BACKGROUND
Atrial fibrillation (AF) in heart failure (HF) is generally considered a negative prognostic factor. Recent studies indicate that the incidence of AF might be decreased by renin angiotensin aldosterone system inhibitors. The identification of a treatment to prevent its occurrence is likely to improve patients outcome. The aims of these subanalyses of Val-HeFT were to assess (a) the effects of valsartan in the prevention of AF, (b) the independent predictors of this event, and (c) the prognostic role of AF occurrence.


METHODS AND RESULTS
The occurrence of AF was evaluated based on adverse event reports in the patients with HF enrolled in Val-HeFT. Patients were randomized to valsartan or placebo on top of their prescribed treatments for HF. During the mean 23 months of follow-up, AF was reported in 287/4395 patients (6.53%) in sinus rhythm at baseline, of whom 113/2205 (5.12%) were allocated to valsartan and 174/2190 (7.95%) to placebo (P = .0002). Multivariable analysis showed that brain natriuretic peptide (BNP) levels at baseline above the median value (HR 2.28, 95% CI 1.75-2.98), age over 70 years (HR 1.51, 95% CI 1.17-1.95), male sex (HR 1.53, 95% CI 1.07-2.18), and the valsartan treatment (HR 0.63, 95% CI 0.49-0.81) were independently associated with AF occurrence. Cox multivariable regression analysis showed that occurrence of AF was independently associated with a worse prognosis, with the adjusted hazard risks for all-cause mortality and combined mortality/morbidity of 1.40 (95% CI 1.16-1.58) and 1.38 (95% CI 1.12-1.70), respectively.


CONCLUSIONS
The results of the present study demonstrate that (a) adding valsartan to prescribed therapy for HF significantly reduces the incidence of AF by 37%; (b) BNP level and advanced age were the strongest independent predictors for AF occurrence; and (c) AF occurrence further worsens the outcome in patients with HF.

Valsartan Reduces the Incidence of Atrial Fibrillation in Patients With Heart Failure: Results From the Valsartan Heart Failure Trial (Val-HeFT)

BACKGROUND\nIn patients with atrial fibrillation that is refractory to drug therapy, radio-frequency ablation of the atrioventricular node and implantation of a permanent pacemaker are an alternative therapeutic approach. The effect of this procedure on long-term survival is unknown.\n\n\nMETHOD\nWe studied all patients who underwent ablation of the atrioventricular node and implantation of a permanent pacemaker at the Mayo Clinic between 1990 and 1998. Observed survival was compared with the survival rates in two control populations: age- and sex-matched members of the Minnesota population between 1970 and 1990 and consecutive patients with atrial fibrillation who received drug therapy in 1993.\n\n\nRESULTS\nA total of 350 patients (mean [+/-SD] age, 68+/-11 years) were studied. During a mean of 36+/-26 months of follow-up, 78 patients died. The observed survival rate was significantly lower than the expected survival rate based on the general Minnesota population (P<0.001). Previous myocardial infarction (P<0.001), a history of congestive heart failure (P=0.02), and treatment with cardiac drugs after ablation (P=0.03) were independent predictors of death. Observed survival among patients without these three risk factors was similar to expected survival (P=0.43). None of the 26 patients with lone atrial fibrillation died during follow-up (37+/-27 months). The observed survival rate among patients who underwent ablation was similar to that among 229 controls with atrial fibrillation (mean age, 67+/-12 years) who received drug therapy (P=0.44).\n\n\nCONCLUSIONS\nIn the absence of underlying heart disease, survival among patients with atrial fibrillation after ablation of the atrioventricular node is similar to expected survival in the general population. Long-term survival is similar for patients with atrial fibrillation, whether they receive ablation or drug therapy. Control of the ventricular rate by ablation of the atrioventricular node and permanent pacing does not adversely affect long-term survival.

Long-term survival after ablation of the atrioventricular node and implantation of a permanent pacemaker in patients with atrial fibrillation

The natural history of atrial fibrillation (AF) is characterized by a gradual worsening with time. The recent finding that AF itself produces changes in atrial function and structure has provided a possible explanation for the progressive nature of this arrhythmia. Electrical remodeling (shortening of atrial refractoriness) develops within the first days of AF and contributes to an increase in stability of AF. However, 'domestication of AF' must also depend on a 'second factor' since the persistence of AF continues to increase after electrical remodeling has been completed. Atrial contractile remodeling (loss of contractility) leads to a reduced atrial transport function after cardioversion of AF. An important clinical consequence is that during several days after restoration of sinus rhythm, the risk of atrial thrombus formation is still high. In addition, the reduction of atrial contractility during AF may enhance atrial dilatation which may add to the persistence of AF. Tachycardia-induced structural remodeling takes place in a different time domain (weeks to months). Myolysis probably contributes to the loss of atrial contractile force. Although it might explain the loss of efficacy of pharmacological cardioversion and the development of permanent AF, the role of structural remodeling in the progression of AF is still unclear. Atrial structural remodeling also occurs as a result of heart failure and other underlying cardiovascular diseases. The associated atrial fibrosis might explain intra-atrial conduction disturbances and the susceptibility for AF. Thus, both AF itself and the underlying heart disease are responsible for the development of the arrhythmogenic substrate. New strategies for prevention and termination of AF should be build on our knowledge of the mechanisms and time course of AF-induced atrial remodeling.

Electrical, Contractile and Structural Remodeling during Atrial Fibrillation.(State-of-the-Art)(Plenary Session 3 (PL3) (A) : Atrial Fibrillation : From bench to bedside)(Special Program)

Background/aims The two-pore-domain potassium channel TASK-1 regulates atrial action potential duration. Due to the atrium-specific expression of TASK-1 in the human heart and the functional upregulation of TASK-1 currents in atrial fibrillation (AF), TASK-1 represents a promising target for the treatment of AF. Therefore, detailed knowledge of the molecular determinants of TASK-1 inhibition may help to identify new drugs for the future therapy of AF. In the current study, the molecular determinants of TASK-1 inhibition by the potent and antiarrhythmic compound A293 (AVE1231) were studied in detail. Methods Alanine-scanning mutagenesis together with two-electrode voltage-clamp recordings were combined with in silico docking experiments. Results Here, we have identified Q126 located in the M2 segment together with L239 and N240 of the M4 segment as amino acids essential for the A293-mediated inhibition of TASK-1. These data indicate a binding site which is different to that of A1899 for which also residues of the pore signature sequence and the late M4 segments are essential. Using in silico docking experiments, we propose a binding site at the lower end of the cytosolic pore, located at the entry to lateral side fenestrations of TASK-1. Strikingly, TASK-1 inhibition by the low affinity antiarrhythmic TASK-1 blockers propafenone, amiodarone and carvedilol was also strongly diminished by mutations at this novel binding site. Conclusion We have identified the A293 binding site in the central cavity of TASK-1 and propose that this site might represent a conserved site of action for many low affinity antiarrhythmic TASK-1 blockers.

/pdf/identification-of-the-a293-ave1231-binding-site-in-the-3ivzvzdd32.pdf

Identification of the A293 (AVE1231) Binding Site in the Cardiac Two-Pore-Domain Potassium Channel TASK-1: a Common Low Affinity Antiarrhythmic Drug Binding Site.

Objectives:Coronary artery diseases are regarded as the main cause of mortality in most countries. The present study aims at evaluating variations and studying its complications in Iranian patients within past 20 years.Methods:This cross-sectional analytical–descriptive study retrospectively evaluated the files of 600 patients with acute myocardial infarction during a 20-year period. Basic data and laboratory information, chemotherapies and intervention treatments of patients were registered in special forms and compared regarding the mentioned time intervals.Results:There were 440 (73.3%) male and 160 (26.7%) female patients and mean age of the patients was 60.03 ± 11.61 years. Mean duration of hospitalization (p < 0.001) and prevalence of smoking (p < 0.001) had significantly decreased in the past two decades. There was no meaningful difference when considering mortality rate (p = 0.533) and cardiac insufficiency (p = 0.403).Conclusion:The results indicate prominent improvement in the management process...

https://journals.sagepub.com/doi/pdf/10.1177/1753944712474093

Twenty-year route of prevalence of risk factors, treatment patterns, complications, and mortality rate of acute myocardial infarction in Iran.

http://www.ijidonline.com/article/S1201971222003496/pdf

COVID-19 prophylaxis with doxycycline and zinc in health care workers: a prospective, randomized, double-blind clinical trial

Insuffisance cardiaque et fibrillation atriale sont deux affections dont la prevalence croit avec le vieillissement de la population. Cette association constitue un probleme auquel le cardiologue est de plus en plus souvent confronte. L’insuffisance cardiaque favorise la fibrillation atriale et la fibrillation atriale aggrave l’insuffisance cardiaque. La prise en charge therapeutique de ces patients est complexe. Elle peut s’envisager de deux manieres : controle de la frequence, c’est-a-dire respect de la fibrillation atriale et prescription de medicaments ralentisseurs, ou controle du rythme : cardioversion lorsque le patient est en fibrillation persistante et maintien du rythme sinusal par les medicaments antiarythmiques. Cependant, les antiarythmiques de classe I sont contre-indiques chez ces patients, les meilleurs resultats etant apportes par l’amiodarone qui peut avoir des effets deleteres extracardiaques. Les methodes therapeutiques non pharmacologiques peuvent egalement avoir leur place, qu’il s’agisse de l’ablation ou de la resynchronisation. Il y a actuellement de plus en plus d’interet manifeste pour les medicaments du systeme renine-angiotensine dans l’insuffisance cardiaque et dans la fibrillation atriale. Au-dela de leur effet therapeutique sur l’insuffisance cardiaque, ils peuvent egalement avoir un effet preventif sur la fibrillation atriale lorsqu’ils sont utilises chez l’hypertendu. Des essais prospectifs randomises de grande ampleur sont actuellement en cours de realisation pour tenter de prouver definitivement cette hypothese.

Fibrillation atriale et insuffisance cardiaque

Atrial fibrillation and heart failure

INTRODUCTION Cardiovascular disease is the most common cause of death in chronic hemodialysis patients(1). Cardiac surgery in hemodialysis patients exposes to higher risks inherent in the particular status of these patients. The aim of our study is to report the perioperative particularities of hemodialysis patients undergoing cardiac surgery, and to determine the impact of preoperative clinical status on hospital and late morbidity and mortality. METHODS Between January 1998 and December 2012, 48 patients in chronic hemodialysis (HD) and candidates for cardiac surgery on cardiopulmonary bypass were retrospectively included. RESULTS The mean age was 56 years. Causes of renal insufficiency were dominated by diabetes (n = 20; 42%) and nephroangiosclerosis (n= 9, 18.8%). The duration of HD was 48.22 ± 44.5 months (1 month -11 years). Surgical procedures included coronary artery bypass grafting CABG (n = 33, 68.75%), Valvular replacement (n = 13, 27%) and combined surgery (n = 2, 4.25%). Nine patients (18.8%) underwent emergency surgery. The mean Euroscore I was 8.82 ± 7.76. Hospital mortality was 20.8%. Postoperative complications were observed in 87.5%patients. Age, diabetic nephropathy, Duration of hemodialysis greater than 54 months, preoperative hemoglobin <9 g / dl, combined surgery and emergency surgery were independent predictors of hospital mortality with odds ratio respectively 1.21; 2.7; 2.54; 1.83; 2.54 and 2.85. The survival rates at 1, 4 and 7 years were respectively 75, 65 and 50%. CONCLUSION Age, diabetic nephropathy, Duration of hemodialysis greater than 54 months, preoperative hemoglobin <9 g / dl, combined surgery and emergency surgery are predictive factors for hospital mortality. Early diagnosis of coronary and valvular damage and preoperative preparation considering these factors could improve the prognosis.

Particularities of cardiac surgery in chronic hemodialysis patients.

Background Stratification of surgical risk is an important step in cardiac surgery, often based on the estimation of operative mortality. The EuroSCORE II (ES II) incorporates several factors in the calculation of mortality, but few are specific to Infectious endocarditis (IE). Aim Our study is aimed to evaluate the predictive power of the Es II in the surgery of IE and to test its discriminating power according to certain specific parameters of the IE. Methods 55 surgical procedures were carried out between January 2000 and June 2012 (37 EI on native valves and 18 on prosthesis). The mortality observed was compared with the mortality predicted by Es II. The discriminant capacity of the Es II model was tested using the receiver operating characteristic (ROC) curve model by comparing the areas under the curve (AsC). Results For our cohort The observed mortality was 30.9 % , the mortality predicted by Es II was 10.5%. in general, the EsII discriminatory capacity for mortality was satisfactory: the ROC AsC was 0,76. By analyzing the subgroups of the endocarditis, Es II lost its discriminating power: theROC AsC was: 0.64 for staphylococcal, 0.62 for the annular abscess and 0.56 for endocarditis on prosthesis. Conclusion The EuroSCORE II model has a satisfactory discriminating power in the IE. However, analysis of subgroups leads to decrease in this discriminating power. Thus, some specific parameters of the IE, which do not appear in the EuroSCORE II model, should be taken into accountwhen analyzing mortality.

Karima Taamallah

Papers

COVID-19 prophylaxis with doxycycline and zinc in health care workers: a prospective, randomized, double-blind clinical trial

Fibrillation atriale et insuffisance cardiaque

Atrial fibrillation and heart failure

Particularities of cardiac surgery in chronic hemodialysis patients.

Value of euroscore II to predict operative mortality in infectious endocarditis surgery.