Association of circulating levels of neopterin with non-culprit plaque vulnerability in CAD patients an angiogram, optical coherent tomography and intravascular ultrasound study

The Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE): protocol for a randomised, double-blind, placebo-controlled trial

BACKGROUND

Inflammation is a key mediator in the development and progression of the atherosclerotic disease process as well as its resultant complications, like myocardial infarction (MI), stroke and cardiovascular (CV) death, and is emerging as a novel treatment target. Trials involving anti-inflammatory medications have demonstrated outcome benefit in patients with known CV disease. In this regard, colchicine appears to hold great promise. However, there are potential drawbacks to colchicine use, as some studies have identified an increased risk of infection, and a non-significant trend for increased all-cause mortality. Thus, a more thorough understanding of the underlying mechanism of action of colchicine is needed to enable a better patient selection for this novel CV therapy.

OBJECTIVE

The primary objective of the Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE) trial is to assess the effect of colchicine on vascular inflammation in the carotid arteries and ascending aorta measured with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in patients with type 2 diabetes mellitus (T2DM) or pre-diabetes who have experienced a recent vascular event (acute coronary syndrome (ACS)/MI, transient ischaemic attack (TIA) or stroke). Secondary objectives include determining colchicine's effect on inflammatory biomarkers (high-sensitivity C reactive protein (hs-CRP) and interleukin-6 (IL-6)). Additionally, we will assess if baseline inflammation imaging or biomarkers are associated with a treatment response to colchicine determined by imaging. Exploratory objectives will look at: (1) the difference in the inflammatory response to colchicine in patients with coronary events compared with patients with cerebral events; (2) the difference in the inflammatory response to colchicine in different vascular beds; (3) the relationship of FDG-PET imaging markers with serum biomarkers and (4) assessment of quality-of-life changes.

METHODS AND DESIGN

CADENCE is a multicentre, prospective, randomised, double-blinded, placebo-controlled study to determine the effect of colchicine on arterial inflammation as assessed with imaging and circulatory biomarkers, specifically carotid arteries and aortic FDG uptake as well as hs-CRP and IL-6 among others. Patients with T2DM or pre-diabetes who have recently experienced a CV event (within 30-120 days after an ACS (ie, ST-elevation MI (STEMI) or non-STEMI)) or TIA/stroke with documented large vessel atherosclerotic disease will be randomised to treatment with either colchicine 0.6 mg oral daily or placebo. Participants will undergo baseline clinical evaluation including EQ5D assessment, blood work for inflammatory markers and FDG PET/CT scan of the ascending aorta and left and right carotid arteries. Patients will undergo treatment for 6 months and have repeat clinical evaluation including EQ5D assessment, blood work for inflammatory markers and FDG PET/CT scan at the conclusion of the study. The primary outcome will be the change in the maximum target to background ratio (TBRmax) in the ascending aorta (or carotid arteries) from baseline to follow-up on FDG PET/CT imaging.

DISCUSSION

Colchicine is an exciting potential new therapy for CV risk reduction. However, its use is associated with side effects and greater understanding of its underlying mechanism of action is needed. Importantly, the current study will determine whether its anti-inflammatory action is an indirect systemic effect, or a more local plaque action that decreases inflammation. The results will also help identify patients who will benefit most from such therapy.

TRIAL REGISTRATION NUMBER

NCT04181996.

Association of systemic inflammatory biomarkers with morphological characteristics of coronary atherosclerotic plaque by intravascular optical coherence tomography

Despite significant advances in preventive, medical, and interventional management, coronary artery disease remains the leading cause of death worldwide. We now know that in the majority of acute coronary syndromes, a thrombotic event is triggered either by the rupture or erosion of the so-called high-risk or 'vulnerable' plaque. However, accurately identifying the individual who is at significant risk of acute event remains the holy grail of preventive cardiology. To better stratify an individual's risk of developing and suffering a cardiovascular event, biomarkers are needed that can accurately predict coronary events and, if possible, monitor disease activity in response to medical or interventional therapies. In order to be able to understand the association of these biomarkers with the morphological substrate of high-risk plaques, intravascular imaging modalities can provide invaluable assistance. Novel imaging tools such as optical coherence tomography (OCT) have not only helped in identifying atherosclerotic plaque characteristics that are unstable but also in estimating global plaque burden. In this study, we provide an overview of our current knowledge of association of various inflammatory markers with atherosclerotic plaque characteristics seen on OCT.

Neopterin and Cardiovascular Events Following Coronary Stent Implantation in Patients with Stable Angina Pectoris

AIM

Neopterin is an activation marker for monocytes/macrophages. We prospectively investigated the predictive value of plasma neopterin levels on 2-year and long-term cardiovascular events in patients with stable angina pectoris (SAP) undergoing coronary stent implantation.

METHODS

We studied 123 consecutive patients with SAP who underwent primary coronary stenting (44 patients with bare metal stent: BMS group and 79 with drug-eluting stent: DES group). Plasma neopterin levels were measured on admission using HPLC. Moreover, one frozen coronary artery specimen after DES and three frozen coronary specimens after BMS were obtained by autopsy or endarterectomy, followed by immunohistochemical staining for neopterin.

RESULTS

Plasma neopterin levels were significantly higher in patients with cardiovascular events than in those without them (P＜0.001). In subgroup analyses, higher levels of plasma neopterin in patients with cardiovascular events (P＜0.001) and a positive correlation between neopterin levels and late lumen loss after stenting (P =0.008) were observed in the BMS group but not in the DES group (P=0.53 and P=0.17, respectively). In long-term cardiovascular events, multivariate Cox regression analysis identified the significance of the high-neopterin group as independent determinants of cardiovascular events (hazard ratio, 2.225; 95% CI, 1.283-3.857; P =0.004). Immunohistochemical staining showed abundant neopterin-positive macrophages in the neointima after BMS implantation but no neopterin-positive macrophages in the neointima after DES implantation.

CONCLUSION

These findings suggest that neopterin is associated with cardiovascular events after coronary stent implantation in patients with SAP. However, there might be a strong association between neopterin and cardiovascular events after BMS but not after DES in these patients.

Inflammatory Mediators Across the Spectrum of Ankle-Brachial Index

Aim: Peripheral artery disease (PAD) is a manifestation of atherosclerosis with poor prognosis. It is generally complicated by vascular calcification, which is located either in the intima as patchy infiltrates; or circumferentially in the media, also known as medial arterial calcification (MAC). Obstructive PAD is reflected by low anklebrachial index (ABI ≤ 0.9), whereas MAC is revealed by high ABI (ABI > 1.4). Considering the increase in cardiovascular mortality at both ends of the ABI spectrum, this study aimed to explore the underlying pathology through cytokines with established prognostic significance; namely pentraxin-3(PTX3), high sensitivity C-reactive protein (hsCRP), copeptin, soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), NT-proBNP, and neopterin.

Methods: We categorized 180 patients with previous multivessel coronary artery bypass grafting surgery into three groups based on their ABI measurements; 60 patients with ABI ≤ 0.9, 60 patients with ABI within 0.91 and 1.4 (normal ABI), and 60 patients with ABI > 1.4 constituted the “PAD,” “normal,” “MAC” groups, respectively. The circulating levels of the biochemical markers were determined.

Results: In the PAD group, the cytokine levels with predominantly proatherogenic actions such as PTX3, hsCRP, copeptin, and sTREM-1 were increased and these cytokine levels declined as the ABI increased. In the MAC group, the cytokine concentrations with pleiotropic actions such as NT-proBNP and neopterin increased and; NT-proBNP and neopterin concentrations decreased as ABI decreased. The linear regression analysis revealed that neopterin (β = 0.72), PTX3 (β = −0.32), and copeptin (β = −0.48) were independent predictors of ABI.

Conclusions: These findings suggest that different inflammatory pathways influence the pathology at the opposing ends of the ABI spectrum. Consequently, we suggest that PTX3, copeptin, and neopterin are promising biomarkers for future research.

Serial volumetric assessment of coronary fibroatheroma by optical frequency domain imaging: insights from the TROFI trial

Aims

Coronary lesions precursors of acute events remain elusive, since they undergo continuous changes and their temporal changes are not very well-characterized. In natural history studies, optical frequency domain imaging (OFDI) has been used only to assess fibroatheromas as a 2D structure and sometimes in a single frame fashion. We aim at describing the serial volumetric modifications of the fibrous cap (FC) of the fibroatheromas as determined by OFDI over a 6-month follow-up period.

Methods and results

In 49 patients, OFDI investigation was performed following treatment of culprit lesion and at 6-month follow-up in patients with ST-segment elevation myocardial infarction (STEMI). A fully automatic volumetric quantification of FC was done in all lipid-containing frames of non-culprit lesions in the infarct related artery. These lesions were matched at baseline and 6-month follow-up. A total of 58 non-culprit lipid rich lesions (34 TCFAs and 24 thick-cap fibroatheroma [ThCFA]) were found in 34 patients at baseline. Overall, there was a FC volume decrease of 1.57 (Inter-quartile Range [IQR] -4.13 to 0.54) mm3 at 6-months. 27% of the lesions changed their phenotype over time (TCFA or ThCFA). TCFAs that became ThCFAs at follow-up had smaller mean and maximal FC as compared with lesions that remained TCFAs (P = 0.01 for both).

Conclusions

Non-culprit fibroatheromas located in the infarct related artery of patients with STEMI had a volumetric reduction of the FC after 6-month follow-up. Quantitative FC assessment was able to differentiate high-risk lesions that became ThCFAs. There was a considerable change of plaque phenotype (TCFAs or ThCFAs) over time.