Current Cardiology Reviews - Volume 15, Issue 3, 2019

Background: Cardiovascular diseases are the leading cause of death among dialysis patients, accounting for about 40% of all their mortalities. Sudden cardiac death (SCD) is culpable for 37.5% of all deaths among patients with end-stage renal disease (ESRD). Implantable cardioverterdefibrillators (ICDs) should be considered in dialysis patients for the primary or secondary prevention of SCD. Recent studies on the implementation of ICD/cardiac resynchronization therapy do not exclude patients with ESRD; however, individualized decisions should be made in this group of patients. A thorough evaluation of the benefits of ICD implementation in patients with ESRD requires several large-scale mortality studies to compare and follow up patients with ESRD with and without ICDs. In the present study, we sought to determine and clarify the complications associated with ICD implementation and management thereof in patients suffering from ESRD. Methods: To assess the complications allied to the implementation of ICDs and their management in patients with ESRD, we reviewed available related articles in the literature. Results and Conclusions: ICD implementation in dialysis patients has several complications, which has limited its usage. Based on our literature review, the complications of ICD implementation can be categorized as follows: (1) Related to implantation procedures, hematoma, and pneumothorax; (2) Related to the device/lead such as lead fracture and lead dislodgment; (3) Infection; and (4) Central vein thrombosis. Hence, the management of the complications of ICDs in this specific group of patients is of vital importance.

The ductus venosus is a vascular shunt situated within the fetal liver parenchyma, connecting the umbilical vein to the inferior vena cava. This vessel acts as a bypass of the liver microcirculation and plays a critical role in the fetal circulation. The ductus venosus allows oxygenated and nutrient-rich venous blood to flow from the placenta to the myocardium and brain. Increased impedance to flow in the fetal ductus venosus is associated with fetal aneuploidies, cardiac defects and other adverse pregnancy outcomes. This review serves to improve our understanding of the mechanisms that regulate the blood flow redistribution between the fetal liver circulation and fetal heart and the clinical significance of the ductus venosus waveform as generated by pressure-volume changes in the fetal heart.

The hypothetical trigger of remote postconditioning (RPost) of the heart is the highmolecular weight hydrophobic peptide(s). Nitric oxide and adenosine serve as intermediaries between the peptide and intracellular structures. The role of the autonomic nervous system in RPost requires further study. In signaling mechanism RPost, kinases are involved: protein kinase C, PI3, Akt, JAK. The hypothetical end effector of RPost is aldehyde dehydrogenase-2, the transcription factors STAT, Nrf2, and also the BKCa channel.

Three-dimensional (3D) printing, also known as additive manufacturing, was developed originally for engineering applications. Since its early advancements, there has been a relentless development in enthusiasm for this innovation in biomedical research. It allows for the fabrication of structures with both complex geometries and heterogeneous material properties. Tissue engineering using 3D bio-printers can overcome the limitations of traditional tissue engineering methods. It can match the complexity and cellular microenvironment of human organs and tissues, which drives much of the interest in this technique. However, most of the preliminary evaluations of 3Dprinted tissues and organ engineering, including cardiac tissue, relies extensively on the lessons learned from traditional tissue engineering. In many early examples, the final printed structures were found to be no better than tissues developed using traditional tissue engineering methods. This highlights the fact that 3D bio-printing of human tissue is still very much in its infancy and more work needs to be done to realise its full potential. This can be achieved through interdisciplinary collaboration between engineers, biomaterial scientists and molecular cell biologists. This review highlights current advancements and future prospects for 3D bio-printing in engineering ex vivo cardiac tissue and associated vasculature, such as coronary arteries. In this context, the role of biomaterials for hydrogel matrices and choice of cells are discussed. 3D bio-printing has the potential to advance current research significantly and support the development of novel therapeutics which can improve the therapeutic outcomes of patients suffering fatal cardiovascular pathologies.

Transcather aortic valve implantation (TAVI) has become a safe and indispensable treatment option for patients with severe symptomatic aortic stenosis who are at high surgical risk. Recently, outcomes after TAVI have improved significantly and TAVI has emerged as a qualified alternative to surgical aortic valve replacement in the treatment of intermediate risk patients and greater adoption of this procedure is to be expected in a wider patients population, including younger patients and low surgical risk patients. However since the aortic valve has close spatial proximity to the conduction system, conduction anomalies are frequently observed in TAVI. In this article, we aim to review the key aspects of pathophysiology, current incidence, predictors and clinical association of conduction anomalies following TAVI.

In patients with atrial fibrillation undergoing percutaneous coronary intervention with the placement of stents, a triple antithrombotic therapy is empirically established, which consists of a combination of dual antithrombotic therapy (aspirin plus a P2Y12 inhibitor) and an oral anticoagulant agent. This choice is guided by the desirable result of reducing cerebrovascular and coronary ischemic events. However, there is an unwelcome outcome: an increased incidence of bleeding. On this matter, in 2018, a North American Perspective Update was published, about a year later it was followed by the publication of the European focus update on the dual antiplatelet therapy. After analysing the main differences between these two consensus documents, this review aims at examining the major studies on which they are based on, as a starting point to define the foundation of new trials that can help shed light on this prominent topic.

Immunoglobulin 4 (IgG4)-related systemic disease (IgG4-RSD) is a systemic inflammatory disease characterized by elevation of serum IgG4. IgG4-RSD can affect any organ in the body, and the list of organs associated with this condition is growing steadily. IgG4-related cardiovascular disease affects the coronary arteries, heart valves, myocardium, pericardium, aorta, pulmonary and peripheral vessels. Echocardiography is the most commonly used non-invasive imaging method. Computed tomography angiography (CTA) can assess aortitis, periarteritis and coronary aneurysms. Coronary CTA is fast, offers high spatial resolution and a wide coverage field of view. Cardiac magnetic resonance imaging (CMR) offers a comprehensive evaluation of the cardiovascular system including cardiac function, extent of myocardial fibrosis, characterise cardiac masses with different pulse sequences and guide to further treatment. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) can provide important information about the extent of disease, the presence of active inflammation and the optimum biopsy site. In general, the role of diagnostic imaging includes establishing the diagnosis, detecting complications, guiding biopsy and documenting response to therapy.

Background: Ablation therapy is the treatment of choice in antiarrhythmic drugrefractory atrial fibrillation (AF). It is performed by either cryoballoon ablation (CBA) or radiofrequency ablation. CBA is gaining popularity due to simplicity with similar efficacy and complication rate compared with RFA. In this meta-analysis, we compare the recurrence rate of AF and the complications from CBA versus RFA for the treatment of AF. Methods: We systematically searched PubMed for the articles that compared the outcome of interest. The primary outcome was to compare the recurrence rate of AF between CBA and RFA. We also included subgroup analysis with complications of pericardial effusion, phrenic nerve palsy and cerebral microemboli following ablation therapy. Results: A total of 24 studies with 3527 patients met our predefined inclusion criteria. Recurrence of AF after CBA or RFA was similar in both groups (RR: 0.84; 95% CI: 0.65, 1.07; I2=48%, Cochrane p=0.16). In subgroup analysis, heterogeneity was less in paroxysmal AF (I2=0%, Cochrane p=0.46) compared to mixed AF (I2=72%, Cochrane p=0.003). Procedure and fluoroscopy time was less by 26.37 and 5.94 minutes respectively in CBA compared to RFA. Complications, pericardial effusion, and silent cerebral microemboli, were not different between the two groups, however, phrenic nerve palsy was exclusively present only in CBA group. Conclusion: This study confirms that the effectiveness of CBA is similar to RFA in the treatment of AF with the added advantages of shorter procedure and fluoroscopy times.