes on the prognosis of patients receiving percutaneous coronary intervention (PCI). Therefore, in this study, the quantitative flow ratio (QFR), an emerging technology of functional evaluation, was used to explore the impact of diabetes on coronary physiology in patients who underwent PCI.

Materials and Methods

Patients who underwent successful PCI and a 1‐year angiographic follow up were retrospectively screened and analyzed by the QFR. Based on the presence or absence of diabetes, 677 enrolled patients (794 vessels) were classified into a diabetes group (211 patients, 261 vessels) and a non‐diabetes group (466 patients, 533 vessels). The results of QFR analysis and clinical outcomes were compared between the two groups.

Results

The two groups reached a similar level of post‐PCI QFR (0.95 ± 0.09 vs 0.96 ± 0.06, P = 0.292). However, at the 1‐year follow up, the QFR was lower (0.93 ± 0.11 vs 0.96 ± 0.07, P < 0.001), and the degree of QFR decline was more obvious (−0.024 ± 0.090 vs −0.008 ± 0.070, P = 0.023) in the diabetes group. Additionally, diabetes was independently associated with functional restenosis (odds ratio 2.164, 95% confidence interval 1.210–3.870, P = 0.009) and target vessel failure (odds ratio 2.654, 95% confidence interval 1.405–5.012, P = 0.003).

Conclusion

As evaluated by the QFR, patients with diabetes received less coronary physiological benefit from PCI, which was consistent with their clinical outcomes.

Coronary Atherosclerotic Plaque Regression: JACC State-of-the-Art Review

Over the last 3 decades there have been substantial improvements in treatments aimed at reducing cardiovascular (CV) events. As these treatments have been developed, there have been parallel improvements in coronary imaging modalities that can assess plaque volumes and composition, using both invasive and noninvasive techniques. Plaque progression can be seen to precede CV events, and therefore, many studies have longitudinally assessed changes in plaque characteristics in response to various treatments, aiming to demonstrate plaque regression and improvements in high-risk features, with the rationale being that this will reduce CV events. In the past, decisions surrounding treatments for atherosclerosis have been informed by population-based risk scores for initiation in primary prevention and low-density lipoprotein cholesterol levels for titration in secondary prevention. If outcome data linking plaque regression to reduced CV events emerge, it may become possible to directly image plaque treatment response to guide management decisions.

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.

Reduced increase of calcium scores using breath-hold in left-sided whole breast irradiation

PURPOSE

In this prospective longitudinal study, Coronary Artery Calcium (CAC) scores determined before the start of whole breast irradiation were compared with those determined 7 years afterwards. The aim was to examine whether the use of a breath-hold (BH) technique is associated with less increase of CAC scores.

METHODS AND MATERIALS

Changes in CAC scores were analysed in 87 breast cancer patients. The results of the following groups were compared: patients receiving right (R) or left-sided radiotherapy using free breathing (L-FB) with those receiving left-sided radiotherapy with BH (L-BH). We compared the changes of CAC scores between these groups over time, testing the hypothesis that a significantly reduced increase of calcium scores is observed when using BH.

RESULTS

For L-BH cases, when compared with L-FB cases, for overall as well as for Left Anterior Descending coronary artery (LAD) CAC scores, we noted significantly less increased CAC scores (p < 0.01). This effect of BH was even more striking in the group with CAC scores >0 at baseline. The attenuated increase over time of CAC scores in the L-BH group was robust to correction for age and statin use (p < 0.05).

CONCLUSION

After a median follow-up of 7.4 years, we found significantly less increased CAC scores when using BH. This is a relevant finding since higher levels of CAC scores are associated with higher probabilities of coronary artery events. Moreover, it underlines the rationale for the use of BH in left-sided whole breast irradiation.

Association of Plasma Marker of Oxidized Lipid with Histologic Plaque Instability in Patients with Peripheral Artery Disease

BACKGROUND

The association between oxidized low-density lipoprotein (OxLDL) and plaque instability in coronary and carotid artery disease is well established. However, the association between OxLDL and the histologic changes of plaque in peripheral artery disease has not been clearly elucidated. This study aims to investigate the association between plasma OxLDL and histologic plaque instability in patients with peripheral artery disease.

METHODS

Prospectively obtained plaques from 48 patients who underwent endovascular atherectomy (n = 20), surgical endarterectomy (n = 9), or bypass surgery (n = 19) for treatment of atherosclerotic femoropopliteal artery disease were evaluated for histologic fibrosis, sclerosis, calcification, necrosis, cholesterol cleft, and foamy macrophages using hematoxylin and eosin, oil red O, and immunohistochemical staining. Unstable plaques were defined as plaques that were positive for foamy macrophages and with lipid content of more than 10% of the total plaque area. Plasma OxLDL levels were measured using an enzyme-linked immunosorbent assay (Mercodia AB, Uppsala, Sweden).

RESULTS

Of the 48 patients, 26 (54%) had unstable plaques. The unstable plaque group was younger, had fewer angiographic total occlusions, less calcification, and more CD68-positive and LOX-1-positive cells than the stable plaque group. Plasma OxLDL levels were significantly higher in the unstable plaque group than in the stable plaque group (57.4 ± 13.9 vs. 47.2 ± 13.6 U/L, P = 0.014). Multivariate analysis revealed that plasma OxLDL level, smoking, angiographic nontotal occlusion, and statin nonuse were independent predictors of unstable plaque.

CONCLUSIONS

Among patients with peripheral artery disease, the histologic instability of femoropopliteal plaque was independently associated with high plasma OxLDL, smoking, nontotal occlusion, and statin nonuse. Further large-scale studies are necessary to evaluate the role of noninvasive OxLDL measurement for predicting plaque instability and future adverse vascular event.

Effect of Statin Therapy on Fibrous Cap Thickness in Coronary Plaque on Optical Coherence Tomography - Review and Meta-Analysis

BACKGROUND

Statin therapy has been shown to result in coronary plaque regression, but the relationship between statin use and stabilization of coronary plaque has not been elucidated. We conducted a systematic review and meta-analysis to evaluate the effect of statin therapy on fibrous cap thickness (FCT) on optical coherence tomography (OCT).Methods and Results:Nine OCT studies (6 randomized controlled trials and 3 observational studies) were enrolled with a total of 341 patients (390 lesions). Arms of the studies were grouped according to statin type and/or dose. Random effects meta-analysis was used to estimate a pooled mean change in FCT from baseline to follow-up. The overall effect mean FCT change was 67.7 µm (95% CI: 51.4-84.1, I²=95.0%, P<0.001). All statin groups had an increase in FCT, but the magnitude of the increase differed according to the statin. Two homogeneous subgroups with I²=0 were identified: mean FCT change was 27.8 µm (for subgroup atorvastatin 5 mg and rosuvastatin), and 61.9 µm (for subgroup atorvastatin 20 mg, fluvastatin 30 mg, and pitavastatin 4 mg). On meta-regression modeling, statin therapy alone explained most of the change in FCT.

CONCLUSIONS

Statin therapy induced a significant increase in FCT as assessed on OCT, independent of coronary risk factors and other medications.

The Goal of Achieving Atherosclerotic Plaque Regression with Lipid-Lowering Therapy: Insights from IVUS Trials

Enormous effort has been put into the prevention of atherosclerosis through risk modification, especially with lipid-lowering therapies. Regression, that is, the reversal of the atherosclerosis process, has long been a goal of atherosclerosis research among basic and clinical investigators. Intravascular ultrasound (IVUS) was developed in the 1990s as an intracoronary imaging technique to observe the details of the vessel walls and to measure the vessel lumen and plaque area with high reproducibility. Compared with the coronary angiogram, IVUS provides far more detailed information on the vessel wall. In this article, we review lipid-lowering trials that have used IVUS and discuss the current understanding of the effectiveness of aggressive lipid-lowering therapy, which inhibits atherosclerotic progression and induces regression and plaque stabilization.

Coronary atheroma regression and adverse cardiac events: A systematic review and meta-regression analysis

BACKGROUND AND AIMS

The relationship between plaque regression induced by dyslipidemia therapies and occurrence of major adverse cardiovascular events (MACE) is controversial. We performed a systematic review and meta-regression of dyslipidemia therapy studies reporting MACE and intravascular ultrasound (IVUS) measures of change in coronary atheroma.

METHODS

Prospective studies of dyslipidemia therapies reporting percent atheroma volume (PAV) measured by IVUS and reporting death, myocardial infarction, stroke, unstable angina or transient ischemic attack (MACE) were included. The association between mean change in PAV and MACE was examined using meta-regression via mixed-effects binomial logistic regression models, unadjusted and adjusted for mean age, baseline PAV, baseline low density lipoprotein-cholesterol and study duration.

RESULTS

The study included 17 prospective studies published between 2001 and 2018 totaling 6333 patients. Study duration varied from 11 to 104 weeks. Mean change in PAV, across the study arms, ranged from -5.6% to 3.1%. MACE ranged from 0 to 72 events per study arm: 13 study arms (38%) reported no events, 8 (24%) reported 1-2 events and 13 (38%) reported 3 or more events. Meta-regression demonstrated a decline in the odds of MACE associated with reduction in mean PAV: unadjusted odds ratio (OR): 0.78, 95% Confidence Interval (CI): [0.63, 0.96], p = 0.018; adjusted OR: 0.82, 95% CI: [0.70, 0.95], p = 0.011, per 1% decrease in mean PAV.

CONCLUSIONS

A 1% reduction in mean PAV as induced by dyslipidemia therapies was associated with a 20% reduction in the odds of MACE.

Intraluminal Ultrasonic Palpation Imaging Technique Revisited for Anisotropic Characterization of Healthy and Atherosclerotic Coronary Arteries: A Feasibility Study

Accurate mechanical characterization of coronary atherosclerotic lesions remains essential for the in vivo detection of vulnerable plaques. Using intravascular ultrasound strain measurements and based on the mechanical response of a circular and concentric vascular model, E. I. Céspedes, C. L. de Korte and A. F. van der Steen developed an elasticity-palpography technique in 2000 to estimate the apparent stress-strain modulus palpogram of the thick subendoluminal arterial wall layer. More recently, this approach was improved by our group to consider the real anatomic shape of the vulnerable plaque. Even though these two studies highlighted original and promising approaches for improving the detection of vulnerable plaques, they did not overcome a main limitation related to the anisotropic mechanical behavior of the vascular tissue. The present study was therefore designed to extend these previous approaches by considering the orthotropic mechanical properties of the arterial wall and lesion constituents. Based on the continuum mechanics theory prescribing the strain field, an elastic anisotropy index was defined. This new anisotropic elasticity-palpography technique was successfully applied to characterize ten coronary plaque and one healthy vessel geometries of patients imaged in vivo with intravascular ultrasound. The results revealed that the anisotropy index-palpograms were estimated with a good accuracy (with a mean relative error of 26.8 ± 48.8%) compared with ground true solutions.

Changes in coronary atherosclerosis, composition, and fractional flow reserve evaluated by coronary computed tomography angiography in patients with type 2 diabetes

Background

The use of coronary computed tomography angiography (CCTA) for noninvasive anatomic detection of coronary artery disease is increasing. Recently, fractional flow reserve (FFR) assessment using routinely acquired CCTA datasets (FFR_CT) has been developed. However, there are no reports about changes in coronary atherosclerosis, composition, and FFR_CT in patients with type 2 diabetes.

Methods

This prospective, multicenter, observational trial evaluated changes in coronary atherosclerosis after alogliptin therapy in patients with type 2 diabetes. Fifty-one patients with type 2 diabetes who underwent CCTA examination and having intermediate coronary artery stenosis were treated with 25 mg of alogliptin. After 48 weeks, CCTA examination was repeated. The primary endpoint was changes in FFR_CT, and the secondary endpoint was changes in total atheroma volume (TAV) from the baseline to the 48-week follow-up.

Results

The FFR_CT decreased from the baseline to follow-up, but not significantly. A significant increase in TAV (from 658.5 mm³ to 668.9 mm³, p = 0.048) was observed. Vessel volume tended to increase, whereas percentage atheroma volume and lumen volume did not change. A significant negative correlation was observed between percentage change in TAV and change in FFR_CT (r = −0.185, p = 0.048). A significant increase in calcified plaques (p = 0.01) and a decrease in intermediate-attenuation plaques (p = 0.006) was observed.

Conclusions

In Japanese patients with diabetes and intermediate coronary artery stenosis, alogliptin could not improve FFR_CT or reduce atheroma volume, whereas the plaque composition changed. A progression of atheroma volume was associated with a reduction in FFR_CT.

Impact of Water- and Lipid-Soluble Statins on Nonculprit Lesions in Patients with Acute Coronary Syndrome

Statins can be differentiated into two types, based on their solubility, which have potentially differing effects on the coronary artery wall. However, suspected differences in statins' effects on plaque composition have not been systemically investigated.Sixty-seven patients with acute coronary syndrome (ACS) were randomly assigned to either atorvastatin (10 mg/day) or rosuvastatin (2.5 mg/day). Intravascular ultrasound (IVUS) and integrated backscatter (IB)-IVUS, an established tool to quantify each plaque's components, were performed immediately after emergent percutaneous coronary intervention (PCI). Follow-up IVUS was performed between 6 and 12 months after PCI. Serial changes in serum lipid profiles and plaque composition volumes were compared between the two groups.Thirty-five patients were eligible for serial IB-IVUS analyses. The mean low-density lipoprotein-cholesterol level significantly decreased in the atorvastatin and rosuvastatin groups (P < 0.001); plaque volumes were also significantly reduced from 82.0 ± 46.2 to 74.9 ± 41.3 mm³ (P = 0.01) and from 74.7 ± 35.3 to 67.7 ± 27.0 mm³ (P = 0.02), respectively. IB-IVUS revealed a significant reduction in fibrous volume from 33.8 ± 20.0 to 27.5 ± 14.9 mm³ (P < 0.01) and from 29.6 ± 13.6 to 24.8 ± 7.6 mm³ (P < 0.05), respectively; however, significant changes were not noted in the volume of the lipid pool for the atorvastatin group and the rosuvastatin group, respectively.Water- and lipid-soluble statins may be similarly effective in reducing coronary plaques in patients with ACS as judged qualitatively and quantitatively. Further study is needed to determine whether differences between water- and lipid-soluble statins affect plaque components.

Clinical indications for coronary artery calcium scoring in asymptomatic patients: Expert consensus statement from the Society of Cardiovascular Computed Tomography

This expert consensus statement summarizes the available data regarding the prognostic value of CAC in the asymptomatic population and its ability to refine individual risk prediction, addresses the limitations identified in the current traditional risk factor-based treatment strategies recommended by the 2013 ACC/AHA Prevention guidelines including use of the Pooled Cohort Equations (PCE), and the US Preventive Services Task Force (USPSTF) Recommendation Statement for Statin Use for the Primary Prevention of Cardiovascular Disease in Adults. It provides CAC based treatment recommendations both within the context of the shared decision making model espoused by the 2013 ACC/AHA Prevention guidelines and independent of these guidelines.

Correlation between serum levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) and atherogenic lipoproteins in patients with coronary artery disease

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of serum low-density lipoprotein (LDL) cholesterol levels. Recently, PCSK9 has additionally been related to metabolic risk factors such as the levels of triglycerides, apolipoprotein B (apoB), insulin, and glucose, as well as body mass index. The purpose of this study was to investigate correlations between serum levels of PCSK9 and apoB-containing atherogenic lipoproteins in patients with coronary artery disease (CAD).

Methods

Serum levels of PCSK9 and lipoprotein(a) [Lp(a)]; small, dense LDL; and oxidized LDL were measured in 101 patients with CAD who were not receiving lipid-lowering therapy.

Results

Serum hetero-dimer PCSK9 levels were positively correlated with serum levels of Lp(a) (r = 0.195, p = 0.05); small, dense LDL (r = 0.336, p = 0.0006); and oxidized LDL (r = 0.268, p = 0.008). Multivariate regression analyses showed that serum hetero-dimer PCSK9 was a significant predictor of serum levels of Lp(a) (β = 0.235, p = 0.01); small, dense LDL (β = 0.143, p = 0.03); and oxidized LDL (β = 0.268, p = 0.008).

Conclusions

Serum PCSK9 levels were positively correlated with serum levels of Lp(a); small, dense LDL; and oxidized LDL in patients with CAD. This suggests that the interaction between serum PCSK9 and apoB-containing lipoproteins plays a role in establishing the atherosclerotic status of patients.

Trial registration

UMIN Clinical Trials Registry, UMIN ID: C000000311.

Pathologic Intimal Thickening Plaque Phenotype: Not as Innocent as Previously Thought. A Serial 3D Intravascular Ultrasound Virtual Histology Study

INTRODUCTION AND OBJECTIVES

Pathologic intimal thickening (PIT) has been considered a benign plaque phenotype. We report plaque phenotypic changes in a baseline/follow-up intravascular ultrasound-based virtual histology study.

METHODS

A total of 61 patients with stable coronary artery disease were analyzed from the HEAVEN trial (89 patients randomized between routine statin therapy vs atorvastatin 80mg and ezetimibe 10mg) with serial intravascular ultrasound imaging of nonculprit vessels. We compared changes in 693 baseline and follow-up 5-mm long segments in a novel risk score, Liverpool Active Plaque Score (LAPS), plaque parameters, and plaque composition.

RESULTS

The PIT showed the highest increase of risk score and, with fibrous plaque, also the LAPS. Necrotic core (NC) abutting to the lumen increased in PIT (22 ± 51.7; P = .0001) and in fibrous plaque (17.9 ± 42.6; P = .004) but decreased in thin cap fibroatheroma (TCFA) (⿿15.14 ± 52.2; P = .001). The PIT was the most likely of all nonthin cap fibroatheroma plaque types to transform into TCFA at follow-up (11% of all TCFA found during follow-up and 35.9% of newly-developed TCFA), but showed (together with fibrous plaque) the lowest stability during lipid-lowering therapy (24.7% of PIT remained PIT and 24.5% of fibrous plaque remained fibrous plaque).

CONCLUSIONS

Over the 1-year follow-up, PIT was the most dynamic of the plaque phenotypes and was associated with an increase of risk score and LAPS (together with fibrous plaque), NC percentage (together with fibrous plaque) and NC abutting to the lumen, despite a small reduction of plaque volume during lipid-lowering therapy. The PIT was the main source for new TCFA segments.

Stabilization of high-risk plaques

The prevalence of atherosclerotic cardiovascular diseases (ASCVDs) is increasing globally and they have become the leading cause of death in most countries. Numerous experimental and clinical studies have been conducted to identify major risk factors and effective control strategies for ASCVDs. The development of imaging modalities with the ability to determine the plaque composition enables us to further identify high-risk plaque and evaluate the effectiveness of different treatment strategies. While intensive lipid-lowering by statins can stabilize or even regress plaque by various mechanisms, such as the reduction of lipid accumulation in a necrotic lipid core, the reduction of inflammation, and improvement of endothelial function, there are still considerable residual risks that need to be understood. We reviewed important findings regarding plaque vulnerability and some encouraging emerging approaches for plaque stabilization.

Prediction of cardiovascular outcomes by imaging coronary atherosclerosis

Over the last two decades, several invasive and non-invasive coronary atherosclerosis imaging modalities have emerged as predictors of cardiovascular outcomes in at-risk population. These modalities have demonstrated independent or incremental prognostic information over existing/standard risk stratification schemes, such as the Framingham risk score (FRS), by identifying characteristics of coronary artery diseases (CADs). In this review, we begin with discussing the importance of pre-test probability and quality of outcome measure, followed by specific findings of each modality in relation to prognosis. We focused on both short and long term prognostic aspects of coronary computed tomography (CT) (including coronary calcium score and coronary angiography) and magnetic resonance imaging as non-invasive tools, as well as invasive modalities including intravascular ultrasound (IVUS), optical coherence tomography (OCT), near infrared spectroscopy and Angioscopy.

Efficacy of Statin Therapy in Inducing Coronary Plaque Regression in Patients with Low Baseline Cholesterol Levels

Aim: The efficacy of statin therapy in inducing coronary plaque regression may depend on baseline cholesterol levels. We aimed to determine the efficacy of statin therapy in inducing coronary plaque regression in statin-naïve patients with low cholesterol levels using serial intravascular ultrasound (IVUS) data from the treatment with statin on atheroma regression evaluated by virtual histology IVUS (TRUTH) study.

Methods: The TRUTH study is a prospective, multicenter trial, comparing the efficacies of pitavastatin and pravastatin in coronary plaque regression in 164 patients. All patients were statin-naïve and received statin therapy only after study enrollment. The primary endpoint was the observation of coronary plaque progression, despite statin therapy.

Results: Serial IVUS data, at baseline and after an 8-month follow-up, were available for 119 patients. The patients were divided into three groups based on non-high-density lipoprotein cholesterol (HDL-C) levels—low: ≤ 140 mg/dl, n = 38; moderate: 141–169 mg/dl, n = 42; and high: ≥ 170 mg/dl, n = 39. Coronary plaque progression was noted in the low cholesterol group, whereas plaque regression was noted in the moderate and high cholesterol groups [%Δplaque volume: 2.3 ± 7.4 vs. − 2.7 ± 10.7 vs. − 3.2 ± 7.5, p = 0.004 (analysis of variance)]. After adjusting for all variables, a low non-HDLC level (≤ 140 mg/dl) was identified as an independent predictor of coronary plaque progression [odds ratio, 3.7; 95% confidence interval, 1.5–9.1, p = 0.004].

Conclusion: Serial IVUS data analysis indicated that statin therapy was less effective in inducing coronary plaque regression in patients with low cholesterol levels but more effective in those with high cholesterol levels at baseline.

University Hospital Medical Information Network (UMIN) (UMIN ID: C000000311).

The Imaging Modulography Technique Revisited for High-Definition Intravascular Ultrasound: Theoretical Framework

Mechanical characterization of atherosclerotic lesions remains an essential step for the detection of vulnerable plaques (VPs). Recently, an intravascular ultrasound (IVUS) elasticity reconstruction method (iMOD) has been tested in vivo by our group. The major limitation of iMOD is the need to estimate the strain field in the entire VP despite attenuated depth penetration signals when using high-definition (HD) IVUS systems. Therefore, an extended iMOD approach (E-iMOD) was designed and applied to coronary lesions of patients imaged in vivo with IVUS. The E-iMOD method (i) quantified necrotic core areas with a mean absolute relative error of 3.5 ± 3.5% and (ii) identified Young's moduli of the necrotic cores and fibrous regions with mean values of 5.7 ± 0.8 kPa and 794.5 ± 22.0 kPa instead of 5 kPa and 800 kPa, respectively. This study demonstrates the potential of the improved HD-IVUS modulography technique E-iMOD to characterize coronary VPs.

Effects of Statin Therapy on Plasma Proprotein Convertase Subtilisin/kexin Type 9 and Sortilin Levels in Statin-Naive Patients with Coronary Artery Disease

AIM

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of serum low-density lipoprotein (LDL) cholesterol levels, and sortilin is linked to lipoprotein metabolism. Although statin therapy increases PCSK9 levels, effects of this therapy on plasma sortilin levels have not been evaluated. The purpose of the present study was to examine the effects of statins on plasma PCSK9 and sortilin levels, and association of statin-induced increase in PCSK9 levels with sortilin.

METHODS

Serum lipid levels and plasma PCSK9 and sortilin levels were measured at baseline and 8 months after statin therapy in 90 statin-naive patients with coronary artery disease (CAD). Pitavastatin 4 mg/day was used to treat 44 patients and pravastatin 20 mg/day to treat the remaining 46 patients.

RESULTS

For both statin groups, significant increases in hetero-dimer PCSK9 levels (pitavastatin: 31%, p＜0.0001; pravastatin: 34%, p=0.03) and decreases in sortilin levels (pitavastatin: －8%, p=0.02; pravastatin: －16%, p=0.002) were observed. Although a reduction in LDL cholesterol was greater in the pitavastatin group than in the pravastatin group, no significant differences were observed in percentage changes in hetero-dimer PCSK9 and sortilin levels. A significant positive correlation was observed between percentage changes in hetero-dimer PCSK9 levels and those in sortilin levels (pitavastatin: r=0.359, p=0.02; pravastatin: r=0.276, p=0.06).

CONCLUSIONS

Use of pitavastatin and pravastatin increased plasma PCSK9 and decreased sortilin levels. Statin-induced increases in PCSK9 were associated with changes in sortilin in statin-naive patients with CAD.

Impact of statin therapy on coronary plaque composition: a systematic review and meta-analysis of virtual histology intravascular ultrasound studies

BACKGROUND

Virtual histology intravascular ultrasound (VH-IVUS) imaging is an innovative tool for the morphological evaluation of coronary atherosclerosis. Evidence for the effects of statin therapy on VH-IVUS parameters have been inconclusive. Consequently, we performed a systematic review and meta-analysis to investigate the impact of statin therapy on plaque volume and its composition using VH-IVUS.

METHODS

The search included PubMed, Cochrane Library, Scopus and Embase (through 30 November 2014) to identify prospective studies investigating the effects of statin therapy on plaque volume and its composition using VH-IVUS.

RESULTS

We identified nine studies with 16 statin treatment arms and 830 participants. There was a significant effect of statin therapy in reducing plaque volume (standardized mean difference (SMD): -0.137, 95 % confidence interval (CI): -0.255, -0.019; P = 0.023), external elastic membrane volume (SMD: -0.097, 95 % CI: -0.183, -0.011; P = 0.027) but not lumen volume (SMD: -0.025, 95 % CI: -0.110, +0.061; P = 0.574). There was a significant reduction in fibrous plaque volume (SMD: -0.129, 95 % CI: -0.255, -0.003; P = 0.045) and an increase of dense calcium volume (SMD: +0.229, 95 % CI: +0.008, +0.450; P = 0.043), while changes in fibro-fatty (SMD: -0.247, 95 % CI: -0.592, +0.098; P = 0.16) and necrotic core (SMD: +0.011, 95 % CI: -0.144, +0.165; P = 0.892) tissue volumes were not statistically significant.

CONCLUSIONS

This meta-analysis indicates a significant effect of statin therapy on plaque and external elastic membrane volumes and fibrous and dense calcium volumes. There was no effect on lumen volume, fibro-fatty and necrotic tissue volumes.

The Effect of Statin Therapy on Coronary Plaque Composition Using Virtual Histology Intravascular Ultrasound: A Meta-Analysis

OBJECTIVE

Previous studies have indicated that statin therapy may promote plaque regression. However, the impact of statin therapy on plaque composition has not been clearly elucidated. We performed a meta-analysis to investigate the effect of statin therapy on coronary plaque composition as assessed by virtual histology intravascular ultrasound (VH-IVUS).

METHODS

Online databases were searched from inception to March 1, 2015. Studies providing VH-IVUS volumetric analyses of coronary plaque composition at baseline and follow-up in patients receiving statin therapy were included. Weighted mean difference (WMD) using a random-effects model was used.

RESULTS

Ten studies involving 682 patients were included. There was a substantial reduction in fibrous volume between baseline and follow-up (WMD: -2.37 mm3, 95% confidence interval (CI) -4.01 to -0.74 mm3, P=0.004), and a significant increase in dense calcium (DC) volume (WMD: 0.89 mm3, 95% CI 0.70 to 1.08 mm3, P<0.00001). No significant change was seen in fibro-fatty and necrotic core (NC) volumes. In stratified analyses, the fibrous volume was decreased significantly (WMD: -3.39 mm3, 95% CI -6.56 to -0.21 mm3, P=0.04) and the absolute DC volume (WMD: 0.99 mm3, 95% CI 0.23 to 1.76 mm3, P=0.01) was increased in the subgroup with ≥12 months follow-up, whereas no significant change was observed in the subgroup with < 12 months follow-up. Similarly, a substantial decrease in fibrous volume (WMD: -2.01 mm3, 95% CI -3.05 to -0.96 mm3, P< 0.0002) and an increase in DC volume (WMD: 0.90 mm3, 95% CI 0.70 to 1.10 mm3, P< 0.00001) were observed in the subgroup with high-intensive statin therapy, while the change in fibrous and DC volumes approached statistical significance (P=0.05 and P=0.05, respectively) in the subgroup with low-intensive statin therapy.

CONCLUSIONS

Statin treatment, particularly of high-intensity and long-term duration, induced a marked modification in coronary plaque composition including a decrease in fibrous tissue and an increase in DC.

Effects of intensive lipid-lowering therapy on coronary plaques composition in patients with acute myocardial infarction: Assessment with serial coronary CT angiography

BACKGROUND

Statins have been shown to possess favourable effects on the cardiovascular system with stabilization of the vulnerable plaque. We sought to assess the effects of early aggressive statin treatment on plaque composition in patients with acute myocardial infarction (AMI), using serial assessment with coronary CT-angiography (CTA).

METHODS

In a prospective randomized blinded endpoint trial patients with AMI were randomized to an intensive lipid lowering treatment receiving statin loading with 80 mg rosuvastatin followed by 40 mg daily or standard statin therapy according to current guidelines. Patients were assessed with CTA at baseline and after 12 months with evaluation of plaque volume and composition.

RESULTS

In total, 140 patients with AMI were randomized and plaque composition was assessed in 96 patients. In the intensive care group LDL-level was median 1.3 [0.9; 1.5] mmol/l at 12 months follow-up and 2.0 [1.7; 2.4] mmol/l in the usual care group, p < 0.001. Plaque volume increased over 12 months with 43.5 (±225.8) mm(3) in the intensive care group and 19.1 (±190.2) mm(3) in the usual care group, p = 0.57. Plaque composition changed over 12 months with an increase in total dense calcium volume by 11.1 (±39.6) mm(3), corresponding to a 23% increase, in the intensive care group and a decreased by -0.4 (±26.6) mm(3) in the usual care group, p < 0.001. Necrotic core volume increased 26.8 (±122.1) mm(3) in the intensive care group and 25.2 (±80.1) mm(3) in the usual care group, p = 0.94.

CONCLUSIONS

Early aggressive lipid lowering therapy significantly increases dense calcium volume in patients with AMI.

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.

Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden: a cross sectional study using whole body magnetic resonance angiography

Background

Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA).

Methods

50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50–70%, 3 = 70–99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated.

Results

The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β −0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β −0.45 p = 0.005).

Conclusion

ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden.

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.

Rationale and design of a randomized clinical study to investigate the effect of ezetimibe, a cholesterol absorption inhibitor, on the regression of intracoronary plaque evaluated by non-obstructive angioscopy and ultrasound: The ZIPANGU study

BACKGROUND AND PURPOSE

It is well recognized that low-density lipoprotein cholesterol (LDL-C)-lowering therapy is effective for primary and secondary prevention of cerebrovascular/cardiovascular disease. Ezetimibe, an inhibitor of the Niemann-Pick C1-Like 1 cholesterol transporter, is a relatively new drug for LDL-C-lowering therapy in addition to statins. However, comparison between an aggressive LDL-C-lowering therapy with a combination of statin and ezetimibe versus a standard LDL-C-lowering therapy with statin alone is still unclear in terms of their effects on stabilization and volume regression of coronary plaque. The ZIPANGU (Ezetimibe clinical investigation for the regression of intracoronary plaque evaluated by angioscopy and ultrasound) study is aimed at comparing these two types of therapy based on indices of plaque characteristics using non-obstructive coronary angioscopy and intravascular ultrasound.

METHODS

The study is a multi-center, prospective, randomized, open-label, blinded-endpoint trial. Through a centralized enrollment method, patients will be allocated to either monotherapy with atorvastatin alone or to combination therapy with atorvastatin (maximum: 20mg/day) and ezetimibe (10mg/day). The target LDL-C level will be <100mg/dL for the monotherapy group and <70mg/dL for the combination therapy group. At the baseline and the follow-up period of 9 months, non-obstructive coronary angioscopy and intravascular ultrasound will be performed to compare the changes in plaque color and volume between the two groups.

CONCLUSIONS

The ZIPANGU study will clarify whether combination therapy with statins and ezetimibe is better for stabilizing coronary plaque as secondary prevention than monotherapy by statins alone. The study will give new insights into lipid-lowering guidelines in Japan.

Lipoprotein(a) is associated with necrotic core progression of non-culprit coronary lesions in statin-treated patients with angina pectoris

Background

Statin therapy results in regression and stabilization of coronary artery plaques, and reduces the incidence of coronary artery disease. However, statin therapy does not effectively halt the accumulation of necrotic core in all patients. The purpose of the present study was to identify the predictors associated with necrotic core progression during statin therapy.

Methods

Coronary atherosclerosis in non-culprit lesions was evaluated using virtual histology intravascular ultrasound at baseline and 8 months after statin therapy. One hundred nineteen patients were divided into 2 groups based on necrotic core progression or regression during an 8-month follow-up period.

Results

Patients with necrotic core progression had higher serum lipoprotein(a) [Lp(a)] levels than patients with regression at baseline (16 mg/dL vs. 12 mg/dL, p = 0.02) and at the 8-month follow-up (17 mg/dL vs. 10 mg/dL, p = 0.006). Patients with necrotic core progression had a higher fibro-fatty plaque volume (1.28 mm³/mm vs. 0.73 mm³/mm, p = 0.002), and less necrotic core (0.56 mm³/mm vs. 1.04 mm³/mm, p < 0.0001) and dense calcium (0.35 mm³/mm vs. 0.56 mm³/mm, p = 0.006) plaque volumes at baseline than patients with regression. Multivariate logistic regression analysis showed that Lp(a) was a significant independent predictor associated with necrotic core progression during statin therapy (odds ratio [OR]: 3.514; 95% confidence interval [CI]: 1.338-9.228; p = 0.01).

Conclusions

Serum Lp(a) is independently associated with necrotic core progression in statin-treated patients with angina pectoris.

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

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.

Low serum docosahexaenoic acid is associated with progression of coronary atherosclerosis in statin-treated patients with diabetes mellitus: results of the treatment with statin on atheroma regression evaluated by intravascular ultrasound with virtual histology (TRUTH) study

Background

Diabetes mellitus (DM) accelerates plaque progression despite the use of statin therapy. The purpose of the present study was to evaluate the determinants of atheroma progression in statin-treated patients with DM.

Methods

Coronary atherosclerosis in nonculprit lesions in a vessel undergoing percutaneous coronary intervention (PCI) was evaluated using virtual histology intravascular ultrasound. The study included 50 patients with DM who had been taking statin therapy for 8 months at the time of PCI.

Results

Twenty-six patients (52%) showed atheroma progression (progressors) and the remaining 24 patients (48%) showed atheroma regression (regressors) after 8 months of follow-up. Fewer progressors than regressors received intensive lipid-lowering therapy with pitavastatin (31% vs. 50%, p = 0.17) and the frequency of insulin use was higher in progressors (31% vs. 13%, p = 0.18). However, neither of these differences reached statistical significance. Risk factor control at baseline and at the 8-month follow-up did not differ between the 2 groups except for serum levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Univariate regression analysis showed that serum EPA (r = -0.317, p = 0.03) and DHA (r = -0.353, p = 0.02) negatively correlated with atheroma progression. Multivariate stepwise regression analysis showed that low serum DHA and pravastatin use were significant independent predictors for atheroma progression during statin therapy (DHA: β = -0.414, type of statin: β = -0.287, p = 0.001).

Conclusions

Low serum DHA is associated with progression of coronary atherosclerosis in statin-treated patients with DM.

Trial registration

UMIN Clinical Trials Registry, UMIN ID: C000000311.

A direct vulnerable atherosclerotic plaque elasticity reconstruction method based on an original material-finite element formulation: theoretical framework

The peak cap stress (PCS) amplitude is recognized as a biomechanical predictor of vulnerable plaque (VP) rupture. However, quantifying PCS in vivo remains a challenge since the stress depends on the plaque mechanical properties. In response, an iterative material finite element (FE) elasticity reconstruction method using strain measurements has been implemented for the solution of these inverse problems. Although this approach could resolve the mechanical characterization of VPs, it suffers from major limitations since (i) it is not adapted to characterize VPs exhibiting high material discontinuities between inclusions, and (ii) does not permit real time elasticity reconstruction for clinical use. The present theoretical study was therefore designed to develop a direct material-FE algorithm for elasticity reconstruction problems which accounts for material heterogeneities. We originally modified and adapted the extended FE method (Xfem), used mainly in crack analysis, to model material heterogeneities. This new algorithm was successfully applied to six coronary lesions of patients imaged in vivo with intravascular ultrasound. The results demonstrated that the mean relative absolute errors of the reconstructed Young's moduli obtained for the arterial wall, fibrosis, necrotic core, and calcified regions of the VPs decreased from 95.3 ± 15.56%, 98.85 ± 72.42%, 103.29 ± 111.86% and 95.3 ± 10.49%, respectively, to values smaller than 2.6 × 10(-8) ± 5.7 × 10(-8)% (i.e. close to the exact solutions) when including modified-Xfem method into our direct elasticity reconstruction method.

Attenuation of cardiac allograft vasculopathy by sirolimus: Relationship to time interval after heart transplantation

BACKGROUND

The aim of the study was to assess temporal changes in plaque size and components after heart transplantation (HTx), and to evaluate the differences in treatment effects on plaque progression between sirolimus and calcineurin inhibitors (CNIs).

METHODS

The study comprised 146 HTx recipients who were converted from CNIs to sirolimus as primary immunosuppressant (sirolimus group, n = 61) and those who were maintained on CNIs (CNI group, n = 85). A retrospective compositional analysis of serial virtual histology-intravascular ultrasound was performed.

RESULTS

During a median follow-up of 2.8 years, there was a significant difference in plaque volume in favor of sirolimus between groups (p = 0.004). When subjects were sub-classified according to the time interval between HTx and study inclusion, those in the early group (≤2 years after HTx) had a greater increase in plaque volume (p = 0.006), characterized by a higher progression rate of fibrous plaque volume (p = 0.01). The treatment difference between groups in plaque volume was identified in the early group in favor of sirolimus with attenuating effects on the progression of fibrous plaque component (both p = 0.03 for interaction). By contrast, there were significant differences in necrotic core and dense calcium volume (both p < 0.05 for interaction) in favor of CNIs in the late group (≥6 years after HTx).

CONCLUSIONS

Compared with continued CNI therapy, sirolimus attenuated plaque progression in recipients with early conversion, but contributed to increases in necrotic core and dense calcium volume in those with late conversion. Our study supports the hypothesis that early initiation of sirolimus offers greater benefits in the treatment of CAV.

The intravascular ultrasound elasticity-palpography technique revisited: a reliable tool for the in vivo detection of vulnerable coronary atherosclerotic plaques

Critical to the detection of vulnerable plaques (VPs) is quantification of their mechanical properties. On the basis of intravascular ultrasound (IVUS) echograms and strain images, E. I. Céspedes, C. L. de Korte CL and A. F. van der Steen (Ultrasound Med Biol 2000;26:385-396) proposed an elasticity-palpography technique (E-PT) to estimate the apparent stress-strain modulus palpogram of the thick endoluminal layer of the arterial wall. However, this approach suffers from major limitations because it was developed for homogeneous, circular and concentric VPs. The present study was therefore designed to improve the E-PT by considering the anatomic shape of the VP. This improved E-PT was successfully applied to six coronary lesions of patients imaged in vivo with IVUS. Our results indicate that the mean relative error of the stress-strain modulus decreased from 61.02 ± 9.01% to 15.12 ± 12.57% when the IE-PT was used instead of the E-PT. The accuracy of the stress-strain modulus palpograms computed using the improved theoretical framework was also investigated with respect to noise, which may affect prediction of plaque vulnerability.

Impacts of age on coronary atherosclerosis and vascular response to statin therapy

Age is a well-established risk factor for cardiovascular disease. Recent trials using intravascular ultrasound (IVUS) have shown that lipid-lowering therapy with statins halts the progression or induces the regression of coronary artery plaques. However, impacts of age on coronary atherosclerosis and vascular response to statin therapy have not been fully evaluated. The effects of 8-month statin therapy on coronary atherosclerosis were evaluated using virtual histology-IVUS. IVUS data were analyzed from 119 patients who were divided into two groups according to age: elderly patients (≥65 years, n = 72) and non-elderly patients (<65 years, n = 47). No patients were taking statins or other lipid-lowering therapies at baseline. At baseline, external elastic membrane (EEM) volume (17.27 vs. 14.95 mm(3)/mm, p = 0.02) and plaque volume (9.49 vs. 8.11 mm(3)/mm, p = 0.03) in the elderly patients were significantly greater than in the non-elderly patients. The EEM volume (-2.4 %, p = 0.007) and plaque volume (-3.1 %, p = 0.007) after 8-month of statin therapy had significantly decreased in the non-elderly patients but not in the elderly patients. A significant positive correlation was observed between age and percentage change in plaque volume (r = 0.265, p = 0.004). A multivariate regression analysis showed that age was a significant predictor of the percentage change in plaque volume during statin therapy (β = 0.223, p = 0.02). Coronary atherosclerosis was more advanced and vascular responses to statin therapy were attenuated in the elderly patients compared to the non-elderly patients.