Use of intravascular ultrasound to compare effects of different strategies of lipid-lowering therapy on plaque volume and composition in patients with coronary artery disease

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.

ANMCO position paper on the management of hypercholesterolaemia in patients with acute coronary syndrome

Patients suffering from acute coronary syndrome (ACS) present a high risk of recurrence and new adverse cardiovascular events after hospital discharge. Elevated plasma LDL-cholesterol (LDL-C) levels have been shown to be a causal factor for the development of coronary heart disease, and robust clinical evidence has documented that LDL-C levels decrease linearly correlates with a reduction in cardiovascular events. Recent studies have also demonstrated the safety and efficacy of an early and significant reduction in LDL-C levels in patients with ACS. In this position paper, Italian Association of Hospital Cardiologists proposes a decision algorithm on early adoption of lipid-lowering strategies at hospital discharge and short-term follow-up of patients with ACS, in the light of the multiple evidence generated in recent years on the treatment of hypercholesterolaemia and the available therapeutic options, considering current reimbursement criteria.

The TBK1/IKKε inhibitor amlexanox improves dyslipidemia and prevents atherosclerosis

Cardiovascular diseases, especially atherosclerosis and its complications, are a leading cause of death. Inhibition of the noncanonical IκB kinases TANK-binding kinase 1 and IKKε with amlexanox restores insulin sensitivity and glucose homeostasis in diabetic mice and human patients. Here we report that amlexanox improves diet-induced hypertriglyceridemia and hypercholesterolemia in Western diet-fed (WD-fed) Ldlr-/- mice and protects against atherogenesis. Amlexanox ameliorated dyslipidemia, inflammation, and vascular dysfunction through synergistic actions that involve upregulation of bile acid synthesis to increase cholesterol excretion. Transcriptomic profiling demonstrated an elevated expression of key bile acid synthesis genes. Furthermore, we found that amlexanox attenuated monocytosis, eosinophilia, and vascular dysfunction during WD-induced atherosclerosis. These findings demonstrate the potential of amlexanox as a therapy for hypercholesterolemia and atherosclerosis.

Reduced Heart Failure and Mortality in Patients Receiving Statin Therapy Before Initial Acute Coronary Syndrome

BACKGROUND

There is uncertainty regarding the impact of statins on the risk of atherosclerotic cardiovascular disease (ASCVD) and its major complication, acute heart failure (AHF).

OBJECTIVES

The aim of this study was to investigate whether previous statin therapy translates into lower AHF events and improved survival from AHF among patients presenting with an acute coronary syndrome (ACS) as a first manifestation of ASCVD.

METHODS

Data were drawn from the International Survey of Acute Coronary Syndromes Archives. The study participants consisted of 14,542 Caucasian patients presenting with ACS without previous ASCVD events. Statin users before the index event were compared with nonusers by using inverse probability weighting models. Estimates were compared by test of interaction on the log scale. Main outcome measures were the incidence of AHF according to Killip class and the rate of 30-day all-cause mortality in patients presenting with AHF.

RESULTS

Previous statin therapy was associated with a significantly decreased rate of AHF on admission (4.3% absolute risk reduction; risk ratio [RR]: 0.72; 95% CI: 0.62-0.83) regardless of younger (40-75 years) or older age (interaction P = 0.27) and sex (interaction P = 0.22). Moreover, previous statin therapy predicted a lower risk of 30-day mortality in the subset of patients presenting with AHF on admission (5.2 % absolute risk reduction; RR: 0.71; 95% CI: 0.50-0.99).

CONCLUSIONS

Among adults presenting with ACS as a first manifestation of ASCVD, previous statin therapy is associated with a reduced risk of AHF and improved survival from AHF. (International Survey of Acute Coronary Syndromes [ISACS] Archives; NCT04008173).

The role of statins in the prevention of preeclampsia

Preeclampsia is a common hypertensive disorder of pregnancy associated with considerable neonatal and maternal morbidities and mortalities. However, the exact cause of preeclampsia remains unknown; it is generally accepted that abnormal placentation resulting in the release of soluble antiangiogenic factors, coupled with increased oxidative stress and inflammation, leads to systemic endothelial dysfunction and the clinical manifestations of the disease. Statins have been found to correct similar pathophysiological pathways that underlie the development of preeclampsia. Pravastatin, specifically, has been reported in various preclinical and clinical studies to reverse the pregnancy-specific angiogenic imbalance associated with preeclampsia, to restore global endothelial health, and to prevent oxidative and inflammatory injury. Human studies have found a favorable safety profile for pravastatin, and more recent evidence does not support the previous teratogenic concerns surrounding statins in pregnancy. With reassuring and positive findings from pilot studies and strong biological plausibility, statins should be investigated in large clinical randomized-controlled trials for the prevention of preeclampsia.

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.

Serum apolipoprotein E levels predict residual cardiovascular risk in patients with chronic coronary syndrome undergoing first percutaneous coronary intervention and on-statin treatment

BACKGROUND AND AIMS

Little is known about the long-term impact of apolipoprotein E (apoE) on residual cardiovascular risk in patients with chronic coronary syndrome (CCS) receiving statin treatment.

METHODS

A total of 1109 consecutive patients (mean age, 67 ± 10 years; 83% men) with CCS who underwent their first intervention between 2000 and 2016 were included in this study. All patients had achieved low-density lipoprotein cholesterol (LDL-C) <100 mg/dL on statin treatment and were divided into two groups based on median serum apoE values. We evaluated the incidence of major adverse cardiovascular events (MACEs), including cardiovascular death, non-fatal acute coronary syndrome, and target vessel revascularization.

RESULTS

A total of 552 and 557 patients were categorized to the higher and lower apoE groups, respectively. There were significant relationships between apoE levels and total cholesterol levels, triglyceride levels, high-density lipoprotein cholesterol levels, and estimated remnant cholesterol, except for LDL-C levels. During the median follow-up period of 5.1 years, 195 patients (17.6%) developed MACEs. Kaplan-Meier analysis revealed that the cumulative incidence of MACEs in the higher apoE group was significantly higher than in the lower apoE group (29.5% vs.23.8% log-rank test, p = 0.019). Using multivariable Cox hazard analysis, serum apoE level (1-mg/dL increase) (hazard ratio 1.15; 95% confidence interval 1.03-1.29, p = 0.013) was the strongest independent predictor of MACEs.

CONCLUSIONS

Serum apoE level could be a strong predictor of residual cardiovascular risk in patients with CCS long-term, even if LDL-C levels are controlled with statin treatment.

Vulnerable atherosclerotic plaque features: findings from coronary imaging

Pathological studies have suggested that features of vulnerable atherosclerotic plaques likely to progress and lead to acute cardiovascular events have specific characteristics. Given the progress of intravascular coronary imaging technology, some large prospective studies have detected features of vulnerable atherosclerotic plaques using these imaging modalities. However, the rate of cardiovascular events, such as acute coronary syndrome, has been found to be considerably reduced in the limited follow-up period available in the statin era. Additionally, not all disrupted plaques lead to thrombus formation with clinical presentation. If sub-occlusive or occlusive thrombus formation does not occur, a thrombus on a disrupted plaque will organize without any symptoms, forming a “healed plaque”. Although vulnerable plaque detection using intracoronary imaging is focused on “thin-cap fibroatheroma” leading to plaque rupture, superficial plaque erosion is increasingly recognized; however, the underlying mechanism of thrombus formation on eroded plaques is not well understood. One of intravascular imaging, optical coherence tomography (OCT) has the highest image resolution and has enabled detailed characterization of the plaque in vivo. Here, we reviewed the status and limitations of intravascular imaging in terms of detecting vulnerable plaque through mainly OCT studies. We suggested that vulnerable plaque should be reconsidered in terms of eroded plaque and healed plaque and that both plaque and circulating blood should be assessed in greater detail accordingly.

Different Approaches in Therapy Aiming to Stabilize an Unstable Atherosclerotic Plaque

Atherosclerotic plaque vulnerability is a vital clinical problem as vulnerable plaques tend to rupture, which results in atherosclerosis complications—myocardial infarctions and subsequent cardiovascular deaths. Therefore, methods aiming to stabilize such plaques are in great demand. In this brief review, the idea of atherosclerotic plaque stabilization and five main approaches—towards the regulation of metabolism, macrophages and cellular death, inflammation, reactive oxygen species, and extracellular matrix remodeling have been presented. Moreover, apart from classical approaches (targeted at the general mechanisms of plaque destabilization), there are also alternative approaches targeted either at certain plaques which have just become vulnerable or targeted at the minimization of the consequences of atherosclerotic plaque erosion or rupture. These alternative approaches have also been briefly mentioned in this review.

Relation of Low-Density Lipoprotein Cholesterol Level to Plaque Rupture

Statin therapy reduces low-density lipoprotein cholesterol (LDL-C), inflammation, and atherosclerotic cardiovascular disease. We investigated the association between LDL-C and statin therapy on the prevalence of plaque rupture (PR). Patients with acute coronary syndromes who underwent optical coherence tomography imaging of the culprit lesion were divided into 4 groups based on LDL-C level and statin use (Group 1: LDL-C ≤ 100 without statin; Group 2; LDL-C ≤ 100 with statin; Group 3: LDL-C > 100 with statin; Group 4: LDL-C > 100 without statin), and the prevalence of PR was compared between the groups. Among 896 patients, PR was diagnosed in 444 (49.6%) patients. The prevalence of PR was significantly different among the 4 groups (p = 0.007): it was highest in the high LDL-C without statin group and lowest in the low LDL-C without statin group (53.9% and 39.2%, respectively). Compared with the high LDL-C without statin group, the low LDL-C without statin and low LDL-C with statin groups had a significantly lower prevalence of PR (p = 0.001, p = 0.040, respectively), and the low LDL-C with statin group had a significantly higher prevalence of calcification (p = 0.037). The patients with naturally low LDL-C have the lowest risk of PR. The patients with low LDL-C achieved by statin therapy had a higher prevalence of calcification. When LDL-C level is elevated, early and aggressive treatment with statin may help to prevent PR by stabilizing plaques through calcification.

Determinants of ST-segment elevation myocardial infarction as clinical presentation of acute coronary syndrome

Antiplatelet agents and statin therapies are widely used in patients with known cardiovascular disease. Plaque rupture (PR) and plaque erosion (PE) are the most frequent underlying mechanisms of acute coronary syndromes (ACS). The conditions and medications that are associated with ST-segment elevation myocardial infarction (STEMI) following PR or PE have not been systematically studied. A total of 838 ACS patients (494 with STEMI, 344 with NSTE-ACS) who were diagnosed with PR or PE by optical coherence tomography were included. The patients were categorized into two groups based on underlying pathology, and the baseline characteristics and culprit plaque morphology associated with STEMI were investigated within each group. Among 838 patients, 467 (55.7%) had PR, and 371 (44.3%) were diagnosed with PE. Among patients with PR, older age, hyperlipidemia, no antiplatelet therapy, higher level of low-density lipoprotein cholesterol, and greater lipid burden and macrophage infiltration were associated with increased probability of STEMI. Among patients with PE, no dual antiplatelet therapy and no statin therapy were associated with increased probability of STEMI. The incidence of STEMI caused by PR was significantly lower on antiplatelet therapy (P < 0.001), and the incidence of STEMI caused by PE was significantly lower on antiplatelet therapy (P < 0.001) or on statin therapy (P < 0.001). Antiplatelet therapy is associated with lower probability of STEMI, regardless of underlying pathology, and statin therapy is associated with lower probability of STEMI in PE as clinical presentation of ACS. Statin therapy prior to the onset of acute coronary syndromes (ACS) may reduce the probability of plaque rupture. Antiplatelet therapy prior to the onset of ACS is associated with reduced probability of ST-segment elevation myocardial infarction (STEMI) following both plaque rupture and plaque erosion, and dual antiplatelet therapy offers additional protection compared to a single antiplatelet agent in plaque erosion. The combination of statin and antiplatelet therapy may have an additive effect on reducing the probability of STEMI caused by plaque erosion. Yellow: lipid pool(necrotic core); red: fibrin-rich thrombus; gray; platelet-rich thrombus.

Different Statin Effects of ST-elevation Versus Non-ST-Elevation Acute Myocardial Infarction After Stent Implantation

BACKGROUND

Intensive statin therapy reduces cardiovascular events in acute coronary syndrome. The data concerning the long-term clinical impacts of statin therapy between ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) after drug-eluting stent implantation are limited. We compared the 2-year clinical outcomes between these 2 groups after statin therapy.

MATERIALS AND METHODS

A total of 30,616 Korean patients with acute myocardial infarction (AMI) were enrolled. Among them, 13,686 patients were classified as group A (STEMI statin user), 3,824 patients were as group B (STEMI statin nonuser), 10,398 patients were as group C (NSTEMI statin user), and 2,708 patients were as group D (NSTEMI statin nonuser). The major clinical endpoint was the occurrence of major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), and any repeat revascularization during a 2-year follow-up period.

RESULTS

After adjustment, the cumulative risks of MACE (adjusted hazard ratio [aHR] = 1.112 [1.002-1.235]; P = 0.047), all-cause death (aHR = 1.271 [1.054-1.532]; P = 0.012), and target vessel revascularization (TVR, aHR = 1.262 [1.049-1.518]; P = 0.014) in group C were significantly higher than group A. The cumulative risks of MACE, all-cause death, and cardiac death of the statin nonuser group (groups B and D) were significantly higher compared with statin user group (groups A and C).

CONCLUSIONS

Statin therapy was more effective in reducing the cumulative risks of MACE, all-cause death, and TVR in the STEMI group than NSTEMI group in Korean patients with AMI after successful drug-eluting stent implantation.

Aged garlic extract reduces low attenuation plaque in coronary arteries of patients with diabetes: A randomized, double-blind, placebo-controlled study

Several previous studies have demonstrated that aged garlic extract (AGE) inhibits the progression of coronary artery calcification and non-calcified plaque (NCP) in the general population. However, its effects on plaque progression in patients with diabetes have not yet been investigated, at least to the best of our knowledge. This study investigated whether AGE reduces the coronary plaque volume measured by cardiac computed tomography angiography (CCTA) in patients with diabetes mellitus (DM). A total of 80 participants with DM with a median age of 57 years were prospectively assigned to consume 2,400 mg AGE/day (after completion, 37 participants) or placebo (after completion, 29 participants) orally. Both groups underwent CCTA at baseline and follow-up 365 days apart. In total, 66 participants completed the study. Coronary plaque volume, including total plaque (TP), dense calcium (DC), fibrous, fibro-fatty and low-attenuation plaque (LAP) volumes were measured based upon pre-defined intensity cut-off values using semi-automated software (QAngio CT). Changes in various plaque types were normalized to the total coronary artery length. The non-parametric Wilcoxon rank-sum test was performed to examine the differences in plaque formation between the 2 groups. No significant differences were found in the baseline characteristics between the AGE and placebo groups. Compared with the placebo group, the AGE group exhibited a statistically significant regression in normalized LAP [median and standard deviation (SD) -0.2 (18.8) vs. 2.5 (69.3), P=0.0415]. No differences were observed in TP, fibrous, or fibrofatty plaque volumes between the AGE and placebo group. On the whole, this study indicated that the %LAP change in the AGE group was significantly greater than that in the placebo group in patients with diabetes. However, further studies are warranted to evaluate whether AGE has the ability to stabilize vulnerable plaque and decrease adverse cardiovascular events.

Fatty acid nitration in human low-density lipoprotein

Lipid nitration occurs during physiological and pathophysiological conditions, generating a variety of biomolecules capable to modulate inflammatory cell responses. Low-density lipoprotein (LDL) oxidation has been extensively related to atherosclerotic lesion development while oxidative modifications confer the particle pro-atherogenic features. Herein, we reviewed the oxidation versus nitration of human LDL protein and lipid fractions. We propose that unsaturated fatty acids present in LDL can be nitrated under mild nitration conditions, suggesting an anti-atherogenic role for LDL carrying nitro-fatty acids (NFA).

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.

Comparison of Vascular Response to Statin Therapy in Patients With Versus Without Diabetes Mellitus

Diabetes mellitus (DM) increases cardiovascular morbidity and mortality. A statin is routinely prescribed to patients with DM. However, whether a statin therapy is equally effective in plaque stabilization in DM patients compared with non-DM patients is unknown. A total of 117 lipid-rich plaques were imaged in 90 patients (54 plaques in 41 DM patients and 63 plaques in 49 non-DM patients) with coronary artery disease, those who were treated with a statin and underwent serial optical coherence tomography imaging were included in this study (mean follow-up period, 362 ± 38 days). The changes in minimum fibrous cap thickness (FCT) and lipid index between baseline and 1-year follow-up were compared between the 2 groups. Minimum FCT increased and lipid index decreased with statin therapy in both groups. No significant differences were observed in percent changes of minimum FCT (p = 0.796) and lipid index (p = 0.336) between DM and non-DM patients. Statin therapy induced a significant increase in FCT and a significant decrease in lipid index in both groups. Vascular response to statin therapy was similar between the 2 groups irrespective of DM status.

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.

Shrinkage as a potential mechanism of recurrent clinical events in patients with a large vulnerable plaque

AIMS

This study aimed to investigate the progression and vascular shrinkage of vulnerable plaque lesions with a plaque burden at least 70% among patients with coronary artery disease by optical coherence tomography (OCT) and intravascular ultrasound (IVUS).

METHODS

Fifty-six OCT-identified vulnerable plaques from 47 patients were included among coronary angiography-identified nonculprit/nontarget lesions. Serial IVUS images were used to assess plaque progression and vascular shrinkage.

RESULTS

Thirty-five small vulnerable plaques (plaque burden <70%, group A) and 21 large vulnerable plaques (plaque burden ≥70%, group B) were identified. The IVUS results at baseline show that mean plaque areas (P < 0.001) and the percentage atheroma volume (PAV) (P < 0.0001) were greater and the minimal lumen area (P < 0.0001) was smaller in group B. The absolute and relative changes in the PAV and mean plaque area from baseline to follow-up were not significantly different. However, the lesions exhibited vessel shrinkage [the mean external elastic membrane (EEM) area (P = 0.02) and mean lumen area (P = 0.03) were significantly smaller in group B] from baseline to follow-up. Patients in group B also exhibited clinical events (recurrent angina symptoms) during the follow-up period. Positive correlations were found between changes in the mean plaque area and the mean EEM area in large vulnerable plaques (r = 0.61, P < 0.0001) and between changes in the mean EEM area and the mean lumen area in large vulnerable plaques (r = 0.61, P < 0.0001).

CONCLUSION

Vulnerable plaque progression was not different between small and large vulnerable plaques. However, large vulnerable plaque lesions tended to exhibit vascular shrinkage, which is possible a cause of coronary artery lumen loss in patients with large vulnerable plaques.

Recent Advances in Understanding the Pathogenesis of Cardiovascular Diseases and Development of Treatment Modalities

Cardiovascular Diseases (CVDs) are a leading cause of morbidity and mortality worldwide. The underlying pathology for cardiovascular disease is largely atherosclerotic in nature and the steps include fatty streak formation, plaque progression and plaque rupture. While there is optimal drug therapy available for patients with CVD, there are also underlying drug delivery obstacles that must be addressed. Challenges in drug delivery warrant further studies for the development of novel and more efficacious medical therapies. An extensive understanding of the molecular mechanisms of disease in combination with current challenges in drug delivery serves as a platform for the development of novel drug therapeutic targets for CVD. The objective of this article is to review the pathogenesis of atherosclerosis, first-line medical treatment for CVD, and key obstacles in an efficient drug delivery.

Prognostic Value and Therapeutic Perspectives of Coronary CT Angiography: A Literature Review

Coronary stenosis severity is both a powerful and a still debated predictor of prognosis in coronary artery disease. Coronary computed tomographic angiography (CCTA) has emerged as a noninvasive technique that enables anatomic visualization of coronary artery disease (CAD). CCTA with newer applications, plaque characterization and physiologic/functional evaluation, allows a comprehensive diagnostic and prognostic assessment of otherwise low-intermediate subjects for primary prevention. CCTA measures the overall plaque burden, differentiates plaque subtypes, and identifies high-risk plaque with good reproducibility. Research in this field may also advance towards an era of personalized risk prediction and individualized medical therapy. It has been demonstrated that statins may delay plaque progression and change some plaque features. The potential effects on plaque modifications induced by other medical therapies have also been investigated. Although it is not currently possible to recommend routinely serial scans to monitor the therapeutic efficacy of medical interventions, the plaque modulation, as a part of risk modification, appears a feasible strategy. In this review we summarize the current evidence regarding vulnerable plaque and effects of lipid lowering therapy on morphological features of CAD. We also discuss the potential ability of CCTA to characterize coronary atherosclerosis, stratify prognosis of asymptomatic subjects, and guide medical therapy.

Sodium-fluoride PET-CT for the non-invasive evaluation of coronary plaques in symptomatic patients with coronary artery disease: a cross-correlation study with intravascular ultrasound

OBJECTIVES

The aim of this study was to evaluate the ¹⁸F-sodium fluoride (¹⁸F-NaF) coronary uptake compared to coronary intravascular ultrasound (IVUS) in patients with symptomatic coronary artery disease.

BACKGROUND

¹⁸F-NaF PET enables the assessment of vascular osteogenesis by interaction with surface hydroxyapatite, while IVUS enables both identification and quantification of intra-plaque components.

METHODS

Forty-four patients with symptomatic coronary artery disease were included in this prospective controlled trial, 32 of them (30 patients with unstable angina and 2 patients with stable angina), representing the final study cohort, got additional IVUS. All patients underwent cardiac ¹⁸F-NaF PET/CT and IVUS within 2 days. ¹⁸F-NaF maximum tissue-to-blood ratios (TBR_max) were calculated for 69 coronary plaques and correlated with IVUS plaque classification.

RESULTS

Significantly increased ¹⁸F-NaF uptake ratios were observed in fibrocalcific lesions (meanTBR_max = 1.42 ± 0.28), thin-cap atheroma with spotty calcifications (meanTBR_max = 1.32 ± 0.23), and thick-cap mixed atheroma (meanTBR_max = 1.28 ± 0.38), while fibrotic plaques showed no increased uptake (meanTBR_max = 0.96 ± 0.18). The ¹⁸F-NaF uptake ratio was consistently higher in atherosclerotic lesions with severe calcification (meanTBR_max = 1.34 ± 0.22). The regional ¹⁸F-NaF uptake was most likely localized in the border region of intensive calcification. Coronary lesions with positive ¹⁸F-NaF uptake showed some increased high-risk anatomical features on IVUS in comparison to ¹⁸F-NaF negative plaques. It included a significant severe plaque burden (70.1 ± 13.8 vs. 61.0 ± 13.8, p = 0.01) and positive remodeling index (1.03 ± 0.08 vs. 0.99 ± 0.07, p = 0.05), as well as a higher percentage of necrotic tissue (37.6 ± 13.3 vs. 29.3 ± 15.7, p = 0.02) in positive ¹⁸F-NaF lesions.

CONCLUSIONS

¹⁸F-NaF coronary uptake may provide a molecular insight for the characterization of coronary atherosclerotic lesions. Specific regional uptake is needed to be determined by histology.

Intravascular Ultrasound Studies of Plaque Progression and Regression: Impact of Lipid-Modifying Therapies

Application of serial intravascular ultrasound imaging within the coronary arteries enables characterization of the factors associated with progression of atherosclerotic plaque. Integration into clinical trials has enabled determination of the impact of medical therapies on coronary disease. These trials have provided important insights into the effects of lipid-modifying agents currently used in clinical practice and of experimental agents at early stages of clinical development. The results of these trials are reviewed.

Effect of alirocumab on coronary atheroma volume in Japanese patients with acute coronary syndromes and hypercholesterolemia not adequately controlled with statins: ODYSSEY J-IVUS rationale and design

BACKGROUND

Serial intravascular ultrasound (IVUS) imaging can be used to evaluate the effect of cholesterol-lowering on coronary atheroma progression and plaque volume, with evidence of potential incremental effects with more aggressive lipid-lowering treatments. Alirocumab is a highly specific, fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9). This study will investigate the effect of alirocumab on coronary artery plaque volume in Japanese patients with a recent acute coronary syndrome (ACS) and hypercholesterolemia while on stable statin therapy.

METHODS

ODYSSEY J-IVUS is a phase IV, open-label, randomized, blinded IVUS analysis, parallel-group, multicenter study in Japanese adults recently hospitalized for an ACS and who have elevated low-density lipoprotein cholesterol (LDL-C) values [≥100mg/dL (2.6mmol/L)] at ACS diagnosis and suboptimal LDL-C control on stable statin therapy. Patients will be randomized (1:1) to receive alirocumab or standard-of-care (SOC). The alirocumab arm will receive alirocumab 75mg every 2 weeks (Q2W) added to statin therapy (atorvastatin ≥10mg/day or rosuvastatin ≥5mg/day), with a dose increase to 150mg Q2W in patients whose LDL-C value remains ≥100mg/dL at week 12. The SOC arm will receive atorvastatin ≥10mg/day or rosuvastatin ≥5mg/day, with dose adjustment to achieve LDL-C <100mg/dL. Post-treatment IVUS imaging will be done at week 36±2. The primary objective is to compare the effect of alirocumab versus SOC on coronary atheroma progression (percent change in normalized total atheroma volume) after 9 months of treatment.

CONCLUSION

ODYSSEY J-IVUS will provide insights into the effect of alirocumab on coronary atherosclerotic plaque volume in patients with a recent ACS and hypercholesterolemia while on stable statin therapy. ClinicalTrials.gov number: NCT02984982.

Plaque volume and plaque risk profile in diabetic vs. non-diabetic patients undergoing lipid-lowering therapy: a study based on 3D intravascular ultrasound and virtual histology

Background

Coronary atherosclerosis progresses faster in patients with diabetes mellitus (DM) and causes higher morbidity and mortality in such patients compared to non-diabetics ones (non-DM). We quantify changes in plaque volume and plaque phenotype during lipid-lowering therapy in DM versus non-DM patients using advanced intracoronary imaging.

Methods

We analyzed data from 61 patients with stable angina pectoris included to the PREDICT trial searching for prediction of plaque changes during intensive lipid-lowering therapy (40 mg rosuvastatin daily). Geometrically correct, fully 3-D representation of the vascular wall surfaces and intravascular ultrasound virtual histology (IVUS-VH) defined tissue characterization was obtained via fusion of two-plane angiography and IVUS-VH. Frame-based indices of plaque morphology and virtual histology analyses were computed and averaged in 5 mm long baseline/follow-up registered vessel segments covering the entire length of the two sequential pullbacks (baseline, 1-year). We analyzed 698 5-mm-long segments and calculated the Liverpool active plaque score (LAPS).

Results

Despite reaching similar levels of LDL cholesterol (DM 2.12 ± 0.91 mmol/l, non-DM 1.8 ± 0.66 mmol/l, p = 0.21), DM patients experienced, compared to non-DM ones, higher progression of mean plaque area (0.47 ± 1.15 mm² vs. 0.21 ± 0.97, p = 0.001), percent atheroma volume (0.7 ± 2.8% vs. − 1.4 ± 2.5%, p = 0.007), increase of LAPS (0.23 ± 1.66 vs. 0.13 ± 1.79, p = 0.018), and exhibited more locations with TCFA (Thin-Cap Fibro-Atheroma) plaque phenotype in 5 mm vessel segments (20.3% vs. 12.5%, p = 0.01). However, only non-DM patients reached significant decrease of LDL cholesterol. Plaque changes were more pronounced in PIT (pathologic intimal thickening) compared to TCFA with increased plaque area in both phenotypes in DM patients.

Conclusion

Based on detailed 3D analysis, we found advanced plaque phenotype and further atherosclerosis progression in DM patients despite the same reached levels of LDLc as in non-DM patients.

Trial registration ClinicalTrials.gov identifier: NCT01773512

Stabilisation of atherosclerotic plaques

Plaque rupture and subsequent thrombotic occlusion of the coronary artery account for as many as three quarters of myocardial infarctions. The concept of plaque stabilisation emerged about 20 years ago to explain the discrepancy between the reduction of cardiovascular events in patients receiving lipid lowering therapy and the small decrease seen in angiographic evaluation of atherosclerosis. Since then, the concept of a vulnerable plaque has received a lot of attention in basic and clinical research leading to a better understanding of the pathophysiology of the vulnerable plaque and acute coronary syndromes. From pathological and clinical observations, plaques that have recently ruptured have thin fibrous caps, large lipid cores, exhibit outward remodelling and invasion by vasa vasorum. Ruptured plaques are also focally inflamed and this may be a common denominator of the other pathological features. Plaques with similar characteristics, but which have not yet ruptured, are believed to be vulnerable to rupture. Experimental studies strongly support the validity of anti-inflammatory approaches to promote plaque stability. Unfortunately, reliable non-invasive methods for imaging and detection of such plaques are not yet readily available. There is a strong biological basis and supportive clinical evidence that low-density lipoprotein lowering with statins is useful for the stabilisation of vulnerable plaques. There is also some clinical evidence for the usefulness of antiplatelet agents, beta blockers and renin-angiotensin-aldosterone system inhibitors for plaque stabilisation. Determining the causes of plaque rupture and designing diagnostics and interventions to prevent them are urgent priorities for current basic and clinical research in cardiovascular area.

Advances in dyslipidemia management for prevention of atherosclerosis: PCSK9 monoclonal antibody therapy and beyond

In 2003, select families with familial hypercholesterolemia were first identified to have gain-of-function mutations for proprotein convertase subtilisin kexin type 9 (PCSK9) followed, in 2006, by the identification of those with lifelong low levels of LDL-C and lowered atherosclerotic cardiovascular disease (ASCVD) risk who had loss-of-function PCSK9 mutations. These discoveries led to the rapid development of PSCK9-targeted monoclonal antibody (PCSK9 mAb) therapies and, in 2015, 2 'fully-humanized' PCSK9 mAbs (alirocumab and evolocumab) were marketed in the United States, Europe, and other countries. In a wide range of high risk patients, with and without ASCVD, these PCSK9 mAbs, as once or twice monthly subcutaneous injections, potently reduce LDL-C 50-65% beyond levels achieved by maximally tolerated statin therapy; approximately one-third of patients achieve LDL-C levels <25 mg/dL. In the US, PCSK9 mAb therapy has current limited indications for persons with ASCVD or familial hypercholesterolemia requiring additional LDL-C reduction beyond maximally tolerated statin therapy. The first of the ASCVD outcomes-driven trials, the FOURIER trial has very recently shown in over 27,000 subjects randomized to evolocumab or placebo on top of moderate or high intensity statin therapy, a 15% risk reduction in the primary and 20% reduction in the secondary outcome over 2.2 years of treatment. Also of interest in patients with coronary artery disease on statin therapies, once-monthly evolocumab treatment, for only 76 weeks, resulted in significant plaque atheroma volume regression, as assessed by serial intravascular ultrasonography imaging, in approximately two-thirds of treated patients. Finally, in development is a highly durable RNA interference therapeutic inhibitor of PCSK9 synthesis which from a single dosage has been shown to maintain, for 6 months, a 75% reduction in PCSK9 levels and 50% reductions in LDL-C levels. The potential role of this vaccination-like product, as well as currently available PCSK9 mAb therapies, represents significant therapeutic advances to address ASCVD residual risk.

Plaque imaging to refine indications for emerging lipid-lowering drugs

Statins have been effective in reducing adverse cardiovascular events. Their benefits have been proportional to the level of plasma LDL-cholesterol reduction and seem to extend to patients with 'normal' levels of cholesterol at outset. Statins are also inexpensive and have a favourable side-effect profile. As a result, they are used widely (almost indiscriminately) in patients with atherosclerotic vascular disease, and in those at risk of disease. Next generation lipid-modifying drugs seem unlikely to offer the same simplicity of application. The recent trials of new classes of lipid modifying drugs underline the need for a risk stratification tool which is not based on patients' category of diagnosis (for example, post-myocardial infarction) but based on the characterization of disease in that individual patient. Mechanistic staging, a process that matches the target of the drug action with an identifiable disease characteristic, may offer an opportunity to achieve more precise intervention. The upshots of this targeted approach will be greater efficacy, requiring smaller clinical trials to demonstrate effectiveness; a reduced number needed to treat to yield benefits and more cost-effective prescribing. This will be important, as purchasers require ever more rigorous demonstration of both efficacy and cost-effectiveness. In this context, we will discuss available pharmacological strategies of lipid reduction in anti-atherosclerotic treatment and how plaque imaging techniques may provide an ideal method in stratifying patients for new lipid-modifying drugs.

Comparative assessment of "plaque/media" change on three modalities of IVUS immediately after implantation of either everolimus-eluting bioresorbable vascular scaffold or everolimus-eluting metallic stent in Absorb II study

The purpose of the study to assess the comparability of immediate changes in plaque/media volume (PV) on three modalities of intravascular ultrasound (IVUS) after implantation of either bioresorbable vascular scaffold (BVS) or everolimus-eluting metallic stent (EES) in Absorb II Study. The two devices have different device volume and ultrasound backscattering that may interfere with the “plaque/media” assessed by three modalities on IVUS: grayscale, backscattering of radiofrequency and brightness function. In a multicenter randomized controlled trial, 501 patients with stable or unstable angina underwent documentary IVUS pre- and post- implantation. The change in plaque/media volume (PV) was categorized into three groups according to the relative PV change in device segment: PV “increased” >+5% (PVI), PV unchanged ±5% (PVU), and PV decreased <−5% (PVD). The change in PV was re-evaluated three times: after subtraction of theoretical device volume, after analysis of echogenicity based on brightness function. In 449 patients, 483 lesions were analyzed pre- and post-implantation. “PVI” was more frequently observed in BVS (53.8%) than EES group (39.4%), p = 0.006. After subtraction of the theoretical device volume, the frequency of “PVI” decreased in both BVS (36.2%) and EES (32.1%) groups and became comparable (p = 0.581). In addition, the percentage of “PVI” was further reduced in both device groups after correction for either radiofrequency backscattering (BVS 34.4% vs. EES 22.6%) or echogenicity (BVS 25.2% vs. EES 9.7%). PV change in device segment was differently affected by BVS and EES devices implantation due to their differences in device volume and ultrasound backscattering. It implies that the lumen volume was also artifactually affected by the type of device implanted. Comparative IVUS assessment of lumen and plaque/media volume changes following implantation of BVS and EES requires specific methodological adjustment.

Comparison of coronary plaque, coronary artery calcification and major adverse cardiac events in Chinese outpatients with and without type 2 diabetes

Objective

Diabetes substantially increases the risk of cardiovascular disease (CAD) and is associated with an increased risk of CAD mortality. The purpose of this study was to investigate the differences in coronary artery plaque, coronary artery calcification (CAC) measured in outpatients with and without type 2 diabetes, and the occurrence rate of a major adverse cardiac event (MACE) throughout follow-up with the same patients.

Methods

Five hundred eighty-eight outpatients with suspected CAD comprising 208 diabetic and 380 non-diabetic patients were enrolled in this study. Coronary artery plaque and CAC scores were detected and measured by dual-source computed tomography. The major MACE during the follow-up period (4.0–20 months) was recorded and its relationship to type 2 diabetes and CAC was investigated.

Results

The diabetes group had higher CAC scores in the left anterior descending, left circumflex, and right coronary arteries and total CAC burden than the group without diabetes. The diabetes group had more diseased coronary segments and more obstructed vessels than the non-diabetes group. Logistic regression analysis demonstrated that diabetes is positively associated with mixed coronary plaque and non-calcified plaque. All patients in the diabetes group and all patients with higher CACs in both groups had a higher incidence rate of MACEs.

Conclusion

Patients with type 2 diabetes have a higher prevalence of obstructive CAD, higher CAC scores, and a higher incidence rate of MACEs than those without diabetes. Diabetes and higher CAC scores were the important predictors of the occurrence of MACEs throughout follow-up with patients.

Prevention of Positive Coronary Artery Remodeling with Statin Therapy in Patients with Coronary Artery Diseases

Since positive coronary artery remodeling with large plaque burden is associated with subsequent coronary events, the authors tested their hypothesis that secondary prevention of coronary events by a statin may be associated with inhibition of the process of positive coronary artery remodeling in underlying coronary atherosclerotic lesions in patients with coronary artery diseases. They evaluated the intravascular ultrasound imaging in angiographically normal coronary lesions at baseline and after 6 months of therapy in 64 patients with coronary artery diseases. External elastic membrane area was defined as the vessel area, and the difference between the vessel and lumen area was calculated as plaque area. The relative echogenicity of coronary plaque to adventitia was evaluated as acoustic characteristics of coronary plaque. Twenty-five patients were treated with a statin and 39 patients did not receive a statin. In patients treated with a statin, plaque area decreased by 12% (p=0.013) compared to an increase in plaque area of 13% (p=0.023) in those who did not receive a statin. The vessel area was not enlarged in patients treated with a statin but did show positive remodeling in patients who had plaque progression without a statin. The relative echogenicity of plaque was unchanged in patients treated with a statin but significantly decreased in patients not receiving a statin. A statin may prevent positive coronary artery remodeling via inhibition of plaque progression in underlying coronary atherosclerotic lesions in patients with coronary artery diseases.

Progression of coronary artery calcification at the crossroads: sign of progression or stabilization of coronary atherosclerosis?

Coronary artery calcification (CAC) has been strongly established as an independent predictor of adverse events, with a significant incremental prognostic value over traditional risk stratification algorithms. CAC progression has been associated with a higher rate of events. In parallel, several randomized studies and meta-analysis have shown the effectiveness of statins to slow progression and even promote plaque regression. However, evidence regarding the effect of routine medical therapy on CAC has yielded conflicting results, with initial studies showing significant CAC regression, and contemporaneous data showing rather the opposite. Accordingly, there is currently a great controversy on whether progression of CAC is a sign of progression or stabilization of coronary artery disease (CAD). The finding of inexorable CAC progression despite the implementation of intensive contemporaneous medical therapy suggests that further understanding of this phenomenon should be undertaken before the implementation of CAC as a surrogate endpoint for longitudinal studies, or for prospective follow-up of patients under routine medical treatment.

Comparison of Intensive Versus Moderate Lipid-Lowering Therapy on Fibrous Cap and Atheroma Volume of Coronary Lipid-Rich Plaque Using Serial Optical Coherence Tomography and Intravascular Ultrasound Imaging

Despite marked clinical benefit, reduction in atheroma volume with statin therapy is minimal. Changes in plaque composition may explain this discrepancy. We aimed in the present study to assess the effect of statin therapy on coronary plaque composition and plaque volume using serial multimodality imaging. From an open-label, single-blinded study, patients with angiographically mild-to-moderate lesion were randomized to receive atorvastatin 60 (AT 60) mg or atorvastatin 20 (AT 20) mg for 12 months. Optical coherence tomography was used to assess fibrous cap thickness (FCT) and intravascular ultrasound to assess atheroma burden at 3 time points: baseline, at 6 months, and at 12 months. Thirty-six lipid-rich plaques in 27 patients with AT 60 mg and 30 lipid-rich plaques in 19 patients with AT 20 mg were enrolled in this study. Low-density lipoprotein cholesterol level was significantly decreased at 6 months without further reduction at 12 months. AT 60 mg induced greater reduction in low-density lipoprotein cholesterol compared with AT 20 mg. Optical coherence tomography revealed continuous increase in FCT from baseline to 6 months and to 12 months in both groups. AT 60 mg induced greater increase in FCT compared with AT 20 mg at both follow-up points. The prevalence of thin-cap fibroatheroma and the presence of macrophage at 6 months were significantly lower in AT 60 mg compared with AT 20 mg. Plaque burden did not change significantly in both groups. In conclusion, both intensive and moderate statin therapy stabilizes coronary plaques, with a greater benefit in the intensive statin group. However, no significant changes in plaque volume were observed over time regardless of the intensity of statin therapy.

Lipid Control and Beyond: Current and Future Indications for Statin Therapy in Stroke

OPINION STATEMENT

Statins are a group of lipid-lowering agents that are competitive inhibitors of the enzyme 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase that have been used to reduce cholesterol levels and prevent cardiovascular events. Statins have been also shown to reduce the risk of stroke. In this review, we cover the role of statins in cerebrovascular disease through lipid-lowering mechanisms and other "pleiotropic" effects that provide protection against cerebrovascular events and potentially contribute to improve functional outcome after stroke.

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.

Microbubble-mediated intravascular ultrasound imaging and drug delivery

Intravascular ultrasound (IVUS) provides radiation-free, real-time imaging and assessment of atherosclerotic disease in terms of anatomical, functional, and molecular composition. The primary clinical applications of IVUS imaging include assessment of luminal plaque volume and real-time image guidance for stent placement. When paired with microbubble contrast agents, IVUS technology may be extended to provide nonlinear imaging, molecular imaging, and therapeutic delivery modes. In this review, we discuss the development of emerging imaging and therapeutic applications that are enabled by the combination of IVUS imaging technology and microbubble contrast agents.

Statins and aspirin: do they really work in women?

Cardiovascular disease continues to be the most common cause of mortality in women in the USA. As a result, greater emphasis has been placed on preventive measures. Studies examining the role of aspirin and HMG-CoA reductase inhibitors (statins) have shown important clinical differences in men versus women in the preventive realm. This has led to inconsistent recommendations by guideline committees and clinicians alike. This review presents a summary of the past and current guidelines. In addition, important clinical trials influencing current era practice are also discussed. Both strengths and limitations of these studies are described in detail, along with recommendations regarding future directions and the scope of aspirin and statin use for primary and secondary prevention of cardiovascular disease.

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.

Statin therapy is associated with lower all-cause mortality in patients with non-obstructive coronary artery disease

OBJECTIVE

Non-obstructive coronary artery disease (CAD) is a frequent clinical condition and is associated with an increase in cardiovascular events. However, appropriate medical therapy for this population is not known. We investigated the association between statin use and risk of all-cause mortality and coronary revascularization in patients with non-obstructive CAD.

METHODS

From 2007 to 2011, we identified 8372 consecutive patients with non-obstructive CAD (1-49% stenosis) documented by coronary computed tomography angiography (CCTA) from 3 medical centers. Patients with statins or aspirin use before CCTA, and a history of revascularization before initial CCTA were excluded. All-cause mortality and a composite of mortality and late coronary revascularization (>90 days after CCTA) were analyzed according to the use of statins.

RESULTS

Mean age of the study population was 61.4 ± 10.9 years and 70.3% were male. Statins were prescribed to 1983 (23.7%) patients. During 828 days of follow-up (IQR 385-1342), 221 (2.6%) cases of all-cause mortality and 295 (3.5%) cases of the composite endpoint were observed. Statin therapy was associated with lower risks of all-cause mortality (adjusted HR 0.397; 95% CI 0.262-0.602; p < 0.0001) and composite endpoint (adjusted HR 0.430; 95% CI 0.310-0.597; p < 0.0001). Association between statin therapy and better clinical outcomes was regardless of age, sex, presence of hypertension or diabetes, coronary artery calcium score, low-density lipoprotein cholesterol levels, high-sensitivity C-reactive protein levels, or glomerular filtration rate.

CONCLUSIONS

Statin therapy was associated with a lower risk of all-cause mortality in patients with non-obstructive CAD documented by CCTA, regardless of combined clinical risk factors.

Echogenicity as a surrogate for bioresorbable everolimus-eluting scaffold degradation: analysis at 1-, 3-, 6-, 12- 18, 24-, 30-, 36- and 42-month follow-up in a porcine model

The objective of the study is to validate intravascular quantitative echogenicity as a surrogate for molecular weight assessment of poly-l-lactide-acid (PLLA) bioresorbable scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California). We analyzed at 9 time points (from 1- to 42-month follow-up) a population of 40 pigs that received 97 Absorb scaffolds. The treated regions were analyzed by echogenicity using adventitia as reference, and were categorized as more (hyperechogenic or upperechogenic) or less bright (hypoechogenic) than the reference. The volumes of echogenicity categories were correlated with the measurements of molecular weight (Mw) by gel permeation chromatography. Scaffold struts appeared as high echogenic structures. The quantification of grey level intensity in the scaffold-vessel compartment had strong correlation with the scaffold Mw: hyperechogenicity (correlation coefficient = 0.75; P < 0.01), upperechogenicity (correlation coefficient = 0.63; P < 0.01) and hyper + upperechogenicity (correlation coefficient = 0.78; P < 0.01). In the linear regression, the R² for high echogenicity and Mw was 0.57 for the combination of hyper and upper echogenicity. IVUS high intensity grey level quantification is correlated to Absorb BVS residual molecular weight and can be used as a surrogate for the monitoring of the degradation of semi-crystalline polymers scaffolds.

Treatment with betablockers is associated with higher grey-scale median in carotid plaques

Background

The presence of echolucent carotid plaques as defined by low ultrasound grey-scale median (GSM) is associated with a higher risk of stroke and myocardial infarction. Betablockers have shown possible anti-atherosclerotic effects. The aim of the present study was to determine if there is an association between carotid plaque GSM and treatment with betablockers.

Methods

The GSM of the carotid plaques of 350 patients who underwent carotid endarterectomy (CEA) for asymptomatic (n = 113) or symptomatic (n = 237) carotid disease was measured. Patients were divided in two groups based on the absence/presence of an on-going long-term (i.e. at least 6 months) oral treatment with betablockers at the time of CEA.

Results

The prevalence and type of preoperative neurological symptoms were similar in the two groups. Patients with betablockers had more frequently arterial hypertension (P < .0001), diabetes (P = .035) and a higher BMI (P = .0004), while patients without betablockers were most frequently smokers (P = .017).

Patients with betablockers revealed to have higher GSM (37.79 ± 25 vs 32.61 ± 23.50 P = .036). Echogenic plaques (i.e. with GSM > 30) showed to be more frequent in patients with betablockers also after correction for age, gender, the occurrence of preoperative symptoms, diabetes, hypertension, smoking and statins use (P = .024).

Conclusions

These results suggest the use of standardized ultrasound techniques as an important tool in evaluating the effect of anti-atherosclerotic medications and underline the need of.further prospective randomized studies on larger patient cohorts in order to confirm these results.

Statins and succinylcholine interaction: A cause of concern for serious muscular damage in anesthesiology practice!

Statins are being extensively used in cardiac patient throughout the globe. Succinylcholine has been the mainstay of profound relaxation during induction and intubation of anesthesia for almost six decades now. The interactive properties of these drugs have been of major concern during routine anesthesiology practice in the last few years. However, no major research trial, prospective studies or meta-analysis are available, which can truly allay the fears of possible potential negative synergistic interactions between these two commonly used drugs. Whatever the evidence is available is hardly enough to support a positive outcome and the results have been drawn from observations of only few small studies. As a result, a continuous need among anesthesiologist fraternity is felt to arrive at a suitable inference, which can predict definite consequences of this synergistic interaction. The present article reviews some of the important observations of few handful studies which were carried out to observe any potential adverse interactions between succinylcholine and statins.

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.