Left atrial appendage morphofunctional indices could be predictive of arrhythmia recurrence post-atrial fibrillation ablation: a meta-analysis

BACKGROUND

Left atrium changes are implicated in atrial fibrillation (AF) substrate and are predictive of AF outcomes. Left atrial appendage (LAA) is an integral component of left atrial structure and could be affected by atrial cardiomyopathy. We aimed to elucidate the association between LAA indices and late arrhythmia recurrence after atrial fibrillation catheter ablation (AFCA).

METHODS

The MEDLINE database, ClinicalTrials.gov, medRxiv and Cochrane Library were searched for studies evaluating LAA and late arrhythmia recurrence in patients undergoing AFCA. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was pre-ablation difference in LAA anatomic or functional indices.

RESULTS

A total of 34 studies were found eligible and five LAA indices were analyzed. LAA ejection fraction and LAA emptying velocity were significantly lower in patients with AF recurrence post-ablation [SMD = - 0.66; 95% CI (- 1.01, - 0.32) and SMD = - 0.56; 95% CI (- 0.73, - 0.40) respectively] as compared to arrhythmia free controls. LAA volume and LAA orifice area were significantly higher in patients with AF recurrence post-ablation (SMD = 0.51; 95% CI 0.35-0.67, and SMD = 0.35; 95% CI 0.20-0.49, respectively) as compared to arrhythmia free controls. LAA morphology was not predictive of AF recurrence post-ablation (chicken wing morphology; OR 1.27; 95% CI 0.79-2.02). Moderate statistical heterogeneity and small case-control studies are the main limitations of our meta-analysis.

CONCLUSIONS

Our findings suggest that LAA ejection fraction, LAA emptying velocity, LAA orifice area and LAA volume differ between patients suffering from arrhythmia recurrence post-ablation and arrhythmia free counterparts, while LAA morphology is not predictive of AF recurrence.

Efficacy, Safety and Feasibility of Superior Vena Cava Isolation in Patients Undergoing Atrial Fibrillation Catheter Ablation: An Up-to-Date Review

Pulmonary vein isolation (PVI) is the cornerstone in atrial fibrillation (AF) ablation; yet, the role of arrhythmogenic superior vena cava (SVC) is increasingly recognized and different ablation strategies have been employed in this context. SVC can act as a trigger or perpetuator of AF, and its significance might be more pronounced in patients undergoing repeated ablation. Several cohorts have examined efficacy, safety and feasibility of SVC isolation (SVCI) among AF patients. The majority of these studies explored as-needed SVCI during index PVI, and only a minority of them included repeated ablation subjects and non-radiofrequency energy sources. Studies of heterogeneous design and intent have explored both empiric and as-needed SVCI on top of PVI and reported inconclusive results. These studies have largely failed to demonstrate any clinical benefit in terms of arrhythmia recurrence, although safety and feasibility are undisputable. Mixed population demographics, small number of enrollees and short follow-up are the main limitations. Procedural and safety data are comparable between empiric SVCI and as-needed SVCI, and some studies suggested that empiric SVCI might be associated with reduced AF recurrences in paroxysmal AF patients. Currently, no study has compared different ablation energy sources in the setting of SVCI, and no randomized study has addressed as-needed SVCI on top of PVI. Furthermore, data regarding cryoablation are still in their infancy, and regarding SVCI in patients with cardiac devices more safety and feasibility data are needed. PVI non-responders, patients undergoing repeated ablation and patients with long SVC sleeves could be potential candidates for SVCI, especially via an empiric approach. Although many technical aspects remain unsettled, the major question to answer is which clinical phenotype of AF patients might benefit from SVCI?

Advances in the Management of Heart Failure with Reduced Ejection Fraction; The Role of SGLT2is, ARNI, Myotropes, Vericiguat, and Anti-inflammatory Agents: A Mini-review

Heart failure with reduced ejection fraction (HFrEF) has been associated with poor prognosis, reduced quality of life, and increased healthcare expenditure. Despite tremendous advances in HFrEF management, reduced survival and a high rate of hospitalization remain unsolved issues. Furthermore, HFrEF morbidity and economic burden are estimated to increase in the following years; hence, new therapies are constantly emerging. In the last few years, a series of landmark clinical trials have expanded our therapeutic armamentarium with a ground-breaking change in HFrEF-related outcomes. Sodium-glucose co-transporter 2 inhibitors (mainly dapagliflozin and empagliflozin) have already revolutionized the management of HFrEF patients via a significant reduction in cardiovascular mortality and heart failure hospitalizations. Furthermore, vericiguat and omecamtiv mecarbil have emerged as promising and novel disease-modifying therapies. The former restores the impaired cyclic guanosine monophosphate pathway, and the latter stimulates cardiac myosin without marked arrhythmogenesis. Both vericiguat and omecamtiv mecarbil have been shown to reduce heart failure admissions. Sacubitril/valsartan is an established and effective therapy in HFrEF patients and should be considered as a replacement for angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs). Lastly, inflammasome activity is implicated in HFrEF pathophysiology, and the role of anti-inflammatory agents in HFrEF trajectories is readily scrutinized, yet available therapies are ineffective. This mini-review summarizes the major and most recent studies in this field, thus covering the current advances in HFrEF therapeutics.

Epicardial Adipose Tissue Hyperinflammation Might be the Broken Thread in Coronary Artery Ectasia Pathogenesis

Inflammation, as assessed by epicardial adipose tissue and serum biomarkers, represents an integral mechanistic link in isolated coronary artery ectasia (iCAE) pathogenesis. This should be further investigated in the context of iCAE management and risk stratification.

Inflammatory Biomarkers in Coronary Artery Ectasia: A Systematic Review and Meta-Analysis

Isolated coronary artery ectasia (CAE) is a relatively rare clinical entity, the pathogenesis of which is poorly understood. More and more evidence is accumulating to suggest a critical inflammatory component. We aimed to elucidate any association between neutrophil to lymphocyte ratio and coronary artery ectasia. A systematic MEDLINE database, ClinicalTrials.gov, medRxiv, Scopus and Cochrane Library search was conducted: 50 studies were deemed relevant, reporting on difference in NLR levels between CAE patients and controls (primary endpoint) and/or on high-sensitive CRP, IL-6, TNF-a and RDW levels (secondary endpoint), and were included in our final analysis. (PROSPERO registration number: CRD42021224195). All inflammatory biomarkers under investigation were found higher in coronary artery ectasia patients as compared to healthy controls (NLR; SMD = 0.73; 95% CI: 0.27–1.20, hs-CRP; SMD = 0.96; 95% CI: 0.64–1.28, IL-6; SMD = 2.68; 95% CI: 0.95–4.41, TNF-a; SMD = 0.50; 95% CI: 0.24–0.75, RDW; SMD = 0.56; 95% CI: 0.26–0.87). The main limitations inherent in this analysis are small case-control studies of moderate quality and high statistical heterogeneity. Our findings underscore that inflammatory dysregulation is implicated in coronary artery ectasia and merits further investigation.

Atrial fibrillation recurrence post pulmonary vein isolation: the complex secrets of left atrial geometry

Buffle et al are to be congratulated for shedding more light on the electrophysiologic links regarding atrial fibrillation recurrence post radiofrequency catheter ablation. The different approaches of left atrium volume and left atrium diameter assessment employed in this study, is a limitation that should not go unnoticed, since angiographically calculated left atrium volume overestimates volume as compared to 3D echo measurements. Further, the timing of change has been reported to have prognostic significance; namely left atrium diameter reduction within the 3 month blanking period has been reported to independently predict prolonged arrhythmia free survival. Hence, we firmly believe that future studies should examine any potential correlations between left atrium diameter and recurrence mechanisms.

Colchicine in Cardiovascular Disease: In-Depth Review

Inflammation plays a prominent role in the development of atherosclerosis and other cardiovascular diseases, and anti-inflammatory agents may improve cardiovascular outcomes. For years, colchicine has been used as a safe and well-tolerated agent in diseases such as gout and familial Mediterranean fever. The widely available therapeutic has several anti-inflammatory effects, however, that have proven effective in a broad spectrum of cardiovascular diseases as well. It is considered standard-of-care therapy for pericarditis, and several clinical trials have evaluated its role in postoperative and postablation atrial fibrillation, postpericardiotomy syndrome, coronary artery disease, percutaneous coronary interventions, and cerebrovascular disease. We aim to summarize colchicine's pharmacodynamics and the mechanism behind its anti-inflammatory effect, outline thus far accumulated evidence on treatment with colchicine in cardiovascular disease, and present ongoing randomized clinical trials. We also emphasize real-world clinical implications that should be considered on the basis of the merits and limitations of completed trials. Altogether, colchicine's simplicity, low cost, and effectiveness may provide an important addition to other standard cardiovascular therapies. Ongoing studies will address complementary questions pertaining to the use of low-dose colchicine for the treatment of cardiovascular disease.

Choroidal thickness in patients with systemic arterial hypertension: a systematic review and meta-analysis

Background:

The global burden of hypertension is constantly increasing with adverse cardiovascular and ocular sequelae. The association between elevated blood pressure and choroidal thickness (CT), as assessed via optical coherence tomography (OCT), is poorly understood.

Objectives and Design:

Studies including hypertensive adults and normotensive controls undergoing OCT were evaluated for inclusion in this meta-analysis. The primary endpoint was CT difference between hypertensive and normotensive adults.

Data Sources and Methods:

We conducted a systematic review and after searching 1011 results from MEDLINE, ClinicalTrials.gov, medRxiv and Cochrane Library, six studies were deemed eligible and were pooled according to a random-effect model.

Results:

A statistically significant reduction in choroidal thickness was found in hypertensive adults ( n = 454) as compared with normotensive controls ( n = 365) [mean difference: −0.77; 95% confidence intervals: (−1.20, −0.34); p = 0.0004]. The main limitations of this meta-analysis are the relatively small population included and the high statistical heterogeneity ( I2 = 87%) among the various studies. Of note, after excluding one study the heterogeneity was markedly reduced.

Conclusion:

Choroidal thickness is reduced among hypertensive subjects compared with normotensive controls. This finding mandates further examination in the context of long-term clinical outcomes.

Early arrhythmia recurrence after cryoballoon ablation in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Early arrhythmia recurrence within the three-month blanking period is a common event that historically has been attributed to reversible phenomena. While its' mechanistic links remain obscure, accumulating evidence support the argument of shortening the blanking period. We aimed to elucidate the association between early and late arrhythmia recurrence after atrial fibrillation cryoablation.

METHODS

The MEDLINE database, ClinicalTrials.gov, medRxiv and Cochrane Library were searched for studies evaluating early and late arrhythmia recurrence rates in patients undergoing cryoablation for AF. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was late arrhythmia recurrence.

RESULTS

Early arrhythmia recurrence was found predictive of decreased arrhythmia-free survival after evaluating 3975 patients with paroxysmal or persistent atrial fibrillation who underwent cryoablation (OR: 5.31; 95% CI: 3.75-7.51). This pattern remained unchanged after sub-analyzing atrial fibrillation type (paroxysmal; OR: 7.16; 95% CI: 4.40-11.65 and persistent; OR: 7.63; 95% CI: 3.62-16.07) as well as cryoablation catheter generation (first generation; OR: 5.15, 95% CI: 2.39-11.11 and advanced generation; OR: 5.83, 95% CI: 3.68-9.23). Studies permitting anti-arrhythmic drug utilization during blanking period or examining early recurrence as a secondary outcome were found to be a significant source of statistical heterogeneity.

CONCLUSION

Our findings suggest that early arrhythmia recurrence is predictive of late outcomes after cryoablation for atrial fibrillation. Identifying which patients deserve earlier re-intervention is an open research avenue. This article is protected by copyright. All rights reserved.

Immunologic Dysregulation and Hypercoagulability as a Pathophysiologic Background in COVID-19 Infection and the Immunomodulating Role of Colchicine

In 2020, SARS-COV-2 put health systems under unprecedented resource and manpower pressure leading to significant number of deaths. Expectedly, researchers sought to shed light on the pathophysiologic background of this novel disease (COVID-19) as well as to facilitate the design of effective therapeutic modalities. Indeed, early enough the pivotal role of inflammatory and thrombotic pathways in SARS-COV-2 infection has been illustrated. The purpose of this article is to briefly present the epidemiologic and clinical features of COVID-19, analyze the pathophysiologic importance of immunologic dysregulation and hypercoagulability in developing disease complications and finally to present an up-to-date systematic review of colchicine's immunomodulating capacity in view of hindering coronavirus complications.

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

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.

Potential Therapeutic Benefits of Sodium-Glucose Cotransporter 2 Inhibitors in the Context of Ischemic Heart Failure: A State-Of-The-Art Review

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of anti-diabetic agents that block the reabsorption of glucose in the proximal convoluted tubule of the nephron, thereby contributing to glycosuria and lowering blood glucose levels. SGLT2 inhibitors have been associated with improved cardiovascular outcomes in patients with diabetes, including a reduced risk of cardiovascular death and hospitalizations for heart failure. Recently, DAPA-HF and EMPEROR REDUCED trials showed the beneficial cardiovascular effect of SGLT2 inhibitors in patients with heart failure with consistently reduced ejection fraction (HFrEF) regardless of the presence of diabetes. Moreover, some exploratory studies suggested that these drugs improve Left Ventricular (LV) systolic function and oppose LV adverse remodeling in patients with HFrEF. However, the exact mechanisms that mediated for this benefit are not fully understood. Beyond glycemic control, enhanced natriuresis, increased erythropoiesis, improved endothelial function, changes in myocardial metabolism, anti-inflammatory and anti-oxidative properties may all play an active role in SGLT2 inhibitors' cardiovascular benefits. A deep understanding of the pathophysiological interplay is key to define which HF phenotype could benefit more from SGLT2 inhibitors. Current clinical evidence on the comparison of different HF etiologies is limited to posthoc subgroup analysis of DAPA-HF and EMPEROR-REDUCED, which showed similar outcomes in patients with or without ischemic HF. On the other hand, in earlier studies of patients suffering from diabetes, rates of classic ischemic endpoints, such as myocardial infarction, stroke or coronary revascularization, did not differ between patients treated with SGLT2 inhibitors or placebo. The aim of this review is to discuss whether SGLT2 inhibitors may improve prognosis in patients with ischemic HF, not only in terms of reducing re-hospitalizations and improving left ventricular function but also by limiting coronary artery disease progression and ischemic burden.

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

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.

Blood pressure variability within a single visit and all-cause mortality

BACKGROUND

Within-visit variability of repeated sequential readings of blood pressure (BP) is an important phenomenon that may affect precision of BP measurement and thus decision making concerning BP-related risk and hypertension management. However, limited data exist concerning predictive ability of within-visit BP variability for clinical outcomes. Therefore, we aimed to investigate the association between the variability of three repeated office BP measurements and the risk of all-cause mortality, independent of BP levels.

METHODS

Data collected through the National Health and Nutrition Examination Survey (NHANES) were analysed. NHANES is a program of studies designed to assess health and nutritional status of adults and children in the United States. A complete set of three sequential BP measurements, together with survival status, were available for 24969 individuals (age 46.8±;19.3 years, 49% males). Multivariable logistic regression models were used to determine the prognostic ability of the examined demographic, clinical, and haemodynamic indices.

RESULTS

Among various examined indices of variability of systolic (SBP) and diastolic (DBP) blood pressure measurements, the standard deviation of DBP (DBPSD) was the stronger independent predictor of mortality (odds ratio 1.064, 95% Confidence Interval: 1.011-1.12) after adjustment for age, sex, body mass index, smoking, SBP, heart rate, history of hypertension, diabetes mellitus, hypercholesterolaemia, and cardiovascular events.

CONCLUSION

Within-visit variability of three sequential office DBP readings may allow for the identification of high-risk patients better than mean SBP and DBP levels. The predictive value of within-visit BP variability and methods to improve its clinical application are worthy of further research.

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

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.

The Greek study in the effects of colchicine in COvid-19 complications prevention (GRECCO-19 study): Rationale and study design

OBJECTIVE

Colchicine has been utilized safely in a variety of cardiovascular clinical conditions. Among its potential mechanisms of action is the non-selective inhibition of NLRP3 inflammasome which is thought to be a major pathophysiologic component in the clinical course of patients with COVID-19. GRECCO-19 will be a prospective, randomized, open-labeled, controlled study to assess the effects of colchicine in COVID-19 complications prevention.

METHODS

Patients with laboratory confirmed SARS-CoV-2 infection (under RT PCR) and clinical picture that involves temperature >37.5 oC and at least two out of the: i. sustained coughing, ii. sustained throat pain, iii. Anosmia and/or ageusia, iv. fatigue/tiredness, v. PaO2<95 mmHg will be included. Patients will be randomised (1:1) in colchicine or control group.

RESULTS

Trial results will be disseminated through peer-reviewed publications and conference presentations.

CONCLUSION

GRECCO-19 trial aims to identify whether colchicine may positively intervene in the clinical course of COVID-19. (ClinicalTrials.gov Identifier: NCT04326790).

The Role of Calcium Handling Mechanisms in Reperfusion Injury

Cardiovascular diseases, such as stroke and myocardial infarction (MI) remain the major cause of death and disability worldwide. However, the mortality of MI has declined dramatically over the past several decades because of advances in medicines (thrombolytic agents, antiplatelet drugs, beta blockers, and angiotensin converting enzyme inhibitors) and approaches to restore tissue perfusion (percutaneous coronary intervention and cardiopulmonary bypass). Animal studies have been shown that these treatments have been effective in reducing acute myocardial ischemic injury and limiting MI size. The paradox is that the process of reperfusion can itself amplify cell injury and death, known as myocardial ischemia-reperfusion injury (I/R). Intensive research has uncovered several complex mechanisms of cardiomyocyte damage after reperfusion,and potential therapeutic targets for preventing I/R. Importantly, it is now recognized that excessive elevation of intracellular and mitochondrial Ca2+during reperfusion predisposes the cells to hypercontracture, proteolysis and mitochondrial failure and eventually to necrotic or apoptotic death. These enormous alterations in cytosolic Ca2+ levels are induced by the Ca2+ channels of the sarcolemma(L-Type Ca2+channels, sodium/calcium exchanger), the endoplasmic/ sarcoplasmic reticulum (SERCA ATPase) and ryanodine receptors, SOCE(store-operated calcium entry), lysosomes and others, which are modified by I/R injury. The overall goal of this review is to describe the different pathways that lead to I/R injury via Ca2+ overload, focus on recent discoveries and highlight prospects for therapeutic strategies for clinical benefit.

"TAVI: Valve in valve. A new field for structuralists? Literature review"

Transcatheter aortic valve implantation (TAVI) led to the foundation of the subspecialty of structural heart interventions and created an emerging area of clinical and technical issues. Soon after TAVI introduction into clinical practice, boundaries were expanded with utilization of valve-in-valve (V-i-V) techniques. V-i-V comprised a diverse subset of patients including TAVI within TAVI, TAVI within a degenerated surgically implanted bioprosthesis, or even TAVI-in-TAVI-in-surgical bioprosthesis. In the present review, we summarize the available literature and present initial experience on the field in Greece.

Colchicum Genus in the Writings of Ancient Greek and Byzantine Physicians

The plants of the Colchicum family were known during the archaic period in Greece for their deleterious properties. Later on, they were used for the treatment of podagra. The treatment was introduced by the ancient Greek physicians and passed on to the Byzantine and Arabian physicians to endure until nowadays. The first plant was most probably named "Medea" from the notorious Colchican witch. As the most common member of the family blossoms in autumn, the plant was named Colchicum autumnale. Various nominations were also used, such as Ephemeron, Hermodactyl, Anima articulorum and Surugen. Our article discusses them, while at the same time presents the most notable authorities who have used Colchicum plants in herbal medicine and toxicology.

Are Drugs Always the Proper Solution to Therapeutic Dilemmas? Non-drug Approaches to the Post-traumatic Stress "Waking Corpse" Syndrome

Jules Cotard (1840-1889), a Parisian neurologist, described a syndrome of delirium negations which was later named after him. Some physicians in antiquity and medieval times, especially in Asia, have noticed this syndrome and categorized it as a symptom of melancholy. They have presented it as a "walking corpse syndrome", inflicting most probably veteran soldiers after suffering during ferocious battles, presenting the first cases of a post war traumatic stress disorder. Philotimus (3rd-2nd century BC) was the first to record it around 3rd century BC, and proposed a simple but pioneering treatment, by just putting a lead hat on the men's heads. Although various combined treatment strategies were proposed by modern psychiatry including pharmaceutical, electroconvulsive therapy, behavioural therapy and supportive psychotherapy, it seems that in antiquity a simple external intervention of supportive therapy was the main concept of confrontation, while drug administration was to be avoided.

Blood Pressure Deviation from the Golden Ratio φ and All-cause Mortality: A Pythagorean View of the Arterial Pulse

Introduction

There is one mathematical element with strong historical and philosophical background that exhibits remarkable properties and applications; the golden ratio (phi). Mathematically, the golden ratio equals approximately 1.61803. A rather provocative geometrical analysis of the arterial pulse according to the golden ratio was recently described, and herein, we aim to set out the hypothesis that individuals with blood pressure (BP) values that follow the golden ratio may have different prognosis than those whose BPs deviate from the divine proportions.

Materials and Methods

We used published data from the National Health and Nutrition Examination Survey during 1999-2010.

Results

We found that the deviation of the BP values from the golden ratio is independently associated with all-cause mortality.

Conclusions

This observation stimulates further research of the potential utility of the golden ratio of BP values on the diagnosis and prediction of BP-related abnormalities and risk.

Coincidental ganglionated plexus modification during radiofrequency pulmonary vein isolation and post-ablation arrhythmia recurrence

Aims

Vagal responses (VR) during left atrial ablation for atrial fibrillation (AF) treatment have been reported to be associated with less recurrences, presumably because they are a sign of ganglionated plexi modification. Our objective was to evaluate whether coincidentally elicited VR during left atrial ablation are associated with lower AF recurrence rates.

Methods and results

This is a post hoc analysis of a prospective study of 291 patients with paroxysmal AF undergoing radiofrequency pulmonary vein isolation (PVI). Vagal responses were defined as episodes of heart rate <40 bpm or asystole lasting >5 s elicited during energy application. Sixty-eight patients (23.4%) had a VR during ablation. In Kaplan-Meier analysis, mean recurrence-free survival was 449 days (95% confidence interval 411-488) in patients with VR when compared with 435 days (95% confidence interval 415-455) in those without (P = 0.310). The 12-month recurrence rate estimates were 25 and 27%, respectively. In an unadjusted Cox model, VR was associated with an odds ratio for recurrence of 0.77 (95% confidence interval 0.46-1.28).

Conclusion

Coincidentally elicited VR during radiofrequency PVI in patients with paroxysmal AF do not appear to be related to lower risk of arrhythmia recurrence. This may mean that, even if a VR is truly a sign of coincidental ablation of a ganglionated plexus, this does not necessarily mean that a therapeutic modification has been effected, at least to a degree associated with clinical benefit.

Invasive treatment in peripheral artery disease

Invasive treatment in peripheral artery disease (PAD) has evolved as a viable alternative to surgical treatment. However, beyond the common pathophysiological substrate, as far as treatment is concerned, each site of atherosclerotic disease (subclavian and vertebral arteries; carotid arteries; intracranial arterial tree; renal arteries; lower extremity arteries) features unique characteristics. Treatment options include medical treatment, endovascular management and/or surgery. Sound clinical evaluation is required as individual patient assessment often limits intervention options, while available data regarding benefits of invasive and surgical management are questioned by advances in medical treatment. In the present article, we aim to summarize existing evidence and guidance on the role of invasive procedures in PAD.

Colchicine in Post-operative Atrial Fibrillation: A Review

Post-operative atrial fibrillation (POAF) is a frequent entity increasing hospitalization duration, stroke and mortality. In the recent years, a few studies have sought to investigate the potential effect of colchicine in POAF prevention after cardiac surgery or catheter pulmonary vein isolation for AF. In the present review article, we intend to provide a synopsis of clinical practice guidelines, summarize and critically approach current evidence for or against colchicine as a means of POAF prevention.

Remote Ischemic Conditioning and Renal Protection

Over the course of the last 2 decades, the concept of remote ischemic conditioning (RIC) has attracted considerable research interest, because RIC, in most of its embodiments offers an inexpensive way of protecting tissues against ischemic damage inflicted by a number of medical conditions or procedures. Acute kidney injury (AKI) is a common side effect in the context of various medical procedures, and RIC has been suggested as a means of reducing its incidence. Outcomes regarding kidney function have been reported in numerous studies that evaluated the effects of RIC in a variety of settings (eg, cardiac surgery, interventions requiring intravenous administration of contrast media). Although several individual studies have implied a beneficial effect of RIC in preserving kidney function, 3 recently published randomized controlled trials evaluating more than 1000 patients each (Effect of Remote Ischemic Preconditioning in the Cardiac Surgery, Remote Ischaemic Preconditioning for Heart Surgery, and ERICCA) were negative. However, AKI or any other index of renal function was not a stand-alone primary end point in any of these trials. On the other hand, a range of meta-analyses (each including thousands of participants) have reported mixed results, with the most recent among them showing benefit from RIC, pinpointing at the same time a number of shortcomings in published studies, adversely affecting the quality of available data. The present review provides a critical appraisal of the current state of this field of research. It is the opinion of the authors of this review that there is a clear need for a common clinical trial framework for ischemic conditioning studies. If the current babel of definitions, procedures, outcomes, and goals persists, it is most likely that soon ischemic conditioning will be "yesterday's news" with no definitive conclusions having been reached in terms of its real clinical utility.

Antiplatelet and Anticoagulation Therapy in Structural Heart Disease Interventions Beyond TAVI

Transcatheter interventions for structural heart disease represent an emerging field in interventional cardiology. Undoubtedly, there is an absolute necessity for antiplatelet and/or anticoagulation treatment prior, during and post such interventions. However, currently administered regimens are mainly based in expert consensus recommendations. In the present review we aim to summarize data regarding anti platelet and/or anticoagulation treatment in the following transcatheter structural heart interventions: left atrial appendage closure, atrial septal defect closure, patent foramen oval closure, paravalvular leak closure.

Atrial Fibrillation During or After TAVI: Incidence, Implications and Therapeutical Considerations

INTRODUCTION

Aortic stenosis is one of the most frequent valvulopathy of modern time necessitating interventional therapy when symptoms arise and stenosis becomes severe. First line treatment has traditionally been surgical aortic valve replacement (SAVR). However in the last decade transcatheter aortic valve implantation (TAVI) with bioprosthetic valves has proved to be a sound solution for high-risk for SAVR or inoperable patients. As expected implantation of the bioprosthetic device requires administration of antiplatelet regimen to the patients for a certain period. Atrial fibrillation (AF) may occur frequently during the peri-procedural period. In this background, the occurrence of AF after device implantation may be a challenging issue.

METHODS

We performed a literature search of PubMed and Embase database. Published articles reporting the incidence, clinical implications and description of antithrombotic regimen of New-onset atrial fibrillation (NOAF) in individuals undergoing TAVI were considered eligible. Incidence, Implications and Antithrombotic Regimen: The overall occurrence of NOAF is reported to be 1%-32% after TAVI. Left atrial enlargement and transapical approach constitute independent predictors for NOAF. Additionally it has been shown that patients with AF face an increased risk of death irrespective of the type of AF. Patients, with a history of AF, present greater rate of death than individuals with NOAF. NOAF is responsible for cerebrovascular events (CVE) occurring in the subacute phase (days 1-30) after the procedure. The risk of stroke/transient ischemic attack after TAVI is increased at least two fold by the presence of atrial fibrillation. Empirically, a dual antiplatelet strategy has been used for patients undergoing TAVR, including aspirin and a thienopyridine. In cases where patients are in need of oral anticoagulation after TAVI a combination of aspirin or thienopyridine with acenocoumarol has been the preferred regimen.

DISCUSSION

Despite the continuously crescent use of TAVI for patients with symptomatic severe aortic stenosis, there are still many aspects of this procedure to be clarified. A lack of data exists from the available clinical trials regarding the appropriate anticoagulation therapy for patients with greater risk for thromboembolic events. As a result, patient's treatment remains at the discretion of the physician.

CONCLUSION

Limited data are available regarding the optimal therapeutic regimen in patients undergoing TAVI who need therapy for AF. Carefully designed clinical studies might further clarify the incidence and interrelation between atrial fibrillation and TAVI. The balance between the efficacy and risk of anticoagulation needs to be further clarified in patients undergoing TAVI.

Antiplatelet Therapy in TAVI: Current Clinical Practice and Recommendations

Transcatheter aortic valve implantation (TAVI) is all the more used therapeutic option for patients suffering from symptomatic severe aortic valvular stenosis declined by surgeons because of high surgical risk. Given the high bleeding and ischemic risk of this vulnerable population, their antithrombotic treatment becomes a crucial issue. There is no consensus on antithrombotic treatment after TAVI and dual antiplatelet therapy (DAPT) with aspirin (indefinitely) and clopidogrel (1-6 months) is, in general, recommended. With regards to patients with an indication for oral anticoagulation (OAC), a combination of OAC plus aspirin or clopidogrel is commonly suggested. This review underscores that it is extremely difficult to compare different antithrombotic regimens in patients undergoing TAVI because of their variable demographic characteristics. Nevertheless, available data suggest that DAPT results to more bleeding events. Still, whether it positively affects ischemic episodes is doubtful. Ongoing trials are expected to draw a clearer picture on the field.

Peri-procedural Anticoagulation in Catheter Ablation for Atrial Fibrillation: A Review

Catheter ablation for rhythm control in atrial fibrillation has been recognized as an established treatment. Patients with atrial fibrillation suffer from an increased risk of thromboembolic events. Long-term stroke risk and mortality have been shown to be reduced after catheter ablation, still the procedure per se is associated with an additive peri-procedural thromboembolic risk. Maintenance of the thrombotic - bleeding equilibrium in such patients during interventional procedures is compelling. Lack of data from randomized studies along with the recent introduction of novel oral anticoagulants in clinical practice has resulted in a wide variance of antithrombotic treatment approaches. Procedural interruption of anticoagulants, switching of anticoagulation scheme (i.e. from novel oral anticoagulants to vitamin K antagonists), bridging with heparin, timing of re-initiation of therapy and/or utilization of novel oral anticoagulants have all been points of dispute. In the present review we present the available data regarding optimal peri-procedural anticoagulation strategies in patients undergoing catheter ablation for atrial fibrillation.

Impact of atherosclerotic plaque components and their distribution on stent deployment: an intravascular-ultrasound virtual histology observational study

BACKGROUND

The aim of this study was to evaluate how the spatial distribution of each plaque element, defined by intravascular-ultrasound virtual histology (IVUS-VH), may affect stent deployment even at high inflation pressures.

METHODS

Thirty-two patients undergoing direct percutaneous coronary intervention and IVUS were evaluated. Fifty-two lesions were treated with drug-eluting stents. Pre-stenting lumen area and real (Rcssla) and average cross-sectional stent lumen area (Acssla) were measured along the whole lesion. Ideal cross-sectional stent lumen area (Icssla) was calculated. Plaque composition was characterized by IVUS-VH. The spatial distribution of each plaque element was quantified by a novel image analysis tool measuring the area and percentage of each plaque component that was adjacent to the lumen. Average stent deployment was defined as: [1 - (Icssla-Acssla)/Icssla]×100%.

RESULTS

Stent expansion was significantly less at the site of maximum calcification compared to the average stent deployment (80±9% vs. 85±13%, P=0.044, respectively). Furthermore, wherever calcium was adjacent to the lumen, stent expansion was impaired compared to sites where calcium was non-luminal (70±23% vs. 80±9%, P=0.01, respectively). In contrast, at the site of maximum necrotic core, stent deployment showed a trend to be less compromised, compared to the average stent deployment.

CONCLUSIONS

An interaction was found between plaque components and their distribution and stent deployment even at high inflation pressures.

Circulating Erythrocyte Microparticles and the Biochemical Extent of Myocardial Injury in ST Elevation Myocardial Infarction

Objectives: Red blood cell microparticles (RBCm) have potential adverse vascular effects and they have been shown to be elevated in ST elevation myocardial infarction (STEMI). The purpose of this study is to investigate their relationship with biochemical infarct size. Methods: RBCm were quantified with flow cytometry in blood drawn from 60 STEMI patients after a primary angioplasty. The creatine kinase-myocardial brain fraction (CK-MB) was measured at predefined time points and the area under the curve (AUC) was calculated. Results: RBCm count was correlated with CK-MB AUC (Spearman's ρ = 0.83, p < 0.001). The CK-MB AUC values per RBCm quartile (lower to upper) were: 3,351 (2,452-3,608), 5,005 (4,450-5,424), 5,903 (4,862-10,594), and 8,406 (6,848-12,782) ng × h/ml, respectively. From lower to upper quartiles, the maximal troponin I values were: 42.2 (23.3-49.3), 49.6 (28.8-54.1), 59.2 (41.4-77.3), and 69.1 (48.0-77.5) ng/ml (p = 0.005). In multivariable analysis, RBCm remained a significant predictor of CK-MB AUC (standardized β = 0.63, adjusted p = 0.001). Conclusions: Erythrocyte microparticles appear to be related to the total myocardial damage biomarker output. The exact pathophysiologic routes, if any, for this interaction remain to be identified. However, these results suggest that erythrocytes may be a - thus far virtually ignored - player in the pathogenesis of ischemic injury.