Epidemiological Profile of Atrial Fibrillation: A Contemporary Perspective

Increased risk of atrial fibrillation in patients with psoriasis: A meta-analysis of observational studies

BACKGROUND

Several epidemiological studies have shown that psoriasis increases the risk of developing atrial fibrillation but evidence of this is still scarce.

AIMS

Our objective was to systematically review, synthesise and critique the epidemiological studies that provided information about the relationship between psoriasis and atrial fibrillation risk.

METHODS

We searched through PubMed, EMBASE and the bibliographies for articles published between 1 January 2000, and 1 November 2017, that reported on the association between psoriasis and atrial fibrillation. All abstracts, full-text articles and sources were reviewed with duplicate data excluded. Summary relative risks (RRs) with 95% CI were pooled using a random effects model.

RESULTS

We identified 252 articles, of these eight unique abstracts underwent full-text review. We finally selected six out of these eight studies comprising 11,187 atrial fibrillation patients. The overall pooled relative risk (RR) of atrial fibrillation was 1.39 (95% CI: 1.257-1.523, P < 0.0001) with significant heterogeneity (I2 = 80.316, Q = 45.723, τ2 = 0.017, P < 0.0001) for the random effects model. In subgroup analysis, the greater risk was found in studies from North America, RR 1.482 (95% CI: 1.119-1.964, P < 0.05), whereas a moderate risk was observed in studies from Europe RR 1.43 (95% CI: 1.269-1.628, P < 0.0001).

LIMITATIONS

We were only able to include six studies with 11,178 atrial fibrillation patients, because only a few such studies have been published.

CONCLUSION

Our results showed that psoriasis is significantly associated with an increased risk of developing atrial fibrillation. Therefore, physicians should monitor patient's physical condition on a timely basis.

Association of soluble suppression of tumorigenicity 2 with new-onset atrial fibrillation in acute myocardial infarction

Background The combination of acute myocardial infarction (AMI) and atrial fibrillation (AF) is still a thorny problem in the clinic. At present, there are few reports on the role of soluble suppression of tumorigenicity 2 (sST2) in AF after AMI. This study was to explore the predictive value of sST2 in patients with AMI for new-onset AF. Methods This is a single-center retrospective clinical observation study. We continuously included AMI patients from September 2019 to November 2021. The concentration of sST2 in blood samples was determined. During admission, suspicious heart rhythm was recorded by electrocardiogram (ECG) monitoring, and new-onset AF was confirmed by immediate body surface ECG. Results After multiple factors were included, age, right coronary artery (RCA), high sensitivity c-reactive protein (hs-CRP), left ventricular ejection fraction (LVEF), and sST2 were still risk factors for new-onset AF. The area under curve (AUC) value of age and sST2 was more than 0.7, which showed good diagnostic value. For re-evaluation, the sST2 was added to the clinical new-onset AF prediction model. It was found that the integrated discrimination improvement (IDI) and net reclassification index (NRI) in the model were improved significantly. Conclusion sST2 is an independent predictor of new-onset AF in patients with AMI and can improve the accuracy of the AF risk model.

Role of Oxidative DNA Damage and Repair in Atrial Fibrillation and Ischemic Heart Disease

Atrial fibrillation (AF) and ischemic heart disease (IHD) represent the two most common clinical cardiac diseases, characterized by angina, arrhythmia, myocardial damage, and cardiac dysfunction, significantly contributing to cardiovascular morbidity and mortality and posing a heavy socio-economic burden on society worldwide. Current treatments of these two diseases are mainly symptomatic and lack efficacy. There is thus an urgent need to develop novel therapies based on the underlying pathophysiological mechanisms. Emerging evidence indicates that oxidative DNA damage might be a major underlying mechanism that promotes a variety of cardiac diseases, including AF and IHD. Antioxidants, nicotinamide adenine dinucleotide (NAD⁺) boosters, and enzymes involved in oxidative DNA repair processes have been shown to attenuate oxidative damage to DNA, making them potential therapeutic targets for AF and IHD. In this review, we first summarize the main molecular mechanisms responsible for oxidative DNA damage and repair both in nuclei and mitochondria, then describe the effects of oxidative DNA damage on the development of AF and IHD, and finally discuss potential targets for oxidative DNA repair-based therapeutic approaches for these two cardiac diseases.

Safety and efficacy of dual versus triple antithrombotic therapy (DAT vs TAT) in patients with atrial fibrillation following a PCI: a systematic review and network meta-analysis

OBJECTIVE

Creating an appropriate antithrombotic therapy for patients with atrial fibrillation (AF) who have undergone percutaneous coronary intervention (PCI) remains a dilemma. Several clinical trials compared the use of a dual antithrombotic therapy (DAT) regimen with a direct oral anticoagulants including (apixaban, dabigatran, edoxaban or rivaroxaban) and a P2Y12 inhibitor versus a triple antithrombotic therapy (TAT) that includes a vitamin K antagonist plus aspirin and a P2Y12 inhibitor in patients with AF who have undergone PCI. However, there are no head-to-head trials comparing the DAT regimens to each other. We aimed to compare the efficacy and safety of DAT regimens using a network meta-analysis (NMA) approach.

DESIGN

A systematic review and NMA of randomised clinical trials.

METHODS

We conducted a systematic literature review to identify relevant randomised clinical trials and performed a Bayesian NMA for International Society on Thrombosis and Haemostasis (ISTH) major or clinically relevant non-major (CRNM) bleeding, all-cause mortality, stroke, myocardial infarction (MI) and stent thrombosis outcomes. We used NetMetaXL V.1.6.1 and WinBUGS V.1.4.3 for the NMA and estimated the probability of ranking the treatments based on the surface under the cumulative ranking curve.

RESULTS

The comparison between DAT regimens showed no significant difference in the safety or efficacy outcomes. Apixaban regimen was ranked first as the preferred therapy in terms of ISTH major or CRNM bleeding and stroke, with a probability of 52% and 54%, respectively. Rivaroxaban regimen was the preferred therapy in terms of MI and stent thrombosis, with a probability of 34% and 27%, respectively. Dabigatran regimen was ranked first in terms of all-cause mortality, with a probability of 28%.

CONCLUSION

The DAT regimens are as safe and effective as TAT regimens. However, ranking probabilities for the best option in the selected outcomes can be used to guide the selection among these agents based on different patients' conditions.

Monocyte Chemoattractant Protein-1-Induced Protein in Age-Related Atrial Fibrillation and Its Association with Circulating Fibrosis Biomarkers

BACKGROUND

Atrial fibrillation (AF), for which age is an independent risk factor, is the most common persistent arrhythmia. Monocyte chemoattractant protein-1-induced protein (MCPIP), a transcription factor that induces a series of inflammation and cell death procedures, has been indicated to cause cardiomyocyte death in ischemic cardiomyopathy. The objective of this research was to investigate the relationship between age-related AF and MCPIP.

METHODS

A total of 1,084 participants were included in this study, including 542 AF patients and 542 non-AF controls. Their medical histories were collected and analyzed. Moreover, blood samples were collected, and ELISA tests for expression of the inflammatory factor MCPIP and the fibrosis biomarkers pro-collagen type III N-terminal peptide (PIIINP) and type I collagen C-terminal telopeptide (ICTP) were conducted. Finally, a correlation analysis of these inflammatory factors and biomarkers was performed based on the ELISA results.

RESULTS

We compared the echocardiography results of AF patients and found that the left ventricular ejection fraction and left atrial appendage velocity decreased with age (p < 0.05). Moreover, ELISA analysis of these samples showed that the expression of MCPIP was the highest in elderly patients with AF (p < 0.05), and there was no significant difference in expression between adult AF patients and elderly controls (p > 0.05). Finally, the correlation analysis demonstrated that the expressions of MCPIP, PIIINP, and ICTP were positively correlated in the elderly AF patient group, the adult AF group, and the elderly control group (p < 0.05).

CONCLUSION

MCPIP expression was higher in age-related AF than in the other patient groups and it was associated with AF-induced fibrosis.

Baseline atrial fibrillation is associated with contrast-induced nephropathy after cardiac catheterization in coronary artery disease: Systemic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia, independently associated with significant mortality and morbidity. Recent studies suggest that AF is potentially associated with contrast-induced nephropathy (CIN) in patients with coronary artery disease (CAD) undergoing catheterization. However, the association was not conclusive. Thus, we assessed the association between AF in patients with CAD and CIN by a systematic review of the literature and a meta-analysis.

HYPOTHESIS

AF is a predictor of CIN in patients with CAD.

METHODS

We comprehensively searched the databases of MEDLINE and EMBASE from inception to April 2018. Included studies were published observational studies that compared the risk of CIN among CAD patients with AF vs those without AF. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals (CIs).

RESULTS

Eight cohort studies from June 2007 to November 2017 were included in this meta-analysis involving 16,691 subjects with CAD (1,030 with AF and 15,661 without its presence). The presence of AF was associated with CIN (pooled risk ratio = 2.17, 95% CI: 1.50-3.14, P < 0.001, I² = 54.1%). In our subgroup analysis by urgency and multivariable adjustment, both groups still showed substantial association between AF and CIN (P < 0.05).

CONCLUSIONS

AF increased the risk of CIN up to two fold among patients with CAD compared to the absence of it. Our study suggests that the presence of AF in CAD is prognostic for the development of CIN.

Patients without comorbidities at the time of diagnosis of atrial fibrillation: causes of death during long-term follow-up compared to matched controls

BACKGROUND

Little is known about the long-term, cause-specific mortality risk in patients without comorbidities at the time of diagnosis of atrial fibrillation (AF).

METHODS

From a nation-wide registry of patients hospitalized with incident AF between 1995 and 2008 we identified 9 519 patients with a first diagnosed AF and no comorbidities at the time of AF diagnosis. They were matched with 12 468 controls. The follow-up continued until December 2008. Causes of death were classified according to the ICD-10 codes.

RESULTS

During follow-up, 11.1% of patients with AF and 8.3% of controls died. Cardiovascular diseases were the most common causes of death and the only diagnoses which showed significantly higher relative risk in patients with AF than controls (HR 2.0, 95% CI 1.8-2.3), and the relative risk was significantly higher in women than in men. Stroke was a more common cause among patients with AF, 13.1% versus 9.7% (HR 2.7, 95% CI 1.8-4.0), while cerebral hemorrhage was more common among controls, 4.7% versus 10.2% (HR 0.9, 95% CI 0.6-1.5). The time from AF diagnosis to death was 6.0 ± 3.1 years.

CONCLUSIONS

In patients with incident AF and no known comorbidities at the time of AF diagnosis, only cardiovascular diseases were more often causes of death as compared to controls. Women carried a significantly higher relative risk than men.

Effect of Atrial Fibrillation on Contrast-Induced Nephropathy Development in Patients With Non-ST-Segment Elevation Myocardial Infarction

We investigated the relationship between atrial fibrillation (AF) and contrast-induced nephropathy (CIN) in patients with non-ST-segment elevation myocardial infarction (NSTEMI); 1045 consecutive patients undergoing percutaneous coronary interventions were enrolled. Risk factors for CIN were investigated. Baseline characteristics, except oral anticoagulant use, were similar between patients with and without AF. Patients with CIN show higher presence of diabetes mellitus (DM), coronary artery bypass graft surgery history, Mehran score, baseline creatinine levels, baseline glomerular filtration rate (GFR), peak troponin levels, left ventricular ejection fraction (LVEF), and presence of AF ( P < .05). In multivariate logistic regression analyses, the presence of DM (odds ratio [OR], 2.333; 95% confidence interval [CI], 1.222-4.457; P = .010), Mehran score (OR, 1.269; 95% CI, 1.152-1.398; P < .001), baseline GFR (OR, 0,954; 95% CI, 0.944-0.964 P < .001), left anterior descending artery originated infarction (OR, 1.594; 95% CI, 1.061-2.398; P = .025), LVEF value (OR, 0.956; 95% CI, 0.926-0.986; P = .005), and the presence of AF (OR, 3.830; 95% CI, 1.239-11.839; P = .020) were independent predictors of CIN. Atrial fibrillation can be related to CIN development in patients with NSTEMI.

Keeping up the balance: role of HDACs in cardiac proteostasis and therapeutic implications for atrial fibrillation

Cardiomyocytes are long-lived post-mitotic cells with limited regenerative capacity. Proper cardiomyocyte function depends critically on the maintenance of a healthy homeostasis of protein expression, folding, assembly, trafficking, function, and degradation, together commonly referred to as proteostasis. Impairment of proteostasis has a prominent role in the pathophysiology of ageing-related neurodegenerative diseases including Huntington's, Parkinson's, and Alzheimer's disease. Emerging evidence reveals also a role for impaired proteostasis in the pathophysiology of common human cardiac diseases such as cardiac hypertrophy, dilated and ischaemic cardiomyopathies, and atrial fibrillation (AF). Histone deacetylases (HDACs) have recently been recognized as key modulators which control cardiac proteostasis by deacetylating various proteins. By deacetylating chromatin proteins, including histones, HDACs modulate epigenetic regulation of pathological gene expression. Also, HDACs exert a broad range of functions outside the nucleus by deacetylating structural and contractile proteins. The cytosolic actions of HDACs result in changed protein function through post-translational modifications and/or modulation of their degradation. This review describes the mechanisms underlying the derailment of proteostasis in AF and subsequently focuses on the role of HDACs herein. In addition, the therapeutic potential of HDAC inhibition to maintain a healthy proteostasis resulting in a delay in AF onset and progression is discussed.

Is atrial fibrillation a risk factor for contrast-induced nephropathy in patients with ST-elevation myocardial infarction?

BACKGROUND

Contrast-induced nephropathy (CIN) is an iatrogenic problem in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). Atrial fibrillation (AF) may also contribute to impaired kidney function. Several factors may contribute to the development of CIN. In patients with STEMI, concomitant AF is associated with higher in-hospital/follow-up mortality and morbidity. Therefore, we aimed to investigate the relationship between AF and CIN developments.

METHODS

In this study, 650 consecutive STEMI patients treated with PPCI were enrolled. Patients with AF at admission who did not achieve a sinus rhythm during 48h after hospitalization were defined as AF patients. CIN was defined by an increase in serum creatinine by >25% or 0.5mg/dL within 72h following contrast media exposure.

RESULTS

Our patients were divided into two groups based on whether they had AF, and although warfarin usage was different, the other parameters were similar between the groups. When our patients were grouped according to CIN development [group 1: CIN (+), group 2: CIN (-)], creatinine levels prior to PPCI (p=0.020), estimated glomerular filtration rate (eGFR) prior to PPCI (p<0.001), left ventricular ejection fraction (LVEF) (p=0.011), AF (p<0.001), and warfarin usage (p=0.016) were different between the two groups. We also performed multivariate logistic regression analyses and found that AF [odds ratio (OR), 6.945; 95% confidence interval (CI), 2.789-17.293; p<0.001], eGFR (OR, 0.973; 95% CI, 0.957-0.989; p=0.001), and LVEF (OR, 0.963; 95% CI, 0.935-0.991; p=0.010) independently predicted CIN development in patients with STEMI.

CONCLUSIONS

The risk factors for CIN are multifactorial and identifying high-risk patients is the most important step for prevention. In addition to traditional risk factors, AF can contribute to CIN development in patients with STEMI.

New insights into symptomatic or silent atrial fibrillation complicating acute myocardial infarction

Atrial fibrillation (AF) is the most frequent heart rhythm disorder in the general population and contributes not only to a major deterioration in quality of life but also to an increase in cardiovascular morbimortality. The onset of AF in the acute phase of myocardial infarction (MI) is a major event that can jeopardize the prognosis of patients in the short-, medium- and long-term, and is a powerful predictor of a poor prognosis after MI. The suspected mechanism underlying the excess mortality is the drop in coronary flow linked to the acceleration and arrhythmic nature of the left ventricular contractions, which reduce the left ventricular ejection fraction. The principal causes of AF-associated death after MI are linked to heart failure. Moreover, the excess risk of death in these heart failure patients has also been associated with the onset of sudden death. Whatever its form, AF has a major negative effect on patient prognosis. In recent studies, symptomatic AF was associated with inhospital mortality of 17.8%, to which can be added mortality at 1year of 18.8%. Surprisingly, silent AF also has a negative effect on the prognosis, as it is associated with an inhospital mortality rate of 10.4%, which remains high at 5.7% at 1year. Moreover, both forms of AF are independent predictors of mortality beyond traditional risk factors. The frequency and seriousness of silent AF in the short- and long-term, which were until recently rarely studied, raises the question of systematically screening for it in the acute phase of MI. Consequently, the use of continuous ECG monitoring could be a simple, effective and inexpensive solution to improve screening for AF, even though studies are still necessary to validate this strategy. Finally, complementary studies also effect of oxidative stress and endothelial dysfunction, which seem to play a major role in triggering this rhythm disorder.

[Measurement of d-dimers in non-valvular atrial fibrillation. First prospective Tunisian study]

Atrial fibrillation can expose to thrombo-embolic complications. Many biomarkers have been tested to refine the stratification of thrombo-embolic risk. The study aim was to assess the interest of the d-dimer testing in this pathology. We conducted a prospective observational study including 50 cases and 19 controls, enrolled at the cardiology department of the Mongi Slim Hospital, from July to November 2012. The d-dimer assay was performed on mini-VIDAS(®) and analyzed according to clinical, echocardiographic and biological data. The mean age of patients was 61.8±10.6years. The mean CHA2DS2-VASc score was 2.58±1.31. The average of D-dimer levels was 590±506ng/ml in patients and 225.26±112.95ng/ml in controls (P=0.02). No significant difference has been found between the d-dimer level and age, sex, type and etiology of atrial fibrillation, the CHA2DS2-VASc score, the left atrial surface. Among patients on acenocoumarol, d-dimer levels was significantly higher in patients with an INR<2 compared to those with an INR≥2 (P=0.004). We identified a positive d-dimer threshold (300ng/ml) in patients distinguishing them significantly with controls (P<0.001). In conclusion, the measurement of d-dimers could help clinicians to identify patients with atrial fibrillation having an increased coagulability and, therefore, an increased thrombo-embolic risk. It could be complementary to the determination of INR in monitoring anticoagulation therapy: d-dimers level refines the thrombo-embolic risk and INR measurement assesses the level of anticoagulation and the bleeding risk.

Identification of acute myocardial infarction in patients with atrial fibrillation and chest pain with a contemporary sensitive troponin I assay

BACKGROUND

The introduction of modern troponin assays has facilitated diagnosis of acute myocardial infarction due to improved sensitivity with corresponding loss of specificity. Atrial fibrillation (AF) is associated with elevated levels of troponin. The aim of the present study was to evaluate the diagnostic performance of troponin I in patients with suspected acute coronary syndrome and chronic AF.

METHODS

Contemporary sensitive troponin I was assayed in a derivation cohort of 90 patients with suspected acute coronary syndrome and chronic AF to establish diagnostic cut-offs. These thresholds were validated in an independent cohort of 314 patients with suspected myocardial infarction and AF upon presentation. Additionally, changes in troponin I concentration within 3 hours were used.

RESULTS

In the derivation cohort, optimized thresholds with respect to a rule-out strategy with high sensitivity and a rule-in strategy with high specificity were established. In the validation cohort, application of the rule-out cut-off led to a negative predictive value of 97 %. The rule-in cut-off was associated with a positive predictive value of 88 % compared with 71 % if using the 99th percentile cut-off. In patients with troponin I levels above the specificity-optimized threshold, additional use of the 3-hour change in absolute/relative concentration resulted in a further improved positive predictive value of 96 %/100 %.

CONCLUSIONS

Troponin I concentration and the 3-hour change in its concentration provide valid diagnostic information in patients with suspected myocardial infarction and chronic AF. With regard to AF-associated elevation of troponin levels, application of diagnostic cut-offs other than the 99th percentile might be beneficial.

Risk of thromboembolism and fatal stroke in patients with psoriasis and nonvalvular atrial fibrillation: a Danish nationwide cohort study

OBJECTIVES

Psoriasis is a chronic inflammatory disease that is associated with a prothrombotic state and cardiovascular disease, including atrial fibrillation and thromboembolism. We therefore evaluated the impact of psoriasis in patients with atrial fibrillation and the performance of the CHA2 DS2 VASc score in these patients.

DESIGN, SETTING AND PARTICIPANTS

The study comprised all Danish patients hospitalized with nonvalvular atrial fibrillation in the period 1997-2011 (n = 99,357). Follow-up started 7 days from discharge and excluded subjects treated with anticoagulation. Poisson regression adjusted for CHA2 DS2 VASc score was used to estimate the incidence rate ratios and 95% confidence intervals.

MAIN OUTCOME MEASURE

Hospitalization or death from thromboembolism.

RESULTS

Mean follow-up was 3.5, 3.1, and 2.8 years for patients with no psoriasis, mild psoriasis and severe psoriasis, respectively. Patients with psoriasis were younger compared to patients without psoriasis, but CHA2DS2VASc score did not differ between the three groups. Thromboembolism rates per 100 patient-years (95% confidence intervals) were 4.8 (4.7-4.9), 4.8 (4.2-5.4) and 6.1 (5.0-7.5) for patients with no psoriasis, mild psoriasis and severe psoriasis, respectively. Importantly, the observed thromboembolism rates in patients with severe psoriasis were markedly higher (2.6- to3.4-fold) than predicted by the CHA2 DS2 VASc score. Relative to no psoriasis, incidence rate ratios were 0.99 (0.87-1.11) and 1.27 (1.02-1.57) for mild and severe psoriasis, respectively. Correspondingly, incidence rate ratios for fatal stroke were 0.97 (0.80-1.12) and 1.51 (1.12-2.05).

CONCLUSIONS

In patients with nonvalvular atrial fibrillation not treated with oral anticoagulation, severe psoriasis was associated with increased risk of thromboembolism. In these patients, CHA2 DS2 VASc underestimated the risk of thromboembolism.

Patients with atrial fibrillation complicated by coronary artery disease. Is a single value of sensitive cardiac troponin I on admission enough?

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in the general population. Cardiac troponin I (cTnI) can be elevated in patients with AF without coexisting coronary artery disease (CAD). The aim of this study was to characterize the diagnostic accuracy and clinical usefulness of a cTnI assay for the diagnosis of CAD in patients with AF.

METHODS

Patients with AF undergoing coronary angiography were included in the study. The workflow chart encompassed measuring of cTnI in all patients at admission and after 6 h.

RESULTS

Patients with CAD were older (73.8 ± 7.6 vs. 65.3 ± 12.9 years) than patients without CAD; for all other characteristics, no significant differences were observed. Of the patients, 39 had CAD [12 patients one-vessel disease (VD), 14 patients 2-VD, 13 patients 3-VD] and 16 patients had acute myocardial infarction and were undergoing percutaneous coronary intervention. There was no significant difference in cTnI concentrations between patients without and with CAD at admission (0.02 vs. 0.03 ng/ml, respectively); however, a difference was noted after 6 h (0.03 vs. 0.06 ng/ml, respectively).

CONCLUSION

AF patients both without and with CAD showed similar cTnI concentrations at admission. A second validation of cTnI is mandatory for all patients.

Association of circulating factor seven activating protease (FSAP) and of oral Omega-3 fatty acids supplements with clinical outcome in patients with atrial fibrillation: the OMEGA-AF study

Factor VII Activating Protease (FSAP) activates factor VII (FVII) as well as pro-urokinase (uPA). Our goal was to evaluate the relation between plasma levels of FSAP and clinical instability in atrial fibrillation (AF) and possible effects of oral omega-3 fatty acids (FA) supplements. 101 patients with persistent AF were analyzed in the OMEGA-AF Study. Plasma FSAP levels were measured at baseline and after 12 weeks of treatment with omega-3 FA. The median FSAP antigen concentration, in contrast to FSAP activity, was higher in patients with persistent AF. The maintenance of SR after successful cardioversion (CV) did not lead to a normalization of FSAP concentration. Supplementation with omega-3 FA but not placebo significantly reduced elevated FSAP concentration. Furthermore, elevated FSAP levels did not indicate a significantly increased risk of recurrence of AF after electrical CV or cardiovascular clinical events during 1 year of follow-up. Plasma FSAP concentration was increased in patients with AF and may be involved in the pathogenesis of this condition. The possible effects of omega-3 FA on clinical AF potential could be linked with modulation of circulating FSAP levels.

Von Willebrand Factor Plasma Levels Variability In Nonvalvular Atrial Fibrillation

Atrial Fibrillation (AF) is the most common cardiac arrhythmia of clinical significance; it increases the risk of mortality due to stroke. The mechanisms behind cerebral thromboembolism in AF are associated with a prothrombotic state, demonstrated by higher levels of von Willebrand Factor (vWF), a multimeric glycoprotein that plays a crucial role in platelet adhesion and aggregation and it has been proposed as a biomarker of endothelial dysfunction. Plasma vWF levels are elevated in patients with nonvalvular Atrial Fibrillation (NVAF) associated to the presence of cardiovascular risk factors. The variability in vWF plasma levels in healthy subjects has a wide distribution, but there is no description available of the variability in AF patients and among types of AF. The aim of this study was to determine the variability of vWF plasma concentrations in patients with NVAF, associated to cardiovascular risk factors. Search strategy included PubMed and Ovid. Keywords used were "Atrial Fibrillation" and "von Willebrand Factor". It includes original articles, with analysis of plasma vWF levels by ELISA, without acute stroke. Review articles and meta-analysis were excluded. Reviewed studies include 22 trials and 6542 patients with nonvalvular AF associated to cardiovascular disease risk factors: age, sex, hypertension, heart failure, diabetes mellitus, prior stroke, coronary artery disease. Variability in vWF plasma levels was wide, with minimum values of 77 IU/dl and maximum values of 245 IU/dl and a mean of 146 IU/dl. Age of patients ranged between 54 and 78 years, and the percentage of males ranged between 23% and 80%. According to type of AF vWF levels were as follows, in paroxysmal AF: 92-264 IU/dl; persistent AF: 76-234 IU/dl; permanent AF: 91-247 IU/dl. The variability in vWF plasma levels is affected by risk factors and the AF type, however vWF levels in AF patients are higher when compared with healthy subjects.

TASK-1 current is inhibited by phosphorylation during human and canine chronic atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia with significant morbidities and only partially adequate therapeutic options. AF is associated with atrial remodeling processes, including changes in the expression and function of ion channels and signaling pathways. TWIK protein-related acid-sensitive K+ channel (TASK)-1, a two-pore domain K+ channel, has been shown to contribute to action potential repolarization as well as to the maintenance of resting membrane potential in isolated myocytes, and TASK-1 inhibition has been associated with the induction of perioperative AF. However, the role of TASK-1 in chronic AF is unknown. The present study investigated the function, expression, and phosphorylation of TASK-1 in chronic AF in atrial tissue from chronically paced canines and in human subjects. TASK-1 current was present in atrial myocytes isolated from human and canine hearts in normal sinus rhythm but was absent in myocytes from humans with AF and in canines after the induction of AF by chronic tachypacing. The addition of phosphatase to the patch pipette rescued TASK-1 current from myocytes isolated from AF hearts, indicating that the change in current is phosphorylation dependent. Western blot analysis showed that total TASK-1 protein levels either did not change or increased slightly in AF, despite the absence of current. In studies of perioperative AF, we have shown that phosphorylation of TASK-1 at Thr383 inhibits the channel. However, phosphorylation at this site was unchanged in atrial tissue from humans with AF or in canines with chronic pacing-induced AF. We conclude that phosphorylation-dependent inhibition of TASK-1 is associated with AF, but the phosphorylation site responsible for this inhibition remains to be identified.

Circulating Endothelial Cells and Platelet Microparticles in Mitral Valve Disease With and Without Atrial Fibrillation

Hypercoagulability in mitral valve disease (MVD), a cause of atrial fibrillation (AF) and stroke, is potentially due to endothelial damage/dysfunction (marked by circulating endothelial cells [CECs]), platelet activation (soluble P-selectin [sPsel], platelet microparticles [PMPs], and soluble CD40 [sCD40]), and oxidized low-density lipoprotein (oxLDL) cholesterol. We measured these variables in 24 patients with MVD as well as in 21 with MVD + AF and compared them with 20 healthy controls (HCs). The CECs and PMPs were measured by flow cytometry; sPsel, oxLDL, and CD40 by enzyme-linked immunosorbent assay. Compared with HCs, sPsel and PMPs were equally higher in MVD and MVD + AF; sCD40 and oxLDL were higher in MVD + AF than in HCs and MVD; and CECs were higher in MVD than in the HCs, with further increases in MVD + AF (all P < .001). We conclude that excess platelet activation is present in MVD regardless of AF, and that increased endothelial damage in MVD is greater when compounded by AF.

Potential use of NOACs in developing countries: pros and cons

PURPOSE

Although vitamin K antagonists (VKAs) are effective for long-term thromboprophylaxis in atrial fibrillation (AF), their limitations have led to widespread underutilisation, especially in the developing world. Novel oral anticoagulants (NOACs) have emerged as promising alternatives to VKAs, although there are some particular considerations and challenges to their introduction in developing countries. This review summarises the current state of antithrombotic management of AF in the developing world, explores the early evidence for the NOACs and describes some of the special considerations that must be taken into account when considering the role of the NOACs within developing countries' health care systems.

METHODS

A literature search was conducted via PubMed and Google Scholar to find articles published in English between the years 2000 to 2014. Search terms used were "atrial fibrillation", "oral anticoagulants", "warfarin", "NOACs", "dabigatran", "rivaroxaban", "apixaban", "edoxaban", "time in therapeutic range", "International Normalized Ratio" "cost-effectiveness", "stroke", "adverse-drug reactions" and "drug-drug interactions", together with the individual names of developing countries as listed by the World Bank. We reviewed the results of randomized clinical trials, relevant retrospective and prospective studies, case-studies and review articles.

RESULTS

Many developing countries lack or have sporadic data on the quality of AF management, making it difficult to anticipate the potential impact of NOACs in these settings. The utilisation of anticoagulants for AF appears highly variable in developing countries. Given the issues associated with VKA therapy in many developing countries, NOACs offer some potential advantages; however, there is insufficient evidence to advocate the widespread replacement of warfarin at present. VKAs may continue to have a role in selected patients or countries, especially if alternative monitoring strategies can be utilised.

CONCLUSION

The evaluation of the introduction of NOACs should consider safety, budget concerns and the quality of oral anticoagulation care achieved by each country. Prospective registries will be important in developing countries to better elucidate the comparative safety, efficacy and cost-effectiveness of NOACs and VKAs as NOACs are introduced into practice.

Ischaemic cardiac outcomes in patients with atrial fibrillation treated with vitamin K antagonism or factor Xa inhibition: results from the ROCKET AF trial

AIMS

We investigated the prevalence of prior myocardial infarction (MI) and incidence of ischaemic cardiovascular (CV) events among atrial fibrillation (AF) patients.

METHODS AND RESULTS

In ROCKET AF, 14 264 patients with nonvalvular AF were randomized to rivaroxaban or warfarin. The key efficacy outcome for these analyses was CV death, MI, and unstable angina (UA). This pre-specified analysis was performed on patients while on treatment. Rates are per 100 patient-years. Overall, 2468 (17%) patients had prior MI at enrollment. Compared with patients without prior MI, these patients were more likely to be male (75 vs. 57%), on aspirin at baseline (47 vs. 34%), have prior congestive heart failure (78 vs. 59%), diabetes (47 vs. 39%), hypertension (94 vs. 90%), higher mean CHADS2 score (3.64 vs. 3.43), and fewer prior strokes or transient ischaemic attacks (46 vs. 54%). CV death, MI, or UA rates tended to be lower in patients assigned rivaroxaban compared with warfarin [2.70 vs. 3.15; hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.73-1.00; P = 0.0509]. CV death, MI, or UA rates were higher in those with prior MI compared with no prior MI (6.68 vs. 2.19; HR 3.04, 95% CI 2.59-3.56) with consistent results for CV death, MI, or UA for rivaroxaban compared with warfarin in prior MI compared with no prior MI (P interaction = 0.10).

CONCLUSION

Prior MI was common and associated with substantial risk for subsequent cardiac events. Patients with prior MI assigned rivaroxaban compared with warfarin had a non-significant 14% reduction of ischaemic cardiac events.

Atrial fibrillation: profile and burden of an evolving epidemic in the 21st century

BACKGROUND

Atrial fibrillation (AF) represents an increasing public health challenge with profound social and economic implications.

METHODS

A comprehensive synthesis and review of the AF literature was performed. Overall, key findings from 182 studies were used to describe the indicative scope and impact of AF from an individual to population perspective.

RESULTS

There are many pathways to AF including advancing age, cardiovascular disease and increased levels of obesity/metabolic disorders. The reported population prevalence of AF ranges from 2.3%-3.4% and historical trends reflect increased AF incidence. Estimated life-time risk of AF is around 1 in 4. Primary care contacts reflect whole population trends: AF-related case-presentations increase from less than 0.5% in those aged 40 years or less to 6-12% for those aged 85 years or more. Globally, AF-related hospitalisations (primary or secondary diagnosis) showed an upward trend (from ~35 to over 100 admissions/10,000 persons) during 1996 to 2006. The estimated cost of AF is greater than 1% of health care expenditure and rising with hospitalisations the largest contributor. For affected individuals, quality of life indices are poor and AF confers an independent 1.5 to 2.0-fold probability of death in the longer-term. AF is also closely linked to ischaemic stroke (3- to 5-fold risk), chronic heart failure (up to 50% develop AF) and acute coronary syndromes (up to 25% develop AF) with consistently worse outcomes reported with concurrent AF. Future projections predict at least a doubling of AF cases by 2050.

SUMMARY

AF represents an evolving, global epidemic providing considerable challenges to minimise its impact from an individual to whole society perspective.

New directions in antiarrhythmic drug therapy for atrial fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and has a significant impact on morbidity and mortality. Current antiarrhythmic drugs for AF suffer from limited safety and efficacy, probably because they were not designed based on specific pathological mechanisms. Recent research has provided important insights into the mechanisms contributing to AF and highlighted several potential novel antiarrhythmic strategies. In this review, we highlight the main pathological mechanisms of AF, discuss traditional and novel aspects of atrial antiarrhythmic drugs in relation to these pathological mechanisms, and present potential novel therapeutic approaches including structure-based modulation of atrial-specific cardiac ion channels, restoring abnormal Ca2+ handling in AF and targeting atrial remodeling.

Trends in atrial fibrillation in patients hospitalized with an acute coronary syndrome

BACKGROUND

Atrial fibrillation is common among patients with cardiovascular disease and is a frequent complication of the acute coronary syndrome. Data are needed on recent trends in the magnitude, clinical features, treatment, and prognostic impact of preexisting and new-onset atrial fibrillation in patients hospitalized with an acute coronary syndrome.

METHODS

The study population consisted of 59,032 patients hospitalized with an acute coronary syndrome at 113 sites in the Global Registry of Acute Coronary Events Study between 2000 and 2007.

RESULTS

A total of 4494 participants (7.6%) with acute coronary syndrome reported a history of atrial fibrillation and 3112 participants (5.3%) developed new-onset atrial fibrillation during their hospitalization. Rates of new-onset atrial fibrillation (5.5%-4.5%) and preexisting atrial fibrillation (7.4%-6.7%) declined during the study. Preexisting atrial fibrillation was associated with older age and greater cardiovascular disease burden, whereas new-onset atrial fibrillation was closely related to the severity of the index acute coronary syndrome. Patients with atrial fibrillation were less likely than patients without atrial fibrillation to receive evidence-based therapies and more likely to develop in-hospital complications, including heart failure. Overall hospital death rates in patients with new-onset and preexisting atrial fibrillation were 14.5% and 8.9%, respectively, compared with 1.2% in those without atrial fibrillation. Short-term death rates in patients with atrial fibrillation declined over the study period.

CONCLUSIONS

Despite a reduction in the rates of, and mortality from, atrial fibrillation, this arrhythmia exerts a significant adverse effect on survival among patients hospitalized with an acute coronary syndrome. Opportunities exist to improve the identification and treatment of patients with acute coronary syndrome with, or at risk for, atrial fibrillation to reduce the incidence and resultant complications of this dysrhythmia.

The prevalence of atrial fibrillation in Hungary

To estimate the prevalence and incidence of atrial fibrillation in the entire population of Hungary. Methods: Analysis of the National Health Insurance Fund Administration database between 2007 and 2009 considering data from 2002. We assumed that patients with atrial fibrillation would turn to health care providers at least once either as outpatients or inpatients in a 5-year period. The National Health Insurance Patient Registry was used to assess the true number of patient visits. Results: The prevalence of atrial fibrillation in Hungary is between 2.37–2.67%. Each year, only about half of these patients seek medical advice. Conclusions: Our survey seems to be the first epidemiological study that aims at estimating the prevalence of atrial fibrillation in the total population of our country. Using a time frame of five to seven years, the prevalence of atrial fibrillation in the total population is significantly higher than it was estimated earlier. However, by using a mathematical model, an even higher prevalence rate of atrial fibrillation (2.95%) was calculated for the total population of Hungary. Orv. Hetil., 2012, 153, 339–342.

Effects of electrical and structural remodeling on atrial fibrillation maintenance: a simulation study

Atrial fibrillation, a common cardiac arrhythmia, often progresses unfavourably: in patients with long-term atrial fibrillation, fibrillatory episodes are typically of increased duration and frequency of occurrence relative to healthy controls. This is due to electrical, structural, and contractile remodeling processes. We investigated mechanisms of how electrical and structural remodeling contribute to perpetuation of simulated atrial fibrillation, using a mathematical model of the human atrial action potential incorporated into an anatomically realistic three-dimensional structural model of the human atria. Electrical and structural remodeling both shortened the atrial wavelength--electrical remodeling primarily through a decrease in action potential duration, while structural remodeling primarily slowed conduction. The decrease in wavelength correlates with an increase in the average duration of atrial fibrillation/flutter episodes. The dependence of reentry duration on wavelength was the same for electrical vs. structural remodeling. However, the dynamics during atrial reentry varied between electrical, structural, and combined electrical and structural remodeling in several ways, including: (i) with structural remodeling there were more occurrences of fragmented wavefronts and hence more filaments than during electrical remodeling; (ii) dominant waves anchored around different anatomical obstacles in electrical vs. structural remodeling; (iii) dominant waves were often not anchored in combined electrical and structural remodeling. We conclude that, in simulated atrial fibrillation, the wavelength dependence of reentry duration is similar for electrical and structural remodeling, despite major differences in overall dynamics, including maximal number of filaments, wave fragmentation, restitution properties, and whether dominant waves are anchored to anatomical obstacles or spiralling freely.

Matrine inhibits pacing induced atrial fibrillation by modulating I(KM3) and I(Ca-L)

AIM

To elucidate the protective effects of Matrine on atrial fibrillation (AF) induced by electric pacing in mice and underlying molecular and ion channel mechanisms.

METHODS

AF was introduced by electric pacing in mice and the incidence and duration of AF were evaluated. Functional expression of M(3) receptor (M(3)-R) and Cav1.2 were explored by western and Real-time PCR, action potential (AP) and the density of (I(KM3)) L-type calcium channel (I(Ca-L)) were both recorded using whole-cell patch in isolated atrial cardiomyocytes.

RESULTS

In control group, incidence and duration of AF induced by electric pacing were 50 ± 17% and 3.68 ± 1.84 s, respectively; after application of carbachol 50 µg/kg both incidence and duration of AF were significantly increased to 86 ± 24% and 65.2 ± 29.0 s. Compared with control group, pretreatment of Matrine for 15 days significantly reduced AF incidence and duration in dose-dependent manner. Atrial membrane-protein expression of M(3)-R was decreased and membrane Cav1.2 expression was up-regulated. In single Matrine-treated atrial cardiomyocyte the density of I(KM3) was significantly decreased by 39% as well compared with control group, P < 0.05, whereas, I(Ca-L) density of atrium was increased by 40%.

CONCLUSION

These data demonstrated at the first time that the anti-AF effects of Matrine may due, at least in part, to down-regulation of I(KM3) density and M(3)-R expression and up-regulation of I(Ca-L )density and α1C/Cav1.2 expression.

The management of patients with atrial fibrillation and dronedarone's place in therapy

The pharmacologic management of atrial fibrillation (AF) includes rate and rhythm control strategies. Antiarrhythmic agents (eg, amiodarone, flecainide, and propafenone) are limited by serious toxicities (including proarrhythmic effects and pulmonary toxicity), which may lead to a reduced net clinical efficacy of rhythm control strategies. Dronedarone, a new antiarrhythmic agent, is effective in the maintenance of sinus rhythm. Dronedarone has also been shown to reduce ventricular rate and the incidence of hospitalization due to cardiovascular events. Dronedarone is recommended by the 2011 American College of Cardiology Foundation/American Heart Association/Heart Rhythm Society guidelines update for the management of AF patients with no or minimal heart disease, coronary artery disease, and hypertension with no left ventricular hypertrophy. Dronedarone is contraindicated in patients with New York Heart Association (NYHA) class IV heart failure or NYHA class II-III heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic.

Psoriasis and risk of atrial fibrillation and ischaemic stroke: a Danish Nationwide Cohort Study

AIMS

Psoriasis is a chronic inflammatory disease and inflammation contributes to the pathogenesis of atrial fibrillation (AF) and ischaemic stroke. We therefore investigated the risk of these endpoints in patients with psoriasis.

METHODS AND RESULTS

Cohort study of the entire Danish population followed from 1997 to 2006 by individual-level-linkage of nationwide prospectively recorded registers. Multivariable Poisson's regression and sensitivity analyses were used to assess the psoriasis-related risk of AF and ischaemic stroke. A total of 36 765 patients with mild psoriasis and 2793 with severe psoriasis were compared with 4 478 926 individuals, i.e., the reference population. In patients with mild psoriasis, the adjusted rate ratios (RRs) for AF were 1.50 (1.21-1.86) and 1.16 (1.08-1.24) in patients aged <50 and ≥50 years, respectively. Patients with severe psoriasis had a higher risk of AF with RRs 2.98 (1.80-4.92) in patients aged <50 years and 1.29 (1.01-1.65) in patients aged ≥50 years. Patients with psoriasis also demonstrated a disease severity-dependent increased risk of ischaemic stroke, i.e. RRs 1.97 (1.66-2.34) and 2.80 (1.81-4.34) in patients aged <50 years with mild and severe psoriasis, and RRs 1.13 (1.04-1.21) and 1.34 (1.04-1.71) in patients aged ≥50 years with mild and severe psoriasis, respectively. A range of sensitivity analyses yielded comparable results.

CONCLUSION

Psoriasis is associated with increased risk of AF and ischaemic stroke. These novel results add to a growing body of evidence, suggesting that patients with psoriasis could be considered at increased cardiovascular risk.

Rhythm control strategies and the role of antiarrhythmic drugs in the management of atrial fibrillation: focus on clinical outcomes

Atrial fibrillation (AF) is a common disorder that significantly impacts the lives of affected patients. The restoration of sinus rhythm may prevent AF progression and reduce the occurrence of negative sequelae; however, available antiarrhythmic drugs (AADs) have largely failed to demonstrate significant benefit relative to rate control with respect to morbidity and mortality outcomes. The review commentary will address current knowledge regarding the pathologic mechanisms of AF, current trials that investigate rate and rhythm strategies, and future therapies that may change treatment approaches based on preliminary evidence suggesting a more favorable safety profile. The observed outcomes are likely a reflection of the limited efficacy plus poor safety and tolerability of available AADS. However, data from patients who attained and maintained sinus rhythm in a number of clinical studies demonstrate that the achievement of normal sinus rhythm can indeed reduce AF-associated morbidity and mortality. Furthermore, the results of trials designed to assess specific morbidity and mortality outcomes such as cardiovascular death hospitalization suggest that the development of safer AF therapies, whether pharmacologic or nonpharmacologic, can potentially improve clinical outcomes.

Management of atrial fibrillation: translating clinical trial data into clinical practice

Atrial fibrillation is a supraventricular tachyarrhythmia with significant consequences in terms of morbidity and mortality. In light of the limitations of available pharmacologic treatment options (suboptimal efficacy plus safety and tolerability issues), atrial fibrillation management should be individualized based on patient characteristics and comorbidities that could influence response to specific management approaches. The importance of adequate anticoagulation should not be overlooked. This review provides a practical guide for primary care physicians, internists, and cardiologists on current management strategies for atrial fibrillation, based on recent guidelines and current clinical data.

The impact of new and emerging clinical data on treatment strategies for atrial fibrillation

INTRODUCTION

The Atrial Fibrillation (AF) Exchange Group, an international multidisciplinary group concerned with the management of AF, was convened to review recent advances in the field and the potential impact on treatment strategies.

METHODS

Issues discussed included epidemiology and the impact of the rising incidence of AF on health care systems, developments in pharmacological and surgical interventions in the management of arrhythmias and thromboprophylaxis, the potential to affect treatment strategies, and barriers to implementing them.

RESULTS

The incidence of AF and the associated burden on health care systems are increasing with aging populations, prevalence of comorbidities and more effective treatment of cardiovascular diseases. Advances in available medical treatments, in particular dronedarone and dabigatran, with other products in development, offer the possibility of changes in treatment paradigms and a greater emphasis on reducing hospitalizations and improvement in long-term outcomes instead of a symptom/safety-driven approach in which the priority is symptom suppression without provoking drug toxicity. Developments in catheter ablation techniques may mean that, in experienced centers, ablation may be offered as first-line treatment in selected patient populations. Barriers to optimal treatment include underdiagnosis, lack of recognition as a serious condition and as a risk factor for stroke, limited access to care, inadequate implementation of guidelines, and poor adherence to treatment.

CONCLUSIONS

The focus of the management of AF may be changing as a consequence of new treatments based on the outcome improvements they offer. However, the benefits will not be fully realized if guidelines and guidance are not observed in routine clinical practice.

New antiarrhythmic drugs for treatment of atrial fibrillation

Inadequacies in current therapies for atrial fibrillation have made new drug development crucial. Conventional antiarrhythmic drugs increase the risk of ventricular proarrhythmia. In drug development, the focus has been on favourable multichannel-blocking profiles, atrial-specific ion-channels, and novel non-channel targets (upstream therapy). Molecular modification of the highly effective multichannel blocker, amiodarone, to improve safety and tolerability has produced promising analogues such as dronedarone, although this drug seems less effective than does amiodarone. Vernakalant, an atrial-selective drug with reduced proarrhythmic risk, might be useful for cardioversion in atrial fibrillation. Ranolazine, another atrial-selective agent initially developed as an antianginal, has efficacy for atrial fibrillation and is being tested in prospective clinical trials. So-called upstream therapy with angiotensin-converting enzyme and angiotensin-receptor inhibitors, statins, or omega-3 fatty acids and fish oil that target atrial remodelling could be effective, but need further clinical validation. We focus on the basic and clinical pharmacology of newly emerging antiarrhythmic drugs and non-traditional approaches such as upstream therapy for atrial fibrillation.

Fatty acid percentage in erythrocyte membranes of atrial flutter/fibrillation patients and controls

PURPOSE

Several epidemiological published data support the protective role of omega-3 consumption in coronary artery disease, sudden cardiac death and ventricular arrhythmias, but interestingly, this is not the case for atrial arrhythmias. The purpose of this study is to evaluate different fatty acid profile between AF/AFL subjects and healthy controls.

METHODS

Gas chromatography was employed to determine fatty acid percentage of erythrocyte membranes from 40 idiopathic AFL/AF patients and 53 healthy control subjects.

RESULTS

AFL/AF erythrocyte membranes had significantly lower percentage of saturated fatty acid (43.1 +/- SD2.2 versus 47.8 +/- SD9.6, p < 0.001), monounsaturated fatty acid (18.2 +/- SD2.5 versus 22.6 +/- SD5.2, p < 0.001) and total trans fatty acid (0.2 +/- SD0.1 vs 1.3 +/- SD1.1, p < 0.001) than controls. Furthermore, fatty acid (FA) profiles of arrhythmic individuals showed an increased percent of total polyunsaturated fatty acid (PUFA) (36.7 +/- SD2.4 versus 26.4 +/- SD10.4, p < 0.001), PUFA n-3 (5.3 +/- SD1.1 versus 2.8 +/- SD1.8, p < 0.001) and n-6 (31.4 +/- SD2.2 versus 23.5 +/- SD9.9, p < 0.001).

CONCLUSION

This study shows that the erythrocyte membranes FA composition of AF/AFL subjects differs from that of healthy controls.