Lipid plaque burden in NSTE-ACS patients with or without COPD: insights from the SCAP Trial

BACKGROUND

Chronic obstructive pulmonary disease (COPD) patients have higher recurrence of adverse events and worse prognosis after acute coronary syndrome (ACS). The underlying pathophysiological mechanism is not fully elucidated.

METHODS

In screening for COPD in ACS (SCAP) Trial (NCT02324660), ACS patients with smoking habit underwent a predischarge screening procedure to detect undiagnosed chronic obstructive pulmonary disease (UCOPD) confirmed with spirometry at 60 days. Patients were then categorized as UCOPD or no-COPD. In 65 NSTE-ACS patients, we performed near infrared spectroscopy (NIRS) in the culprit and at least one non-culprit vessel (151 vessels overall), and we calculated the SYNTAX I Score. Primary endpoint was max lipid core burden index (LCBI) 4 mm. Secondary endpoints were SYNTAX Score I and vessel LCBI.

RESULTS

Max LCBI 4 mm and vessel LCBI were significantly higher in the UCOPD compared to the no-COPD group (UCOPD 388±122, no-COPD 264±131, P<0.001; UCOPD 118±50, no-COPD 82±42, P<0.001, respectively). UCOPD patients showed higher max LCBI 4 mm and LCBI vessel both in culprit and non-culprit vessels. SYNTAX Score I was comparable between the two groups (UCOPD: 13.5 [5.5-24], no-COPD: 12.5 [5-24.5], P=0.7).

CONCLUSIONS

NSTE-ACS patients with UCOPD showed a higher LCBI compared to those without COPD, while SYNTAX Score I was comparable between the two groups.

Exosomes in ischemic heart disease: novel carriers for bioinformation

The occurrence of ischemic heart disease(IHD) is a multi-step chain process from potential risk factors to overt clinical diseases. Vascular cells, blood cells, cardiomyocytes and stem cells are all involved in the pathophysiological links via continual and polynary crosstalk. Exosomes,as powerful vectors for intercellular communication,have been a hotspot for basic and clinical research. Plenty of evidence has shown that exosomes largely participate in the evolution of IHD, including endothelial dysfunction, lipid deposition, atheromatous plaque formation and rupture, myocardial ischemia-reperfusion(I/R) injury,and heart failure (HF), while the rules for detailed communication in the different stages of this continuous disease are still poorly understood. This review will systematically describe characteristics of exosomal crosstalk between different cells in the diverse periods, and also cast light on the potential and challenges for exosome application as therapeutic targets, hoping to offer supporting background for the following research.

Adipose-Derived Exosomes Exert Proatherogenic Effects by Regulating Macrophage Foam Cell Formation and Polarization

Background

Obesity is causally associated with atherosclerosis, and adipose tissue (AT)–derived exosomes may be implicated in the metabolic complications of obesity. However, the precise role of AT‐exosomes in atherogenesis remains unclear. We herein aimed to assess the effect of AT‐exosomes on macrophage foam cell formation and polarization and subsequent atherosclerosis development.

Methods and Results

Four types of exosomes isolated from the supernatants of ex vivo subcutaneous AT and visceral AT (VAT) explants that were derived from wild‐type mice and high‐fat diet (HFD)–induced obese mice were effectively taken up by RAW264.7 macrophages. Both treatment with wild‐type VAT exosomes and HFD‐VAT exosomes, but not subcutaneous AT exosomes, markedly facilitated macrophage foam cell generation through the downregulation of ATP‐binding cassette transporter (ABCA1 and ABCG1)–mediated cholesterol efflux. Decreased expression of liver X receptor‐α was also observed. Among the 4 types of exosomes, only HFD‐VAT exosomes significantly induced M1 phenotype transition and proinflammatory cytokine (tumor necrosis factor α and interleukin 6) secretion in RAW264.7 macrophages, which was accompanied by increased phosphorylation of NF‐κB‐p65 but not the cellular expression of NF‐κB‐p65 or IκB‐α. Furthermore, systematic intravenous injection of HFD‐VAT exosomes profoundly exacerbated atherosclerosis in hyperlipidemic apolipoprotein E–deficient mice, as indicated by the M1 marker (CD16/32 and inducible nitric oxide synthase)–positive areas and the Oil Red O/Sudan IV–stained area, without affecting the plasma lipid profile and body weight.

Conclusions

This study demonstrated a proatherosclerotic role for HFD‐VAT exosomes, which is exerted by regulating macrophage foam cell formation and polarization, indicating a novel link between AT and atherosclerosis in the context of obesity.

Lipid Lowering Therapy to Modify Plaque Microstructures

Due to the pandemics of obesity and diabetes mellitus, especially in the Western countries, atherosclerotic cardiovascular disease (ASCVD) has become a major health burden and is expected to increase in the future. Modifying lipid targets, especially low-density lipoprotein cholesterol (LDL-C) level, has become the first-line therapy for primary and secondary prevention of ASCVD. Intravascular imaging modalities have contributed to elucidating clinical efficacy of lipid lowering therapy on atherosclerotic plaques. Optical coherence tomography (OCT) is a high-resolution imaging tool enables visualization of plaque microstructures associated with its instability. This modality has demonstrated favorable changes in plaque microstructures under lowering LDL-C level. In addition, clinical studies using OCT have suggested potential association of other lipid targets, including triglyceride and high-density lipoprotein cholesterol with plaque microstructures. Given continuing cardiovascular risks despite statin therapy, OCT will be an important imaging modality to evaluate novel therapeutic approaches that potentially modulates plaque instability.

Outcome after Elective Percutaneous Coronary Intervention Depends on Age in Patients with Stable Coronary Artery Disease - An Analysis of Relative Survival in a Multicenter Cohort and an OCT Substudy

Background

Age is a strong predictor of survival in patients with coronary artery disease. In elder patients with increasing co-morbidities percutaneous coronary intervention (PCI) is associated with more complications and worse outcome. The calculation of relative survival rates adjusts for the “background” mortality in the general population by correcting for age and gender. We analyzed if elder patients after elective PCI have a worse relative survival compared to younger patient groups.

Methods

A total of 8,342 patients who underwent elective PCI at two high volume centers between 1998 and 2009 were analyzed.

Results

The survival of our patients after PCI (observed survival) was slightly lower compared to the general population (expected survival) resulting in a slightly decreasing relative survival curve. In a multivariate Cox regression model age amongst others was a strong predictor of survival. Stratifying patients according to their age the relative survival curves of younger patients (Quartile 1: <58 years; 2,046 patients), elder patients (Quartile 3: 66–73 years; 2,090 patients) and very old patients (Quartile 4: >73 years; 2,307 patients) were similar. The relative survival of mid-aged patients (Quartile 2: 58–65 years; 1,899 patients) was better than that of all other patient groups. The profile of cardiovascular risk factors differs between the various groups resulting in different composition and burden of coronary plaques in an optical coherence tomography sub-study.

Conclusion

Patients after elective PCI have a slightly worse long-term survival compared to the age- and sex-matched general population. This is also true for different groups of age except for mid-aged patients between 58 and 63 years. Elder patients between 66 and 73 years and above 73 years have a similar relative survival compared to younger patients below 58 years, and might therefore have similar benefit from elective PCI.