Atherosclerosis inflammation and burden in young adult smokers and vapers measured by PET/MR

Uncovering atherosclerotic cardiovascular disease by PET imaging

Assessing atherosclerosis severity is essential for precise patient stratification. Specifically, there is a need to identify patients with residual inflammation because these patients remain at high risk of cardiovascular events despite optimal management of cardiovascular risk factors. Molecular imaging techniques, such as PET, can have an essential role in this context. PET imaging can indicate tissue-based disease status, detect early molecular changes and provide whole-body information. Advances in molecular biology and bioinformatics continue to help to decipher the complex pathogenesis of atherosclerosis and inform the development of imaging tracers. Concomitant advances in tracer synthesis methods and PET imaging technology provide future possibilities for atherosclerosis imaging. In this Review, we summarize the latest developments in PET imaging techniques and technologies for assessment of atherosclerotic cardiovascular disease and discuss the relationship between imaging readouts and transcriptomics-based plaque phenotyping.

Update on Positron Emission Tomography/Magnetic Resonance Imaging: Cancer and Inflammation Imaging in the Clinic

Hybrid PET/MRI is highly valuable, having made significant strides in overcoming technical challenges and offering unique advantages such as reduced radiation, precise data coregistration, and motion correction. Growing evidence highlights the value of PET/MRI in broad clinical aspects, including inflammatory and oncological imaging in adults, pregnant women, and pediatrics, potentially surpassing PET/CT. This newly integrated solution may be preferred over PET/CT in many clinical conditions. However, further technological advancements are required to facilitate its broader adoption as a routine diagnostic modality.

Effect of PCSK9 inhibition in combination with statin therapy on intracranial atherosclerotic stenosis: A high-resolution MRI study

Introduction

Intracranial atherosclerotic stenosis (ICAS) is a common cause of stroke worldwide. Evolocumab, a proprotein convertase subtilisin/kexin type-9 inhibitor (PCSK9i), effectively lowers low-density lipoprotein (LDL) and produces favorable changes in coronary atherosclerosis. This study aimed to determine the effects of PCSK9i on intracranial plaques in moderate-intensity statin-treated individuals with ICAS.

Methods

This prospective, observational study monitored the imaging and clinical outcomes of individuals with ICAS who were consecutively treated with moderate-intensity statins with or without PCSK9i. Individuals underwent monthly visits and repeat high-resolution MRI (HR-MRI) at week 12. The primary outcome was a change in HR-MRI after 12 weeks of treatment and the secondary outcome was major vascular events during follow-up.

Results

Forty-nine individuals were studied (PCSK9i group: 26 individuals with 28 abnormal vascular regions; statin group: 23 with 27 regions). The PCSK9i group showed a significant reduction in the normalized wall index (0.83 vs. 0.86, p = 0.028) and stenosis degree (65.5 vs. 74.2%, p = 0.01). Similarly, a greater percentage of individuals with a good response to the efficacy of treatment were treated in the PCSK9i group than that in the statin group (75 vs. 44.4%, p = 0.021). The incidence of major vascular events was overall similar between the groups. The treatment options (OR = 8.441, p = 0.01) and prior diabetes (OR = 0.061, p = 0.001) were significantly associated with the efficacy of treatment.

Discussion

Statin and PCSK9i combination treatment stabilized intracranial atherosclerotic plaques more often compared to statins alone, as documented by HR-MRI. Further study is warranted to determine if combination treatment improves clinical outcomes in ICAS.

Clinical testing of the cardiovascular effects of e-cigarette substitution for smoking: a living systematic review

Some persons who smoke have substituted e-cigarettes for tobacco cigarettes, either completely or partially. What effect does this have on cardiovascular functioning? We conducted a living systematic review on human clinical studies measuring the cardiovascular effects of e-cigarette substitution for smoking. The Scopus, PubMed, and CENTRAL Cochrane Library databases were searched on January 31 and April 29, 2021. Three secondary searches and a grey literature search were conducted. Included study designs were randomized controlled trials, quasi-experimental clinical trials, and cohort studies. Risk of bias and study quality were evaluated with the JBI Critical Appraisal tools and the Oxford Catalogue of Bias. The systematic review covered 25 studies comprising 1810 participants who smoked. Twenty studies were rated at high risk of bias, and five as some concerns. A tabular synthesis by direction of effect was conducted due to heterogeneity in the data. Nearly two-thirds of the test analyses indicated that e-cigarette use had no significance difference compared with tobacco cigarettes on heart rate, blood pressure, and in other cardiovascular tests. In two studies, participants with hypertension experienced a clinically relevant reduction in systolic blood pressure after 1 year of e-cigarette use. E-cigarette substitution incurs no additional cardiovascular risks, and some possible benefits may be obtained, but the evidence is of low to very low certainty. An update search on May 30, 2022 retrieved five studies that did not alter our conclusion.Registration PROSPERO #CRD42021239094.

Hybrid PET/MRI in Infection and Inflammation: An Update About the Latest Available Literature Evidence

PET/MRI has been reported to be promising in the diagnosis and evaluation of infection and inflammation including brain disorders, bone and soft tissue infections and inflammations, cardiovascular, abdominal, and systemic diseases. However, evidence came out manly from anecdotal cases or small cohorts. The present review aimed to update the latest available evidence about the role of PET/MRI in infection and inflammation. The search (January, 1 2018-July, 8 2022) on PubMed produced 504 results. Sixty-five articles were selected and included in the qualitative synthesis. The number of publications on PET/MRI in the 3 years 2018-2020 was comparable, while it increased in 2021 and 2022 (from 11 to 17 and 15, respectively). [¹⁸F]FDG and ⁶⁸Ga-DOTA-FAPI-04 were the most frequently used (42/65) and innovative radiopharmaceuticals, respectively. [¹⁸F]fluoride (9/65), translocator protein (TSPO)-targeted PET agents (6/65), CXCR4 receptor targeting tracer and β-amyloid plaques binding radiopharmaceuticals (2/65 and 2/65, respectively) were also used. Most PET/MRI studies in the period 2018-2022 focused on inflammation (55/65), and cardiovascular diseases represented the most frequent field of interest (30/65), also when considering each year singularly. An increasing trend in bone and joint publications was observed in the considered period (12/65). Other topics included neurology (11/65), inflammatory bowel disease (8/65), and other (4/65). PET/MRI technology demonstrated to be useful in infection and inflammation, being superior to each single modality and/or facilitating diagnosis in a number of conditions (eg, cardiac sarcoidosis, myocarditis, endocarditis), and/or allowing to provide insightful information about disease biology and apply innovative radiopharmaceuticals (eg, neurology, atherosclerosis). Publications focused on PET/MRI in large vessel vasculitis and aortic diseases include both diagnostic and discovery objectives. The current review corroborates the potential of PET/MRI - combining in a single examination the high soft tissue contrast, high resolution, and functional information of MRI, with molecular data provided by PET technology - to positively impact on the management of infectious diseases and inflammatory conditions.

Neural-hematopoietic-inflammatory axis in nonsmokers, electronic cigarette users, and tobacco smokers

Amygdala activity in context of the splenocardiac model has not been investigated in healthy, young adults and has not been compared between nonsmokers, electronic cigarette users, and smokers. The purpose of the current study was to determine whether fluorodeoxyglucose positron emission tomography/computer tomography (FDG PET/CT) scans would demonstrate positively correlated metabolic activity in the amygdala, bone marrow, spleen, and aorta, elucidating activation of the splenocardiac axis in otherwise healthy young people who use tobacco products compared to nonusers. Moreover, the study was conducted to evaluate whether electronic cigarette users and tobacco smokers have similar levels of inflammation compared to nonusers. In 45 healthy adults (mean age = 25 years), including nonsmoker (n = 15), electronic cigarette user (n = 16), and smoker (n = 14) groups, metabolic activity in the amygdala, spleen, aorta, bone marrow of thoracic vertebrae, and adjacent erector spinae skeletal muscle was quantified through visualization of radioactive glucose (18 FDG) uptake by FDG-PET/CT. The maximum standardized uptake value for each region was calculated for correlation analyses and comparisons between groups. In correlation analyses, metabolic activity of the amygdala correlated with metabolic activity in the aorta (r = 0.757), bone marrow (r = 0.750), and spleen (r = 0.665), respectively. Metabolic activity in the aorta correlated with 18 FDG uptake in the thoracic vertebrae (r = 0.703) and spleen (r = 0.594), respectively. Metabolic activity in the spleen also correlated with 18 FDG uptake in the bone marrow (r = 0.620). Metabolic activity in the adjacent erector spinae skeletal muscle (our control tissue) was not positively correlated with any other region of interest. Finally, there were no statistically significant mean differences in metabolic activity between the three groups: nonsmokers, electronic cigarette users, and smokers in any target tissue. Amygdala metabolic activity, as measured by 18 FDG uptake in FDG-PET/CT scans, positively correlated with inflammation in the splenocardiac tissues, including: the aorta, bone marrow, and spleen, underscoring the existence of a neural-hematopoietic-inflammatory axis in healthy, young adults.

How Electronic Cigarette Affects the Vascular System

The popularity of the electronic cigarette has soared in the last decades. However, the health effect of smoking electronic cigarettes on the vascular system is unclear. This systematic review examines the electronic cigarettes’ effect on the vascular system from recent evidence. A systematic search was conducted in MEDLINE (PubMed) database from January 2016 to August 2021 for studies assessing the vascular effect of chronic use of electronic cigarettes on human and animal. The Cochrane Risk of Bias 2, NIH Quality Assessment for Cross-Sectional Study, and SYRCLE’s Risk of Bias were used to assess the risk of bias in interventional, observational, and animal study, respectively. A narrative synthesis of evidence is provided to describe results. From 101 retrieved studies related to electronic cigarettes effect on the vascular system, a total of 16 studies are included in this review. The overall results indicated that electronic cigarette use is associated with adverse events in the vascular, including the incident of elevated oxidative stress, endothelial dysfunction, inflammation, arterial stiffness, and the development of atherosclerotic lesion. Further studies should broaden perspectives and reveal more about the mechanism of how electronic cigarettes impact on vascular system.