High-Risk Coronary Plaque Features: A Narrative Review

The value of neutrophil-to-lymphocyte ratio in predicting severity of coronary involvement and long-term outcome of percutaneous coronary intervention in patients with acute coronary syndrome: a systematic review and meta-analysis

BACKGROUND

The value of counting inflammatory cells and especially their counting ratio in predicting adverse clinical outcomes in patients with acute coronary syndrome (ACS) undergoing revascularization has been shown, but the results of studies have been very diverse and paradoxical. The aim of the current study was to systematically review the studies that investigated the role of increased neutrophil-to-lymphocyte ratio (NLR) in predicting long-term clinical outcomes in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

METHODS

Data abstraction was independently performed by both un-blinded reviewers on deeply assessing Medline, Web of Knowledge, Google Scholar, Scopus, and Cochrane Central Register of Controlled Trials and using the relevant keywords. The risk of bias for each study was assessed using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions and the QUADAS-2 tool. Statistical analysis was performed using the Stata software. Overall, 14 articles published between 2010 and 2021 were eligible for the final analysis.

RESULTS

A total of 20,846 ACS patients undergoing PCI were included. Higher values of NLR were associated with higher numbers of involved coronaries (RR: 1.175, 95%CI 1.021-1.353, P = 0.024). Increasing the value of NLR was associated with a 3.4 times increase in long-term death (RR: 3.424, 95%CI 2.325-5.025, P = 0.001). Similarly, higher values of NLR were significantly associated with a higher likelihood of long-term MACE (RR: 2.604, 95%CI 1.736-3.906, P = 0.001).

CONCLUSIONS

NLR has a high value in predicting both the severity of coronary artery involvement and long-term adverse clinical outcomes following the PCI procedure.

Epicardial adipose tissue volume, plaque vulnerability and myocardial ischemia in non-obstructive coronary artery disease

Background

Epicardial adipose tissue (EAT) accumulation has been associated with inflammation, atherosclerosis and microvascular dysfunction. Whether increased EAT volume is associated with coronary plaque vulnerability and demand myocardial ischemia in patients with non-obstructive coronary artery disease (CAD) is less explored.

Methods

In 125 patients (median age 63[58, 69] years and 58% women) with chest pain and non-obstructive CAD, EAT volume was quantified on non-contrast cardiac CT images. EAT volume in the highest tertile (>125 ml) was defined as high EAT volume. Total coronary plaque volume and plaque vulnerability were quantified by coronary CT angiography (CCTA). Demand myocardial ischemia was detected by contrast dobutamine stress echocardiography.

Results

High EAT volume was more common in men and associated with higher BMI, hypertension, increased left ventricular mass index (LVMi), C-reactive protein (CRP) and positive remodelling (all p < 0.05). There was no difference in age, coronary calcium score, total and non-calcified plaque volume or presence of demand myocardial ischemia between groups (all p ≥ 0.34). In a multivariable model, obesity (p = 0.006), hypertension (p = 0.007) and LVMi (p = 0.016) were independently associated with high EAT volume. Including plaque vulnerability in an alternative model, positive remodelling (p = 0.038) was independently associated with high EAT volume.

Conclusion

In non-obstructive CAD, high EAT volume was associated with cardiometabolic risk factors, inflammation and plaque vulnerability, while there was no association with demand myocardial ischemia or coronary plaque volume. Following our results, the role of EAT volume as a biomarker in non-obstructive CAD remains unclear.

Stress-Related Neural Activity Associates With Coronary Plaque Vulnerability and Subsequent Cardiovascular Events

BACKGROUND

Stress-related neural activity (SNA) assessed by amygdalar activity can predict cardiovascular events. However, its mechanistic linkage with plaque vulnerability is not fully elucidated.

OBJECTIVES

The authors aimed to investigate the association of SNA with coronary plaque morphologic and inflammatory features as well as their ability in predicting major adverse cardiovascular events (MACE).

METHODS

A total of 299 patients with coronary artery disease (CAD) and without cancer underwent 18F-fluorodexoyglucose positron emission tomography/computed tomography (PET/CT) and available coronary computed tomographic angiography (CCTA) between January 1, 2013, and December 31, 2020. SNA and bone-marrow activity (BMA) were assessed with validated methods. Coronary inflammation (fat attenuation index [FAI]) and high-risk plaque (HRP) characteristics were assessed by CCTA. Relations between these features were analyzed. Relations between SNA and MACE were assessed with Cox models, log-rank tests, and mediation (path) analyses.

RESULTS

SNA was significant correlated with BMA (r = 0.39; P < 0.001) and FAI (r = 0.49; P < 0.001). Patients with heightened SNA are more likely to have HRP (40.7% vs 23.5%; P = 0.002) and increase risk of MACE (17.2% vs 5.1%, adjusted HR 3.22; 95% CI: 1.31-7.93; P = 0.011). Mediation analysis suggested that higher SNA associates with MACE via a serial mechanism involving BMA, FAI, and HRP.

CONCLUSIONS

SNA is significantly correlated with FAI and HRP in patients with CAD. Furthermore, such neural activity was associated with MACE, which was mediated in part by leukopoietic activity in the bone marrow, coronary inflammation, and plaque vulnerability.

Evaluation of pericoronary adipose tissue attenuation on CT

Pericoronary adipose tissue (PCAT) is the fat deposit surrounding coronary arteries. Although PCAT is part of the larger epicardial adipose tissue (EAT) depot, it has different pathophysiological features and roles in the atherosclerosis process. While EAT evaluation has been studied for years, PCAT evaluation is a relatively new concept. PCAT, especially the mean attenuation derived from CT images may be used to evaluate the inflammatory status of coronary arteries non-invasively. The most commonly used measure, PCAT_MA, is the mean attenuation of adipose tissue of 3 mm thickness around the proximal right coronary artery with a length of 40 mm. PCAT_MA can be analyzed on a per-lesion, per-vessel or per-patient basis. Apart from PCAT_MA, other measures for PCAT have been studied, such as thickness, and volume. Studies have shown associations between PCAT_MA and anatomical and functional severity of coronary artery disease. PCAT_MA is associated with plaque components and high-risk plaque features, and can discriminate patients with flow obstructing stenosis and myocardial infarction. Whether PCAT_MA has value on an individual patient basis remains to be determined. Furthermore, CT imaging settings, such as kV levels and clinical factors such as age and sex affect PCAT_MA measurements, which complicate implementation in clinical practice. For PCAT_MA to be widely implemented, a standardized methodology is needed. This review gives an overview of reported PCAT methodologies used in current literature and the potential use cases in clinical practice.