Coronary calcium significantly affects quantitative analysis of coronary ultrasound: importance for atherosclerosis progression/regression studies

From Cells to Plaques: The Molecular Pathways of Coronary Artery Calcification and Disease

Coronary artery calcification (CAC) is a hallmark of atherosclerosis and a critical factor in the development and progression of coronary artery disease (CAD). This review aims to address the complex pathophysiological mechanisms underlying CAC and its relationship with CAD. We examine the cellular and molecular processes that drive the formation of calcified plaques, highlighting the roles of inflammation, lipid accumulation, and smooth muscle cell proliferation. Additionally, we explore the genetic and environmental factors that contribute to the heterogeneity in CAC and CAD presentation among individuals. Understanding these intricate mechanisms is essential for developing targeted therapeutic strategies and improving diagnostic accuracy. By integrating current research findings, this review provides a comprehensive overview of the pathways linking CAC to CAD, offering insights into potential interventions to mitigate the burden of these interrelated conditions.

Synergistic actions between angiotensin-converting enzyme inhibitors and statins in atherosclerosis

AIMS

Hypertension and hypercholesterolemia are independent risk factors for atherosclerotic cardiovascular disease (ASCVD) by acting directly on the endothelium and activating the renin-angiotensin aldosterone system (RAAS) and mevalonate pathways. This review examines how the severity and duration of these risk factors may influence the cardiovascular risk through a reciprocal interplay leading to oxidative stress and pro-inflammatory response.

DATA SYNTHESIS

The review highlights the clinical evidence supporting the benefits of statins and angiotensin-converting enzyme (ACE) inhibitors for hypertension, lipid disorders and ASCVD management, both individually and combined, at all stages of the cardiovascular continuum.

CONCLUSION

Drug strategies incorporating an ACE-inhibitor and a statin, and in particular perindopril and atorvastatin, have consistently demonstrated reductions in the rate of ASCVD events in patients with hypertension and lipid disorders, cementing their position as first-line therapies for the management of atherosclerosis complications.

The Role of Angiotensin Antagonism in Coronary Plaque Regression: Insights from the Glagovian Model

The benefit of antagonizing the effect of the renin angiotensin aldosterone system (RAAS), notably by the use of angiotensin-converting enzyme inhibitor (ACEi) and angiotensin II type 1 receptor blocker (ARB) for coronary artery disease (CAD), has been demonstrated in multiple studies, which may be attributed to their ability to inhibit the deleterious effect of RAAS to the cardiovascular system. It is well known that angiotensin II (Ang II) plays a vital role in atheromatous plaque formation and progression through multiple pathways, including inflammatory and arterial remodeling aspects. Significant coronary atheromatous plaque regression has been previously demonstrated in various studies using statin agents. Similar results have been reported in different studies using angiotensin inhibitor agents, notably ARB agents. Analysis from various trials utilizing ARB showed a significant plaque regression using olmesartan and telmisartan as evaluated by IVUS studies. In contrary, the use of ACEi did not demonstrated significant plaque regression, which may be attributed to the heavy plaque calcification in respective studies. On this review, we aim to present the basic mechanism on the role of RAAS in plaque modulation and its arterial remodeling aspect, which is then integrated with the clinical evidence based on the available intravascular ultrasonography (IVUS) studies on coronary arteries.

Pharmacological and Nutritional Modulation of Vascular Calcification

Vascular calcification is an independent predictor of cardiovascular disease, and therefore, inhibition or regression of this processes is of clinical importance. The standard care regarding prevention and treatment of cardiovascular disease at this moment mainly depends on drug therapy. In animal and preclinical studies, various forms of cardiovascular drug therapy seem to have a positive effect on vascular calcification. In particular, calcium channel blockers and inhibitors of the renin-angiotensin-aldosteron system slowed down arterial calcification in experimental animals. In humans, the results of trials with these drugs are far less pronounced and often contradictory. There is limited evidence that the development of new atherosclerotic lesions may be retarded in patients with coronary artery disease, but existing lesions can hardly be influenced. Although statin therapy has a proven role in the prevention and treatment of cardiovascular morbidity and mortality, it is associated with both regression and acceleration of the vascular calcification process. Recently, nutritional supplements have been recognized as a potential tool to reduce calcification. This is particularly true for vitamin K, which acts as an inhibitor of vascular calcification. In addition to vitamin K, other dietary supplements may also modulate vascular function. In this narrative review, we discuss the current state of knowledge regarding the pharmacological and nutritional possibilities to prevent the development and progression of vascular calcification.

A Review of the Role of Bradykinin and Nitric Oxide in the Cardioprotective Action of Angiotensin-Converting Enzyme Inhibitors: Focus on Perindopril

The functional integrity of the endothelium is essential for vascular health. In addition to maintaining a delicate balance between vasodilation and vasoconstriction, the endothelium has numerous other complex roles involved in the maintenance of vascular homeostasis. Chronic exposure to cardiovascular risk factors and oxidative stress results in an imbalance in these functions, creating an environment that favors reduced vasodilation and a proinflammatory and prothrombic state. The involvement of endothelial dysfunction in all stages of the cardiovascular continuum makes it an important target for treatment. One of the major endothelial-derived factors involved in the maintenance of endothelial function is nitric oxide (NO). Angiotensin-converting enzyme (ACE) inhibitors increase NO production both directly and indirectly by preventing production of angiotensin II (which diminishes NO production) and inhibiting the degradation of bradykinin (which stimulates local release of NO). Among the ACE inhibitors, perindopril appears to have the greatest effects on bradykinin and has demonstrated efficacy in a number of markers of endothelial dysfunction including arterial stiffness and progression of atherosclerosis. There is also strong evidence supporting the use of perindopril-based therapy for the treatment of hypertension and for reducing the risk of cardiovascular morbidity and mortality in a wide range of patients across the cardiovascular continuum.Funding: The journal's Rapid Service Fee was funded by Servier.

Ca2+ Flux: Searching for a Role in Efferocytosis of Apoptotic Cells in Atherosclerosis

In atherosclerosis, macrophages in the arterial wall ingest plasma lipoprotein-derived lipids and become lipid-filled foam cells with a limited lifespan. Thus, efficient removal of apoptotic foam cells by efferocytic macrophages is vital to preventing the dying foam cells from forming a large necrotic lipid core, which, otherwise, would render the atherosclerotic plaque vulnerable to rupture and would cause clinical complications. Ca2+ plays a role in macrophage migration, survival, and foam cell generation. Importantly, in efferocytic macrophages, Ca2+ induces actin polymerization, thereby promoting the formation of a phagocytic cup necessary for efferocytosis. Moreover, in the efferocytic macrophages, Ca2+ enhances the secretion of anti-inflammatory cytokines. Various Ca2+ antagonists have been seminal for the demonstration of the role of Ca2+ in the multiple steps of efferocytosis by macrophages. Moreover, in vitro and in vivo experiments and clinical investigations have revealed the capability of Ca2+ antagonists in attenuating the development of atherosclerotic plaques by interfering with the deposition of lipids in macrophages and by reducing plaque calcification. However, the regulation of cellular Ca2+ fluxes in the processes of efferocytic clearance of apoptotic foam cells and in the extracellular calcification in atherosclerosis remains unknown. Here, we attempted to unravel the molecular links between Ca2+ and efferocytosis in atherosclerosis and to evaluate cellular Ca2+ fluxes as potential treatment targets in atherosclerotic cardiovascular diseases.

Femoral Intima-media Thickness, Risk Factors, and Markers of Inflammation in Cardiovascular Disease

Introduction: The burden of coronary artery disease (CAD) and peripheral vascular pathologies caused by atherosclerosis is constantly increasing. There is continuous research aiming to develop new methods that can evaluate the extent of atherosclerotic disease in different vascular beds, thus estimating global risk. Similar to carotid artery thickness, which is an established marker for increased cardiovascular risk and cerebrovascular disease, femoral intima-media thickness (f-IMT) may have the same role in case of peripheral arterial involvement. The aim of the study was determine whether f-IMT, determined at the level of the superficial femoral artery, is related to traditional risk factors, markers of peripheral vascular atherosclerosis and inflammation.

Material and methods: Forty-six patients with known cardiovascular disease were included in the study. Demographical data, cardiovascular history, and risk factors were assessed. We determined metabolic parameters (uric acid, fasting glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides), renal function (creatinine and GFR), and inflammation status for all patients. Each patient underwent ultrasound examination of the superficial femoral artery, by which f-IMT was determined for right and left limbs. Ankle-brachial index was also calculated. Data from the low (f-IMT <0.75 mm) and high (f-IMT >0.75 mm) f-IMT groups were compared and correlation coefficients were determined in each groups for f-IMT in relation to the other parameters.

Results: Mean age was 71.08 ± 9.78 years. 86.95% of the patients suffered from hyper-tension, 56.62% had coronary heart disease, and 21.73% had a history of stroke. More females had history of hypertension and CAD. The most prevalent cardiovascular risk factors were dyslipidemia (68.86%), diabetes (21.73%), and smoking (21.73%). There were significant differences between gender groups for total cholesterol levels (161.36 ± 25.04 mg/dL, 95%CI 150.26–172.47 in males vs. 201.33 ± 52.73 mg/dL, 95%CI 170.07–223.60 in females, p = 0.02), creatinine values (1.04 ± 0.22 mg/dL, 95%CI 0.94–1.14 for males vs. 0.91 ± 0.23 mg/dL, 95%CI 0.81–1.00 for females, p = 0.018), and left f-IMT (0.87 ± 0.18 mm, 95%CI 0.79–0.95 for males vs. 0.75 ± 0.10 mm, 95%CI 0.70–0.79 for females, p = 0.0049). In the group with low f-IMT, a significant, reverse correlation was established between f-IMT, uric acid (r = −0.483, p = 0.042), and right ABI (r = −730, p = 0.0006). In the group with high f-IMT, age (r = 0.408, p = 0.031), fasting glucose (r = 0.407, p = 0.034), total cholesterol (r = 0.429, p = 0.02), HDL-cholesterol (r = −0.56, p = 0.0019), triglycerides (r = 0.45, p = 0.01), hs-CRP (r = 0.45, p = 0.01), and left ABI (r = −0.71, p <0.0001) showed a significant correlation to f-IMT.

Conclusions: Increased femoral intima-media thickness is related to age, cardiovascular risk factors, and markers of peripheral arterial disease. Patients with higher f-IMT have a more augmented inflammatory status. Based on these correlations, in patients with cardiovascular disease, f-IMT could become a marker for increased cardiovascular risk.

Vascular legacy beyond blood pressure control: benefits of perindopril/indapamide combination in hypertensive patients with diabetes

OBJECTIVES

Much of the chronic care of patients with type 2 diabetes mellitus and hypertension involves the prevention of diabetic complications. Renin-angiotensin system inhibitors are recommended as first-line therapies because of their nephroprotective properties. Their combination with metabolically neutral diuretics is recommended to reduce blood pressure, morbidity and mortality. Our objective was to review the mechanisms by which the combination of the angiotensin-converting enzyme inhibitor, perindopril, and metabolically neutral thiazide-like diuretic, indapamide, targets the pathways involved in microvascular and macrovascular diabetic complications.

METHODS

For this narrative review, extensive literature searches were performed using PubMed/Medline. Articles published in English describing clinical trials and mechanism of action studies that were relevant to the treatment of patients with perindopril and/or indapamide were included.

RESULTS

Perindopril/indapamide treatment has been shown to reduce blood pressure and to have significant beneficial effects on arterial distensibility, kidney structure and function, and endothelial function. Recent data also suggests that perindopril may reduce the deleterious accumulation of advanced glycation end products in diabetic tissue. In the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation diabetes trial, perindopril/indapamide treatment significantly reduced the relative risk of microvascular and macrovascular events by 9%, cardiovascular mortality by 18%, and all-cause mortality by 14%. Interestingly, 6 years after the end of the double-blind period, follow-up data showed that the beneficial effects on mortality continued to be significant even though differences in blood pressure and glycated hemoglobin levels had not been significant for several years. Together this data suggests that treatment with perindopril/indapamide has microvascular and macrovascular effects that extend beyond blood pressure lowering and that this treatment might confer a long-lasting beneficial vascular legacy.

CONCLUSION

Moving forward, understanding the pathophysiological bases of the effects that extend beyond those of blood pressure control will help us differentiate between anti-hypertensive choices.

Enhanced characterization of calcified areas in intravascular ultrasound virtual histology images by quantification of the acoustic shadow: validation against computed tomography coronary angiography

We enhance intravascular ultrasound virtual histology (VH) tissue characterization by fully automatic quantification of the acoustic shadow behind calcified plaque. VH is unable to characterize atherosclerosis located behind calcifications. In this study, the quantified acoustic shadows are considered calcified to approximate the real dense calcium (DC) plaque volume. In total, 57 patients with 108 coronary lesions were included. A novel post-processing step is applied on the VH images to quantify the acoustic shadow and enhance the VH results. The VH and enhanced VH results are compared to quantitative computed tomography angiography (QTA) plaque characterization as reference standard. The correlation of the plaque types between enhanced VH and QTA differs significantly from the correlation with unenhanced VH. For DC, the correlation improved from 0.733 to 0.818. Instead of an underestimation of DC in VH with a bias of 8.5 mm(3), there was a smaller overestimation of 1.1 mm(3) in the enhanced VH. Although tissue characterization within the acoustic shadow in VH is difficult, the novel algorithm improved the DC tissue characterization. This algorithm contributes to accurate assessment of calcium on VH and could be applied in clinical studies.

Combination therapy in the extended cardiovascular continuum: a focus on perindopril and amlodipine

The progression of cardiovascular disease could be regarded as following atherosclerosis-related and age-related pathways. The starting points for these pathways are different--risk factors or aortic ageing--but they conclude in the same way: end-stage heart disease. Together these interlinked pathways form the extended cardiovascular continuum. Renin-angiotensin-aldosterone system (RAAS) inhibitors have been shown to interrupt or slow the progression of cardiovascular disease along one pathway, the cardiovascular atherosclerotic continuum. Cardiovascular protection with RAAS inhibitors varies; different RAAS inhibitors offer different levels of protection. Similarly, calcium channel blockers (CCBs) also have clearly shown protective effect of cardiovascular system, especially as it regards cerebrovascular disease risk. The AngloScandinavian Cardiac Outcomes Trial (ASCOT) showed that a combination of the angiotensin-converting enzyme (ACE) inhibitor perindopril and CCB amlodipine offered better cardiovascular protection in at-risk hypertensive patients than beta-blocker and thiazide. By attenuating the deleterious effects of cardiovascular disease at multiple stages of the extended cardiovascular continuum on top of lowering blood pressure (BP), perindopril and amlodipine could interrupt and slow the progression of cardiovascular disease. These antihypertensive agents have complementary vascular effects that enhance cardiovascular protection and reduce side-effects. Evidence from ASCOT shows that antihypertensive and vascular effects of amlodipine with and without perindopril have translated into real-life clinical benefits. A strategy using ACE inhibitors and CCBs, such as perindopril and amlodipine, to target multiple stages in both pathways of cardiovascular disease could effectively reduce cardiovascular risk and lower BP.

RAS inhibitors' dose-dependent efficacy: myth or reality?

OBJECTIVE

Treatment of hypertension remains challenging in clinical practice. One major problem is incorrect utilization of the principal drug classes. Drugs from each class are currently used in accordance with an assumption that the blood pressure (BP) lowering effect is dose dependent. While this is true for most drugs, it is not appropriate for all drugs that block the renin-angiotensin system (RAS).

METHODS

This review is based on a PubMed/Cochrane database search for articles on the dose-dependent effect of RAS blockers on BP and cardiovascular protection.

RESULTS

Of the RAS blockers, most angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) have a flat dose-response curve for BP decrease, meaning an increase in dose prolongs duration of action, but does not yield greater potency. Perindopril is the only ACE inhibitor to show a real dose-response curve for BP decrease. While the effectiveness of RAS blockers on target organ damage is dose dependent and at least partially unrelated to BP control, there is evidence that the only way to obtain a beneficial effect is to use them at full dose. Thus, RAS blockers need to be used at the correct dose, based on the results of controlled clinical trials and meta-analysis. Furthermore, for all-cause mortality, ACE inhibitors have been shown to be better than ARBs, a specific efficacy supported by perindopril-based studies including ASCOT-BPLA (the Anglo-Scandinavian Cardiac Outcomes Trial-BP Lowering Arm), ADVANCE (the Action in Diabetes and Vascular disease: PreterAx and DiamicroN-MR Controlled Evaluation trial) and HYVET (HYpertension in the Very Elderly Trial).

CONCLUSION

In hypertensive patients, a strategy based on ACE inhibitors with dose-dependent efficacy such as perindopril as optimal treatment should lead both to improved BP control and to a better protection from target organ damage, thereby reducing the incidence of cardiovascular events.

Can antihypertensive medication interfere with the vicious cycle between hypertension and vascular calcification?

Vascular calcification is a phenomenon of disturbed calcium deposition, as part of the calcium that is supposed to be deposited to our bones, is lodged to our vessels. There are two forms of vascular calcification, each with a distinct anatomical distribution and clinical relevance, namely the intimal and medial calcification. Studies have demonstrated that hypertension may cause vascular calcification but also that both types of calcification, especially medial, promote arterial rigidity and hence hypertension. Implications of this two-way road are largely unknown as there is no consensus yet on their exact clinical value. However, several antihypertensive medications seem to be able to interfere with the cycle of high blood pressure and vascular calcium deposits. The present review summarizes the up-to-date data regarding the effect of antihypertensive medication on vascular calcification.