Publications by authors named "Georgios Giannopoulos"

173 Publications

Angiographic severity in acute coronary syndrome patients with and without standard modifiable risk factors.

Front Cardiovasc Med 2022 22;9:934946. Epub 2022 Jul 22.

Department of Cardiology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.

Background: Routine coronary artery disease (CAD) secondary prevention strategies target standard modifiable cardiovascular risk factors (SMuRFs), which include: diabetes mellitus, dyslipidemia, hypertension, and smoking. However, a significant proportion of patients with acute coronary syndrome (ACS) present without any SMuRFs. The angiographic severity of disease in this population has not yet been investigated.

Methods: After propensity score matching of patients without SMuRFs and patients with ≥1 SMuRFs (ratio 1:3), we used zero-inflated negative binomial regression modeling to investigate the relationship of SMuRF-less status with the angiographic severity of CAD, as measured by the SYNTAX score. Survival analysis was performed to investigate differences in all-cause mortality at 30 days and at the end of follow-up period.

Results: We analyzed 534 patients presenting with ACS who underwent coronary angiography. Of them, 56 (10.5%) presented without any SMuRF. After propensity score matching, the median SYNTAX score was 13.8 (IQR 0-22.1) in 56 SMuRF-less patients and 14 (IQR 5-25) in 166 patients with ≥1 SMuRFs. SMuRF-less status was associated with increased odds of zero SYNTAX score [zero-part model: odds ratio = 2.11, 95% confidence interval (CI): 1.03-4.33], but not with decreased SYNTAX score among patients with non-zero SYNTAX score (count-part model: incidence rate ratio = 0.99, 95% CI: 0.79-1.24); the overall distribution of the SYNTAX score was similar between the two groups ( = 0.26). The 30-day risk for all-cause mortality was higher for SMuRF-less patients compared to patients with ≥1 SMuRFs [hazard ratio (HR) = 3.58, 95% CI: 1.30-9.88]; however, the all-cause mortality risk was not different between the two groups over a median 1.7-year follow-up (HR = 1.72, 95% CI: 0.83-3.57).

Conclusion: Among patients with ACS, the absence of SMuRFs is associated with increased odds for non-obstructive CAD and with increased short-term mortality rates.
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http://dx.doi.org/10.3389/fcvm.2022.934946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9353176PMC
July 2022

Coronary Embolism as a Cause for Acute Coronary Syndromes: When you Hear Hoofbeats, it may be wise to Sometimes Think of Zebras.

Trends Cardiovasc Med 2022 Jul 28. Epub 2022 Jul 28.

3rd Department of Cardiology, Aristotle University of Thessaloniki, Thessaloniki, Greece.

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http://dx.doi.org/10.1016/j.tcm.2022.07.006DOI Listing
July 2022

Syncope without prodromes is associated with excessive plasma release of adenosine at the time of syncope during head-up tilt table test.

Int J Cardiol 2022 Sep 16;363:43-48. Epub 2022 Jun 16.

3rd Cardiology Department, Hippokration General Hospital, Aristotle University Medical School, Konstantinoupoleos 49, 54642 Thessaloniki, Greece. Electronic address:

Background: In syncopal patients without underlying structural disease, we sought to investigate the association of Adenosine Plasma Levels (ADP) with the clinical presentation of neurally mediated syncope (NMS) and the outcomes of Head-Up Tilt Table Test (HUTT) and Adenosine test (ADT).

Methods: We studied 124 patients with different clinical types of NMS, i.e., Vasovagal (VVS, n=58), non-prodromes (NPS, n=18), or situational syncope (SS, n=48), using a standard protocol including HUTT and ADT. During HUTT, ADP was measured in the supine position, at table tilting and in syncope.

Results: Baseline ADP did not differ among groups. ADP at syncope were higher in NPS (n=5) compared to VVS (n=20): 0.23 vs. 0.12 μΜ, p=0.03, and SS (n=22): 0.04 μΜ, p=0.02. In NPS, ADP increased from supine to syncope (n=5): 0.15 vs. 0.23 μΜ, p=0.04. In VVS, ADP increased only from supine to tilt position: 0.11 vs. 0.14 μΜ, p=0.02. In SS, ADP did not change during HUTT. In positive vasodepressor HUTT, ADP increased from supine to tilt position (p=0.002) and at syncope (p=0.01). In SS, 20.0% exhibited cardioinhibitory HUTT vs. 6.8% in other forms of syncope (p=0.04). In SS, 22.9% manifested positive ADT vs 6.6% in other types of syncope (p=0.012).

Conclusion: The subset of NPS patients with positive HUTT, show excessive ADP release at the time of syncope. This may explain the lack of prodromes in this form of syncope. Such observations contribute to the understanding of distinct profiles of clinical forms of syncope and may differentiate the management approach accordingly.
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http://dx.doi.org/10.1016/j.ijcard.2022.06.045DOI Listing
September 2022

Left Distal Radial Artery Access for Coronary Angiography and Interventions: A 12-Month All-Comers Study.

J Invasive Cardiol 2022 Jul 17;34(7):E505-E509. Epub 2022 Jun 17.

General Hospital Papageorgiou, Ring Road of Thessaloniki, Nea Efkarpia, Thessaloniki, 56403, Greece.

Background: Interventional cardiologists prefer the right radial artery (RA) approach for coronary angiography and interventions, mainly for ergonomic reasons. However, the use of the left RA presents certain advantages, and the snuffbox approach has further potential advantages, including lower probability for RA occlusion, avoidance of direct puncture of the RA (thus maintaining its suitability for use as a graft), as well as easier and faster hemostasis.

Methods: Consecutive patients scheduled for coronary catheterization were included, using the left distal RA (ldRA) in the anatomical snuffbox as the default vascular access site.

Results: Out of 2034 consecutive cases, the ldRA was used as initial vascular access in 1977 patients (97.2%). The procedural failure rate was 9.9% (21.9% inability to puncture the artery, 75.0% inability to advance the wire, 3.1% other reasons). There was a sharp decrease in failure rate after about the first 200 cases (20.8% in the first decile vs 8.7% throughout the rest of the caseload; P<.001). No or very weak palpable pulse was the most important predictor of failure (odds ratio, 16.0; 95% confidence interval, 11.2-23.1; P<.001), in addition to older age, small stature, and female gender (although, after adjustment for height, the latter was no longer significant).

Conclusion: In a large series of consecutive patients scheduled for left heart catheterization, through a period of 12 months, with virtually no exclusions except those few imposed by anatomy or compelling clinical needs, the ldRA arterial access approach was shown to be highly effective, feasible, and safe.
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July 2022

Different venous approaches for implantation of cardiac electronic devices. A network meta-analysis.

Pacing Clin Electrophysiol 2022 06 18;45(6):717-725. Epub 2022 May 18.

Cardiology Department, Athens General Hospital "G. Gennimatas", Athens, Greece.

Objectives: Many of the complications arising from cardiac device implantation are associated to the venous access used for lead placement. Previous analyses reported that cephalic vein cutdown (CVC) is safer but less effective than subclavian vein puncture (SVP). However, comparisons between these techniques and axillary vein puncture (AVP) - guided either by ultrasound or fluoroscopy - are lacking. Thus, we aimed to compare safety and efficacy of these approaches.

Methods: We searched for articles assessing at least two different approaches regarding the incidence of pneumothorax and/or lead failure (LF). When available, bleeding and infectious complications as well as procedural success were analyzed. A frequentist random effects network meta-analysis model was adopted.

Results: Thirty-six studies were analyzed. Most articles assessed SVP versus CVC. Compared to SVP, both CVC and AVP were associated with reduced odds of pneumothorax (OR: 0.193, 95%CI: 0.136-0.275 and OR: 0.128, 95%CI: 0.050-0.329; respectively) and LF (OR: 0.63, 95%CI: 0.406-0.976 and OR: 0.425, 95%CI: 0.286-0.632; respectively). No significant differences between AVP and CVC were demonstrated. Limited data suggests no major impact of different approaches on infectious and bleeding complications. Initial CVC approach required significantly more often an alternate/additional venous access for lead placement, compared to both AVP and SVP. No differences between these two were identified.

Conclusion: Both AVP and CVC seem to decrease incident pneumothorax and LF, compared to SVP. Initial AVP approach seems to decrease the need of alternate venous access, compared to CVC. These results suggest that AVP should be further clinically tested.
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http://dx.doi.org/10.1111/pace.14510DOI Listing
June 2022

P-Wave Beat-to-Beat Analysis to Predict Atrial Fibrillation Recurrence after Catheter Ablation.

Diagnostics (Basel) 2022 Mar 28;12(4). Epub 2022 Mar 28.

3rd Cardiology Department, Hippokrateion University Hospital, Aristotle University of Thessaloniki, 546 42 Thessaloniki, Greece.

The identification of patients prone to atrial fibrillation (AF) relapse after catheter ablation is essential for better patient selection and risk stratification. The current prospective cohort study aims to validate a novel P-wave index based on beat-to-beat (B2B) P-wave morphological and wavelet analysis designed to detect patients with low burden AF as a predictor of AF recurrence within a year after successful catheter ablation. From a total of 138 consecutive patients scheduled for AF ablation, 12-lead ECG and 10 min vectorcardiogram (VCG) recordings were obtained. Univariate analysis revealed that patients with higher B2B P-wave index had a two-fold risk for AF recurrence (HR: 2.35, 95% CI: 1.24-4.44, : 0.010), along with prolonged P-wave, interatrial block, early AF recurrence, female gender, heart failure history, previous stroke, and CHADS-VASc score. Multivariate analysis of assessable predictors before ablation revealed that B2B P-wave index, along with heart failure history and a history of previous stroke or transient ischemic attack, are independent predicting factors of atrial fibrillation recurrence. Further studies are needed to assess the predictive value of the B2B index with greater accuracy and evaluate a possible relationship with atrial substrate analysis.
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http://dx.doi.org/10.3390/diagnostics12040830DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9028701PMC
March 2022

Nonlinear Finite Element Analysis of γ-Graphyne Structures under Shearing.

Molecules 2022 Mar 7;27(5). Epub 2022 Mar 7.

Department of Aerospace Science and Technology, National and Kapodistrian University of Athens, 34400 Psachna, Greece.

In this study, a nonlinear, spring-based finite element approach is employed in order to predict the nonlinear mechanical response of graphyne structures under shear loading. Based on Morse potential functions, suitable nonlinear spring finite elements are formulated simulating the interatomic interactions of different graphyne types. Specifically, the four well-known types of γ-graphyne, i.e., graphyne-1 also known as graphyne, graphyne-2 also known as graphdiyne, graphyne-3, and graphyne-4 rectangular sheets are numerically investigated applying appropriate boundary conditions representing shear load. The obtained finite element analysis results are employed to calculate the in-plane shear stress-strain behaviour, as well as the corresponding mechanical properties as shear modulus and shear strength. Comparisons of the present graphyne shearing response predictions with other corresponding estimations are performed to validate the present research results.
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http://dx.doi.org/10.3390/molecules27051729DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8911817PMC
March 2022

Alcohol Consumption and the Risk of Incident Atrial Fibrillation: A Meta-Analysis.

Diagnostics (Basel) 2022 Feb 13;12(2). Epub 2022 Feb 13.

3rd Department of Cardiology, Medical School, Aristotle University of Thessaloniki, Hippocration General Hospital, 546 42 Thessaloniki, Greece.

Alcohol consumption is a known, modifiable risk factor for incident atrial fibrillation (AF). However, it remains unclear whether the protective effect of moderate alcohol consumption-that has been reported for various cardiovascular diseases also applies to the risk for new-onset AF. The purpose of this meta-analysis was to evaluate the role of different drinking patterns (low: <14 grams/week; moderate: <168 grams/week; and heavy: >168 grams/week) on the risk for incident AF. Major electronic databases were searched for observational cohorts examining the role of different drinking behaviors on the risk for incident AF. We analyzed 16 studies (13,044,007 patients). Incident AF rate was 2.3%. Moderate alcohol consumption significantly reduced the risk for new-onset AF when compared to both abstainers (logOR: -0.20; 95%CI: -0.28--0.12; I2: 96.71%) and heavy drinkers (logOR: -0.28; 95%CI: -0.37--0.18; I2: 95.18%). Heavy-drinking pattern compared to low also increased the risk for incident AF (logOR: 0.14; 95%CI: 0.01-0.2; I2: 98.13%). Substantial heterogeneity was noted, with more homogeneous results documented in cohorts with follow-up shorter than five years. Our findings suggest a J-shaped relationship between alcohol consumption and incident AF. Up to 14 drinks per week seem to decrease the risk for developing AF. Because of the substantial heterogeneity observed, no robust conclusion can be drawn. In any case, our results suggest that the association between alcohol consumption and incident AF is far from being a straightforward dose-response effect.
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http://dx.doi.org/10.3390/diagnostics12020479DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8871230PMC
February 2022

The ERNCIP survey on COVID-19: Emergency & Business Continuity for fostering resilience in critical infrastructures.

Saf Sci 2021 Jul 1;139:105161. Epub 2021 Feb 1.

European Commission, Joint Research Centre (JRC), Ispra, Italy.

Among the many repercussions of the COVID-19 emergency to be assessed, those on critical infrastructures and the associated businesses and professions are certainly important ones. In this paper, we document the conception, implementation and outcome of a survey organized by European Commission's Joint Research Centre and entitled & . This was conducted in April-May 2020 with the participation of critical infrastructure experts (including professionals from the academia and research institutions, infrastructure operators and industry representatives, public authorities and members of security agencies), involved as stakeholders in the European Reference Network for Critical Infrastructure Protection (ERNCIP). Themes explored through this study include an assessment of the business continuity status and the evaluation of emergency management and disaster recovery aspects, as experienced from the perspective of different sectors, organization types and personal perceptions of the respondents.
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http://dx.doi.org/10.1016/j.ssci.2021.105161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8545769PMC
July 2021

Design of Laminated Composite Plates with Carbon Nanotube Inclusions against Buckling: Waviness and Agglomeration Effects.

Nanomaterials (Basel) 2021 Aug 31;11(9). Epub 2021 Aug 31.

General Department, National and Kapodistrian University of Athens, 34400 Psachna, Greece.

In the present study, a buckling analysis of laminated composite rectangular plates reinforced with multiwalled carbon nanotube (MWCNT) inclusions is carried out using the finite element method (FEM). The rule of mixtures and the Halpin-Tsai model are employed to calculate the elastic modulus of the nanocomposite matrix. The effects of three critical factors, including random dispersion, waviness, and agglomeration of MWCNTs in the polymer matrix, on the material properties of the nanocomposite are analyzed. Then, the critical buckling loads of the composite plates are numerically determined for different design parameters, such as plate side-to-thickness ratio, elastic modulus ratio, boundary conditions, layup schemes, and fiber orientation angles. The influence of carbon nanotube fillers on the critical buckling load of a nanocomposite rectangular plate, considering the modified Halpin-Tsai micromechanical model, is demonstrated. The results are in good agreement with experimental and other theoretical data available in the open literature.
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http://dx.doi.org/10.3390/nano11092261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8470375PMC
August 2021

Molecular Insights in Atrial Fibrillation Pathogenesis and Therapeutics: A Narrative Review.

Diagnostics (Basel) 2021 Aug 31;11(9). Epub 2021 Aug 31.

Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.

The prevalence of atrial fibrillation (AF) is bound to increase globally in the following years, affecting the quality of life of millions of people, increasing mortality and morbidity, and beleaguering health care systems. Increasingly effective therapeutic options against AF are the constantly evolving electroanatomic substrate mapping systems of the left atrium (LA) and ablation catheter technologies. Yet, a prerequisite for better long-term success rates is the understanding of AF pathogenesis and maintenance. LA electrical and anatomical remodeling remains in the epicenter of current research for novel diagnostic and treatment modalities. On a molecular level, electrical remodeling lies on impaired calcium handling, enhanced inwardly rectifying potassium currents, and gap junction perturbations. In addition, a wide array of profibrotic stimuli activates fibroblast to an increased extracellular matrix turnover via various intermediaries. Concomitant dysregulation of the autonomic nervous system and the humoral function of increased epicardial adipose tissue (EAT) are established mediators in the pathophysiology of AF. Local atrial lymphomononuclear cells infiltrate and increased inflammasome activity accelerate and perpetuate arrhythmia substrate. Finally, impaired intracellular protein metabolism, excessive oxidative stress, and mitochondrial dysfunction deplete atrial cardiomyocyte ATP and promote arrhythmogenesis. These overlapping cellular and molecular alterations hinder us from distinguishing the cause from the effect in AF pathogenesis. Yet, a plethora of therapeutic modalities target these molecular perturbations and hold promise in combating the AF burden. Namely, atrial selective ion channel inhibitors, AF gene therapy, anti-fibrotic agents, AF drug repurposing, immunomodulators, and indirect cardiac neuromodulation are discussed here.
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http://dx.doi.org/10.3390/diagnostics11091584DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8470040PMC
August 2021

The role of left atrial peak systolic strain in atrial fibrillation recurrence after catheter ablation. A systematic review and meta-analysis.

Acta Cardiol 2021 Aug 20:1-9. Epub 2021 Aug 20.

Cardiology Department, Athens General Hospital "G. Gennimatas", Athens, Greece.

Background: This systematic review and meta-analysis was performed to assess the prognostic role of left atrial peak systolic longitudinal strain (LA-PLSsys) as a predictor of atrial fibrillation (AF) recurrence after catheter ablation.

Methods: We systematically searched major electronic databases and grey literature for studies assessing the role of pre-ablation LA-PLSsys, measured in at least two segments, in post-ablation AF recurrence, after a follow-up period of at least 6 months.

Results: Seventeen eligible studies were included, resulting in 1704 patients (68.6% men) with a pooled mean age of 59.9 ± 10.6 years, 65.9% with paroxysmal AF. Recurrence occurred in 32.7% of patients. Those without recurrence had significantly higher LA-PLSsys (pooled mean ± : 22.22 ± 10.64%, weighted mean difference: 5.43%, 95%CI: 4.03-6.84%, : 82.7%). Subgroup analysis revealed that the methodology used (echocardiographic view and segments assessed), was a significant source of heterogeneity ( = 0.02). Meta-regression analysis demonstrated that the effect size was inversely related to the baseline LA volume index ( = 0.004), while concerns are also raised about patients with extremely high/low pre-ablation LA strain.

Conclusions: Pre-ablation LA-PLSsys seems to be a useful predictor of post-ablation AF recurrence, that could optimise patients selection. Nevertheless, the substantial heterogeneity that was noted may limit its clinical use. Further investigation using a uniform methodological assessment technique is required to derive a reference range, with adequate positive and negative predictive value for recurrence.
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http://dx.doi.org/10.1080/00015385.2021.1965747DOI Listing
August 2021

Could Sodium/Glucose Co-Transporter-2 Inhibitors Have Antiarrhythmic Potential in Atrial Fibrillation? Literature Review and Future Considerations.

Drugs 2021 Aug 23;81(12):1381-1395. Epub 2021 Jul 23.

2nd Department of Cardiology, Attikon Hospital, National and Kapodistrian University of Athens, 1 Rimini Str., Chaidari, Attiki, Athens, Greece.

The global burden of atrial fibrillation (AF) is constantly increasing, necessitating novel and effective therapeutic options. Sodium glucose co-transporter 2 (SGLT2) inhibitors have been introduced in clinical practice as glucose-lowering medications. However, they have recently gained prominence for their potential to exert substantial cardiorenal protection and are being evaluated in large clinical trials including patients with type 2 diabetes and normoglycemic adults. In this review we present up-to-date available evidence in a pathophysiology-directed manner from cell to bedside. Preclinical and clinical data regarding a conceivable antiarrhythmic effect of SGLT2 inhibitors are beginning to accumulate. Herein we comprehensively present data that explore the potential pathophysiological link between SGLT2 inhibitors and AF. With regard to clinical data, no randomized controlled trials evaluating SGLT2 inhibitors effects on AF as a pre-specified endpoint are available. However, data from randomized controlled trial post-hoc analysis as well as observational studies point to a possible beneficial effect of SGLT2 inhibitors on AF. Meta-analyses addressing this question report inconsistent results and the real magnitude of AF prevention by SGLT2 inhibition remains unclear. Still, while (i) pathophysiologic mechanisms involved in AF might be favorably affected by SGLT2 inhibitors and (ii) emerging, yet inconsistent, clinical data imply that SGLT2 inhibitor-mediated cardiorenal protection could also exert antiarrhythmic effects, the argument of whether these novel drugs will reduce AF burden is unsettled and mandates appropriately designed and adequately sized randomized controlled studies.
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http://dx.doi.org/10.1007/s40265-021-01565-3DOI Listing
August 2021

The prognostic role of late gadolinium enhancement on cardiac magnetic resonance in patients with nonischemic cardiomyopathy and reduced ejection fraction, implanted with cardioverter defibrillators for primary prevention. A systematic review and meta-analysis.

J Interv Card Electrophysiol 2022 Apr 3;63(3):523-530. Epub 2021 Jul 3.

Cardiology Department, Athens General Hospital "G. Gennimatas,", 154 Mesogion Avenue, 11527, Athens, Greece.

Background: Previous studies suggest that late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is associated with arrhythmic events in patients with nonischemic cardiomyopathy (NICM), while others have questioned the role of left ventricular ejection fraction (LVEF) as a sole predictor of future events.

Objectives: To evaluate the role of LGE on CMR in identifying patients with NICM and reduced LVEF for whom a benefit from defibrillator implantation for primary prevention is not anticipated, thus they are mainly exposed to potential risks.

Methods: Major electronic databases were searched for studies reporting the incidence of appropriate device therapy (ADT), sudden cardiac death (SCD), and cardiac death based on the presence of LGE on CMR, among patients with NICM and reduced LVEF, implanted with a cardioverter defibrillator for primary prevention.

Results: Eleven studies (1652 patients, 947 with LGE) were included in the final analysis. LGE presence was strongly associated with ADT (logOR: 1.95, 95%CI: 1.21-2.69) and cardiac death (logOR: 0.91, 95%CI: 0.14-1.68), but not with SCD (logOR: 0.26, 95%CI: -1.09-1.6). Diagnostic accuracy analysis demonstrated that contrast enhancement is a sensitive marker of future ADT and cardiac death (93%, 95%CI: 85.8-96.7%; 82.9%, 95%CI: 70.6-90.7%; respectively), with moderate specificity ( 44%, 95%CI: 27.2-62.6%; 37.7%, 95%CI: 23.4-54.6%; respectively).

Conclusion: LGE is a highly sensitive predictor of ADT and cardiac death in NICM patients implanted with a defibrillator for primary prevention. However, due to moderate specificity, derivation of a cutoff with adequate predictive values and probably a multifactorial approach are needed to improve discrimination of patients who will not benefit from ICDs.
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http://dx.doi.org/10.1007/s10840-021-01027-6DOI Listing
April 2022

Thermomechanical Behavior of Bone-Shaped SWCNT/Polyethylene Nanocomposites via Molecular Dynamics.

Materials (Basel) 2021 Apr 24;14(9). Epub 2021 Apr 24.

Department of Aerospace Science and Technology, National and Kapodistrian University of Athens, GR-34400 Psachna Evias, Greece.

In the present study, the thermomechanical effects of adding a newly proposed nanoparticle within a polymer matrix such as polyethylene are being investigated. The nanoparticle is formed by a typical single-walled carbon nanotube (SWCNT) and two equivalent giant carbon fullerenes that are attached with the nanotube edges through covalent bonds. In this way, a bone-shaped nanofiber is developed that may offer enhanced thermomechanical characteristics when used as a polymer filler, due to each unique shape and chemical nature. The investigation is based on molecular dynamics simulations of the tensile stress-strain response of polymer nanocomposites under a variety of temperatures. The thermomechanical behavior of the bone-shaped nanofiber-reinforced polyethylene is compared with that of an equivalent nanocomposite filled with ordinary capped single-walled carbon nanotubes, in order to reach some coherent fundamental conclusions. The study focuses on the evaluation of some basic, temperature-dependent properties of the nanocomposite reinforced with these innovative bone-shaped allotropes of carbon.
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http://dx.doi.org/10.3390/ma14092192DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8123148PMC
April 2021

Linking healthcare and societal resilience during the Covid-19 pandemic.

Saf Sci 2021 Aug 19;140:105291. Epub 2021 Apr 19.

Institute for Risk and Disaster Reduction, University College London, London, United Kingdom.

Coronavirus disease 2019 (Covid-19) has highlighted the link between public healthcare and the broader context of operational response to complex crises. Data are needed to support the work of the emergency services and enhance governance. This study develops a Europe-wide analysis of perceptions, needs and priorities of the public affected by the Covid-19 emergency. An online multilingual survey was conducted from mid-May until mid-July 2020. The questionnaire investigates perceptions of public healthcare, emergency management and societal resilience. In total, N = 3029 valid answers were collected. They were analysed both as a whole and focusing on the most represented countries (Italy, Romania, Spain and the United Kingdom). Our findings highlight some perceived weaknesses in emergency management that are associated with the underlying vulnerability of the global interconnected society and public healthcare systems. The spreading of the epidemic in Italy represented a 'tipping point' for perceiving Covid-19 as an 'emergency' in the surveyed countries. The respondents uniformly suggested a preference for gradually restarting activities. We observed a tendency to ignore the cascading effects of Covid-19 and possible concurrence of threats. Our study highlights the need for practices designed to address the next phases of the Covid-19 crisis and prepare for future systemic shocks. Cascading effects that could compromise operational capacity need to be considered more carefully. We make the case for the reinforcement of cross-border coordination of public health initiatives, for standardization in business continuity management, and for dealing with the recovery at the European level.
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http://dx.doi.org/10.1016/j.ssci.2021.105291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8054640PMC
August 2021

Atrial fibrillation risk in patients suffering from type I diabetes mellitus. A review of clinical and experimental evidence.

Diabetes Res Clin Pract 2021 Apr 27;174:108724. Epub 2021 Feb 27.

General Hospital of Athens "G.Gennimatas", Athens, Greece.

Atrial fibrillation (AF) and diabetes mellitus (DM) are commonly encountered in clinical practice. Although, the long term macrovascular and microvascular sequela of DM are well validated, the association between the less prevalent type 1 DM (T1DM) and atrial arrhythmogenesis is poorly understood. In the present review we highlight the current experimental and clinical data addressing this complex interaction. Animal studies support that T1DM, characterized by insulin deficiency and glycemic variability, impairs phosphatidylinositol 3‑kinase (PI3K)/protein kinase B signaling pathway. This pathway holds a central role in atrial electrical and structural remodeling responsible for arrhythmia initiation and maintenance. The molecular ''footprint'' of T1DM in atrial myocytes seems to involve a state of increased oxidative stress, impaired glucose transportation, ionic channel dysregulation and eventually fibrosis. On the contrary only a few clinical studies have examined the role of T1DM as an independent risk factor for AF development, and are discussed here. Further research is needed to solidify the real magnitude of this association and to investigate the clinical implications of PI3K molecular signaling pathway in atrial fibrillation management.
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http://dx.doi.org/10.1016/j.diabres.2021.108724DOI Listing
April 2021

A stand-alone structured educational programme after myocardial infarction: a randomised study.

Heart 2021 Jan 22. Epub 2021 Jan 22.

2nd Department of Cardiology, National and Kapodistrian University of Athens, Faculty of Medicine, Athens, Greece.

Background: Acute myocardial infarction (MI) is a major clinical manifestation of coronary artery disease. Post-MI morbidity and mortality can be reduced by lifestyle changes and aggressive risk factor modification. These changes can be applied more effectively if the patient is actively involved in the process. The hypothesis of this study was that an educational programme in post-MI patients could lead to reduced incidence of cardiovascular events.

Methods: Post-MI patients were prospectively randomised into two groups. Patients in the intervention arm were scheduled to attend an 8-week-long educational programme on top of usual treatment, while controls received optimal treatment. The primary endpoint was the composite of all-cause death, MI, cerebrovascular event and unscheduled hospitalisation for cardiovascular causes. Endpoint adjudication was blinded.

Results: 329 patients (238 men) were included, with a mean follow-up time of 17±4 months. In the primary analysis, mean primary end point-free survival time was 597 days (95% CI 571 to 624) in controls, compared with 663 days (95% CI 638 to 687) in the intervention group (p<0.001). The HR in the univariate Cox regression analysis was 0.48 (95% CI 0.32 to 0.73; p=0.001). The raw rates of the primary endpoint were 20.8% (6 deaths, 13 MIs, 2 strokes and 14 hospitalisations) vs 36.6% (8 deaths, 22 MIs, 7 strokes and 22 hospitalisations), respectively (OR 0.46, 95% CI 0.28 to 0.74; p=0.002).

Conclusion: These results suggest that a relatively short adult education programme offered to post-MI patients has beneficial effects, resulting in reduced risk of cardiovascular events.

Trial Registration Number: NCT04007887.
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http://dx.doi.org/10.1136/heartjnl-2020-318414DOI Listing
January 2021

Colchicine administered early in acute myocardial infarction: ready, set … go?

Eur Heart J 2021 07;42(28):2802

2nd Department of Cardiology, "Attikon" University Hospital, National and Kapodistrian University of Athens, 1 Rimini Str., Chaidari, 124 62, Athens, Greece.

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http://dx.doi.org/10.1093/eurheartj/ehab010DOI Listing
July 2021

Trace Metal Availability Affects Greenhouse Gas Emissions and Microbial Functional Group Abundance in Freshwater Wetland Sediments.

Front Microbiol 2020 30;11:560861. Epub 2020 Sep 30.

Department of Biology, Virginia Commonwealth University, Richmond, VA, United States.

We investigated the effects of trace metal additions on microbial nitrogen (N) and carbon (C) cycling using freshwater wetland sediment microcosms amended with micromolar concentrations of copper (Cu), molybdenum (Mo), iron (Fe), and all combinations thereof. In addition to monitoring inorganic N transformations (NO , NO , NO, NH ) and carbon mineralization (CO, CH), we tracked changes in functional gene abundance associated with denitrification (, , ), dissimilatory nitrate reduction to ammonium (DNRA; ), and methanogenesis (). With regards to N cycling, greater availability of Cu led to more complete denitrification (i.e., less NO accumulation) and a higher abundance of the and genes, which encode for Cu-dependent reductases. In contrast, we found sparse biochemical evidence of DNRA activity and no consistent effect of the trace metal additions on gene abundance. With regards to C mineralization, CO production was unaffected, but the amendments stimulated net CH production and Mo additions led to increased gene abundance. These findings demonstrate that trace metal effects on sediment microbial physiology can impact community-level function. We observed direct and indirect effects on both N and C biogeochemistry that resulted in increased production of greenhouse gasses, which may have been mediated through the documented changes in microbial community composition and shifts in functional group abundance. Overall, this work supports a more nuanced consideration of metal effects on environmental microbial communities that recognizes the key role that metal limitation plays in microbial physiology.
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http://dx.doi.org/10.3389/fmicb.2020.560861DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7561414PMC
September 2020

SGLT-2i and Cardiovascular Prognosis.

Curr Pharm Des 2020 ;26(32):3905-3907

Unit of Heart and Diabetes, First Department of Cardiology, Hippokration Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.

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http://dx.doi.org/10.2174/138161282632200811172751DOI Listing
January 2021

Vibration Analysis of Carbon Fiber-Graphene-Reinforced Hybrid Polymer Composites Using Finite Element Techniques.

Materials (Basel) 2020 Sep 23;13(19). Epub 2020 Sep 23.

General Department, National and Kapodistrian University of Athens, 34400 Psachna, Greece.

In this study, a computational procedure for the investigation of the vibration behavior of laminated composite structures, including graphene inclusions in the matrix, is developed. Concerning the size-dependent behavior of graphene, its mechanical properties are derived using nanoscopic empiric equations. Using the appropriate Halpin-Tsai models, the equivalent elastic constants of the graphene reinforced matrix are obtained. Then, the orthotropic mechanical properties of a composite lamina of carbon fibers and hybrid matrix can be evaluated. Considering a specific stacking sequence and various geometric configurations, carbon fiber-graphene-reinforced hybrid composite plates are modeled using conventional finite element techniques. Applying simply support or clamped boundary conditions, the vibrational behavior of the composite structures are finally extracted. Specifically, the modes of vibration for every configuration are derived, as well as the effect of graphene inclusions in the natural frequencies, is calculated. The higher the volume fraction of graphene in the matrix, the higher the natural frequency for every mode. Comparisons with other methods, where it is possible, are performed for the validation of the proposed method.
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http://dx.doi.org/10.3390/ma13194225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7579207PMC
September 2020

Thermomechanical Response of Fullerene-Reinforced Polymers by Coupling MD and FEM.

Materials (Basel) 2020 Sep 17;13(18). Epub 2020 Sep 17.

Department of Mechanical Engineering and Aeronautics, School of Engineering, University of Patras, GR-26500 Patras, Greece.

The aim of the present study is to provide a computationally efficient and reliable hybrid numerical formulation capable of characterizing the thermomechanical behavior of nanocomposites, which is based on the combination of molecular dynamics (MD) and the finite element method (FEM). A polymeric material is selected as the matrix-specifically, the poly(methyl methacrylate) (PMMA) commonly known as Plexiglas due to its expanded applications. On the other hand, the fullerene C is adopted as a reinforcement because of its high symmetry and suitable size. The numerical approach is performed at two scales. First, an analysis is conducted at the nanoscale by utilizing an appropriate nanocomposite unit cell containing the C at a high mass fraction. A MD-only method is applied to accurately capture all the internal interfacial effects and accordingly its thermoelastic response. Then, a micromechanical, temperature-dependent finite element analysis takes place using a representative volume element (RVE), which incorporates the first-stage MD output, to study nanocomposites with small mass fractions, whose atomistic-only simulation would require a substantial computational effort. To demonstrate the effectiveness of the proposed scheme, numerous numerical results are presented while the investigation is performed in a temperature range that includes the PMMA glass transition temperature, .
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http://dx.doi.org/10.3390/ma13184132DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7560406PMC
September 2020

Myocardial Injury in COVID-19-Can We Successfully Target Inflammation?

JAMA Cardiol 2020 09;5(9):1069-1070

Attikon Hospital, 2nd Department of Cardiology, National and Kapodistian University of Athens Medical School, Athens, Greece.

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http://dx.doi.org/10.1001/jamacardio.2020.2569DOI Listing
September 2020

Implantable Cardiac Monitoring in the Secondary Prevention of Cryptogenic Stroke.

Ann Neurol 2020 11 4;88(5):946-955. Epub 2020 Sep 4.

Second Department of Neurology, "Attikon" University Hospital, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece.

Objective: In this study, we sought to evaluate the impact of implantable cardiac monitoring (ICM) in the prevention of stroke recurrence after a cryptogenic ischemic stroke or transient ischemic attack (TIA).

Methods: We evaluated consecutive patients with cryptogenic ischemic stroke or TIA admitted in a comprehensive stroke center during an 8-year period. We compared the baseline characteristics and outcomes between patients receiving conventional cardiac monitoring with repeated 24-hour Holter-monitoring during the first 5 years in the outpatient setting and those receiving continuous cardiac monitoring with ICM during the last 3 years. Associations on the outcomes of interest were further assessed in multivariable regression models adjusting for potential confounders.

Results: We identified a total of 373 patients receiving conventional cardiac monitoring and 123 patients receiving ICM. Paroxysmal atrial fibrillation (PAF) detection was higher in the ICM cohort compared to the conventional cardiac monitoring cohort (21.1% vs 7.5%, p < 0.001). ICM was independently associated with an increased likelihood of PAF detection during follow-up (hazard ratio [HR] = 1.94, 95% confidence interval [CI] = 1.16-3.24) in multivariable analyses. Patients receiving ICM were also found to have significantly higher rates of anticoagulation initiation (18.7% vs 6.4%, p < 0.001) and lower risk of stroke recurrence (4.1% vs 11.8%, p = 0.013). ICM was independently associated with a lower risk of stroke recurrence during follow-up (HR = 0.32, 95% CI = 0.11-0.90) in multivariable analyses.

Interpretation: ICM appears to be independently associated with a higher likelihood of PAF detection and anticoagulation initiation after a cryptogenic ischemic stroke or TIA. ICM was also independently related to lower risk of stroke recurrence in our cryptogenic stroke / TIA cohort. ANN NEUROL 2020;88:946-955.
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http://dx.doi.org/10.1002/ana.25886DOI Listing
November 2020

A Case of Meningococcal and HSV-2 Meningitis in a Patient Being Treated with Ustekinumab for Pityriasis Rubra Pilaris.

Eur J Case Rep Intern Med 2020 22;7(8):001615. Epub 2020 May 22.

Second Propaedeutic Department of Internal Medicine and Research Institute, University General Hospital Attikon, National and Kapodistrian University of Athens, Athens, Greece.

Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory papulosquamous dermatosis affecting both adults and children. Six subtypes of PRP have been described. Recently, the management of PRP with biologic immunosuppressive agents regularly used in psoriasis has been supported by several case reports and series. Ustekinumab is an anti-IL12/23 IgG1 kappa human monoclonal antibody. It has been approved for the treatment of Crohn's disease, plaque psoriasis, psoriatic arthritis and ulcerative colitis. It has also been reported to be effective as an off-label treatment for PRP. Current data are equivocal regarding infectious disease risk with ustekinumab administration. We describe a case of meningococcal and HSV-2 infection of the central nervous system in a patient being treated with ustekinumab for PRP.

Learning Points: The administration of biologic immunosuppressive agents can result in severe life-threatening infections.Research is required on the infection potential of ustekinumab.Physicians should be aware of the possibility of infectious disease when prescribing biologic agents.Vaccination is essential in immunosuppressed adults.
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http://dx.doi.org/10.12890/2020_001615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7417051PMC
May 2020

The role of cardiology specialties in times of crisis.

Eur Heart J 2020 08;41(31):2935-2936

Department of Cardiology, 'G. Gennimatas' General Hospital of Athens, Athens, Greece.

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http://dx.doi.org/10.1093/eurheartj/ehaa572DOI Listing
August 2020

Systemic autoimmune diseases, anti-rheumatic therapies, COVID-19 infection risk and patient outcomes.

Rheumatol Int 2020 09 11;40(9):1353-1360. Epub 2020 Jul 11.

Joint Rheumatology Program, First Department of Propaedeutic Internal Medicine, National and Kapodistrian University of Athens Medical School, 17 Agiou Thoma Street, 11527, Athens, Greece.

As of June 10th 2020 about 7.2 million individuals have tested positive for, and more than 410,000 have died due to COVID-19. In this review we outline the pathophysiology that underpins the potential use of anti-rheumatic therapies for severe COVID-19 infection and summarize the current evidence regarding the risk and outcome of COVID-19 in patients with systemic autoimmune diseases. Thus far there is no convincing evidence that any disease-modifying anti-rheumatic drug (conventional synthetic, biologic or targeted synthetic) including hydroxychloroquine, may protect against severe COVID-19 infection; answers about their possible usefulness in the management of the cytokine storm associated with severe COVID-9 infection will only arise from ongoing randomized controlled trials. Evidence on COVID-19 risk and outcome in patients with systemic autoimmune diseases is extremely limited; thus, any conclusions would be unsafe and should be seen with great caution. At present, the risk and severity (hospitalization, intensive care unit admission and death) of COVID-19 infection in people with autoimmune diseases do not appear particularly dissimilar to the general population, with the possible exception of hospitalization in patients exposed to high glucocorticoid doses. At this stage it is impossible to draw any conclusions for differences in COVID-19 risk and outcome between different autoimmune diseases and between the various immunomodulatory therapies used for them. More research in the field is obviously required, including as a minimum careful and systematic epidemiology and appropriately controlled clinical trials.
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http://dx.doi.org/10.1007/s00296-020-04629-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7353833PMC
September 2020

Effect of Colchicine vs Standard Care on Cardiac and Inflammatory Biomarkers and Clinical Outcomes in Patients Hospitalized With Coronavirus Disease 2019: The GRECCO-19 Randomized Clinical Trial.

JAMA Netw Open 2020 06 1;3(6):e2013136. Epub 2020 Jun 1.

Department of Cardiology, Ioannina University Hospital, University of Ioannina, Ioannina, Greece.

Importance: Severe acute respiratory syndrome coronavirus 2 infection has evolved into a global pandemic. Low-dose colchicine combines anti-inflammatory action with a favorable safety profile.

Objective: To evaluate the effect of treatment with colchicine on cardiac and inflammatory biomarkers and clinical outcomes in patients hospitalized with coronavirus disease 2019 (COVID-19).

Design, Setting, And Participants: In this prospective, open-label, randomized clinical trial (the Greek Study in the Effects of Colchicine in COVID-19 Complications Prevention), 105 patients hospitalized with COVID-19 were randomized in a 1:1 allocation from April 3 to April 27, 2020, to either standard medical treatment or colchicine with standard medical treatment. The study took place in 16 tertiary hospitals in Greece.

Intervention: Colchicine administration (1.5-mg loading dose followed by 0.5 mg after 60 min and maintenance doses of 0.5 mg twice daily) with standard medical treatment for as long as 3 weeks.

Main Outcomes And Measures: Primary end points were (1) maximum high-sensitivity cardiac troponin level; (2) time for C-reactive protein to reach more than 3 times the upper reference limit; and (3) time to deterioration by 2 points on a 7-grade clinical status scale, ranging from able to resume normal activities to death. Secondary end points were (1) the percentage of participants requiring mechanical ventilation, (2) all-cause mortality, and (3) number, type, severity, and seriousness of adverse events. The primary efficacy analysis was performed on an intention-to-treat basis.

Results: A total of 105 patients were evaluated (61 [58.1%] men; median [interquartile range] age, 64 [54-76] years) with 50 (47.6%) randomized to the control group and 55 (52.4%) to the colchicine group. Median (interquartile range) peak high-sensitivity cardiac troponin values were 0.0112 (0.0043-0.0093) ng/mL in the control group and 0.008 (0.004-0.0135) ng/mL in the colchicine group (P = .34). Median (interquartile range) maximum C-reactive protein levels were 4.5 (1.4-8.9) mg/dL vs 3.1 (0.8-9.8) mg/dL (P = .73), respectively. The clinical primary end point rate was 14.0% in the control group (7 of 50 patients) and 1.8% in the colchicine group (1 of 55 patients) (odds ratio, 0.11; 95% CI, 0.01-0.96; P = .02). Mean (SD) event-free survival time was 18.6 (0.83) days the in the control group vs 20.7 (0.31) in the colchicine group (log rank P = .03). Adverse events were similar in the 2 groups, except for diarrhea, which was more frequent with colchicine group than the control group (25 patients [45.5%] vs 9 patients [18.0%]; P = .003).

Conclusions And Relevance: In this randomized clinical trial, participants who received colchicine had statistically significantly improved time to clinical deterioration. There were no significant differences in high-sensitivity cardiac troponin or C-reactive protein levels. These findings should be interpreted with caution.

Trial Registration: ClinicalTrials.gov Identifier: NCT04326790.
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http://dx.doi.org/10.1001/jamanetworkopen.2020.13136DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315286PMC
June 2020
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