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.

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.

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.

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

INTRODUCTION: Early arrhythmia recurrence within the 3-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 atrial fibrillation. 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 (odds ratio [OR]: 5.31; 95% confidence interval [CI]: 3.75-7.51). This pattern remained unchanged after subanalyzing 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 antiarrhythmic drug utilization during the 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 reintervention is an open research avenue.

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.

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

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.

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 3­kinase (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.

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

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.

Ticagrelor versus clopidogrel in patients with STEMI treated with thrombolysis: the MIRTOS trial.

AIMS: We aimed to demonstrate whether coronary microvascular function is improved after ticagrelor administration compared to clopidogrel administration in STEMI subjects undergoing thrombolysis. METHODS AND RESULTS: MIRTOS is a multicentre study of ticagrelor versus clopidogrel in STEMI subjects treated with fibrinolysis. We enrolled 335 patients <75 years old with STEMI eligible for thrombolysis, of whom 167 were randomised to receive clopidogrel and 168 to receive ticagrelor together with thrombolysis. Primary outcome was the difference in post-PCI corrected TIMI frame count (CTFC). All clinical events were recorded in a three-month follow-up period. From the 335 patients who were randomised, 259 underwent PCI (129 clopidogrel and 130 ticagrelor) and 154 angiographies were analysable for the study primary endpoint. No significant difference was found between the clopidogrel (n=85) and ticagrelor (n=69) groups for CTFC (24.33±17.35 vs 28.33±17.59, p=0.10). No significant differences were observed in MACE and major bleeding events between randomisation groups (OR 2.0, 95% CI: 0.18-22.2, p=0.99). CONCLUSIONS: Thrombolysis with ticagrelor in patients <75 years old was not able to demonstrate superiority compared to clopidogrel in terms of microvascular injury, while there was no difference between the two groups in MACE and major bleeding events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02429271. EudraCT Number 2014-004082-25.

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).

"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.

Calcium Ions in Inherited Cardiomyopathies.

Inherited cardiomyopathies are a known cause of heart failure, although the pathways and mechanisms leading from mutation to the heart failure phenotype have not been elucidated. There is strong evidence that this transition is mediated, at least in part, by abnormal intracellular Ca(2+) handling, a key ion in ventricular excitation, contraction and relaxation. Studies in human myocytes, animal models and in vitro reconstituted contractile protein complexes have shown consistent correlations between Ca(2+) sensitivity and cardiomyopathy phenotype, irrespective of the causal mutation. In this review we present the available data about the connection between mutations linked to familial hypertrophic (HCM), dilated (DCM) and restrictive (RCM) cardiomyopathy, right ventricular arrhythmogenic cardiomyopathy/dysplasia (ARVC/D) as well as left ventricular non-compaction and the increase or decrease in Ca(2+) sensitivity, together with the results of attempts to reverse the manifestation of heart failure by manipulating Ca(2+) homeostasis.

A comparison of low versus standard heparin dose for prevention of forearm artery occlusion after 5 French coronary angiography.

BACKGROUND: Radial artery occlusion (RAO) remains the Achilles' heel of transradial coronary procedures. Standard over lower systemic anticoagulation levels are believed to reduce RAO rates but this is ill-supported by scientific evidence. We compared whether standard in comparison with less intensive anticoagulation was superior in preventing vessel closure. METHODS AND RESULTS: The two arms of this analysis included 731 pooled patients with the same inclusion and exclusion criteria. We assessed forearm arterial access site occlusion rate by unfractionated heparin (UFH) dose in an individual participant data meta-analysis of this randomized study and of consecutive eligible patients from our previous trial. We randomized 308 consecutive patients undergoing transradial coronary angiography with 5 French (5 Fr) catheters without need to crossover to receive 2500 or 5000 UFH units. The primary end-point was the ultrasonographically determined vessel occlusion rate. Incident RAOs in the randomized arm were 15.9% vs. 14%, in the low and standard UFH dose, respectively (p=0.7). Corresponding figures for forearm arterial occlusion rates in the pooled population were 13.0% vs. 9.9% (relative risk: 1.3, 95% confidence interval - CI: 0.88-1.98; p=0.2). Procedural and fluoroscopy duration was less than 15 and 3 min, respectively. The mean UFH dose difference was 3.52 (95% CI: -0.45 to 7.49) units per kilo body weight between occluded (n=84) and patent forearm arteries (n=647); (p=0.053). CONCLUSIONS: Incident forearm arterial occlusions were high despite using 5 Fr catheters for a short-lasting procedure. Systemic anticoagulation with standard over lower UFH dose did not reduce the frequency of RAOs after coronary angiography.

A predictive score of radial artery spasm in patients undergoing transradial percutaneous coronary intervention.

OBJECTIVE: Radial artery spasm may hinder completion of transradial angiography or PCI, leading to access site crossover, prolonged procedure times and complications. The aim of this study was to derive a radial artery spasm risk score in patients undergoing elective percutaneous coronary intervention (PCI), prospectively validate it, and apply it in a real-life clinical setting. METHODS: The study population consisted of 3 cohorts of patients undergoing elective PCI with transradial access: the derivation cohort (N=1006), the validation cohort (N=576) and the intervention cohort (N=140), consisting of patients with high risk score, in whom intensified spasm-preventive measures were applied. RESULTS: Multivariable analysis in the derivation cohort showed that 5 weighted factors could be used to construct a risk score for spasm: body-mass index, height, current smoking, hypertension and peripheral artery disease (c-statistic 0.945, with an optimal cut-off of 4). In the validation cohort, the cut-off of 4 predicted spasm with a sensitivity of 84.5% and a specificity of 74.7%. In the intervention cohort, which included only patients with a spasm-risk score of ≥4, the rate of spasm was drastically reduced (odds ratio 0.32, 95% confidence interval 0.17-0.61), compared to the corresponding high spasm risk subgroup of patients of the validation cohort. CONCLUSION: A spasm risk score can be used to predict radial artery spasm during elective transradial PCI. Using this score, a high spasm risk patient subgroup can be identified, where intensive spasm-preventive measures can lead to a significant reduction in the frequency of spasm.

Innate immune inflammatory response in the acutely ischemic myocardium.

The "holy grail" of modern interventional cardiology is the salvage of viable myocardial tissue in the distribution of an acutely occluded coronary artery. Thrombolysis and percutaneous coronary interventions, provided they can be delivered on time, can interrupt the occlusion and save tissue. At the same time restoring the patency of the coronary vessels and providing the ischemic myocardium with blood can cause additional tissue damage. A key element of ischemic and reperfusion injury and major determinant of the evolution of damage in the injured myocardium is the inflammatory response. The innate immune system initiates and directs this response which is a prerequisite for subsequent healing. The complement cascade is set in motion following the release of subcellular membrane constituents. Endogenous 'danger' signals known as danger-associated molecular patterns (DAMPs) released from ischemic and dying cells alert the innate immune system and activate several signal transduction pathways through interactions with the highly conserved Toll like receptors (TLRs). Reactive oxygen species (ROS) generation directly induces pro-inflammatory cascades and triggers formation of the inflammasome. The challenge lies into designing strategies that specifically block the inflammatory cascades responsible for tissue damage without affecting those concerned with tissue healing.

Central sympathetic inhibition to reduce postablation atrial fibrillation recurrences in hypertensive patients: a randomized, controlled study.

BACKGROUND: The autonomic system is an important determinant of atrial arrhythmogenesis. Current evidence indicates that a combined sympathovagal drive is most commonly responsible for eliciting atrial fibrillation (AF) episodes. The purpose of this study was to test whether moxonidine, a centrally acting sympathoinhibitory agent, can lead to a reduction in postablation AF recurrence. METHODS AND RESULTS: This was a prospective, double-blinded, randomized study of 291 hypertensive patients with symptomatic paroxysmal AF who were scheduled to undergo pulmonary vein isolation. Patients were randomly assigned to receive either moxonidine (0.2-0.4 mg daily) or placebo, along with standard antihypertensive treatment. No significant differences in blood pressure levels were observed between the 2 groups. In the primary outcome analysis, mean recurrence-free survival was 467 days (95% CI, 445-489 days) in the moxonidine group as compared with 409 days (95% CI, 381-437 days) in control subjects (log rank test, P=0.006). The calculated 12-month recurrence rate estimates were 36.9% in the control group and 20.0% in the moxonidine group (P=0.007). Moxonidine treatment was associated with lower recurrence risk after adjustment for age, body mass index, number of AF episodes in the previous year, and left atrial diameter (adjusted hazard ratio, 0.35 [95% CI, 0.22-0.55]; P<0.001). CONCLUSIONS: Treatment with moxonidine is associated with less AF recurrences after ablation treatment for drug-refractory AF in patients with hypertension. The observed effect does not appear to depend on the antihypertensive action of this agent. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01791699.