Utility and Validity of the HFA-PEFF and H2FPEF Scores in Patients With Symptomatic Atrial Fibrillation.

BACKGROUND: Diagnosis of heart failure with preserved ejection fraction (HFpEF) in patients with atrial fibrillation (AF) represents a significant clinical challenge. Two diagnostic scoring tools have been developed to aid the noninvasive diagnosis of HFpEF: the HFA-PEFF (Heart Failure Association Pre-test assessment, Echocardiography and natriuretic peptide, Functional testing, Final etiology) and the H2FPEF scoring systems. OBJECTIVES: The purpose of this study was to evaluate the performance of these 2 scoring tools for the diagnosis of HFpEF against a gold standard of invasive evaluation in a cohort of patients with AF. METHODS: The authors recruited consecutive patients with symptomatic AF and preserved ejection fraction who were scheduled for an AF ablation procedure. Gold-standard invasive diagnosis of HFpEF was performed at the AF ablation procedure using mean left atrial pressure at rest and following infusion of 500 mL fluid. Each participant was scored according to the noninvasive HFA-PEFF and H2FPEF scoring systems. Sensitivity and specificity analyses were performed to assess the accuracy of these scoring systems in diagnosing HFpEF. RESULTS: In total, 120 participants were recruited. HFpEF was diagnosed invasively in 88 (73.3%) participants, whereas 32 (26.7%) had no HFpEF. Using the HFA-PEFF score, 38 (31.7%) participants had a high probability of HFpEF and 82 (68.3%) had low/intermediate probability of HFpEF. Using the H2FPEF tool, 72 (60%) participants had a high probability of HFpEF and 48 (40%) had intermediate probability. A high HFA-PEFF (≥5 points) score could diagnose HFpEF with a sensitivity of 40% and a specificity of 91%, and a high H2FPEF score (≥6 points) could diagnose HFpEF with a sensitivity of 69% and specificity of 66%. Overall diagnostic accuracy was similar using both tools (AUC: 0.663 vs 0.707, respectively; P = 0.636). CONCLUSIONS: Against a gold standard of invasively diagnosed HFpEF, the HFA-PEFF and H2FPEF scores demonstrate only moderate accuracy in patients with AF and should be utilized with caution in this cohort of patients. (Characterising Left Atrial Function and Compliance in Atrial Fibrillation; ACTRN12620000639921).

Exercise echocardiography to assess left atrial function in patients with symptomatic AF.

Background: Left atrial (LA) function contributes to the augmentation of cardiac output during exercise. However, LA response to exercise in patients with atrial fibrillation (AF) is unknown. We explored the LA mechanical response to exercise and the association between LA dysfunction and exercise intolerance. Methods: We recruited consecutive patients with symptomatic AF and preserved left ventricular ejection fraction (LVEF). Participants underwent exercise echocardiography and cardiopulmonary exercise testing (CPET). Two-dimensional and speckle-tracking echocardiography were performed to assess LA function at rest and during exercise. Participants were grouped according to presenting rhythm (AF vs sinus rhythm). The relationship between LA function and cardiorespiratory fitness in patients maintaining SR was assessed using linear regression. Results: Of 177 consecutive symptomatic AF patients awaiting AF ablation, 105 met inclusion criteria; 31 (29.5 %) presented in AF whilst 74 (70.5 %) presented in SR. Patients in SR augmented LA function from rest to exercise, increasing LA emptying fraction (LAEF) and LA reservoir strain. In contrast, patients in AF demonstrated reduced LAEF and reservoir strain at rest, with failure to augment either parameter during exercise. This was associated with reduced VO2Peak compared to those in SR (18.4 ± 5.6 vs 22.5 ± 7.7 ml/kg/min, p = 0.003). In patients maintaining SR, LAEF and reservoir strain at rest and during exercise were associated with VO2Peak, independent of LV function. Conclusion: The maintenance of SR in patients with AF is associated with greater LA reservoir function at rest and greater augmentation with exercise compared to patients in AF. In patients in SR, reduced LA function is associated with reduced exercise tolerance, independent of LV function.

Identification of Subclinical Heart Failure With Preserved Ejection Fraction in Patients With Symptomatic Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) commonly coexist. We hypothesize that patients with symptomatic AF but without overt clinical HF commonly exhibit subclinical HFpEF according to established hemodynamic criteria. OBJECTIVES: The authors sought to use invasive hemodynamics to investigate the prevalence and implications of subclinical HFpEF in AF ablation patients. METHODS: Consecutive symptomatic AF ablation patients were prospectively recruited. Diagnosis of subclinical HFpEF was undertaken by invasive assessment of left atrial pressure (LAP). Participants had HFpEF if the baseline mean LAP was >15 mm Hg and early HFpEF if the mean LAP was >15 mm Hg after a 500-mL fluid challenge. LA compliance was assessed invasively by monitoring the LAP and LA diameter during direct LA infusion of 15 mL/kg normal saline. LA compliance was calculated as Δ LA diameter/ΔLAP. LA cardiomyopathy was further studied with exercise echocardiography and electrophysiology study. Functional impact was evaluated using cardiopulmonary exercise testing and the AF Symptom Severity questionnaire. RESULTS: Of 120 participants, 57 (47.5%) had HFpEF, 31 (25.8%) had early HFpEF, and 32 (26.7%) had no HFpEF. Both HFpEF and early HFpEF were associated with lower LA compliance compared with those without HFpEF (P < 0.001). Participants with HFpEF and early HFpEF also displayed decreased LA emptying fraction (P = 0.004), decreased LA voltage (P = 0.001), decreased VO2peak (P < 0.001), and increased AF symptom burden (P = 0.002) compared with those without HFpEF. CONCLUSIONS: Subclinical HFpEF is common in AF ablation patients and is characterized by a LA cardiomyopathy, decreased cardiopulmonary reserve and increased symptom burden. The diagnosis of HFpEF may identify patients with AF with the potential to benefit from novel HFpEF therapies. (Characterising Left Atrial Function and Compliance in Atrial Fibrillation; ACTRN12620000639921).

Influence of exercise training on the left atrium: implications for atrial fibrillation, heart failure, and stroke.

The left atrium (LA) plays a critical role in receiving pulmonary venous return and modulating left ventricular (LV) filling. With the onset of exercise, LA function contributes to the augmentation in stroke volume. Due to the growing focus on atrial imaging, there is now evidence that structural remodeling and dysfunction of the LA is associated with adverse outcomes including incident cardiovascular disease. In patients with established disease, pathological changes in atrial structure and function are associated with exercise intolerance, increased hospital admissions and mortality, independent of left ventricular function. Exercise training is widely recommended in patients with cardiovascular disease to improve patient outcomes and maintain functional capacity. There are widely documented changes in LV function with exercise, yet less attention has been given to the LA. In this review, we first describe LA physiology at rest and during exercise, before exploring its association with cardiac disease outcomes including atrial fibrillation, heart failure, and stroke. The adaptation of the LA to short- and longer-term exercise training is evaluated through review of longitudinal studies of exercise training in healthy participants free of cardiovascular disease and athletes. We then consider the changes in LA structure and function among patients with established disease, where adverse atrial remodeling may be implicated in the disease process. Finally, we consider important future directions for assessment of atrial structure and function using novel imaging modalities, in response to acute and chronic exercise.

Malignant Airway Obstruction and Endobronchial Stent Placement: A Systematic Review on the Efficacy and Safety.

The systematic review aims to evaluate the efficacy and safety of endobronchial stent placement for malignant airway obstruction.  A comprehensive search was conducted across multiple databases to identify relevant studies. Cohort studies, randomized controlled trials, and case-control studies examining the outcomes of endobronchial stent placement in patients with malignant airway obstruction were included. Data on pre-treatment evaluation, such as pulmonary function testing, dyspnea severity scoring systems, arterial blood gas parameters, imaging, and degree of obstruction, were also collected. Primary outcomes of interest included post-procedure stenosis, pulmonary function testing evaluation, blood gas parameters, and survival outcomes. Secondary outcomes encompassed improvements in clinical status, dyspnea grade, and procedure-related complications. A total of 27 studies met the inclusion criteria and were included in the systematic review. The included studies demonstrated promising outcomes of endobronchial stent placement in managing malignant airway obstruction. Post-procedure airway diameters, pulmonary function testing, and blood gas parameters improved significantly. Survival outcomes varied among studies. Furthermore, endobronchial stent placement was associated with improvements in clinical status and dyspnea grade. Procedure-related complications ranged from pain, hemoptysis and mucus plugging to stent obstruction, migration and pneumothorax.  This systematic review suggests that endobronchial stent placement is an effective and safe intervention for managing malignant airway obstruction. It offers significant improvements in post-procedure stenosis, pulmonary function testing, blood gas parameters, and clinical outcomes. However, further studies with larger sample sizes and standardized reporting are warranted to better evaluate the long-term efficacy and safety of endobronchial stent placement for malignant airway obstruction.

The Efficacy and Safety of Autologous Blood Patch for Persistent Air Leaks: A Systematic Review and Meta-Analysis.

Persistent air leaks (PALs) are associated with prolonged hospital stays, contamination and sustained infection of the pleural space, and significant morbidity. A fistulous tract between the alveoli and the pleural space is referred to as an alveolar-pleural fistula (APF), whereas a fistulous tract between the bronchiole and the pleural space is referred to as a bronchopleural fistula (BPF). There is no consensus on the treatment, and multiple modalities exist for the management of persistent air leak (PAL). Autologous blood patch (ABP) is a relatively safe and inexpensive method that has been used for many years for the treatment of PALs. We conducted an electronic database search between 08/24/2022 and 08/27/2022 in PubMed, Embase, and Cochrane using keywords. The following keywords were used: "Blood patch" OR "Autologous blood patch" AND "pleurodesis." Our study included all original studies with the prime focus on the etiology of PALs, clinical characteristics, procedural details of ABP, and outcomes of the proposed treatment. The primary outcomes that were the focus of our study were the time to seal the air leak, the time to remove the chest tube after air leak cessation, and the time to discharge from the hospital. To determine the safety of ABP, we also evaluated the procedural outcomes. Our findings suggest a statistically significant decrease in the time to air leak cessation when compared to the control group (mean difference of -3.75 {95% CI: -5.65 to -1.85; P=0.001}) with considerable heterogeneity of I2=85% and P=0.001. However, the difference was not statistically significant when a lower dose of ABP (50 mL) was compared to a higher dose (100 mL) (mean difference of 1.48 {95% CI: -0.07 to 3.02; P=0.06}) and considerable heterogeneity of I2=80% and P=0.03. There was no statistically significant difference in the time to discharge when compared to the control group (mean difference of -2.12 {95% CI: -4.83 to 0.59; P=0.13}) and considerable heterogeneity (I2=95% and P<0.001). When compared to the control group, ABP did not provide any statistically significant difference in the risk ratio for infection (1.18 {95% CI: 0.52 to 2.65; P=0.70} and moderate heterogeneity {I2=33% and P=0.20}), pain (1.18 {95% CI: 0.52 to 2.65; P=0.70} and moderate heterogeneity {I2=33% and P=0.20}), and fever (0.54 {95% CI: 0.27 to 1.10; P=0.09} and no heterogeneity {I2=0% and P=0.50}). Our study concludes that using ABP caused a statistically significant decrease in the time to air leak cessation when compared to the control group. However, the procedure does not provide a statistically significant difference in the time to discharge from the hospital when compared to conservative treatment. Similarly, there was no statistically significant difference in the risk ratio for complications such as infection, pain, and fever when compared to conservative management. More studies need to be conducted to fully understand the efficacy and safety of ABP in the management of PALs.

Malignant Airway Obstruction and the Use of Nd:YAG Laser: A Systematic Review on Its Efficacy and Safety.

Endobronchial malignancies with significant airway obstruction can lead to multiple complications including pneumonia, and atelectasis over a period of time. Various intraluminal treatments have proven their value in palliative treatment for advanced malignancies. Nd:YAG (neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12) laser has established its role as a major palliative intervention due to its minimal side effects and improvement in quality of life by relieving local symptoms. The systematic review was conducted with the goal of elucidating the patient characteristics, pre-treatment parameters, clinical outcomes, and possible complications resulting from the use of the Nd:YAG laser. A thorough literature search for relevant studies was conducted on PubMed, Embase, and Cochrane Library from the inception of the idea to November 24, 2022. Our study included all original studies including retrospective studies and prospective trials, but excluded case reports, case series with less than 10 patients, and studies with incomplete or irrelevant data. A total of 11 studies were included in the analysis. The primary outcomes focused on the evaluation of pulmonary functional tests, postprocedural stenosis, blood gas parameters after the procedure, and survival outcomes. Improvement in clinical status, improvement in objective scale for dyspnea, and complications were the secondary outcomes. Our study shows that Nd:YAG laser treatment is an effective form of palliative treatment to provide subjective and objective improvement in patients with advanced and inoperable endobronchial malignancies. Due to the heterogeneous study populations in the studies reviewed and the presence of many limitations, more studies are still warranted to reach a definitive conclusion.

Phenobarbital and Alcohol Withdrawal Syndrome: A Systematic Review and Meta-Analysis.

Alcohol withdrawal syndrome (AWS) is a complication frequently encountered among patients who are chronic alcohol abusers. It is considered to have a significant impact on the United States healthcare system. It not only has a toll on the healthcare spending but also contributes to significant morbidity and mortality. Benzodiazepines are considered first line in the treatment of AWS. Since patients with alcohol use disorder have downregulated gamma aminobutyric acid (GABA) receptors, this often leads to benzodiazepine resistance. Phenobarbital is also used in the management of alcohol withdrawal syndrome. Here we present a systematic review and meta-analysis of the efficacy and safety of the drug. We conducted an electronic database search for relevant studies published between the inception of the project and November 20, 2022, in three databases, including Medline/PubMed, Embase, and Cochrane Library. Our study included all original studies with prime focus on the baseline characteristics of patients admitted to the intensive care unit (ICU) for alcohol withdrawal syndrome and management/monitoring protocol implemented for its treatment. The primary outcomes that were the focus of our study consisted of changes in the length of hospital stay, length of ICU stay, and changes in scoring systems (for alcohol withdrawal assessment and monitoring) following the implementation of phenobarbital. The secondary outcomes included complications such as intubation and mortality. Based on our analysis, the mean difference in hospital stay was statistically significant at -2.6 (95% CI, -4.48, -0.72, P=0.007) for phenobarbital compared to the benzodiazepine group. We were unable to comment on the heterogeneity in our meta-analysis due to the standard deviation not being reported in one study. There was no statistically significant difference regarding the length of stay in the intensive care unit compared to the control/comparative arm, with a mean difference of -1.17 (95% CI, -1.17, 0.09, P=0.07), with considerable heterogeneity (I2=77%, P=0.002). Our meta-analysis also investigated the risk of intubation between the phenobarbital and the control/comparative group. There was statistically significant difference in the incidence of intubation, relative risk (RR) 0.52 (95% CI, 0.25, 1.08, P=0.08), with considerable heterogeneity (I2=80%, P=0.0001). Our study concludes that phenobarbital is an effective tool in the management of AWS in an ICU setting. However, various studies have reported contradictory results, and vital information appears to be lacking. Moreover, there is a lack of uniformity in terms of phenobarbital dosing. Drug administration should be adapted according to the severity of the symptoms. Further studies need to be conducted discussing the safety profile and adverse effects of the drug when it comes to the management of alcohol withdrawal syndrome.

The Burden of Cardiac Implantable Electronic Device Checks in the Peri-MRI Setting: The CHECK-MRI Study.

BACKGROUND: Most modern cardiac implantable electronic device (CIED) systems are now compatible with magnetic resonance imaging (MRI) scans. The requirement for both pre- and post-MRI CIED checks imposes significant workload to the cardiac electrophysiology service. Here, we sought to determine the burden of CIED checks associated with MRI scans. METHODS: We identified all CIED checks performed peri-MRI scans at our institution over a 3-year period between 1 July 2017 to 30 June 2020, comprising three separate financial years (FY). Device check reports, MRI scan reports and clinical summaries were collated. The workload burden was determined by assessing the occasions and duration of service. Analysis was performed to determine cost burden/projections for this service and identify factors contributing to the workload. RESULTS: A total of 739 CIED checks were performed in the peri-MRI scan setting (370 pre- and 369 post-MRI scan), including 5% (n=39) that were performed outside of routine hours (weekday <8 am or >5 pm, and weekends). MRIs were performed for 295 patients (75±13 years old, 64% male) with a CIED (88% permanent pacemaker, and 12% high voltage device), including 49 who had more than one MRI scan. The proportion of total MRI scans for patients with a CIED in-situ increased each FY (from 0.5% of all MRIs in FY1, to 0.9% in FY2, to 1.0% in FY3). The weekly workload increased (R2=0.2, p<0.001), but with week-to-week variability due to ad hoc scheduling (209 days with only one MRI vs 78 days with ≥2 MRIs for CIED patients). The projected annual cost of this service will increase to AUD$161,695 in 10 years for an estimated annual 546 MRI scans for CIED patients. CONCLUSIONS: There is an increasing workload burden and expense associated with CIED checks in the peri-MRI setting. Appropriate budgeting, staff allocation and standardisation of automated CIED pre-programming features among manufacturers are urgently needed.

Hypertension and atrial fibrillation.

Hypertension is the most prevalent cardiovascular risk factor underlying atrial fibrillation and is present in up to 40% of patients with atrial fibrillation. Furthermore, attributable risk studies have shown that a history of hypertension contributes to up to 24% of incident atrial fibrillation. New data suggest that even early forms of hypertension (prehypertension and aortic stiffness) are associated with an increased risk of atrial fibrillation development. Hypertension and prehypertension are therefore critical mediators for the development of atrial fibrillation. Mechanisms for the association between hypertension and atrial fibrillation include diffuse electro-structural changes to the left atrium, driven by the haemodynamic and neurohormonal influences of hypertension and other, frequently coexisting, cardiovascular risk factors. Management of hypertension in atrial fibrillation should focus not only on blood pressure reduction but also on a comprehensive risk factor modification strategy. Such strategies have been shown to be associated with significant improvements in atrial fibrillation symptom burden as well as improved arrhythmia-free survival and reversal of the progression of atrial fibrillation. These strategies should focus on dietary modifications as well as prescribed exercise programmes involving a multidisciplinary team and patient-centred atrial fibrillation care. Risk factor management, supplemented by antihypertensive medications as needed, provides the optimum strategy for improving outcomes and even reversing the natural progression of atrial fibrillation in patients with hypertension.

Cardiorespiratory fitness, obesity and left atrial function in patients with atrial fibrillation.

Background: Low cardiorespiratory fitness (CRF) and obesity are related to the development and maintenance of atrial fibrillation (AF). The aim of this study was to determine the association between CRF, obesity and left atrial (LA) mechanical parameters in patients with AF. Methods: A cohort of 154 consecutive paroxysmal and persistent AF patients (Age: 62 ± 10, 26% female) referred for exercise stress testing and transthoracic echocardiography were included. We included patients in sinus rhythm with preserved left ventricular ejection fraction who were able to complete a maximal exercise test. Left atrial strain in the reservoir (LASr), booster (LASb) and conduit (LASc) phases were assessed using dedicated software. LA stiffness, emptying fraction (LAEF) and LA to LV ratio were calculated using previously described formulas. Results: CRF was positively associated with LAEF (ß = 1.3, 95% CI 0.1-2.3, p = 0.02), reservoir (ß = 1.5, 95% CI 0.9-2.1, p < 0.001), booster (ß = 0.8, 95% CI 0.4-1.2, p < 0.001) and conduit strain (ß = 0.7, 95% CI 0.3-1.1, p = 0.001). We observed an inverse association between CRF and both LA stiffness index (ß = -0.02, 95% CI (-0.03)-(-0.01), p < 0.001) and LA to LV ratio (ß = -0.03, 95% CI (-0.04)-(-0.01), p < 0.001). Obese patients had significantly higher indexed LA volumes compared to overweight and normal BMI patients. The association between obesity and measures of LA function and stiffness did not reach statistical significance. Conclusion: Among AF patients, higher CRF was independently associated with greater LA function and compliance. Obesity was associated with higher LA volumes yet preserved mechanical function.

Frequency and prognostic significance of atrial fibrillation in acute pulmonary embolism: A pooled analysis.

OBJECTIVE: To summarize data on the prevalence/incidence, risk factors and prognosis of atrial fibrillation (AF) in patients with acute pulmonary embolism (aPE). METHODS: MEDLINE, Embase, and Web of Science were searched to identify all published studies providing relevant data through December 12, 2021. Random-effects meta-analysis method was used to pool estimates. RESULTS: We included 27 studies reporting data from a pooled population of 819,380 patients. The prevalence rates were 11.3% for pre-existing AF, 4.7% for newly diagnosed AF, and 13.2% for prevalent (total) AF. Predictors of newly diagnosed AF (from one study) included congestive heart failure (adjusted odds ratio [aOR] 3.33, 95% CI: 1.81-6.12), ischemic heart disease (aOR 3.25, 95% CI: 1.65-6.39), massive PE (aOR 2.67, 95% CI: 1.19-5.99). Overall, AF was associated with increased risk of short-term (aOR 1.54, 95% CI: 1.44-1.64) and long-term mortality (aOR 1.58, 95% CI: 1.26-1.97). In subgroup analyses, all types of AF were associated with increased risk of short-term mortality: pre-existing AF (aOR 1.90, 95% CI: 1.59-2.27), newly diagnosed AF (aOR 1.51, 95% CI: 1.18-1.93), and prevalent AF (aOR 1.50, 95% CI: 1.42-1.60). Pre-existing AF (aOR 2.08, 95% CI: 1.27-3.42) and prevalent AF (aOR 1.29, 95% CI: 1.02-1.63) were also associated with higher long-term mortality. CONCLUSION: AF is present in about one in eight patients with aPE, and is associated with increased short- and long-term mortality. AF might improve risk stratification in patients with aPE.

Coronavirus disease 2019 and renal transplantation.

Ever since the severe acute respiratory syndrome virus causing coronavirus disease 2019 (COVID-19) struck the world, global health strategies have changed significantly. According to the Centers for Disease Control and Prevention, kidney transplant recipients are stratified as being high risk of developing fatal illness from COVID-19 infection. Kidney transplant is the gold-standard treatment for end-stage kidney disease subjects. During the pandemic, significant concerns have emerged regarding continuation of kidney transplant surgeries and management of kidney transplant recipients post-transplant. The added risk of immunosuppression in this cohort was and remains a theoretical concern, posing a potential risk of transplantation rather than benefit. This comprehensive review aims to cover most of the faced challenges in kidney transplantation in different stages of the pandemic. In addition, it will elucidate the epidemiology, nature, course of the disease, surgical consideration in donors and recipients as well as role of immunosuppression and management of COVID-19 infected kidney transplant recipients during these extraordinary circumstances.

Current systematic reviews and meta-analyses of COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has left a significant impact on the world's health, economic and political systems; as of November 20, 2020, more than 57 million people have been infected worldwide, with over 1.3 million deaths. While the global spotlight is currently focused on combating this pandemic through means ranging from finding a treatment among existing therapeutic agents to inventing a vaccine that can aid in halting the further loss of life. AIM: To collect all systematic reviews and meta-analyses published related to COVID-19 to better identify available evidence, highlight gaps in knowledge, and elucidate further meta-analyses and umbrella reviews that are yet to be performed. METHODS: We explored studies based on systematic reviews and meta-analyses with the key-terms, including severe acute respiratory syndrome (SARS), SARS virus, coronavirus disease, COVID-19, and SARS coronavirus-2. The included studies were extracted from Embase, Medline, and Cochrane databases. The publication timeframe of included studies ranged between January 01, 2020, to October 30, 2020. Studies that were published in languages other than English were not considered for this systematic review. The finalized full-text articles are freely accessible in the public domain. RESULTS: Searching Embase, Medline, and Cochrane databases resulted in 1906, 669, and 19 results, respectively, that comprised 2594 studies. 515 duplicates were subsequently removed, leaving 2079 studies. The inclusion criteria were systematic reviews or meta-analyses. 860 results were excluded for being a review article, scope review, rapid review, panel review, or guideline that produced a total of 1219 studies. After screening articles were categorized, the included articles were put into main groups of clinical presentation, epidemiology, screening and diagnosis, severity assessment, special populations, and treatment. Subsequently, there was a second subclassification into the following groups: gastrointestinal, cardiovascular, neurological, stroke, thrombosis, anosmia and dysgeusia, ocular manifestations, nephrology, cutaneous manifestations, D-dimer, lymphocyte, anticoagulation, antivirals, convalescent plasma, immunosuppressants, corticosteroids, hydroxychloroquine, renin-angiotensin-aldosterone system, technology, diabetes mellitus, obesity, pregnancy, children, mental health, smoking, cancer, and transplant. CONCLUSION: Among the included articles, it is clear that further research is needed regarding treatment options and vaccines. With more studies, data will be less heterogeneous, and statistical analysis can be better applied to provide more robust clinical evidence. This study was not designed to give recommendations regarding the management of COVID-19.

Liver transplantation during global COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory disease respiratory syndrome coronavirus-2 has significantly impacted the health care systems globally. Liver transplantation (LT) has faced an unequivocal challenge during this unprecedented time. This targeted review aims to cover most of the clinical issues, challenges and concerns about LT during the COVID-19 pandemic and discuss the most updated literature on this rapidly emerging subject.

Regulation of sinus node pacemaking and atrioventricular node conduction by HCN channels in health and disease.

The funny current, If, was first recorded in the heart 40 or more years ago by Dario DiFrancesco and others. Since then, we have learnt that If plays an important role in pacemaking in the sinus node, the innate pacemaker of the heart, and more recently evidence has accumulated to show that If may play an important role in action potential conduction through the atrioventricular (AV) node. Evidence has also accumulated to show that regulation of the transcription and translation of the underlying Hcn genes plays an important role in the regulation of sinus node pacemaking and AV node conduction under normal physiological conditions - in athletes, during the circadian rhythm, in pregnancy, and during postnatal development - as well as pathological states - ageing, heart failure, pulmonary hypertension, diabetes and atrial fibrillation. There may be yet more pathological conditions involving changes in the expression of the Hcn genes. Here, we review the role of If and the underlying HCN channels in physiological and pathological changes of the sinus and AV nodes and we begin to explore the signalling pathways (microRNAs, transcription factors, GIRK4, the autonomic nervous system and inflammation) involved in this regulation. This review is dedicated to Dario DiFrancesco on his retirement.

Atrial Fibrillation and Heart Failure: Epidemiology, Pathophysiology, Prognosis, and Management.

Atrial fibrillation (AF) and heart failure (HF) have similar risk factors, frequently coexist, and potentiate each other in a vicious cycle. Evidence suggests the presence of AF in both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) increases the risk of all-cause mortality and stroke, particularly when AF is incident. Catheter ablation may be an effective strategy in controlling symptoms and improving quality of life in AF-HFrEF. Strong data guiding management of AF-HFpEF are lacking largely due to its challenging diagnosis. Improving outcomes associated with these coexistent conditions requires further careful investigation.