Hyperhomocysteinemia and recurrent carotid stenosis

The combined impact of persistent infections and human genetic variation on C-reactive protein levels

Multiple human pathogens establish chronic, sometimes life-long infections. Even if they are often latent, these infections can trigger some degree of local or systemic immune response, resulting in chronic low-grade inflammation. There remains an incomplete understanding of the potential contribution of both persistent infections and human genetic variation on chronic low-grade inflammation. We searched for potential associations between seropositivity for 13 persistent pathogens and the plasma levels of the inflammatory biomarker C-reactive protein (CRP), using data collected in the context of the UK Biobank and the CoLaus|PsyCoLaus Study, two large population-based cohorts. We performed backward stepwise regression starting with the following potential predictors: serostatus for each pathogen, polygenic risk score for CRP, and demographic and clinical factors known to be associated with CRP. We found evidence for an association between Chlamydia trachomatis (P-value = 5.04e - 3) and Helicobacter pylori (P-value = 8.63e - 4) seropositivity and higher plasma levels of CRP. We also found an association between pathogen burden and CRP levels (P-value = 4.12e - 4). These results improve our understanding of the relationship between persistent infections and chronic inflammation, an important determinant of long-term morbidity in humans.

UMOD and the architecture of kidney disease

The identification of genetic factors associated with the risk, onset, and progression of kidney disease has the potential to provide mechanistic insights and therapeutic perspectives. In less than two decades, technological advances yielded a trove of information on the genetic architecture of chronic kidney disease. The spectrum of genetic influence ranges from (ultra)rare variants with large effect size, involved in Mendelian diseases, to common variants, often non-coding and with small effect size, which contribute to polygenic diseases. Here, we review the paradigm of UMOD, the gene coding for uromodulin, to illustrate how a kidney-specific protein of major physiological importance is involved in a spectrum of kidney disorders. This new field of investigation illustrates the importance of genetic variation in the pathogenesis and prognosis of disease, with therapeutic implications.

Trends and complications associated with acute new-onset heart failure: a National Readmissions Database-based cohort study

Literature regarding recent trends and outcomes of acute new-onset heart failure (AHF) with preserved ejection fraction (AHFpEF) and reduced ejection fraction (AHFrEF) is limited. The objective of this study is to study the outcomes of AHFpEF and AHFrEF in the USA. Data from the National Readmissions Database (NRD) sample that constitutes 49.1% of the stratified sample of all hospitals in the USA, representing more than 95% of the national population, were analyzed for hospitalization visits for acute heart failure. ICD-9 and ICD-10 codes were used to identify AHF. A total of 2,559,102 adult index AHF patients (mean age 70.79 ± 14.58 years, 49.4% females), 1,028,970 (40.2%) AHFpEF and 1,330,999 (52%) AHFrEF, were recorded in the National Readmissions Database for the years 2016-2018. A total of 152,465 (5.96%) acute heart failure, 47,271 (4.6%) AHFpEF and 91,973 (6.91%) AHFrEF, died during hospitalization, and 45,810 (1.9%) were readmitted in 30 days among alive discharges. Higher complication rates which included ventricular arrhythmias, acute coronary, and cerebrovascular events were observed among AHFrEF than AHFpEF. Higher proportion of patients with AHFrEF needed intensive care unit and ventilatory support during the hospitalization. The trend of incidence of AHFrEF, mortality among AHFrEF, and overall mortality worsened while AHFpEF improved over the study years 2012-2018 (p-trend < 0.05). Coronary procedures improved mortality rates among AHFpEF and AHFrEF. AHF is very common and is associated with significant mortality. The incidence of AHFrEF and mortality among AHFrEF had worsened, which calls for urgent intervention. Improved recognition of AHF is needed, and guideline-directed treatment of underlying risk factors including coronary artery disease can improve mortality. Graphic abstract of the analysis presented (created with BioRender.com).

Association of napping with incident cardiovascular events in a prospective cohort study

Objective

There is controversy regarding the effect of napping on cardiovascular disease (CVD), with most studies failing to consider napping frequency. We aimed to assess the relationship of napping frequency and average nap duration with fatal and non-fatal CVD events.

Methods

3462 subjects of a Swiss population based cohort with no previous history of CVD reported their nap frequency and daily nap duration over a week, and were followed over 5.3 years. Fatal and non-fatal CVD events were adjudicated. Cox regressions were performed to obtain HRs adjusted for major cardiovascular risk factors and excessive daytime sleepiness or obstructive sleep apnoea.

Results

155 fatal and non-fatal events occurred. We observed a significantly lower risk for subjects napping 1–2 times weekly for developing a CVD event (HR 0.52, 95% CI 0.28 to 0.95) compared with non-napping subjects, in unadjusted as well as adjusted models. The increased HR (1.67, 95% CI 1.10 to 2.55) for subjects napping 6–7 times weekly disappeared in adjusted models (HR 0.89, 95% CI 0.58 to 1.38). Neither obstructive sleep apnoea nor excessive daytime sleepiness modified this lower risk. No association was found between nap duration and CVD events.

Conclusion

Subjects who nap once or twice per week have a lower risk of incident CVD events, while no association was found for more frequent napping or napping duration. Nap frequency may help explain the discrepant findings regarding the association between napping and CVD events.

Early Carotid Occlusion After Endarterectomy in a Patient With a Mutation for MTHFR A1298C Polymorphism

INTRODUCTION

Significant carotid stenosis is a well-documented risk factor for ischemic stroke. Carotid endarterectomy (CEA) and carotid artery stenting are effective procedures for the prevention of stroke in patients with this disease. However, the occurrence of restenosis could contribute to an increase in the risk of ischemic stroke.

CASE REPORT

A 79-year-old woman was admitted to the Neurosurgical Department to undergo a CEA because of a progressive stenosis. At the 3-month radiologic follow-up, the examinations showed a carotid restenosis. She was immediately started on a double-antiplatelet therapy. Blood samples revealed high levels of homocysteine and genetic tests showed a homozygous mutation for methylene tetrahydrofolate reductase A1298C polymorphism. Folic acid associated with pyridoxine was added to the treatment. Radiologic follow-ups showed no changes in the stenosis degree.

CONCLUSIONS

Even if the association between homocysteine and carotid restenosis after CEA is unclear, an initial screening before the surgical procedure could be useful to promptly treat this condition and probably reduce the risk of this complication. In the case of homozygous mutation, the selection of patients and the appropriate therapy could reduce the risk of carotid restenosis.

Diagnostic value of the combined measurement of serum hcy, serum cys C, and urinary microalbumin in type 2 diabetes mellitus with early complicating diabetic nephropathy

Diabetic nephropathy (DN) is a major cause of end-stage kidney disease, and therefore early diagnosis and intervention may help reverse renal damage. One hundred and sixty-eight patients with T2DM and 56 healthy volunteers (control group) were enrolled at Shandong University Qilu Hospital between April 2010 and October 2012. All subjects underwent blood sampling for sera homocysteine (Hcy) and cystatin C (Cys C) assays and a urine microalbumin test. The patients were divided into three groups according to the urine microalbumin excretion rate (UMAER): the simple DM group (SDM group, n = 51), the early-stage DN group (EDN group, n = 60), and the clinical DN and renal failure group (CDN group, n = 57). Correlation analysis was performed to examine the association between sera Hcy and Cys C levels with UMAER. Our findings showed that sera Hcy level, Cys C level, and UMAER increased significantly in the SDM group (P < 0.05, P < 0.01), the EDN group (P < 0.01), and the CDN group (P < 0.01) as compared with the control group. These three biochemical markers also increased significantly with DN progression (P < 0.01). Correlation analysis showed that sera Hcy and Cys C levels were positively correlated with UMAER (r = 0.702, P < 0.01; r = 0.873, P < 0.01). In conclusion, our results showed that sera Hcy and Cys C levels increased consistently with the development and progression of DN as indicated by UMAER. Sera Hcy and Cys C are sensitive biomarkers for the detection of early-stage DN and monitoring its progression.

Carotid restenosis is associated with plasma ADMA concentrations in carotid endarterectomy patients

BACKGROUND

The aim of this work has been to study the association between plasma asymmetric dimethylarginine (ADMA) concentrations and carotid stenosis in a group of 64 patients undergoing carotid endarterectomy (CEA).

METHODS

Arginine, ADMA and symmetric dimethylarginine (SDMA) were measured using capillary electrophoresis with UV detection. An evaluation of plasma concentrations of total cysteine (tCys) and total homocysteine (tHcy) was also performed.

RESULTS

Pearson's analysis show a positive correlation between ADMA and carotid stenosis (r=0.37, p=0.003), which is also confirmed after stepwise multiple linear regression analysis. ADMA plasma concentrations were significantly associated with tHcy (r=0.40, p=0.001) and to a lesser extent, even if not significantly, with tCys (r=0.23, p=0.07).

CONCLUSIONS

Our data suggest that plasma ADMA is involved in carotid narrowing after CEA intervention. This suggests that this molecule may have an important role in the events that lead to stenosis.

Design of a Cooling Guide Catheter for Rapid Heart Cooling

Cardiovascular disease is the leading cause of death in the United States. Despite decades of care path improvements approximately 30% of heart attack victims die within 1 year after their first heart attack. Animal testing has shown that mild hypothermia, reducing tissue temperatures by 2–4°C, has the potential to save heart tissue that is not adequately perfused with blood. This paper describes the design of a cooling guide catheter that can provide rapid, local cooling to heart tissue during emergency angioplasty. Using standard materials and dimensions found in typical angioplasty guide catheters, a closed-loop cooling guide catheter was developed. Thermal fluid modeling guided the interior geometric design. After careful fabrication and leak testing, a mock circulatory system was used to measure catheter cooling capacity. At blood analog flow rates ranging from 20 ml/min to 70 ml/min, the corresponding cooling capacity varied almost linearly from 20 W to 45 W. Animal testing showed 18 W of cooling delivered by the catheter can reduce heart tissue temperatures rapidly, approximately 3° in 5 min in some locations. Future animal testing work is needed to investigate if this cooling effect can save heart tissue.

Ginsenoside Rb1 attenuates homocysteine-augmented guidewire injury-induced intimal hyperplasia in mice

BACKGROUND

Intimal hyperplasia (IH) is the primary cause for post-angioplasty restenosis. The purpose of this study is to investigate the effects of homocysteine (Hcy) and ginsenoside Rb1 (Rb1) on IH using a guidewire injury animal model.

METHODS

In 12-wk-old C57BL/6J mice, the left common carotid artery (CCA) was denudated with a guidewire and the right CCA was used as the uninjured control. They were treated with saline (NS), Hcy, Rb1, or Hcy + Rb1 for 4 wk prior to sacrifice. Animals were sacrificed at 4, 6, or 8 wk. Both CCAs were harvested and intimal-medium thickness (IMT) ratios were calculated. Local macrophage distribution was also studied.

RESULTS

Histology analyses demonstrated consistent internal elastic lamina disruption and focal IH in the injured CCA segments. The degree of IH correlated to the lengths of time following injury. Hcy treated group had significant increase in IMT compared with the NS group (P < 0.05), while Rb1 group was similar to the NS group. In addition, Hcy + Rb1 group showed significant improvement in IMT compared with Hcy group (P < 0.01). Furthermore, Hcy significantly increased local macrophage content as compared with either lesion alone or Rb1 treated animals.

CONCLUSIONS

Our study showed that Hcy increased the degree of IH and macrophage content in the injured CCA and that Rb1 attenuated these adverse effects. These changes might be mediated through antioxidative effects of Rb1. Our data suggests a potential clinical application of ginseng in controlling Hcy-related vascular injuries.