Computed Histological Quantification of Atherosclerotic Plaque Microcalcifications

Percutaneous Coronary Intervention Is Not Superior to Optimal Medical Therapy in Chronic Coronary Syndrome: A Meta-Analysis

(1) Background and Aim: Conflicting evidence exists regarding the benefits of percutaneous coronary intervention (PCI) on survival and symptomatic relief of patients with chronic coronary syndrome (CCS) compared with optimal medical therapy (OMT). This meta-analysis is to evaluate the short- and long-term clinical benefit of PCI over and above OMT in CCS. (2) Methods: Main endpoints were major adverse cardiac events (MACEs), all-cause mortality, cardiovascular (CV) mortality, myocardial infarction (MI), urgent revascularization, stroke hospitalization, and quality of life (QoL). Clinical endpoints at very short (≤3 months), short- (<12 months), and long-term (≥ 12 months) follow-up were evaluated. (3) Results: Fifteen RCTs with a total of 16,443 patients with CCS (PCI n = 8307 and OMT n = 8136) were included in the meta-analysis. At mean follow-up of 27.7 months, the PCI group had similar risk of MACE (18.2 vs. 19.2 %; p < 0.32), all-cause mortality (7.09 vs. 7.88%; p = 0.56), CV mortality (8.74 vs. 9.87%; p = 0.30), MI (7.69 vs. 8.29%; p = 0.32), revascularization (11.2 vs. 18.3%; p = 0.08), stroke (2.18 vs. 1.41%; p = 0.10), and hospitalization for anginal symptoms (13.5 vs. 13.9%; p = 0.69) compared with OMT. These results were similar at short- and long-term follow-up. At the very short-term follow-up, PCI patients had greater improvement in the QoL including physical limitation, angina frequency, stability, and treatment satisfaction (p < 0.05 for all) but such benefits disappeared at the long-term follow-up. (4) Conclusions: PCI treatment of CCS does not provide any long-term clinical benefit compared with OMT. These results should have significant clinical implications in optimizing patient's selection for PCI treatment.

The Role of Inflammation in Cardiovascular Disease

Atherosclerosis is a chronic inflammatory disease, in which the immune system has a prominent role in its development and progression. Inflammation-induced endothelial dysfunction results in an increased permeability to lipoproteins and their subendothelial accumulation, leukocyte recruitment, and platelets activation. Recruited monocytes differentiate into macrophages which develop pro- or anti-inflammatory properties according to their microenvironment. Atheroma progression or healing is determined by the balance between these functional phenotypes. Macrophages and smooth muscle cells secrete inflammatory cytokines including interleukins IL-1β, IL-12, and IL-6. Within the arterial wall, low-density lipoprotein cholesterol undergoes an oxidation. Additionally, triglyceride-rich lipoproteins and remnant lipoproteins exert pro-inflammatory effects. Macrophages catabolize the oxidized lipoproteins and coalesce into a lipid-rich necrotic core, encapsulated by a collagen fibrous cap, leading to the formation of fibro-atheroma. In the conditions of chronic inflammation, macrophages exert a catabolic effect on the fibrous cap, resulting in a thin-cap fibro-atheroma which makes the plaque vulnerable. However, their morphology may change over time, shifting from high-risk lesions to more stable calcified plaques. In addition to conventional cardiovascular risk factors, an exposure to acute and chronic psychological stress may increase the risk of cardiovascular disease through inflammation mediated by an increased sympathetic output which results in the release of inflammatory cytokines. Inflammation is also the link between ageing and cardiovascular disease through increased clones of leukocytes in peripheral blood. Anti-inflammatory interventions specifically blocking the cytokine pathways reduce the risk of myocardial infarction and stroke, although they increase the risk of infections.

Coronary Computed Tomography Angiography Analysis of Calcium Content to Identify Non-culprit Vulnerable Plaques in Patients With Acute Coronary Syndrome

Background

Aside from the culprit plaque, the presence of vulnerable plaques in patients with acute coronary syndrome (ACS) may be associated with future cardiac events. A link between calcification and plaque rupture has been previously described.

Aim

To assess whether analysis of the calcium component of coronary plaques using CT angiography, coronary computed tomographic angiography (CCTA) can help to detect additional vulnerable plaques in patients with non-ST elevation myocardial infarction (NSTEMI).

Materials And Methods

Cross sectional study of consecutive patients referred for NSTEMI from 30 July to 30 August 2018 with CCTA performed before coronary angiography with systematic optical coherence tomography (OCT) analysis of all coronary arteries within 24 h of clinical onset of NSTEMI. Three types of plaques were defined: culprit plaques defined by angiography (vulnerable culprit plaques–VCP) – plaques with a fibrous cap thickness < 65 microns or thrombus in OCT (vulnerable non-culprit plaque–VNCP) – plaques with a fibrous cap thickness ≥ 65 microns in OCT (stable plaque–SP).

Results

A total of 134 calcified plaques were identified in 29 patients (73% male, 59 ± 14 years) with 29(22%) VCP, 28(21%) VNCP and 77(57%) SP. Using CCTA analysis of the calcium component, factors associated with vulnerable plaques were longer calcification length, larger calcification volume, lower calcium mass, higher Agatston score plaque-specific (ASp), presence of spotty calcifications and an intimal position in the wall. In multivariate analysis, ASp, calcification length and spotty calcifications were independently associated to vulnerable plaques. There was no difference between VCP and VNCP.

Conclusions

CCTA analysis of calcium component of the plaque could help to identify additional vulnerable plaques in NSTEMI patients.

Advances in CT Techniques in Vascular Calcification

Vascular calcification, a common pathological phenomenon in atherosclerosis, diabetes, hypertension, and other diseases, increases the incidence and mortality of cardiovascular diseases. Therefore, the prevention and detection of vascular calcification play an important role. At present, various techniques have been applied to the analysis of vascular calcification, but clinical examination mainly depends on non-invasive and invasive imaging methods to detect and quantify. Computed tomography (CT), as a commonly used clinical examination method, can analyze vascular calcification. In recent years, with the development of technology, in addition to traditional CT, some emerging types of CT, such as dual-energy CT and micro CT, have emerged for vascular imaging and providing anatomical information for calcification. This review focuses on the latest application of various CT techniques in vascular calcification.