Coronary artery disease affecting the atrial branches is an independent determinant of atrial fibrillation after myocardial infarction

Prevalence and Impact of Concomitant Atrial Fibrillation in Patients Undergoing Percutaneous Coronary Intervention for Acute Myocardial Infarction

Background: Concomitant atrial fibrillation (AF) is associated with an adverse prognosis in patients with acute myocardial infarction (MI). However, it remains unclear whether this is due to a causal effect of AF or whether AF acts as a surrogate marker for comorbidities in this population. Furthermore, there are limited data on whether coronary artery disease distribution impacts the risk of developing AF. Methods: Consecutive patients admitted with acute MI and treated using percutaneous coronary intervention (PCI) at a single centre were retrospectively identified. Associations between AF and major adverse cardiac and cerebrovascular events (MACCEs) over a median of five years of follow-up were assessed using Cox regression, with adjustment for confounding factors performed using both multivariable modelling and a propensity-score-matched analysis. Results: AF was identified in N = 65/1000 (6.5%) of cases; these patients were significantly older (mean: 73 vs. 65 years, p < 0.001), with lower creatinine clearance (p < 0.001), and were more likely to have a history of cerebrovascular disease (p = 0.011) than those without AF. In addition, patients with AF had a greater propensity for left main stem (p = 0.001) or left circumflex artery (p = 0.004) involvement. Long-term MACCE rates were significantly higher in the AF group than in the non-AF group (50.8% vs. 34.2% at five years), yielding an unadjusted hazard ratio (HR) of 1.86 (95% CI: 1.32-2.64, p < 0.001). However, after adjustment for confounding factors, AF was no longer independently associated with MACCEs, either on multivariable (adjusted HR: 1.25, 95% CI: 0.81-1.92, p = 0.319) or propensity-score-matched (HR: 1.04, 95% CI: 0.59-1.82, p = 0.886) analyses. Conclusions: AF is observed in 6.5% of patients admitted with acute MI, and those with AF are more likely to have significant diseases involving left main or circumflex arteries. Although unadjusted MACCE rates were significantly higher in patients with AF, this effect was not found to remain significant after adjustment for comorbidities. As such, this study provided no evidence to suggest that AF is independently associated with MACCEs.

Coronary Angiography-Derived Index of Microcirculatory Resistance Associated With New-Onset Atrial Fibrillation in Patients With STEMI

BACKGROUND

Coronary angiography-derived index of microcirculatory resistance (caIMR) can effectively assess coronary microvascular dysfunction in patients with ST-segment elevation myocardial infarction (STEMI). This study aimed to explore the role of caIMR in the occurrence of new-onset atrial fibrillation (NOAF) in patients with STEMI.

METHODS

This was a single-centre retrospective clinical observational study. Patients diagnosed with STEMI from September 2019 to December 2022 were included. caIMR was calculated using computational flow and pressure simulations. During admission, suspicious heart rhythm was recorded by electrocardiographic (ECG) monitoring, and NOAF was confirmed by an immediate 12-lead ECG.

RESULTS

A total of 739 patients were enrolled, including 57 (7.7) with NOAF. caIMR was significantly correlated with microvascular obstruction (R = 0.604; P < 0.001) and infarct size (R = 0.514; P < 0.001). After adjusting for potential confounding factors, the results showed that caIMR (odds ratio 1.058, 95% confidence interval 1.035-1.083; P < 0.001) was an independent risk factor for NOAF in patients with STEMI. Receiver operating characteristic analysis showed that the area under the curve of caIMR for predicting NOAF was 0.716. Compared with the caIMR < 27.35 U group, the caIMR ≥ 27.35 U group had higher high-sensitivity troponin T and N-terminal pro-B-type natriuretic peptide levels. When caIMR was added to the model, the reclassification and discriminant abilities improved significantly.

CONCLUSIONS

Higher caIMR was an independent risk factor for NOAF in patients with STEMI. The caIMR had high specificity and sensitivity for predicting NOAF in patients with STEMI. The integration of caIMR into clinical risk factors showed significantly increased predictability for NOAF in patients with STEMI.

Optimizing Atrial Fibrillation Care: Comparative Assessment of Anticoagulant Therapies and Risk Factors

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) is a common arrhythmia associated with various risk factors and significant morbidity and mortality.

MATERIALS AND METHODS

This article presents findings from a study involving 345 patients with permanent AF. This study examined demographics, risk factors, associated pathologies, complications, and anticoagulant therapy over the course of a year.

RESULTS

The results showed a slight predominance of AF in males (55%), with the highest incidence in individuals aged 75 and older (49%). Common risk factors included arterial hypertension (54%), dyslipidemia, diabetes mellitus type 2 (19.13%), and obesity (15.65%). Comorbidities such as congestive heart failure (35.6%), mitral valve regurgitation (60%), and dilated cardiomyopathy (32%) were prevalent among the patients. Major complications included congestive heart failure (32%), stroke (17%), and myocardial infarction (5%). Thromboembolic and bleeding risk assessment using CHA2DS2-VASc and HAS-BLED scores demonstrated a high thromboembolic risk in all patients. The majority of patients were receiving novel oral anticoagulants (NOACs) before admission (73%), while NOACs were also the most prescribed antithrombotic therapy at discharge (61%).

CONCLUSIONS

This study highlights the importance of risk factor management and appropriate anticoagulant therapy in patients with AF, to reduce complications and improve outcomes. The results support the importance of tailored therapeutic schemes, for optimal care of patients with AF.

A Predictive Model of New-Onset Atrial Fibrillation After Percutaneous Coronary Intervention in Acute Myocardial Infarction Based on the Lymphocyte to C-Reactive Protein Ratio

Purpose

Lymphocyte to C-reactive protein ratio (LCR) is a recognized systemic inflammatory marker and novel prognostic indicator for several cancers. This study investigated the relationship between preoperative LCR and new-onset atrial fibrillation (NOAF) in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI).

Patients and Methods

Patients with AMI (n=662) with no history of atrial fibrillation (AF) were enrolled and classified into NOAF and non-NOAF groups based on the occurrence of postoperative NOAF during hospitalization. Logistic regression models were used to analyze NOAF risk factors and to assess the association between preoperative LCR and NOAF incidence. We constructed a new nomogram from the selected NOAF risk factors, and tested its predictive performance, degree of calibration, and clinical utility using receiver operating characteristic and calibration curves, decision curve analysis, and clinical impact curves.

Results

Overall, 84 (12.7%) patients developed NOAF during hospitalization. The LCR was significantly lower in the NOAF group. Preoperative LCR accurately predicted NOAF after AMI and was correlated with increased NOAF risk. Age, body mass index, diabetes, serum albumin levels, uric acid levels, left atrium (LA) diameter, left ventricular ejection fraction, left circumflex artery stenosis > 50%, and Killip class II status were independent predictors of NOAF after AMI. In addition, a new nomogram combined with LCR was constructed to stratify the risk of NOAF in patients with AMI. The performance of the new nomogram was satisfactory, as shown by the receiver operating characteristic curve, calibration curve, decision curve analysis and clinical impact curve.

Conclusion

Preoperative LCR was an independent predictor of NOAF in patients with AMI after PCI. The novel nomogram combined with LCR could rapidly and individually identify and treat patients at a high risk of NOAF.

Serum fibrinogen-to-albumin ratio predicts new-onset atrial fibrillation risk during hospitalization in patients with acute myocardial infarction after percutaneous coronary intervention: a retrospective study

BACKGROUND

New-onset atrial fibrillation (NOAF) is a common adverse outcome of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) and is closely correlated with hospital stay and prognosis. In recent years, serum fibrinogen-to-albumin ratio (FAR), a novel biomarker for inflammation and thrombosis, has been used to predict the severity and prognosis of coronary artery disease. Our study aimed to investigate the relationship between FAR and NOAF during hospitalization after PCI in patients with AMI.

METHODS

We retrospectively analyzed the incidence of NOAF during hospitalization and follow-up in 670 patients with AMI after PCI. Data were collected on patient age, sex, body mass index, medical history, current medication, heart failure, laboratory tests, culprit blood vessels, echocardiographic characteristics, and AMI type. The enrolled patients were divided into NOAF and non-NOAF groups. The baseline characteristics of patients in the two groups were compared, and the predictive correlation between FAR and NOAF was evaluated using logistic regression analysis and the receiver operating characteristic curve.

RESULTS

Fifty-three (7.9%) patients developed NOAF during hospitalization. The occurrence of NOAF was found to be independently associated with higher FAR besides older age, higher neutrophil count, greater left atrial size, worse Killip class upon admission, lower body mass index, lower platelet count, lower left ventricle ejection fraction, and target left circumflex artery disease. FAR exhibited a better predictive value for the occurrence of NOAF during hospitalization (area under the curve, 0.732; 95% confidence interval, 0.659-0.808).

CONCLUSIONS

FAR is a robust tool for predicting NOAF risk during hospitalization in patients with AMI after PCI and has a better predictive value than serum fibrin and serum albumin levels alone.

The bidirectional association between atrial fibrillation and myocardial infarction

Atrial fibrillation (AF) is associated with an increased risk of myocardial infarction (MI) and vice versa. This bidirectional association relies on shared risk factors as well as on several direct and indirect mechanisms, including inflammation, atrial ischaemia, left ventricular remodelling, myocardial oxygen supply-demand mismatch and coronary artery embolism, through which one condition can predispose to the other. Patients with both AF and MI are at greater risk of stroke, heart failure and death than patients with only one of the conditions. In this Review, we describe the bidirectional association between AF and MI. We discuss the pathogenic basis of this bidirectional relationship, describe the risk of adverse outcomes when the two conditions coexist, and review current data and guidelines on the prevention and management of both conditions. We also identify important gaps in the literature and propose directions for future research on the bidirectional association between AF and MI. The Review also features a summary of methodological approaches for the study of bidirectional associations in population-based studies.

Hypoxia Promotes Atrial Tachyarrhythmias via Opening of ATP-Sensitive Potassium Channels

BACKGROUND

Hypoxia-ischemia predisposes to atrial arrhythmia. Atrial ATP-sensitive potassium channel (KATP) modulation during hypoxia has not been explored. We investigated the effects of hypoxia on atrial electrophysiology in mice with global deletion of KATP pore-forming subunits.

METHODS

Whole heart KATP RNA expression was probed. Whole-cell KATP current and action potentials were recorded in isolated wild-type (WT), Kir6.1 global knockout (6.1-gKO), and Kir6.2 global knockout (6.2-gKO) murine atrial myocytes. Langendorff-perfused hearts were assessed for atrial effective refractory period (ERP), conduction velocity, wavefront path length (WFPL), and arrhymogenicity under normoxia/hypoxia using a microelectrode array and programmed electrical stimulation. Heart histology was assessed.

RESULTS

Expression patterns were essentially identical for all KATP subunit RNA across human heart, whereas in mouse, Kir6.1 and SUR2 (sulphonylurea receptor subunit) were higher in ventricle than atrium, and Kir6.2 and SUR1 were higher in atrium. Compared with WT, 6.2-gKO atrial myocytes had reduced tolbutamide-sensitive current and action potentials were more depolarized with slower upstroke and reduced peak amplitude. Action potential duration was prolonged in 6.1-gKO atrial myocytes, absent of changes in other ion channel gene expression or atrial myocyte hypertrophy. In Langendorff-perfused hearts, baseline atrial ERP was prolonged and conduction velocity reduced in both KATP knockout mice compared with WT, without histological fibrosis. Compared with baseline, hypoxia led to conduction velocity slowing, stable ERP, and WFPL shortening in WT and 6.1-gKO hearts, whereas WFPL was stable in 6.2-gKO hearts due to ERP prolongation with conduction velocity slowing. Tolbutamide reversed hypoxia-induced WFPL shortening in WT and 6.1-gKO hearts through ERP prolongation. Atrial tachyarrhythmias inducible with programmed electrical stimulation during hypoxia in WT and 6.1-gKO mice correlated with WFPL shortening. Spontaneous arrhythmia was not seen.

CONCLUSIONS

KATP block/absence leads to cellular and tissue level atrial electrophysiological modification. Kir6.2 global knockout prevents hypoxia-induced atrial WFPL shortening and atrial arrhythmogenicity to programmed electrical stimulation. This mechanism could be explored translationally to treat ischemically driven atrial arrhythmia.

Role of autophagy in simulated ischemic-reperfused left atrial myocardium

BACKGROUND AND AIM

Autophagy has recently emerged as a potential and promising therapeutic approach to maintain cardiac cellular homeostasis. The aim of the present study was to investigate the role of autophagy in the ischemic-reperfused atrial myocardium.

METHODS

Isolated rat left atria subjected to simulated ischemia-reperfusion were used. The bathing medium contained either 10 mM d-glucose or 10 mM d-glucose and 1.2 mM palmitate. 3-methyladenine (3-MA) was used as pharmacological autophagy inhibitor.

RESULTS

LC3-II/LC3-I ratio, an indicator of autophagosome formation, was significantly enhanced during reperfusion, this increase being slowed by the exposure to high palmitate concentration and prevented by 3-MA. Beclin-1 was significantly increased during reperfusion period in both metabolic conditions, and pharmacological inhibition of AMPK partially prevented LC3-II/LC3-I ratio increase. Autophagy inhibition significantly increased mitochondrial damage and impaired mitochondrial ATP synthesis rate at reperfusion. Tissue ATP content recovery and contractile reserve were also reduced during this period, these effects being more pronounced either in 3-MA treated atria and ischemic-reperfused atria incubated with palmitate. Moreover, severe tachyarrhythmias were observed in the presence of 3-MA, in both metabolic conditions. This phenomenon was partially prevented by mitochondrial inner membrane ion channels blocker, PK11195.

CONCLUSION

Present study provides new insights into the role of autophagy in ischemic-reperfused atrial myocardium. The observation of greater deterioration in mitochondrial structure and function when this process was inhibited, suggests an association between autophagy and the structural and functional preservation of mitochondria. Exogenous metabolic substrates, to which the myocardium is exposed during ischemia-reperfusion, might not affect this process.

Predicting new onset atrial fibrillation post acute myocardial infarction: Echocardiographic assessment of left atrial size

BACKGROUND

Atrial fibrillation (AF) commonly occurs following acute myocardial infarction (AMI). Left atrial (LA) size has been reported to predict new onset AF in this cohort, however, the optimal metric of left atrial size for risk stratification following AMI is unknown.

METHODS

Patients presenting to a tertiary hospital with incident AMI (NSTEMI or STEMI) and no history of AF were recruited. All patients underwent guideline-based workup and management for AMI, including transthoracic echocardiographic assessment. Three alternative metrics of left atrial size were determined: LA area, maximal and minimal LA volume indexed to body surface area (LAVImax and LAVImin). The primary endpoint was new onset AF diagnoses.

RESULTS

Four hundred thirty three patients were included in the analysis, of which 7.1% had a new diagnosis of AF within a median follow-up of 3.8 years. Univariate predictors of incident AF included age, hypertension, revascularization with CABG, NSTEMI presentation, right atrial area, and all three metrics of LA size. Among three multivariable models created for the prediction of new onset AF utilizing alternate metrics of LA size, LAVImin was the only LA size metric found to be an independent predictor.

CONCLUSIONS

LAVImin is an independent predictor of new onset AF post AMI. LAVImin outperforms echocardiographic assessment of diastolic dysfunction and alternative metrics of LA size (including LA area and LAVImax) for risk stratification. Further studies are needed to validate our findings in post AMI patients, and evaluate whether LAVImin holds similar advantages over LAVImax in other cohorts.

Oral anticoagulant therapy for patients with new-onset atrial fibrillation following acute myocardial infarction: A narrative review

Background

To evaluate the advantages and disadvantages of anticoagulant therapy and provide a piece of information on anti-thrombotic treatment strategies for patients with new-onset atrial fibrillation (NOAF) and acute myocardial infarction (AMI).

Methods

Literature from PubMed and Google scholar were screened until August 2022. Studies assessing oral anticoagulant (OAC) treatments for NOAF in patients with AMI were evaluated for inclusion.

Results

Three retrospective cohort studies were included. In the study performed by Madsen et al., patients with previously diagnosed AMI with or without NOAF were followed up for 5.8 years. About 38% of NOAF patients with anticoagulant therapies, which could reduce long-term mortality [adjusted hazard ratio (HR): 0.69; 95% confidence interval (CI): 0.47–1.00]. Hofer et al. performed a single-center cohort study containing 1,372 patients with AMI with an 8.6-year follow-up period. Dual anti-thrombotic therapy (DAT) did not show the effect on the survival in NOAF (adjusted HR: 0.97; 95% CI: 0.65–1.57), while triple antithrombotic therapy (TAT) could reduce long-term cardiovascular mortality (adjusted HR: 0.86; 95% CI: 0.45–0.92). Petersen et al. also did a cohort study with 1-year follow-up duration. It showed that anticoagulant therapies demonstrated positive results (HR: 0.78; 95% CI: 0.41–1.47).

Conclusion

Recent studies have shown that anticoagulant therapy in AMI-NOAF patients can obviously reduce the mortality of AMI-NOAF patients, especially OAC therapy. Further clinical trials could confirm these findings.

Asymptomatic left circumflex artery stenosis is associated with higher arrhythmia recurrence after persistent atrial fibrillation ablation

Background

The pathophysiology of persistent atrial fibrillation (AF) remains unclear. While several studies have demonstrated an association between myocardial infarction and atrial fibrillation, the role of stable coronary artery disease (CAD) is still unknown. As a result, we aimed to assess the association between CAD obstruction and AF recurrence after persistent AF ablation in patients with no history of CAD.

Materials and methods

This observational retrospective study included consecutive patients who underwent routine preprocedural cardiac computed tomography (CCT) before persistent AF ablation between September 2015 and June 2018 in 5 European University Hospitals. Exclusion criteria were CAD or coronary revascularization previously known or during follow-up. Obstructive CAD was defined as luminal stenosis ≥ 50%.

Results

All in all, 496 patients (mean age 61.8 ± 10.0 years, 76.2% males) were included. CHA₂DS₂–VASc score was 0 or 1 in 225 (36.3%) patients. Obstructive CAD was present in 86 (17.4%) patients. During the follow-up (24 ± 19 months), 207 (41.7%) patients had AF recurrence. The recurrence rate was not different between patients with and without obstructive CAD (43.0% vs. 41.5%, respectively; P = 0.79). When considering the location of the stenosis, the recurrence rate was higher in the case of left circumflex obstruction: 56% vs. 32% at 2 years (log-rank P ≤ 0.01). After Cox multivariate analysis, circumflex artery obstruction (HR 2.32; 95% CI 1.36–3.98; P < 0.01) was independently associated with AF recurrence.

Conclusion

Circumflex artery obstruction detected with CCT was independently associated with 2-fold increase in the risk of AF recurrence after persistent AF ablation. Further research is necessary to evaluate this pathophysiological relationship.

Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease

BACKGROUND

Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD.

METHODS

In total, 12104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death. RESULTS;: Over a mean follow-up of 46.0±18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0% vs. 41.9%, P = 0.03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9% vs. 31.2%;P = 0.04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], P = 0.03). The composite secondary endpoints were significantly higher in the SCAD group (12.70% vs. 8.54%, P = 0.02), mainly due to thromboembolism events (8.16% vs. 4.41%, P<0.01).

CONCLUSIONS

SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD. This article is protected by copyright. All rights reserved.

Clinical Relevance of Sinus Rhythm Mapping to Quantify Electropathology Related to Atrial Fibrillation

Progression of AF is accompanied by structural and electrical remodelling, resulting in complex electrical conduction disorders. This is defined as electropathology and it increases with the progression of AF. The severity of electropathology, thus, defines the stage of AF and is a major determinant of effectiveness of AF therapy. As specific features of AF-related electropathology are still unknown, it is essential to first quantify the electrophysiological properties of atrial tissue and then to examine the inter- and intra-individual variation during normal sinus rhythm. Comparison of these parameters between patients with and without a history of AF unravels quantified electrophysiological features that are specific to AF patients. This can help to identify patients at risk for early onset or progression of AF. This review summarises current knowledge on quantified features of atrial electrophysiological properties during sinus rhythm and discusses its relevance in identifying AF-related electropathology.

Epicardial adipose tissue, obesity and the occurrence of atrial fibrillation: an overview of pathophysiology and treatment methods

INTRODUCTION

Obesity is a chronic disease, which has significant health consequences and is a staggering burden to health care systems. Obesity can have harmful effects on the cardiovascular system, including heart failure, hypertension, coronary heart disease, and atrial fibrillation (AF). One of the possible substrates might be epicardial adipose tissue (EAT), which can be the link between AF and obesity. EAT is a fat deposit located between the myocardium and the visceral pericardium. Numerous studies have demonstrated that EAT plays a pivotal role in this relationship regarding atrial fibrillation.

AREAS COVERED

This review will focus on the role of obesity and the occurrence of atrial fibrillation (AF) and examine the connection between these and epicardial adipose tissue (EAT). The first part of this review will explain the pathophysiology of EAT and its association with the occurrence of AF. Secondly, we will review bariatric and metabolic surgery and its effects on EAT and AF.

EXPERT COMMENTARY

In this review, the epidemiology, pathophysiology, and treatments methods of AF are explained. Secondly the effects on EAT were elucidated. Due to the complex pathophysiological link between EAT, AF, and obesity, it is still uncertain which treatment strategy is superior.

Conduction Heterogeneity: Impact of Underlying Heart Disease and Atrial Fibrillation

OBJECTIVES

The goal of this study is to investigate the impact of various underlying heart diseases (UHDs) and prior atrial fibrillation (AF) episodes on conduction heterogeneity.

BACKGROUND

It is unknown whether intra-atrial conduction during sinus rhythm differs between various UHD or is influenced by AF episodes.

METHODS

Epicardial sinus rhythm mapping of the right atrium, Bachmann's bundle (BB), left atrium and pulmonary vein area was performed in 447 participants (median age: 67 [interquartile range (IQR): 59 to 73] years) with or without AF undergoing cardiac surgery for ischemic heart disease, (ischemic and) valvular heart disease, or congenital heart disease. Conduction times (CTs) were defined as Δ local activation time between 2 adjacent electrodes and used to assess frequency (CTs ≥ 4 ms) and magnitude of conduction disorders (in increments of 10 ms).

RESULTS

When comparing the 3 types of UHD, there were no differences in frequencies and magnitude of CTs at all locations (p ≥ 0.017 and p ≥ 0.005, respectively). Prior AF episodes were associated with conduction slowing throughout both atria (14.9% [IQR: 11.8 to 17.0] vs. 12.8% [IQR: 10.9 to 14.6]; p < 0.001). At BB, CTs with magnitudes ≥30 ms were more common in patients with AF (n = 56.2% vs. n = 36.0%; p < 0.004).

CONCLUSIONS

UHD has no impact on the frequency and severity of conduction disorders. AF episodes are associated with more conduction disorders throughout both atria and with more severe conduction disorders at BB. The next step will be to determine the relevance of these conduction disorders for AF development and maintenance.

The Blinding Period Following Ablation Therapy for Atrial Fibrillation: Proarrhythmic and Antiarrhythmic Pathophysiological Mechanisms

Atrial fibrillation (AF) causes heart failure, ischemic strokes, and poor quality of life. The number of patients with AF is estimated to increase to 18 million in Europe in 2050. Pharmacological therapy does not cure AF in all patients. Ablative pulmonary vein isolation is recommended for patients with drug-resistant symptomatic paroxysmal AF but is successful in only about 60%. In patients in whom ablative therapy is successful on the long term, recurrence of AF may occur in the first weeks to months after pulmonary vein ablation. The early recurrence (or delayed cure) of AF is not understood but forms the basis for the generally accepted 3-month blinding (or blanking) period after ablation therapy, which is not included in the evaluation of the eventual success rate of the procedures. The underlying pathophysiological processes responsible for early recurrence and the delayed cure are unknown. The implicit assumption of the blinding period is that the AF mechanism in this period is different from the ablation-targeted AF mechanism (ectopy from the pulmonary veins). In this review, we evaluate the temporary and long-lasting pro- and antiarrhythmic effects of each of the pathophysiological processes and interventions (necrosis, ischemia, oxidative stress, edema, inflammation, autonomic nervous activity, tissue repair, mechanical remodeling, and use of antiarrhythmic drugs) occurring in the blinding period that can modulate AF mechanisms. We propose that stretch-reducing ablation scar is a permanent antiarrhythmic mechanism that develops during the blinding period and is the reason for delayed cure.

Comparison of prognosis and outcomes of catheter ablation versus drug therapy in patients with atrial fibrillation and stable coronary artery disease: A prospective propensity-score matched cohort study

Background

Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist.

Hypothesis

To investigate the prognosis of catheter ablation versus drug therapy in patients with AF and SCAD.

Methods

In total, 25 512 patients with AF in the Chinese AF Registry between 2011 and 2019 were screened for SCAD. 815 patients with AF and SCAD underwent catheter ablation therapy were matched with patients by drug therapy in a 1:1 ratio. Primary end point was composite of thromboembolism, coronary events, major bleeding, and all‐cause death. The secondary endpoints were each component of the primary endpoint and AF recurrence.

Results

Over a median follow‐up of 45 ± 23 months, the patients in the catheter ablation group had a higher AF recurrence‐free rate (53.50% vs. 18.41%, p < .01). In multivariate analysis, there was no significant difference between the strategy of catheter ablation and drug therapy in primary composite end point (adjusted HR 074, 95%CI 0.54–1.002, p = .0519). However, catheter ablation was associated with fewer all‐cause death independently (adjusted HR 0.36, 95%CI 0.22–0.59, p < .01). In subgroup analysis, catheter ablation was an independent risk factor for all‐cause death in the high‐stroke risk group (adjusted HR 0.39, 95%CI 0.23–0.64, p < .01), not in the low‐medium risk group (adjusted HR 0.17, 95%CI 0.01–2.04, p = .17).

Conclusions

In the patients with AF and SCAD, catheter ablation was not independently associated with the primary composite endpoint compared with drug therapy. However, catheter ablation was an independent protective factor of all‐cause death

Acute atrial ischemia associates with early but not late new-onset atrial fibrillation in STEMI patients treated with primary PCI: relationship with in-hospital outcomes

BACKGROUND

New-onset atrial fibrillation (NOAF), both early (EAF) or late (LAF), may complicate ST-segment elevation myocardial infarction (STEMI). The mechanisms underlying EAF or LAF are poorly described. We investigated atrial branch occlusion and EAF or LAF onset in STEMI patients undergoing primary percutaneous coronary intervention.

METHODS

This was a retrospective cohort study including 155 STEMI patients. Patients were divided into 3 groups: sinus rhythm (SR), EAF, or LAF. Clinical characteristics, angiographic features including occlusion of atrial branches, namely ramus ostia cavae superioris (ROCS), atrio-ventricular node artery (AVNA), right intermediate atrial artery (RIAA), and left intermediate atrial artery, were assessed. We also investigated in-hospital adverse events (AEs) and death.

RESULTS

Mean age was 63.8±11.9 years; 78.7% were men. NOAF was detected in 22 (14.2%) patients: 10 (6.4%) EAF and 12 LAF (7.7%). Compared to EAF, LAF patients were older (p=0.013), with higher GRACE risk score (p=0.014) and Killip class (p=0.015), depressed ejection fraction (p=0.007), elevated filling pressures (p=0.029), higher C-reactive protein (p=0.014) and more with thrombolysis in myocardial infarction flow <3 (p=0.015). Compared to SR, EAF was associated with higher prevalence of occluded ROCS (p=0.010), AVNA (p=0.005), and RIAA (p<0.001). Moreover, EAF patients had more frequently ≥2 diseased atrial branches than SR (19.5%, p<0.001) and LAF (25%, p<0.030) patients. LAF patients had a higher in-hospital AEs (p=0.019 vs SR; p=0.029 vs EAF) and death (p=0.004 vs SR).

CONCLUSIONS

The occlusion of atrial branches is associated with EAF but not LAF following STEMI. LAF patients had worse in-hospital AEs and mortality.

The relation between the atrial blood supply and the complexity of acute atrial fibrillation

Background

Patients with a history of myocardial infarction and coronary artery disease (CAD) have a higher risk of developing AF. Conversely, patients with atrial fibrillation (AF) have a higher risk of developing myocardial infarction, suggesting a link in underlying pathophysiology. The aim of this study was to assess whether coronary angiographic parameters are associated with a substrate for AF in patients without a history of AF.

Methods

During cardiac surgery in 62 patients (coronary artery bypass grafting (CABG;n = 47), aortic valve replacement (AVR;n = 9) or CABG + AVR (n = 6)) without a history of clinical AF (age 65.4 ± 8.5 years, 26.2% female), AF was induced by burst pacing. The preoperative coronary angiogram (CAG) was assessed for the severity of CAD, and the adequacy of atrial coronary blood supply as quantified by a novel scoring system including the location and severity of right coronary artery disease in relation to the right atrial branches. Epicardial mapping of the right atrium (256 unipolar electrodes) was used to assess the complexity of induced AF.

Results

There was no association between the adequacy of right atrial coronary blood supply on preoperative CAG and AF complexity parameters. Multivariable analysis revealed that only increasing age (B0.232 (0.030;0.433),p = 0.03) and the presence of 3VD (B3.602 (0.187;7.018),p = 0.04) were independently associated with an increased maximal activation time difference.

Conclusions

The adequacy of epicardial right atrial blood supply is not associated with increased complexity of induced atrial fibrillation in patients without a history of clinical AF, while age and the extent of ventricular coronary artery disease are.

Angiotensin-converting enzyme 2: a double-edged sword in COVID-19 patients with an increased risk of heart failure

The coronavirus disease (COVID-19) pandemic is a global health priority. Given that cardiovascular diseases (CVD) are the leading cause of morbidity around the world and that several trials have reported severe cardiovascular damage in patients infected with SARS-CoV-2, a substantial number of COVID-19 patients with underlying cardiovascular diseases need to continue their medications in order to improve myocardial contractility and to prevent the onset of major adverse cardiovascular events (MACEs), including heart failure. Some of the current life-saving medications may actually simultaneously expose patients to a higher risk of severe COVID-19. Angiotensin-converting enzyme 2 (ACE2), a key counter regulator of the renin-angiotensin system (RAS), is the main entry gate of SARS-CoV-2 into human host cells and an established drug target to prevent heart failure. In fact, ACE inhibitors, angiotensin II receptor blockers, and mineralocorticoid antagonists may augment ACE2 levels to protect organs from angiotensin II overload. Elevated ACE2 expression on the host cell surface might facilitate viral entrance, at the same time sudden nonadherence to these medications triggers MACEs. Hence, safety issues in the use of RAS inhibitors in COVID-19 patients with cardiac dysfunction remain an unsolved dilemma and need paramount attention. Although ACE2 generally plays an adaptive role in both healthy subjects and patients with systolic and/or diastolic dysfunction, we conducted a literature appraisal on its maladaptive role. Understanding the exact role of ACE2 in COVID-19 patients at risk of heart failure is needed to safely manage RAS inhibitors in frail and non-frail critically ill patients.

Coronary Flow Disturbance Phenomenon After Percutaneous Coronary Intervention Is Associated with New-Onset Atrial Fibrillation in Patients with Acute Myocardial Infarction

Atrial fibrillation (AF) is a common complication of acute myocardial infarction (AMI). Although previous studies have investigated mortality rates and the incidences of adverse events associated with new-onset AF (NOAF) in patients with AMI, the effects of emergency percutaneous coronary intervention (PCI) on the incidence of NOAF in patients with AMI remain unclear. The purpose of this study was to investigate the relationship of clinical characteristics, medical history, and the coronary flow disturbance phenomenon (TIMI < 3) following emergency PCI with NOAF in patients with AMI. Between 2012 and 2016, 731 patients with AMI underwent PCI at our facility. Among these, 52 had a history of chronic/paroxysmal AF before admission and were excluded. The remaining 679 patients (mean age 66.4 years, 532 males) were analyzed in this retrospective observational study.New-onset AF was observed in 45 patients (6.6%). In univariate analysis, the hazard ratios (HRs) for patient age (HR 1.04, 95%CI 1.02-1.07), Killip II-IV (HR 2.34, 95%CI 1.29-4.23), elevated D-dimer level (> 1.0 μg/mL; HR 3.32; 95%CI 1.77-6.23), and coronary flow disturbance phenomenon (HR 5.61; 95%CI 2.88-10.9) were significantly higher in the NOAF group. In multivariate analysis, an elevated D-dimer level (> 1.0 μg/mL; HR 2.44; 95%CI 1.17-5.11) and coronary flow disturbance phenomenon (HR 4.61; 95%CI 2.29-9.27) were found to be independent risk factors for NOAF. An elevated D-dimer level at admission and the presence of coronary flow disturbance phenomenon after PCI were risk factors for NOAF following emergency PCI in patients with AMI.

The interplay between atrial fibrillation and acute myocardial infarction

Atrial fibrillation is the most frequently occurring supraventricular arrhythmia in patients presenting with acute myocardial infarction. It is associated with worse outcomes when it coexists with acute myocardial infarction and results in increased morbidity and mortality. Both conditions are closely related to each other and share similar pathophysiological pathways. The management of atrial fibrillation in patients with acute myocardial infarction is challenging since triple antithrombotic therapy is indicated, but this results in a markedly increased risk of bleeding events and mortality. This review addresses the interactions between both conditions including common risk factors, possible mechanisms through which acute myocardial infarction contributes to development of atrial fibrillation and vice versa, and the problem of using anticoagulation in the management of these patients.

Impact of Atrial Fibrillation on Acute Coronary Syndrome-Analysis of In-Hospital Outcomes and 30-Day Readmissions

With an aging population and significant overlap of risk factors, the cohort of patients with acute coronary syndrome (ACS) and concomitant atrial fibrillation (AF) is a sizable and growing one, with implications on cardiac reserve, anticoagulation and antiplatelet therapies, and related complications. The present study uses a large national database to analyze the impact of AF on patients admitted with an ACS. We queried the 2012 to 2014 National Readmissions Database to identify patients admitted with an ACS using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9 CM) codes. These patients were then subcategorized based on the presence or absence of AF. Analysis of their initial hospitalization, 30-day readmissions and healthcare utilization and the economic burden was performed. Among 1,558,205 patients with ACS, 270,966 (17.4%) were noted to have concomitant AF. At baseline, these patients were older and more likely female, with a significantly higher burden of comorbidities. Patients with AF had longer and more complicated index hospitalizations with significantly higher mortality rates (8.6% vs 4.6%). Coronary artery bypass graft was the preferred method of revascularization in patients with AF as compared to percutaneous coronary intervention. The 30-day readmissions were higher in the AF group (15.6 vs 10.8%), largely driven by noncardiac causes. This was associated with higher healthcare utilization with longer hospitalizations during index admission. Patients admitted with ACS and concomitant AF is a high-risk population with increased in-hospital complications and mortality, as well as short term readmissions. Coronary artery bypass graft appears favored over percutaneous coronary intervention for revascularization in patients with AF.

New-Onset Atrial Fibrillation in St-Segment Elevation Myocardial Infarction: Predictors and Impact on Therapy And Mortality

Backgrund

New-onset atrial fibrillation complicating acute myocardial infarction represents an important challenge, with prognostic significance.

Objective

To study the incidence, impact on therapy and mortality, and to identify predictors of development of new-onset atrial fibrillation during hospital stay for ST-segment elevation myocardial infarction.

Methods

We studied all patients with ST-elevation myocardial infarction included consecutively, between 2010 and 2017, in a Portuguese national registry and compared two groups: 1 - no atrial fibrillation and 2 - new-onset atrial fibrillation. We adjusted a logistic regression model data analysis to assess the impact of new-onset atrial fibrillation on in-hospital mortality and to identify independent predictors of its development. A p value < 0.05 was considered significant.

Results

We studied 6325 patients, and new-onset atrial fibrillation was found in 365 (5.8%). Reperfusion was successfully accomplished in both groups with no difference regarding type of reperfusion. In group 2, therapy with beta-blockers and angiotensin-conversion enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) was less frequent, 20.6% received anticoagulation at discharge and 16.1% were on triple therapy. New-onset atrial fibrillation was associated with more in-hospital complications and mortality. However, it was not found as an independent predictor of in-hospital mortality. We identified age, prior stroke, inferior myocardial infarction and complete atrioventricular block as independent predictors of new-onset atrial fibrillation.

Conclusion

New-onset atrial fibrillation remains a frequent complication of myocardial infarction and is associated with higher rate of complications and in-hospital mortality. Age, prior stroke, inferior myocardial infarction and complete atrioventricular block were independent predictors of new onset atrial fibrillation. Only 36.7% of the patients received anticoagulation at discharge.

Lifestyle and Risk Factor Modification for Reduction of Atrial Fibrillation: A Scientific Statement From the American Heart Association

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is associated with substantial morbidity, mortality, and healthcare use. Great strides have been made in stroke prevention and rhythm control strategies, yet reducing the incidence of AF has been slowed by the increasing incidence and prevalence of AF risk factors, including obesity, physical inactivity, sleep apnea, diabetes mellitus, hypertension, and other modifiable lifestyle-related factors. Fortunately, many of these AF drivers are potentially reversible, and emerging evidence supports that addressing these modifiable risks may be effective for primary and secondary AF prevention. A structured, protocol-driven multidisciplinary approach to integrate lifestyle and risk factor management as an integral part of AF management may help in the prevention and treatment of AF. However, this aspect of AF management is currently underrecognized, underused, and understudied. The purpose of this American Heart Association scientific statement is to review the association of modifiable risk factors with AF and the effects of risk factor intervention. Implementation strategies, care pathways, and educational links for achieving impactful weight reduction, increased physical activity, and risk factor modification are included. Implications for clinical practice, gaps in knowledge, and future directions for the research community are highlighted.

Procedural-related coronary atrial branch occlusion during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction and atrial arrhythmias at follow-up

OBJECTIVES

To evaluate the frequency of procedural-related atrial branch occlusion in ST-segment elevation myocardial infarction (STEMI) patients and its association with atrial arrhythmias at 1-year follow-up.

BACKGROUND

Atrial ischemia due to procedural-related coronary atrial branch occlusion in elective percutaneous coronary intervention (PCI) has been associated with atrial arrhythmias. Its role in a STEMI scenario is unknown.

METHODS

STEMI patients treated with primary PCI were classified according to the loss or patency of an atrial branch at the end of the procedure. The occurrence of atrial arrhythmias was documented on 24-hr Holter-ECG at 3 and 6 months or on ECG during 1-year follow-up visits.

RESULTS

Of 900 patients, 355 (age 61 ± 12 years, 79% male) underwent primary PCI involving the origin of an atrial branch. Procedural-related coronary atrial branch occlusion was observed in 18 (5%) individuals). During 1-year follow-up, 33% of patients with procedural-related atrial branch occlusion presented atrial arrhythmias, as compared with 55% in those with a patent atrial branch (p = .088). Age, no previous history of myocardial infarction, and a reduced flow in the culprit vessel were the only independent correlates of atrial arrhythmias.

CONCLUSIONS

The frequency of procedural-related atrial branch occlusion during primary PCI is low (5%) and is not associated with increased frequency of atrial arrhythmias at 1-year follow-up.

Early Atrial Fibrillation During Acute Myocardial Infarction May Not Be an Indication for Long-Term Anticoagulation

Patients with new-onset of atrial fibrillation (NOAF) during acute myocardial infarction (AMI) currently receive long-term oral anticoagulation. The risk for stroke of “early” versus “late” onset of atrial fibrillation (AF) has not been elucidated. Consecutively, AMI patients admitted to a tertiary medical center were analyzed. We excluded patients with preexisting AF, AMI onset ≥24 hours prior to admission, significant valvular disease, fever >38.5°C, in-hospital death, or coronary artery bypass graft. Atrial fibrillation was verified by electrocardiography and medical records. Overall 7061 patients were included, 1.4% developed “early-paroxysmal AF (PAF)” that resolved within 24 hours of admission and 2.5% had “late-AF” beyond the first 24 hours. Median follow-up was ≈6 years. Primary end points included ischemic stroke and all-cause mortality. Stroke rates were higher only in patients with late-AF versus no-AF but not in the early-PAF: 10.6% versus 4.2%, 5.3%, respectively ( P < .001). Death rates were higher in patients with late-AF and early-PAF versus no-AF: 55.3%, 43.2%, and 29.2%, respectively ( P < .001). Congestive heart failure, hypertension, age ≥75, diabetes mellitus, a stroke or transient ischemic attack, vascular disease, age 65-74, female (CHA2DS2-VASc) score underestimated stroke risk in the late-AF group. In conclusion, the study generates the hypothesis that patients with early-PAF may not have a high stroke risk questioning the indication for long-term anticoagulation.

Atrial fibrillation observed in a patient with esophageal cancer treated with fluorouracil

Fluorouracil (5-FU), a commonly used anticancer agent, has potent cardiotoxicity that is mediated by vascular endothelial injury and vasospasm. Here, we report a patient demonstrating atrial fibrillation (AF), which was most likely induced by vasospasm mediated by 5-FU.

A 69-year-old man presented with dysphagia and was diagnosed with advanced esophageal cancer. Frequent paroxysms of atrial fibrillation (AF) were observed during combination chemotherapy including 5-FU. AF was refractory to disopyramide, but was sensitive to antianginal agents (nicorandil and nitroglycerin transdermal patch). Coronary angiography performed within the chemotherapeutic period demonstrated moderate stenosis in the right coronary artery (RCA). Severe spasm at the proximal portion of the atrial branch in RCA was induced by provocation test using acetylcholine. Our case indicated that 5-FU predisposed vasospasm in RCA and the subsequent atrial ischemia may lead to AF.

<Learning objective: Fluorouracil (5-FU), a commonly used anticancer agent, induces cardiac ischemic events and sometimes leads to the paroxysms of atrial fibrillation (AF). Coronary-dilating agents should be considered for the treatment of AF which occurs after the administration of 5-FU and is refractory to antiarrhythmic agents.>

[Specific Features of the Course of Acute Coronary Syndrome in Patients with Newly Developed Atrial Fibrillation in Clinical Practice According to the Data of the Register of Acute Coronary Syndrome]

AIM

to elucidate risk factors of development of atrial fibrillation (AF) in patients with acute coronary syndrome (ACS), and to assess of patient's adherence to oral anticoagulant therapy (OAT) during 12 months after ACS episode according to the data of the Total ACS Registry for the Krasnodar Territory.

MATERIALS AND METHODS

In this retrospective analysis we used Registry data on patients with ACS and concomitant AF, consecutively admitted to cardiological departments of the S.V. Ochapovsky Territorial Clinical Hospital from 20/11/2015 to 20/02/18. Number of patients in the analyzed group was 201 (52 with AF which first appeared in connection with the index ACS). Survivors after hospital discharge were contacted by telephone and at planned visits. The analysis included assessment of rates of the following outcomes: inhospital death, hemorrhagic and thromboembolic complications, prognostic efficacy of the CRISADE and HAS BLED scores, and expediency of prescription to patients with ACS and concomitant first AF episode of prolonged OAT after hospital discharge.

RESULTS

Demographic and anamnestic data of patients with the first AF attack at the background of ACS were like those of patients with other types of AF. This group of patients was characterized by more severe course of the disease, but this produced no impact on inhospital mortality and rate of complications, as well as on mortality for 12 months after hospital discharge.

CONCLUSION

The results of this analysis are important for understanding distinctive characteristics of patients with AF first developed during ACS.

Atrial Infarction-Induced Spontaneous Focal Discharges and Atrial Fibrillation in Sheep: Role of Dantrolene-Sensitive Aberrant Ryanodine Receptor Calcium Release

BACKGROUND

The mechanisms underlying spontaneous atrial fibrillation (AF) associated with atrial ischemia/infarction are incompletely elucidated. Here, we investigate the mechanisms underlying spontaneous AF in an ovine model of left atrial myocardial infarction (LAMI).

METHODS AND RESULTS

LAMI was created by ligating the atrial branch of the left anterior descending coronary artery. ECG loop recorders were implanted to monitor AF episodes. In 7 sheep, dantrolene-a ryanodine receptor blocker-was administered in vivo during the 8-day observation period (LAMI-D, 2.5 mg/kg, IV, BID). LAMI animals experienced numerous spontaneous AF episodes during the 8-day monitoring period that were suppressed by dantrolene (LAMI, 26.1±5.1; sham, 4.3±1.1; LAMI-D, 2.8±0.8; mean±SEM episodes per sheep, P<0.01). Optical mapping showed spontaneous focal discharges (SFDs) originating from the ischemic/normal-zone border. SFDs were calcium driven, rate dependent, and enhanced by isoproterenol (0.03 µmol/L, from 210±87 to 3816±1450, SFDs per sheep) but suppressed by dantrolene (to 55.8±32.8, SFDs per sheep, mean±SEM). SFDs initiated AF-maintaining reentrant rotors anchored by marked conduction delays at the ischemic/normal-zone border. NOS1 (NO synthase-1) protein expression decreased in ischemic zone myocytes, whereas NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) oxidase and xanthine oxidase enzyme activities and reactive oxygen species (DCF [6-carboxy-2',7'-dichlorodihydrofluorescein diacetate]-fluorescence) increased. CaM (calmodulin) aberrantly increased [³H]ryanodine binding to cardiac RyR2 (ryanodine receptors) in the ischemic zone. Dantrolene restored the physiological binding of CaM to RyR2.

CONCLUSIONS

Atrial ischemia causes spontaneous AF episodes in sheep, caused by SFDs that initiate reentry. Nitroso-redox imbalance in the ischemic zone is associated with intense reactive oxygen species production and altered RyR2 responses to CaM. Dantrolene administration normalizes the CaM response, prevents LAMI-related SFDs, and AF initiation. These findings provide novel insights into the mechanisms underlying ischemia-related atrial arrhythmias.

Value of Syntax Score II in Prediction of New-Onset Atrial Fibrillation in Patients With NSTE-ACS Undergoing Percutaneous Coronary Intervention

New-onset atrial fibrillation (NOAF) has been associated with poor outcome in patients with acute coronary syndromes (ACSs). The objective of this study was to investigate the relationship between the development of NOAF and severity of coronary artery disease using the SYNTAX score (SS) and SYNTAX score II (SSII) in patients with non-ST-segment elevation ACS (NSTE-ACS) who were treated with percutaneous coronary intervention (PCI). A total of 662 patients with NSTE-ACS were consecutively enrolled. The incidence of NOAF was 11.4% among the patients with NSTE-ACS. Mean age was significantly higher in NOAF group ( P = .011). White blood cell count, peak troponin I, high sensitivity C-reactive protein, uric acid, left atrial volume index, and ratio between early mitral inflow velocity and mitral annular early diastolic velocity were significantly higher in NOAF group (respectively, P = .024, P = .017, P = .002, P = .009, P = .025, P < .001, and P < .001). The hemoglobin, ejection fraction, and post PCI thrombolysis in myocardial infarction grade <3 were significantly lower in NOAF group ( P = 001, P = .010, P = .038). The SS and SSII were significantly higher in NOAF group (all P < .001). According to the results of multivariate logistic regression analysis, the SSII was correlated with NOAF ( P < .001) in the study groups. We demonstrated that high SSII is significantly associated with NOAF.

The value of syntax score to predict new-onset atrial fibrillation in patients with acute coronary syndrome

BACKGROUND AND AIM

New-onset atrial fibrillation (NOAF) has been associated with poor outcome in patients with acute coronary syndromes (ACS). Also, Syntax score (SS) is a scoring system that is derived from angiographic images and is associated with long-term mortality and major adverse cardiac events. In this study, we aimed to assess the relationship between SS and NOAF with known predictors of atrial fibrillation.

METHODS

In a prospective, single-center, cross-sectional study, 692 patients who were diagnosed with coronary artery disease for the first time were enrolled consecutively. NOAF was defined as atrial fibrillation, which was documented after hospital admission. SS was calculated by a computer software. Multivariable logistic regression analyzes were used to detect the relationship between variables and NOAF.

RESULTS

New-onset atrial fibrillation was detected in 82 patients (11.8%). Patients with NOAF had higher SS (22, interquartile range 18.3-25.1, vs. 12, interquartile range 7-19.5, p < 0.001). According to multivariable logistic regression analysis for NOAF, SS were independently and significantly associated (OR, 1.103; 95% confidence interval, 1.047-1.163; p < 0.001). Other independent predictors of NOAF were TIMI flow <3, C reactive protein, left ventricular ejection fraction, left atrial volume index and E/E' ratio. The optimal cut-off value for SS was 18 for the development of NOAF with 82% sensitivity and 68% specificity (area under the curve: 0.795, 95% confidence interval 0.749-0.841, p < 0.001).

CONCLUSION

Syntax score may be helpful to identify for patients who would develop atrial fibrillation in the setting of ACS.

The imminent epidemic of atrial fibrillation and its concomitant diseases - Myocardial infarction and heart failure - A cause for concern

Atrial fibrillation (AF) is increasingly common in the general population. It often coincides with myocardial infarction (MI) and heart failure (HF) which are also diseases in older adults. All three conditions share common cardiovascular risk factors. While hypertension and obesity are central risk factors for all three diseases, smoking and diabetes appear to have less impact on AF. To date, age is the single most important risk factor for AF in the general population. Further, epidemiological studies suggest a strong association of AF to MI and HF. The underlying pathophysiological mechanisms are complex and not fully understood. Both MI and HF can trigger development of AF, mainly by promoting structural and electrical atrial remodeling. On the other hand, AF facilitates HF and MI development via multiple mechanisms, resulting in a vicious circle of cardiac impairment and adverse cardiovascular prognosis. Consequently, to prevent and treat the coincidence of AF and HF or MI a strict optimization of cardiovascular risk factors is required.

Atrial Fibrillation and Acute Myocardial Infarction – An Inflammation-Mediated Association

Atrial fibrillation (AF) is an increasingly widespread healthcare problem. AF can frequently present as a complication in acute coronary syndromes (ACS), especially in ST-elevation acute myocardial infarction (AMI), in which case it is the most frequent supraventricular rhythm disturbance with an estimated incidence of 6.8-21%. The presence of AF in ACS heralds worse outcomes in comparison to subjects in sinus rhythm, and several studies have shown that in AMI patients, both new-onset and pre-existing AF are associated with a higher risk of major adverse cardiovascular and cerebrovascular events during hospitalization. The cause of newonset AF in AMI is multifactorial. Although still incompletely understood, the mechanisms involved in the development of AF in acute myocardial ischemic events include the neurohormonal activation of the sympathetic nervous system that accompanies the AMI, ischemic involvement of the atrial myocytes, ventricular dysfunction, and atrial overload. The identification of patients at risk for AF is of great significance as it may lead to prompt therapeutic interventions and closer follow-up, thus improving prognosis and decreasing cardiovascular and cerebrovascular events. The present manuscript aims to summarize the current research findings related to new-onset AF in AMI patients, as well as the predictors and prognostic impact of this comorbid association.

NEW-ONSET ATRIAL FIBRILLATION IN SETTINGS OF ACUTE CORONARY SYNDROME. CURRENT ISSUES

The present review is focuses on new onset atrial fibrillation (AF) in conditions of acute coronary syndrome (ACS). Literature sources from PubMed and Scopus was used. AF is common in the general population and in the ACS population, at that new onset AF, and AF, which was by the time of ACS development are determined. Appearance of AF is more likely amongst the elderly patients with congestive heart failure, with signs of the hemodynamic instability and with the left atrium dilatation. It is well-known about the predictors of adverse outcome in ACS. According to some literature data new onset AF leads to worsening of prognosis, and in line with other sources a reason of its association with high level of mortality is due to the severity of ACS and appearance of AF is not independent predictor of death. The absence of subjective symptoms at the time of paroxysm of new onset AF does not allow estimating its duration and distinguishing between the new onset AF, persistent and constant AF. It is possible to trace the relationship between the myocardial ischemia and AF appearance. Inefficient reperfusion during percutaneous coronary intervention or thrombolytic therapy is accompanied by the onset of AF, on the contrary, when effective patency of coronary artery is achieved, AF appears significantly less often. New onset AF in ACS, in particular, accompanied by cardiogenic shock, requires emergency pharmacological or electrical cardioversion. In some cases, active cardioversion is not necessary, because of spontaneous cardiac rhythm conversion. In conclusions, it is necessary to point out, that ambiguity and multifactority of this problem demands investigation of arrhythmogenesis mechanisms and development of special risk stratification instruments for the new onset AF in ACS.

Cardiac computed tomography in patients with symptomatic new-onset atrial fibrillation, rule-out acute coronary syndrome, but with intermediate pretest probability for coronary artery disease admitted to a chest pain unit

Background

Atrial fibrillation (AF) and coronary artery disease (CAD) may be encountered coincidently in a large portion of patients. However, data on coronary artery calcium burden in such patients are lacking. Thus, we sought to determine the value of cardiac computed tomography (CCT) in patients presenting with new-onset AF associated with an intermediate pretest probability for CAD admitted to a chest pain unit (CPU).

Methods

Calcium scores (CS) of 73 new-onset, symptomatic AF subjects without typical clinical, electrocardiographic, or laboratory signs of acute coronary syndrome (ACS) admitted to our CPU were analyzed. In addition, results from computed tomography angiography (CTA) were related to coronary angiography findings whenever available.

Results

Calcium scores of zero were found in 25%. Median Agatston score was 77 (interquartile range: 1–270) with gender- and territory-specific dispersal. CS scores above average were present in about 50%, high (> 400)-to-very high (> 1000) CS scores were found in 22%. Overall percentile ranking showed a relative accordance to the reference percentile distribution. Additional CTA was performed in 47%, revealing stenoses in 12%. Coronary angiography was performed in 22% and resulted in coronary intervention or surgical revascularization in 7%. On univariate analysis, CS > 50th percentile failed to serve as an independent determinant of significant stenosis during catheterization.

Conclusions

Within a CPU setting, relevant CAD was excluded or confirmed in almost 50%, the latter with a high proportion of coronary angiographies and subsequent coronary interventions, underlining the diagnostic value of CCT in symptomatic, non-ACS, new-onset AF patients when admitted to a CPU.

Coronary Artery Calcium as an Independent Surrogate Marker in the Risk Assessment of Patients With Atrial Fibrillation and an Intermediate Pretest Likelihood for Coronary Artery Disease Admitted to a German Chest Pain Unit

BACKGROUND

About 10% of patients admitted to a chest pain unit (CPU) exhibit atrial fibrillation (AF).

HYPOTHESIS

To determine whether calcium scores (CS) are superior over common risk scores for coronary artery disease (CAD) in patients presenting with atypical chest pain, newly diagnosed AF, and intermediate pretest probability for CAD within the CPU.

METHODS

In 73 subjects, CS was related to the following risk scores: Global Registry of Acute Coronary Events (GRACE) score, including a new model of a frequency-normalized approach; Thrombolysis In Myocardial Infarction score; European Society of Cardiology Systematic Coronary Risk Evaluation (SCORE); Framingham risk score; and Prospective Cardiovascular Münster Study score. Revascularization rates during index stay were assessed.

RESULTS

Median CS was 77 (interquartile range, 1-270), with higher values in men and the left anterior descending artery. Only the modified GRACE (ρ = 0.27; P = 0.02) and the SCORE (ρ = 0.39; P < 0.005) were significantly correlated with CS, whereas the GRACE (τ = 0.21; P = 0.04) and modified GRACE (τ = 0.23; P = 0.02) scores were significantly correlated with percentile groups. Only the CS significantly discriminated between those with and without stenosis (P < 0.01).

CONCLUSIONS

Apart from modified GRACE score, overall correlations between risk scores and calcium burden, as well as revascularization rates during index stay, were low. By contrast, the determination of CS may be used as an additional surrogate marker in risk stratification in AF patients with intermediate pretest likelihood for CAD admitted to a CPU.

A Review of the Relationship of Atrial Fibrillation and Acute Coronary Syndrome

Atrial fibrillation (AF) is the most common arrhythmia encountered by clinicians. Clinical decision-making focuses on reducing ischemic stroke risk in AF patients; however, AF is also associated with an increased risk of acute coronary syndromes (ACS). Patients with ACS and concurrent AF are less likely to receive appropriate therapies and more likely to experience adverse outcomes than ACS patients in sinus rhythm (SR). Clinicians may be able to stratify ACS patients at increased risk of AF development based on clinical characteristics. Evidence supporting specific therapeutic options for prevention of ACS in AF patients or for prevention of AF in ACS patients is limited, however there is some evidence of differing effects among oral anticoagulant regimens in these populations. Investigations of the relationship of AF with the full spectrum of ACS are not well described and should be the focus of future research.

Relation of Atrial Fibrillation in Acute Myocardial Infarction to In-Hospital Complications and Early Hospital Readmission

Atrial fibrillation (AF) is a common complication of acute myocardial infarction (AMI) and contributes to high rates of in-hospital adverse events. However, there are few contemporary studies examining rates of AF in the contemporary era of AMI or the impact of new-onset AF on key in-hospital and postdischarge outcomes. We examined trends in AF in 6,384 residents of Worcester, Massachusetts, who were hospitalized with confirmed AMI during 7 biennial periods between 1999 and 2011. Multivariate logistic regression analysis was used to examine associations between occurrence of AF and various in-hospital and postdischarge complications. The overall incidence of AF complicating AMI was 10.8%. Rates of new-onset AF increased from 1999 to 2003 (9.8% to 13.2%), and decreased thereafter. In multivariable adjusted models, patients developing new-onset AF after AMI were at a higher risk for in-hospital stroke (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.6 to 4.1), heart failure (OR 2.0, 95% CI 1.7 to 2.4), cardiogenic shock (OR 3.7, 95% CI 2.8 to 4.9), and death (OR 2.3, 95% CI 1.9 to 3.0) than patients without AF. Development of AF during hospitalization for AMI was associated with higher rates of readmission within 30 days after discharge (21.7% vs 16.0%), but no significant difference was noted in early postdischarge 30-day all-cause mortality rates (8.3% vs 5.1%). In conclusion, new-onset AF after AMI is strongly related to in-hospital complications of AMI and higher short-term readmission rates.