Chlamydia pneumoniae infection is not involved in carotid artery stenosis

Atherosclerosis Associated With COVID-19: Acute, Tends to Severely Involve Peripheral Arteries, and May be Reversible

Arterial stiffness was reported with corona virus disease 2019 (COVID-19). We studied atherosclerosis in COVID-19 directly through duplex ultrasound measurements and their relation to co-morbidities, clinical and laboratory severity markers, and serum interleukin (IL) 6 and 17. Serum IL 6 and 17, average carotid intima-media thickness (cIMT), diameter and peak systolic velocities (PSV) of tibial, ulnar, radial arteries, and ankle brachial index (ABI) were measured in 44 COVID-19 patients and 44 healthy controls. Serum IL6, IL17, PSV, and cIMT were higher while diameter was lower (P ≤ .01) in cases. Clinical severity index correlated positively with age, co-morbidities, ferritin, IL6, IL17, cIMT, and PSV (P ≤ .04) and negatively with diameter and ABI (P = .04). Patients with severe lymphopenia had higher PSV, IL6, and IL17 and lower diameter (P < .00001). Ferritin positively correlated with PSV and negatively with diameter and ABI (P ≤ .01). Those who received an IL6 inhibitor (tocilizumab) showed lower PSV and higher diameter (P ≤ .01). In multiple regression analysis, IL17 and (age, co-morbidities) were related to (PSV, diameter) and cIMT (P ≤ .001, ≤0.02), respectively. COVID-19 may be associated with subclinical acute and may be reversible atherosclerosis severely involving peripheral arteries.

Carotid stiffness, intima-media thickness and aortic augmentation index among adults with SARS-CoV-2

New Findings

What is the central question of this study?

We sought to investigate whether carotid stiffness, carotid intima–media thickness and the aortic augmentation index are altered in young adults 3–4 weeks after contraction of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) compared with young healthy adults.

What is the main finding and its importance?

We found that carotid stiffness, Young's modulus and the aortic augmentation index were greater in young adults who tested positive for SARS‐CoV‐2 compared with healthy young adults. These findings provide additional evidence for detrimental effects of SARS‐CoV‐2 on young adult vasculature, which might have implications for cardiovascular health.

Abstract

Contracting severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has been observed to cause decrements in vascular function of young adults. However, less is known about the impact of SARS‐CoV‐2 on arterial stiffness and structure, which might have additional implications for cardiovascular health. The purpose of this study was to assess the carotid artery stiffness and structure using ultrasound and the aortic augmentation index (AIx) using applanation tonometry in young adults after they tested positive for SARS‐CoV‐2. We hypothesized that carotid artery stiffness, carotid intima–media thickness (cIMT) and aortic AIx would be elevated in young adults with SARS‐CoV‐2 compared with healthy young adults. We evaluated 15 young adults (six male and nine female; 20 ± 1 years of age; body mass index, 24 ± 3 kg m⁻²) 3–4 weeks after a positive SARS‐CoV‐2 test result compared with young healthy adults (five male and 10 female; 23 ± 1 years of age; body mass index, 22 ± 2 kg m⁻²) who were evaluated before the coronavirus 2019 pandemic. Carotid stiffness, Young's modulus and cIMT were assessed using ultrasound, whereas aortic AIx and aortic AIx standardized to 75 beats min⁻¹ (AIx@HR75) were assessed from carotid pulse wave analysis using SphygmoCor. Group differences were observed for carotid stiffness (control, 5 ± 1 m s⁻¹; SARS‐CoV‐2, 6 ± 1 m s⁻¹), Young's modulus (control, 396 ± 120 kPa; SARS‐CoV‐2, 576 ± 224 kPa), aortic AIx (control, 3 ± 13%; SARS‐CoV‐2, 13 ± 9%) and aortic AIx@HR75 (control, −3 ± 16%; SARS‐CoV‐2, 10 ± 7%; P < 0.05). However, cIMT was similar between groups (control, 0.42 ± 0.06 mm; SARS‐CoV‐2, 0.44 ± 0.08 mm; P > 0.05). This cross‐sectional analysis revealed higher carotid artery stiffness and aortic stiffness among young adults with SARS‐CoV‐2. These results provide further evidence of cardiovascular impairments among young adults recovering from SARS‐CoV‐2 infection, which should be considered for cardiovascular complications associated with SARS‐CoV‐2.

A high ankle-brachial index is associated with increased cardiovascular disease morbidity and lower quality of life

OBJECTIVES

The purpose of this study is to determine if an ankle-brachial index (ABI) >or=1.40 is associated with reduced quality of life (QoL).

BACKGROUND

Ankle-brachial index values >or=1.40 have been associated with some cardiovascular disease (CVD) risk factors and increased mortality, but the relationship to other disease morbidity such as reduced QoL has not been previously evaluated.

METHODS

The PARTNERS (PAD Awareness, Risk and Treatment: New Resources for Survival) program was a national cross-sectional study of 7,155 patients age >50 years recruited from 350 primary care sites. All sites performed the ABI using a Doppler device and a standardized technique.

RESULTS

A total of 296 subjects had an ABI >or=1.40 in at least 1 leg, and 4,420 had an ABI between 0.90 and 1.40. Diabetes, male gender, and waist circumference were positively associated with a high ABI, and smoking and dyslipidemia were inversely associated with a high ABI. After adjustment for age, gender, and the traditional CVD risk factors, and accounting for multiple comparisons, the high ABI group had significantly higher odds for foot ulcers (p < 0.005) and borderline associations with heart failure, stroke, and neuropathy. After the same adjustments and adjusting for patients with other CVD, the high ABI group scored 2.0 points lower on the physical component scale on the Medical Outcomes Study Standard Form-36 and 5.5 points lower on the Walking Impairment Questionnaire walking distance domain (p < 0.05 for both).

CONCLUSION

Individuals with a high ABI have higher odds for foot ulcers and neuropathy, as well as lower scores on some physical functioning QoL domains.

Lack of association between infectious burden and carotid atherosclerosis in Japanese patients

Several infectious agents, such as Chlamydia pneumoniae, cytomegalovirus (CMV), herpes simplex virus (HSV), and Helicobacter pylori, have been implicated in the pathogenesis of atherosclerosis; however, but the contribution of infection may vary among races and geographic conditions. The present study investigates the association between the presence of these pathogens and carotid atherosclerosis and examines the relevance of an infectious burden during atherogenesis in Japanese patients undergoing carotid endarterectomy. We investigated a total of 50 carotid atherosclerotic plaques resected during carotid endarterectomy by polymerase chain reaction (PCR) for C. pneumoniae, CMV, HSV, and H. pylori and by immunocytochemistry (ICC) for C. pneumoniae. We also examined the presence of antibodies to IgG and/or IgA for each pathogen in blood samples. We detected HSV DNA in 2 specimens (4%) and positive ICC for C. pneumoniae in 8 (16%). The results of PCR, ICC, or serum antibodies, as well as the number of seropositive antibodies, did not correlate with severely stenotic, ulcerative, or symptomatic plaques. Our findings indicate that the detection rate of infectious agents within atherosclerotic plaques was significantly lower in our patients than that in other studies. Thus, an inflammatory mechanism might not correlate with the pathogenesis of carotid atherosclerosis among Japanese patients with severe carotid artery stenosis.

The association of carotid plaque inflammation and Chlamydia pneumoniae infection with cerebrovascular symptomatology

OBJECTIVE

Inflammation and infection have been implicated in the pathogenesis of carotid artery atherosclerosis, but their role in cerebrovascular disease symptomatology is not so well defined. We hypothesized that carotid disease symptomatology was associated with specific serologic markers of inflammation and Chlamydia pneumoniae infection and the presence of the pathogen and concentration of tumor necrosis factor-alpha (TNF-alpha) on the atheroma.

METHODS

In 2004, 78 patients underwent carotid endarterectomy in our department, 46 of whom were symptomatic (group A) and 32 were asymptomatic (group B). A detailed medical history, the presence of atherosclerosis risk factors, ankle-brachial index and boxy mass index were recorded. We measured preoperatively the levels of C-reactive protein, fibrinogen, TNF-alpha, and the titers of immunoglobulin (Ig) A and IgG antibodies against C pneumoniae in the serum. Finally, the atherosclerotic plaques of all patients were immunohistochemically examined for the presence of C pneumoniae and their TNF-alpha concentration was determined.

RESULTS

Isolation of the pathogen on the atheromatous lesion was statistically correlated with several risk factors and some of the variables that were tested. After testing independence of association, using the multiple regression analysis, only male gender (P = .024), hypertension (P = .008), hypercholesterolemia (P = .001), and TNF-alpha plaque values (P = .008) remained significantly associated. Hypertension, serum levels of fibrinogen and anti-C pneumoniae immunoglobulin A, detection of C. pneumoniae on the plaque, and plaque TNF-alpha values were significantly correlated with carotid disease symptomatology. After multiple analyses, only the presence of the pathogen on the lesion (P = .008) and atheroma TNF-alpha levels (P = .025) remained significantly associated with cerebrovascular events.

CONCLUSIONS

It seems that hypertensive hypercholesterolemic men are more likely to have C. pneumoniae infected carotid plaques and that these plaques have higher TNF-alpha concentrations. Cerebrovascular disease symptomatology is strongly correlated with both C. pneumoniae infection and TNF-alpha concentration of the atheroma.

Chlamydia pneumoniae infection related atherosclerotic clinical variables on carotid stenosis

OBJECTIVE

Research results showed that Chlamydia pneumoniae infection is related to atherosclerosis. C. pneumoniae infection may exacerbate atherogenesis. We investigated the presence of this microorganism for patients who underwent carotid endarterectomy and evaluated clinical values of C. pneumoniae infection on carotid stenosis.

METHODS

Twenty patients with carotid stenosis were enrolled in this prospective study between 1997 and 1999. The patients were observed on whether they were positive or negative in four C. pneumoniae measures, namely; IgA titers, IgG titers, presence of electron microscopy, and immunocytochemistry in the endarterectomy specimens. Possible clinical findings for atherosclerosis were also observed of Chlamydial measures such as the percentage of carotid stenosis, cholesterol and triglyceride levels, smoking status, symptomatic or non-transient ischaemic attack or stroke, previous ischaemic event, calcification at surgery, ulceration on angiographies, ulceration at surgery and hypertension were included in this evaluation.

RESULTS

Specific C. pneumoniae IgG were detected as positive in 9 (45%) of 20 patient samples. These patients were regarded as having chronic Chlamydia pneumoniae infection. None of the patients were positive for IgA antibody. This result demonstrated no evidence of reinfection. Immunocytochemistry and electron microscopy were positive in 7 (35%) of the 20 patients and correlated with positive serological results. The proportion of previous ischaemic events, calcification at surgery, ulceration on angiography, and ulceration at surgery were found significantly higher ( p < 0.05 ) for patients who are positive for chlamydial measures than those who are negative.

CONCLUSION

The results of this study demonstrated an association between C. pneumoniae to atherosclerosis. The proportion of patients who are positive for Chlamydia measures (IgG titers, electron microscopy, and immunocytochemistry) is significantly higher for those who were positive for each of these clinical variables (PIE, CALCI, U1, and U2) than who were negative. We emphasise, the higher incidence in clinical variables of PIE, CALCI, U1, and U2 in Chlamydia measures positive group may support the association of C. pneumoniae with atherosclerotic events.

Increased prevalence of Chlamydophila pneumoniae but not Epstein-Barr antibodies in essential hypertensives

Conflicting data exist regarding the relationship between Chlamydophila pneunoniae (C. pneumoniae) and hypertension. In this study, both C. pneumoniae IgG and IgA titres and Epstein-Barr virus antibody levels were measured in 146 sustained hypertensives defined by 24 h ambulatory blood pressure monitoring (ABPM) and 54 normotensives. C. pneumoniae antibodies were measured by microimmunofluorescence test. IgG > or = 80 and IgA > or = 40 were defined as elevated antibody titres. Epstein-Barr antibodies were measured in order to investigate whether a possible association exists between hypertension and other, similarly widespread in the general population, intracellular microorganisms. All participants underwent casual blood pressure (BP) readings and 24 h ABPM. Subjects having mean 24 h systolic/diastolic ambulatory BP>125/80 mmHg, with or without antihypertensive medication were defined as hypertensives. Controls were free of any history or clinical evidence of hypertension, cardiovascular or pulmonary disease. Of the total participants, 77 hypertensives (52.7%) and 10 normotensives (18.5%) had IgA titres > or = 40 (crosstabs P < 0.000), whereas 76 hypertensives (52.1%) and 15 normotensives (27.8%) had IgG titres > or = 80, (crosstabs P < 0.002). No difference was found in Epstein-Barr antibodies, between hypertensives and normotensives. In conclusion, C. pneumoniae, but not Epstein-Barr, antibody levels were found significantly higher in sustained hypertensives, suggesting high frequency of chronic C. pneumoniae, infections in this specific group of patients.