Comprehensive risk reduction in patients with atrial fibrillation: emerging diagnostic and therapeutic options--a report from the 3rd Atrial Fibrillation Competence NETwork/European Heart Rhythm Association consensus conference

Acquired risk factors and incident atrial fibrillation according to age and genetic predisposition

BACKGROUND AND AIMS

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. Investigations of risk factor profiles for AF according to age and genetic risk groups are essential to promote individualized strategies for the prevention and control of AF.

METHODS

A total of 409 661 participants (mean age, 56 years; 46% men) free of AF at baseline and with complete information about risk factors were included from the UK Biobank cohort. The hazard ratios and population-attributable risk (PAR) percentages of incident AF associated with 23 risk factors were examined, including 3 social factors, 7 health behaviours, 6 cardiometabolic factors, 6 clinical comorbidities, and the genetic risk score (GRS), across 3 age groups (40-49, 50-59, and 60-69 years) and 3 genetic risk groups (low, moderate, and high GRS).

RESULTS

After a follow-up of 5 027 587 person-years, 23 847 participants developed AF. Most cardiometabolic factors and clinical comorbidities showed a significant interaction with age, whereby the associations were generally strengthened in younger groups (Pinteraction < .002). However, only low LDL cholesterol, renal dysfunction, and cardiovascular disease showed a significant interaction with genetic risk, and the associations with these factors were stronger in lower genetic risk groups (Pinteraction < .002). Cardiometabolic factors consistently accounted for the largest number of incident AF cases across all age groups (PAR: 36.2%-38.9%) and genetic risk groups (34.0%-41.9%), with hypertension and overweight/obesity being the two leading modifiable factors. Health behaviours (PAR: 11.5% vs. 8.7%) and genetic risk factors (19.1% vs. 14.3%) contributed to more AF cases in the 40-49 years group than in the 60-69 years group, while the contribution of clinical comorbidities remained relatively stable across different age groups. The AF risk attributable to overall cardiometabolic factors (PAR: 41.9% in the low genetic risk group and 34.0% in the high genetic risk group) and clinical comorbidities (24.7% and 15.9%) decreased with increasing genetic risk. The impact of social factors on AF was relatively low across the groups by age and genetic risk.

CONCLUSIONS

This study provided comprehensive information about age- and genetic predisposition-related risk factor profiles for AF in a cohort of UK adults. Prioritizing risk factors according to age and genetic risk stratifications may help to achieve precise and efficient prevention of AF.

Incidental parasympathetic cardiac denervation during atrial fibrillation ablation using high power short duration: a marker of long-term success

BACKGROUND

There are multiple factors in both technique and substrate that lead to recurrence of atrial fibrillation after ablation. We sought to examine whether the degree of heart rate increase (HRI) caused by concurrent high-power-short-duration (HPSD) incidental parasympathetic denervation during AF ablation predicts long term success. Between December 2018 and December 2021, prospectively enrolled 214 patients who presented in sinus rhythm at AF ablation. Used 50 W of power and contact force (CF) of 5-15 g and 10-20 g at a flow rate of 40 mL/min on the anterior and posterior left atrial walls, respectively.

RESULTS

Males were 143 (66.8%) and paroxysmal was 124 (57.9%) patients. Mean age 61.1 ± 12.3 years and follow-up time was 32.8 ± 13.2 months. Arrhythmia occurred after 90 days in 39 (18.2%) patients, 19 (48.7%) from the paroxysmal and 20 (51.3%) from the persistent AF patients. Recurrence group showed a lower HRI from a mean of 57 ± 7.7 to 64.4 ± 10.4 bpm (12.3%) while in success group HRI was from 53.8 ± 9.7 to 66.8 ± 11.6 bpm [(24.2%) p = 0.04]. We divided HRI in 3 percentiles of ≤ 8%, > 8 ≤ 37% and > 37%. A predictor of recurrence was identified in those in the first (< 8%, p = 0.006) and a predictor of success in the later (> 37%, p = 0.01) HRI percentile.

CONCLUSION

Atrial fibrillation ablation with HPSD incidental cardiac parasympathetic denervation identified that patients with lower heart rate increase are prone to recurrence while those with higher heart rate increase had higher maintenance of sinus rhythm at a long-term follow-up.

Microprotein Dysregulation in the Serum of Patients with Atrial Fibrillation

The incidence rate of atrial fibrillation (AF) has stayed at a high level in recent years. Despite the intensive efforts to study the pathologic changes of AF, the molecular mechanism of disease development remains unclarified. Microproteins are ribosomally translated gene products from small open reading frames (sORFs) and are found to play crucial biological functions, while remain rare attention and indistinct in AF study. In this work, we recruited 65 AF patients and 65 healthy subjects for microproteomic profiling. By differential analysis and cross-validation between independent datasets, a total of 4 microproteins were identified as significantly different, including 3 annotated ones and 1 novel one. Additionally, we established a diagnostic model with either microproteins or global proteins by machine learning methods and found the model with microproteins achieved comparable and excellent performance as that with global proteins. Our results confirmed the abnormal expression of microproteins in AF and may provide new perspectives on the mechanism study of AF.

Interaction of Cardiovascular Nonmodifiable Risk Factors, Comorbidities and Comedications With Ischemia/Reperfusion Injury and Cardioprotection by Pharmacological Treatments and Ischemic Conditioning

Preconditioning, postconditioning, and remote conditioning of the myocardium enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and the potential to provide novel therapeutic paradigms for cardioprotection. While many signaling pathways leading to endogenous cardioprotection have been elucidated in experimental studies over the past 30 years, no cardioprotective drug is on the market yet for that indication. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic preclinical evaluation of promising cardioprotective therapies prior to their clinical evaluation, since ischemic heart disease in humans is a complex disorder caused by or associated with cardiovascular risk factors and comorbidities. These risk factors and comorbidities induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury and responses to cardioprotective interventions. Moreover, some of the medications used to treat these comorbidities may impact on cardioprotection by again modifying cellular signaling pathways. The aim of this article is to review the recent evidence that cardiovascular risk factors as well as comorbidities and their medications may modify the response to cardioprotective interventions. We emphasize the critical need for taking into account the presence of cardiovascular risk factors as well as comorbidities and their concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple comorbidities. SIGNIFICANCE STATEMENT: Ischemic heart disease is a major cause of mortality; however, there are still no cardioprotective drugs on the market. Most studies on cardioprotection have been undertaken in animal models of ischemia/reperfusion in the absence of comorbidities; however, ischemic heart disease develops with other systemic disorders (e.g., hypertension, hyperlipidemia, diabetes, atherosclerosis). Here we focus on the preclinical and clinical evidence showing how these comorbidities and their routine medications affect ischemia/reperfusion injury and interfere with cardioprotective strategies.

Management of atrial fibrillation: two decades of progress - a scientific statement from the European Cardiac Arrhythmia Society

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. The aim of this review was to evaluate the progress made in the management of AF over the two last decades.

RESULTS

Clinical classification of AF is usually based on the presence of symptoms, the duration of AF episodes and their possible recurrence over time, although incidental diagnosis is not uncommon. The majority of patients with AF have associated cardiovascular diseases and more recently the recognition of modifiable risk factors both cardiovascular and non-cardiovascular which should be considered in its management. Among AF-related complications, stroke and transient ischaemic accidents (TIAs) carry considerable morbidity and mortality risk. The use of implantable devices such as pacemakers and defibrillators, wearable garments and subcutaneous cardiac monitors with recording capabilities has enabled to access the burden of "subclinical AF". The recent introduction of non-vitamin K antagonists has led to improve the prevention of stroke and peripheral embolism. Agents capable of reversing non-vitamin K antagonists have also become available in case of clinically relevant major bleeding. Transcatheter closure of left atrial appendage represents an option for patients unable to take oral anticoagulation. When treating patients with AF, clinicians need to select the most suitable strategy, i.e. control of heart rate and/or restoration and maintenance of sinus rhythm. The studies comparing these two strategies have not shown differences in terms of mortality. If an AF episode is poorly tolerated from a haemodynamic standpoint, electrical cardioversion is indicated. Otherwise, restoration of sinus rhythm can be obtained using intravenous pharmacological cardioversion and oral class I or class III antiarrhythmic is used to prevent recurrences. During the last two decades after its introduction in daily practice, catheter ablation has gained considerable escalation in popularity. Progress has also been made in AF associated with heart failure with reduced or preserved ejection fraction.

CONCLUSIONS

Significant progress has been made within the past 2 decades both in the pharmacological and non-pharmacological managements of this cardiac arrhythmia.

Further Advances in Atrial Fibrillation Research: A Metabolomic Perspective

Atrial fibrillation involves an important type of heart arrhythmia caused by a lack of control in the electrical signals that arrive in the heart, produce an irregular auricular contraction, and induce blood clotting, which finally can lead to stroke. Atrial fibrillation presents some specific characteristics, but it has been treated and prevented using conventional methods similar to those applied to other cardiovascular diseases. However, due to the influence of this pathology on the mortality caused by cerebrovascular accidents, further studies on the molecular mechanism of atrial fibrillation are required. Our aim here is provide a compressive review of the use of metabolomics on this condition, from the study of the metabolic profile of plasma to the development of animal models. In summary, most of the reported studies highlighted alterations in the energetic pathways related to the development of the condition.

Differences in Atrial Remodeling in Hypertrophic Cardiomyopathy Compared to Hypertensive Heart Disease and Athletes' Hearts

Background: Hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and athletes’ heart share an increased prevalence of atrial fibrillation. Atrial cardiomyopathy in these patients may have different characteristics and help to distinguish these conditions. Methods: In this single-center study, we prospectively collected and analyzed electrocardiographic (12-lead ECG, signal-averaged ECG (SAECG), 24 h Holter ECG) and echocardiographic data in patients with HCM and HHD and in endurance athletes. Patients with atrial fibrillation were excluded. Results: We compared data of 27 patients with HCM (70% males, mean age 50 ± 14 years), 324 patients with HHD (52% males, mean age 75 ± 5.5 years), and 215 endurance athletes (72% males, mean age 42 ± 7.5 years). HCM patients had significantly longer filtered P-wave duration (153 ± 26 ms) and PR interval (191 ± 48 ms) compared to HHD patients (144 ± 16 ms, p = 0.012 and 178 ± 31, p = 0.034, respectively) and athletes (134 ± 14 ms, p = 0.001 and 165 ± 26 ms, both p < 0.001, respectively). HCM patients had a mean of 4.9 ± 16 premature atrial complexes per hour. Premature atrial complexes per hour were significantly more frequent in HHD patients (27 ± 86, p < 0.001), but not in athletes (2.7 ± 23, p = 0.639). Left atrial volume index (LAVI) was 43 ± 14 mL/m2 in HCM patients and significantly larger than age- and sex-corrected LAVI in HHD patients 30 ± 10 mL/m2; p < 0.001) and athletes (31 ± 9.5 mL/m2; p < 0.001). A borderline interventricular septum thickness ≥13 mm and ≤15 mm was found in 114 (35%) HHD patients, 12 (6%) athletes and 3 (11%) HCM patients. Conclusions: Structural and electrical atrial remodeling is more advanced in HCM patients compared to HHD patients and athletes.

Ablation Therapy for Persistent Atrial Fibrillation

Atrial Fibrillation (AF) is the most common form of electrical disturbance of the heart and contributes to significant patient morbidity and mortality. With a better understanding of the mechanisms of atrial fibrillation and improvements in mapping and ablation technologies, ablation has become a preferred therapy for patients with symptomatic AF. Pulmonary Vein Isolation (PVI) is the cornerstone for AF ablation therapy, but particularly in patients with AF occurring for longer than 7 days (persistent AF), identifying clinically significant nonpulmonary vein targets and achieving durability of ablation lesions remains an important challenge.

Direct Oral Anticoagulants in Patients with Obesity and Atrial Fibrillation: Position Paper of Italian National Association of Hospital Cardiologists (ANMCO)

The use of the direct oral anticoagulants dabigatran, rivaroxaban, apixaban and edoxaban (DOACs) offers some major advantages over warfarin and other vitamin K antagonists (VKAs). One advantage is the possibility to use a fixed dose in normal-weight patients, overweight patients and patients with obesity. However, the "one size fits all" strategy raised a concern regarding the possibility to undertreat patients with a high body mass index. No randomized controlled trials (RCTs) have ever compared VKAs and DOACs in this population. We analyzed data from the literature on DOAC pharmacokinetics and pharmacodynamics, results from the four pivotal phase III trials on non-valvular atrial fibrillation, retrospective observational studies and metanalyses. While we are aware of the limitation imposed by the absence of specific RCTs, we propose the position of the Italian Association of Hospital Cardiologists (ANMCO) on the use of DOACs in patients with obesity based on the existing evidence.

Risks associated with discontinuation of oral anticoagulation in newly diagnosed patients with atrial fibrillation: Results from the GARFIELD-AF Registry

BACKGROUND

Oral anticoagulation (OAC) in atrial fibrillation (AF) reduces the risk of stroke/systemic embolism (SE). The impact of OAC discontinuation is less well documented.

OBJECTIVE

Investigate outcomes of patients prospectively enrolled in the Global Anticoagulant Registry in the Field-Atrial Fibrillation study who discontinued OAC.

METHODS

Oral anticoagulation discontinuation was defined as cessation of treatment for ≥7 consecutive days. Adjusted outcome risks were assessed in 23 882 patients with 511 days of median follow-up after discontinuation.

RESULTS

Patients who discontinued (n = 3114, 13.0%) had a higher risk (hazard ratio [95% CI]) of all-cause death (1.62 [1.25-2.09]), stroke/systemic embolism (SE) (2.21 [1.42-3.44]) and myocardial infarction (MI) (1.85 [1.09-3.13]) than patients who did not, whether OAC was restarted or not. This higher risk of outcomes after discontinuation was similar for patients treated with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) (p for interactions range = 0.145-0.778). Bleeding history (1.43 [1.14-1.80]), paroxysmal vs. persistent AF (1.15 [1.02-1.29]), emergency room care setting vs. office (1.37 [1.18-1.59]), major, clinically relevant nonmajor, and minor bleeding (10.02 [7.19-13.98], 2.70 [2.24-3.25] and 1.90 [1.61-2.23]), stroke/SE (4.09 [2.55-6.56]), MI (2.74 [1.69-4.43]), and left atrial appendage procedures (4.99 [1.82-13.70]) were predictors of discontinuation. Age (0.84 [0.81-0.88], per 10-year increase), history of stroke/transient ischemic attack (0.81 [0.71-0.93]), diabetes (0.88 [0.80-0.97]), weeks from AF onset to treatment (0.96 [0.93-0.99] per week), and permanent vs. persistent AF (0.73 [0.63-0.86]) were predictors of lower discontinuation rates.

CONCLUSIONS

In GARFIELD-AF, the rate of discontinuation was 13.0%. Discontinuation for ≥7 consecutive days was associated with significantly higher all-cause mortality, stroke/SE, and MI risk. Caution should be exerted when considering any OAC discontinuation beyond 7 days.

Predictors of sinus rhythm 6 weeks after cardioversion of atrial fibrillation: a pre-planned post hoc analysis of the X-VeRT trial

AIMS

Using a pre-planned post hoc analysis of patients included in X-VeRT, we evaluated predictors of sinus rhythm at 6 weeks after planned cardioversion.

METHODS AND RESULTS

Receiver operating characteristic curves and logistic regression models were used to evaluate continuous and categorical variables as predictors of sinus rhythm 6 at weeks from cardioversion (end of study). The primary analysis was performed in successfully cardioverted patients with an evaluable electrocardiogram at end of study. A second analysis evaluated additional patients who spontaneously restored sinus rhythm before planned cardioversion. Of the 1504 patients with atrial fibrillation of >48 h or of unknown duration who were randomly assigned to either rivaroxaban or vitamin K antagonist, 1039 (64.6 ± 10.3 years, 73.4% male) underwent planned cardioversion and were included in this study. Patients receiving early cardioversion (i.e. between 1 and 5 days from hospitalization) had a 67% higher probability to have sinus rhythm at end of study than those who received delayed cardioversion (i.e. between 21 and 56 days from hospitalization) [odds ratio (OR) 1.67, confidence interval (CI) 1.27-2.18; P < 0.0001]. In a multivariate analysis of 17 baseline variables, patients with a CHADS2 score of 0 were 33% less likely to be in sinus rhythm than those with a CHADS2 score ≥2 (OR 0.66, CI 0.47-0.94; P = 0.0225). In the secondary analysis, spontaneous restoration of sinus rhythm was also found to predict sinus rhythm at end of study (OR 8.62, CI 1.54-48.16; P = 0.0142).

CONCLUSION

In X-VeRT, early cardioversion and high CHADS2 scores predicted sinus rhythm at 6 weeks from cardioversion.

World Heart Federation Roadmap on Atrial Fibrillation - A 2020 Update

The World Heart Federation (WHF) commenced a Roadmap initiative in 2015 to reduce the global burden of cardiovascular disease and resultant burgeoning of healthcare costs. Roadmaps provide a blueprint for implementation of priority solutions for the principal cardiovascular diseases leading to death and disability. Atrial fibrillation (AF) is one of these conditions and is an increasing problem due to ageing of the world's population and an increase in cardiovascular risk factors that predispose to AF. The goal of the AF roadmap was to provide guidance on priority interventions that are feasible in multiple countries, and to identify roadblocks and potential strategies to overcome them. Since publication of the AF Roadmap in 2017, there have been many technological advances including devices and artificial intelligence for identification and prediction of unknown AF, better methods to achieve rhythm control, and widespread uptake of smartphones and apps that could facilitate new approaches to healthcare delivery and increasing community AF awareness. In addition, the World Health Organisation added the non-vitamin K antagonist oral anticoagulants (NOACs) to the Essential Medicines List, making it possible to increase advocacy for their widespread adoption as therapy to prevent stroke. These advances motivated the WHF to commission a 2020 AF Roadmap update. Three years after the original Roadmap publication, the identified barriers and solutions were judged still relevant, and progress has been slow. This 2020 Roadmap update reviews the significant changes since 2017 and identifies priority areas for achieving the goals of reducing death and disability related to AF, particularly targeted at low-middle income countries. These include advocacy to increase appreciation of the scope of the problem; plugging gaps in guideline management and prevention through physician education, increasing patient health literacy, and novel ways to increase access to integrated healthcare including mHealth and digital transformations; and greater emphasis on achieving practical solutions to national and regional entrenched barriers. Despite the advances reviewed in this update, the task will not be easy, but the health rewards of implementing solutions that are both innovative and practical will be great.

Predicting Silent Atrial Fibrillation in the Elderly: A Report from the NOMED-AF Cross-Sectional Study

Background: Silent atrial fibrillation (SAF) is common and is associated with poor outcomes. Aims: to study the risk factors for AF and SAF in the elderly (≥65 years) general population and to develop a risk stratification model for predicting SAF. Methods: Continuous ECG monitoring was performed for up to 30 days using a vest-based system in a cohort from NOMED-AF, a cross-sectional study based on a nationwide population sample. The independent risk factors for AF and SAF were determined using multiple logistic regression. ROC analysis was applied to validate the developed risk stratification score. Results: From the total cohort of 3014 subjects, AF was diagnosed in 680 individuals (mean age, 77.5 ± 7.9; 50.1% men) with AF, and, of these, 41% had SAF. Independent associations with an increased risk of AF were age, male gender, coronary heart disease, thyroid diseases, prior ischemic stroke or transient ischemic attack (ICS/TIA), diabetes, heart failure, chronic kidney disease (CKD), obesity, and NT-proBNP >125 ng/mL. The risk factors for SAF were age, male gender, ICS/TIA, diabetes, heart failure, CKD, and NT-proBNP >125 ng/mL. We developed a clinical risk scale (MR-DASH score) that achieved a good level of prediction in the derivation cohort (AUC 0.726) and the validation cohort (AUC 0.730). Conclusions: SAF is associated with various clinical risk factors in a population sample of individuals ≥65 years. Stratifying individuals from the general population according to their risk for SAF may be possible using the MR-DASH score, facilitating targeted screening programs of individuals with a high risk of SAF.

Electrocardiographic Imaging for Atrial Fibrillation: A Perspective From Computer Models and Animal Experiments to Clinical Value

Electrocardiographic imaging (ECGI) is a technique to reconstruct non-invasively the electrical activity on the heart surface from body-surface potential recordings and geometric information of the torso and the heart. ECGI has shown scientific and clinical value when used to characterize and treat both atrial and ventricular arrhythmias. Regarding atrial fibrillation (AF), the characterization of the electrical propagation and the underlying substrate favoring AF is inherently more challenging than for ventricular arrhythmias, due to the progressive and heterogeneous nature of the disease and its manifestation, the small volume and wall thickness of the atria, and the relatively large role of microstructural abnormalities in AF. At the same time, ECGI has the advantage over other mapping technologies of allowing a global characterization of atrial electrical activity at every atrial beat and non-invasively. However, since ECGI is time-consuming and costly and the use of electrical mapping to guide AF ablation is still not fully established, the clinical value of ECGI for AF is still under assessment. Nonetheless, AF is known to be the manifestation of a complex interaction between electrical and structural abnormalities and therefore, true electro-anatomical-structural imaging may elucidate important key factors of AF development, progression, and treatment. Therefore, it is paramount to identify which clinical questions could be successfully addressed by ECGI when it comes to AF characterization and treatment, and which questions may be beyond its technical limitations. In this manuscript we review the questions that researchers have tried to address on the use of ECGI for AF characterization and treatment guidance (for example, localization of AF triggers and sustaining mechanisms), and we discuss the technological requirements and validation. We address experimental and clinical results, limitations, and future challenges for fruitful application of ECGI for AF understanding and management. We pay attention to existing techniques and clinical application, to computer models and (animal or human) experiments, to challenges of methodological and clinical validation. The overall objective of the study is to provide a consensus on valuable directions that ECGI research may take to provide future improvements in AF characterization and treatment guidance.

Atrial high‑rate episodes and risk of major adverse cardiovascular events in patients with dual chamber permanent pacemakers: a retrospective study

Patients with atrial high-rate episodes (AHRE) are at higher risk of major adverse cardiovascular events (MACE). The cutoff threshold for AHRE duration for MACE, with/without history of atrial fibrillation (AF) or myocardial infarction (MI), is unknown. A total of 481 consecutive patients with/without history of AF or MI receiving dual-chamber pacemaker implantation were included. The primary outcome was a composite endpoint of MACE after AHRE ≥ 5 min, ≥ 6 h, and ≥ 24 h. AHRE was defined as > 175 bpm (MEDTRONIC) or > 200 bpm (BIOTRONIK) lasting ≥ 5 min. Cox regression analysis with time-dependent covariates was conducted. Patients' mean age was 75.3 ± 10.7 years and 188 (39.1%) developed AHRE ≥ 5 min, 115 (23.9%) ≥ 6 h, and 83 (17.3%) ≥ 24 h. During follow-up (median 39.9 ± 29.8 months), 92 MACE occurred (IR 5.749%/year, 95% CI 3.88-5.85). AHRE ≥ 5 min (HR 5.252, 95% CI 2.575-10.715, P < 0.001) and ≥ 6 h (HR 2.548, 95% CI 1.284-5.058, P = 0.007) was independently associated with MACE, but not AHRE ≥ 24 h. Patients with history of MI (IR 17.80%/year) had higher MACE incidence than those without (IR 3.77%/year, p = 0.001). Significant differences were found between MACE patients with/without history of AF in AHRE ≥ 5 min but not AHRE ≥ 6 h or ≥ 24 h. Patients with dual-chamber pacemakers who develop AHRE have increased risk of MACE, particularly after history of AF or MI.

The relationship of the serum endocan level with the CHA2DS2-VASc score in patients with paroxysmal atrial fibrillation

Background

In this study considering the relationship between serum endocan and CHA₂DS₂-VASc score, we assumed that endocan level could be a new biomarker for stroke risk in patients with paroxysmal atrial fibrillation (PAF). It was examined that endocan could be an alternative to determine the risk of stroke and anticoagulation strategy in patients with PAF. The CHA₂DS₂-VASc scores were calculated for 192 patients with PAF, and their serum endocan levels were measured. The patients were divided into two groups as those with low to moderate (0-1) and those with high (≥ 2) CHA₂DS₂-VASc scores, and the endocan levels were compared between these two groups.

Results

The serum endocan level was significantly higher in the high CHA₂DS₂-VASc score group (p < 0.001). In the multivariate logistic regression analysis, endocan, C-reactive protein, and low-density lipoprotein were found to be independent determinants of the CHA₂DS₂-VASc score. The predictive value of endocan was analyzed using the ROC curve analysis, which revealed that endocan predicted a high stroke risk (CHA₂DS₂-VASc ≥ 2) at 82.5% sensitivity and 71.2% specificity at the cutoff value of 1.342.

Conclusion

This study indicates that endocan is significantly associated with CHA₂DS₂-VASc score. We demonstrated that endocan could be a new biomarker for the prediction of a high stroke risk among patients diagnosed with PAF.

Examining the lower range of the association between alcohol intake and risk of incident hospitalization with atrial fibrillation

Background

Evidence is sparse on the association between alcohol intakes in the lower range and risk of atrial fibrillation (AF). We aimed to investigate self-reported low and moderate alcohol intakes and subsequent risk of incident AF among current drinkers.

Methods

Norwegian population-based health examination surveys assessing self-reported daily alcohol intake (mean grams per day) were linked to health and population registers. Hazard ratios (HR) (95% confidence interval) for time to incident (first) hospitalization with AF by alcohol intake level were assessed by Cox regression, with adjustment for educational level and cardiovascular risk factors except blood pressure.

Results

The study population included 234,392 participants (49% men). Incident hospitalization with AF was identified in 5043 (2.2%) persons during a mean follow-up of 9 years. Compared to a very low alcohol intake of <1 unit weekly, a moderate consumption in the range of 1 to <2 units daily increased the risk of incident AF by 18% (HR 1.18 [1.06-1.32]). The average risk of incident AF increased by 9% per daily alcohol unit of 12 g (HR 1.09 [1.03, 1.14]). In sex-stratified analyses significant associations were found in men only.

Conclusions

We found that less than two alcohol units/day significantly increased the risk of incident AF, however, in men only. Reduction of even a moderate alcohol intake may thus reduce the risk of AF at the population level.

Atrial fibrillation: villain or bystander in vascular brain injury

Atrial fibrillation (AF) and stroke are inextricably connected, with classical Virchow pathophysiology explaining thromboembolism through blood stasis in the fibrillating left atrium. This conceptualization has been reinforced by the remarkable efficacy of oral anticoagulant (OAC) for stroke prevention in AF. A number of observations showing that the presence of AF is neither necessary nor sufficient for stroke, cast doubt on the causal role of AF as a villain in vascular brain injury (VBI). The requirement for additional risk factors before AF increases stroke risk; temporal disconnect of AF from a stroke in patients with no AF for months before stroke during continuous ECG monitoring but manifesting AF only after stroke; and increasing recognition of the role of atrial cardiomyopathy and atrial substrate in AF-related stroke, and also stroke without AF, have led to rethinking the pathogenetic model of cardioembolic stroke. This is quite separate from recognition that in AF, shared cardiovascular risk factors can lead both to non-embolic stroke, or emboli from the aorta and carotid arteries. Meanwhile, VBI is now expanded to include dementia and cognitive decline: research is required to see if reduced by OAC. A changed conceptual model with less focus on the arrhythmia, and more on atrial substrate/cardiomyopathy causing VBI both in the presence or absence of AF, is required to allow us to better prevent AF-related VBI. It could direct focus towards prevention of the atrial cardiomyopathy though much work is required to better define this entity before the balance between AF as villain or bystander can be determined.

A novel framework for noninvasive analysis of short-term atrial activity dynamics during persistent atrial fibrillation

ECG-based representation of atrial fibrillation (AF) progression is currently limited. We propose a novel framework for a more sensitive noninvasive characterization of the AF substrate during persistent AF. An atrial activity (AA) recurrence signal is computed from body surface potential map (BSPM) recordings, and a set of characteristic indices is derived from it which captures the short- and long-term recurrent behaviour in the AA patterns. A novel measure of short- and long-term spatial variability of AA propagation is introduced, to provide an interpretation of the above indices, and to test the hypothesis that the variability in the oscillatory content of AA is due mainly to a spatially uncoordinated propagation of the AF waveforms. A simple model of atrial signal dynamics is proposed to confirm this hypothesis, and to investigate a possible influence of the AF substrate on the short-term recurrent behaviour of AA propagation. Results confirm the hypothesis, with the model also revealing the above influence. Once the characteristic indices are normalized to remove this influence, they show to be significantly associated with AF recurrence 4 to 6 weeks after electrical cardioversion. Therefore, the proposed framework improves noninvasive AF substrate characterization in patients with a very similar substrate. Graphical Abstract Schematic representation of the proposed framework for the noninvasive characterization of short-term atrial signal dynamics during persistent AF. The proposed framework shows that the faster the AA is propagating, the more stable its propagation paths are in the short-term (larger values of Speed in the bottom right plot should be interpreted as lower speed of propagation of the corresponding AA propagation patters).

Predicting recurrent atrial fibrillation after catheter ablation: a systematic review of prognostic models

AIMS

We assessed the performance of modelsf (risk scores) for predicting recurrence of atrial fibrillation (AF) in patients who have undergone catheter ablation.

METHODS AND RESULTS

Systematic searches of bibliographic databases were conducted (November 2018). Studies were eligible for inclusion if they reported the development, validation, or impact assessment of a model for predicting AF recurrence after ablation. Model performance (discrimination and calibration) measures were extracted. The Prediction Study Risk of Bias Assessment Tool (PROBAST) was used to assess risk of bias. Meta-analysis was not feasible due to clinical and methodological differences between studies, but c-statistics were presented in forest plots. Thirty-three studies developing or validating 13 models were included; eight studies compared two or more models. Common model variables were left atrial parameters, type of AF, and age. Model discriminatory ability was highly variable and no model had consistently poor or good performance. Most studies did not assess model calibration. The main risk of bias concern was the lack of internal validation which may have resulted in overly optimistic and/or biased model performance estimates. No model impact studies were identified.

CONCLUSION

Our systematic review suggests that clinical risk prediction of AF after ablation has potential, but there remains a need for robust evaluation of risk factors and development of risk scores.

Atrial fibrillation ablation in heart failure

Atrial fibrillation (AF) and heart failure (HF) commonly coexist in the same patient and either condition predisposes to the other. Several mechanisms promote the pathophysiological relationship between AF and HF, reducing quality of life, increasing the risk of stroke, and worsening HF progression. Although restoration and maintenance of sinus rhythm would be ideal for those patients, several trials comparing rhythm and rate control failed to show a benefit of rhythm control strategy, achieved with pharmacological therapy, in terms of hospitalization for HF or death. Catheter ablation is a well-established option for symptomatic AF patients, resistant to drug therapy, with normal cardiac function. Several recent studies have shown an improvement in clinical outcomes after AF ablation in HF patients highlighting the emerging role of the invasive approach in this subset of patients. However, several concerns regarding patients’ selection and standardization of the procedure still remain to be addressed.

Comparing Safety and Efficacy of Dabigatran and Factor Xa Inhibitors for Stroke Prevention in Hemophiliacs with Non-Valvular Atrial Fibrillation

BACKGROUND

Atrial fibrillation, a progressively rising global health problem, is also rising in Hemophiliacs due to an increase in life expectancy in them. While treating Hemophiliacs with AF, deciding eligibility, choosing the anticoagulant based on risk-benefit ratio are tough decisions for physicians to make. This review paper aims to explore and compare existing studies, reviews and consensus papers to assess the safety of different Novel Oral Anticoagulants (NOACS) in this population.

METHODS

Thorough literature search was conducted on Pubmed using Atrial Fibrillation, Hemophilia A, Oral anticoagulants, stroke prevention, Dabigatran, factor Xa inhibitors as keywords separately and in combinations. Papers in English language only from the past 5 years were selected for review. After removing duplicate results, 80 papers were selected and after applying different exclusion criteria and according to relevance, 40 papers were finalized for review.

RESULTS

The keywords AF, Stroke prevention, oral anticoagulants, Hemophilia a, Factor Xa inhibitors and Dabigatran gave 24899, 13619, 8964, 3503, 2850, 2799 results, respectively. Combination keywords also showed some papers and out of short-listed 80 relevant papers 35 were finalized. Reviewing and analyzing these papers revealed no clinical trials in hemophiliacs with AF in the past 5 years and 5 clinical trials comparing NOACs with Warfarin in general population. Rest were systematic reviews, consensus papers and meta-analyses on management in this group. A few compared these drugs for AF in the general population but not specifically in Hemophiliacs and others. consensus papers developed suggestions for management and showed that NOACs are superior to Warfarin but need individual evaluation in Hemophiliacs with AF.

CONCLUSIONS

Patients with Hemophilia can also have thrombo-embolism despite their bleeding tendency and NOACs are a better option in them because of less need for monitoring, no food interactions and fewer drug interactions. This comparative review emphasized the need for more work to develop proper guidelines for thrombo-prophylaxis management in this specific group.

Prognostic models for predicting incident or recurrent atrial fibrillation: protocol for a systematic review

BACKGROUND

Atrial fibrillation (AF) is the arrhythmia most commonly diagnosed in clinical practice. It is associated with significant morbidity and mortality. Prevalence of AF and complications of AF, estimated by hospitalisations, have increased dramatically in the last decade. Being able to predict AF would allow tailoring of management strategies and a focus on primary or secondary prevention. Models predicting recurrent AF would have particular clinical use for the selection of rhythm control therapy. There are existing prognostic models which combine several predictors or risk factors to generate an individualised estimate of risk of AF. The aim of this systematic review is to summarise and compare model performance measures and predictive accuracy across different models and populations at risk of developing incident or recurrent AF.

METHODS

Methods tailored to systematic reviews of prognostic models will be used for study identification, risk of bias assessment and synthesis. Studies will be eligible for inclusion where they report an internally or externally validated model. The quality of studies reporting a prognostic model will be assessed using the Prediction Study Risk Of Bias Assessment Tool (PROBAST). Studies will be narratively described and included variables and predictive accuracy compared across different models and populations. Meta-analysis of model performance measures for models validated in similar populations will be considered where possible.

DISCUSSION

To the best of our knowledge, this will be the first systematic review to collate evidence from all studies reporting on validated prognostic models, or on the impact of such models, in any population at risk of incident or recurrent AF. The review may identify models which are suitable for impact assessment in clinical practice. Should gaps in the evidence be identified, research recommendations relating to model development, validation or impact assessment will be made. Findings will be considered in the context of any models already used in clinical practice, and the extent to which these have been validated.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ( CRD42018111649 ).

Antiarrhythmic therapy in the treatment of atrial fibrillation: yesterday, today, tomorrow

Atrial fibrillation (AF) is the most common heart rhythm disorder encountered in clinical practice. Each year, the number of patients with AF significantly increases. It is associated with an increase of life expectancy and frequency of cardiovascular pathologies. Treatment of AF remains one of the most difficult tasks of modern cardiology. Currently, only a few antiarrhythmic drugs are available for use in Russia. More and more new attempts are being made to create a universal antiarrhythmic drug with a high level of anti-relapsing efficacy and adverse effects. The accumulated information suggests that the tactics of management of patients with arrhythmias will be intended to improving the new surgical and interventional treatment methods with use of anticoagulants and antiarrhythmic drugs. The multidisciplinary team of specialists on AF treatment should include an expert (cardiologist) in antiarrhythmic drug therapy, an interventional electrophysiologist, and a cardiac surgeon — master the technology of interventional or surgical ablation. Effective interaction of specialists of various levels will improve the results of rhythm control and prevention of complications in patients with AF.

Exercise-based cardiac rehabilitation improves exercise capacity and health-related quality of life in people with atrial fibrillation: a systematic review and meta-analysis of randomised and non-randomised trials

Objective

The aim of this study was to undertake a contemporary review of the impact of exercise-based cardiac rehabilitation (CR) targeted at patients with atrial fibrillation (AF).

Methods

We conducted searches of PubMED, EMBASE and the Cochrane Library of Controlled Trials (up until 30 November 2017) using key terms related to exercise-based CR and AF. Randomised and non-randomised controlled trials were included if they compared the effects of an exercise-based CR intervention to a no exercise or usual care control group. Meta-analyses of outcomes were conducted where appropriate.

Results

The nine randomised trials included 959 (483 exercise-based CR vs 476 controls) patients with various types of AF. Compared with control, pooled analysis showed no difference in all-cause mortality (risk ratio (RR) 1.08, 95% CI 0.77 to 1.53, p=0.64) following exercise-based CR. However, there were improvements in health-related quality of life (mean SF-36 mental component score (MCS): 4.00, 95% CI 0.26 to 7.74; p=0.04 and mean SF-36 physical component score: 1.82, 95% CI 0.06 to 3.59; p=0.04) and exercise capacity (mean peak VO2: 1.59 ml/kg/min, 95% CI 0.11 to 3.08; p=0.04; mean 6 min walk test: 46.9 m, 95% CI 26.4 to 67.4; p<0.001) with exercise-based CR. Improvements were also seen in AF symptom burden and markers of cardiac function.

Conclusions

Exercise capacity, cardiac function, symptom burden and health-related quality of life were improved with exercise-based CR in the short term (up to 6 months) targeted at patients with AF. However, high-quality multicentre randomised trials are needed to clarify the impact of exercise-based CR on key patient and health system outcomes (including health-related quality of life, mortality, hospitalisation and costs) and how these effects may vary across AF subtypes.

Combinational Biomarkers for Atrial Fibrillation Derived from Atrial Appendage and Plasma Metabolomics Analysis

Atrial fibrillation (AF) is one of the most common types of arrhythmias and often leads to clinical complications. The objectives of this study were to offer insights into the metabolites of AF and to determine biomarkers for AF diagnosis or prediction. Sixty atrial appendage samples (AF group: 30; non-AF group: 30) and 163 plasma samples (AF group: 48; non-AF group: 115) from 49 AF patients and 116 non-AF patients were subjected to liquid chromatography positive ion electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) metabolomics analysis. Consequently, 24 metabolites in atrial appendage samples and 24 metabolites in plasma samples were found to reflect metabolic differences between AF and non-AF patients (variable importance in projection (VIP) ≥ 1, P ≤ 0.05). Five identical metabolites including creatinine, D-glutamic acid, choline, hypoxanthine, and niacinamide (VIP ≥ 1.5, P < 0.01, FDR < 0.05) in atrial appendage and plasma samples were considered prominent features of AF patients, and the D-glutamine and D-glutamate metabolic pathway was also identified as a feature of AF patients. Finally, in plasma samples, the combination of D-glutamic acid, creatinine, and choline had an AUC value of 0.927 (95% CI: 0.875-0.979, P < 0.001) and displayed 90.5% sensitivity and 83.3% specificity; this group of metabolites was thus defined as a combinational biomarker for the recognition of AF and non-AF patients.

Prospective evaluation of left atrial function and late gadolinium enhancement with 3 T MRI in patients with atrial fibrillation before and after catheter ablation

In a prospective, randomized study we performed left atrial (LA) functional imaging and late gadolinium enhancement (LGE) in patients undergoing pulmonary vein isolation with ablation of the anterior mitral line to evaluate LA function and visibility of the anterior mitral line and to explore the relationship of these factors to short- and long-term procedural success. Functional imaging of the LA and LGE-visualization 15 min post i.v. administration of gadobutrol was performed on a 3 T MRI system before and after ablation. Patients were grouped in (a) subjects with sinus rhythm, and (b) subjects without sinus rhythm at the follow-up-MRI. Eight patients were excluded due to poor image quality. 37 patients were allotted to group a, 4 patients to group b. Group a showed a significant improvement in ejection fraction (22.3 ± 7.1% vs. 27.2 ± 5.5%; p < 0.001), end-systolic volume (111.6 ± 48.3 ml vs. 96.9 ± 37.2 ml; p = 0.002), stroke volume (30.2 ± 12.6 ml vs. 35.6 ± 12.6 ml; p = 0.003) and LGE (12.5% vs. 83.7%; p < 0.001). Group b showed no significant changes in functional parameters or LGE. Patients with successful therapy at 12 months showed significantly lower volumes in the baseline MRI. Scarring along the ablation pathways could be visualized with LGE. Patients with successful CA showed a significant improvement in LA cardiac parameters. Pre-ablation atrial volume seems to be a predictor for long-term success.

Atrial Structural Remodeling Gene Variants in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is a common arrhythmia for which the genetic studies mainly focused on the genes involved in electrical remodeling, rather than left atrial muscle remodeling. To identify rare variants involved in atrial myopathy using mutational screening, a high-throughput next-generation sequencing (NGS) workflow was developed based on a custom AmpliSeq™ panel of 55 genes potentially involved in atrial myopathy. This workflow was applied to a cohort of 94 patients with AF, 76 with atrial dilatation and 18 without. Bioinformatic analyses used NextGENe® software and in silico tools for variant interpretation. The AmpliSeq custom-made panel efficiently explored 96.58% of the targeted sequences. Based on in silico analysis, 11 potentially pathogenic missense variants were identified that were not previously associated with AF. These variants were located in genes involved in atrial tissue structural remodeling. Three patients were also carriers of potential variants in prevalent arrhythmia-causing genes, usually associated with AF. Most of the variants were found in patients with atrial dilatation (n=9, 82%). This NGS approach was a sensitive and specific method that identified 11 potentially pathogenic variants, which are likely to play roles in the predisposition to left atrial myopathy. Functional studies are needed to confirm their pathogenicity.

Predictors of sinus rhythm after electrical cardioversion of atrial fibrillation: results from a data mining project on the Flec-SL trial data set

Aims

Data mining is the computational process to obtain information from a data set and transform it for further use. Herein, through data mining with supportive statistical analyses, we identified and consolidated variables of the Flecainide Short-Long (Flec-SL-AFNET 3) trial dataset that are associated with the primary outcome of the trial, recurrence of persistent atrial fibrillation (AF) or death.

Methods and results

The 'Ranking Instances by Maximizing the Area under the ROC Curve' (RIMARC) algorithm was applied to build a classifier that can predict the primary outcome by using variables in the Flec-SL dataset. The primary outcome was time to persistent AF or death. The RIMARC algorithm calculated the predictive weights of each variable in the Flec-SL dataset for the primary outcome. Among the initial 21 parameters, 6 variables were identified by the RIMARC algorithm. In univariate Cox regression analysis of these variables, increased heart rate during AF and successful pharmacological conversion (PC) to sinus rhythm (SR) were found to be significant predictors. Multivariate Cox regression analysis revealed successful PC as the single relevant predictor of SR maintenance. The primary outcome risk was 3.14 times (95% CI:1.7-5.81) lower in those who had successful PC to SR than those who needed electrical cardioversion.

Conclusions

Pharmacological conversion of persistent AF with flecainide without the need for electrical cardioversion is a powerful and independent predictor of maintenance of SR. A strategy of flecainide pretreatment for 48 h prior to planned electrical cardioversion may be a useful planning of a strategy of long-term rhythm control.

Mortality in patients with atrial fibrillation and common co-morbidities - a cohort study in primary care

OBJECTIVE

To study the association between cardiovascular co-morbidities and mortality risk in primary care patients with atrial fibrillation.

METHODS

The study population included all adults (n = 12,283) ≥ 45 years diagnosed with AF at 75 primary care centres in Sweden between 2001 and 2007. The outcome was mortality (until 2010) and data were explored for co-morbidities using Cox regression with hazard ratios (HRs). Analyses were performed stratified by sex and by age-group (45-64, 65-74 and ≥75 years of age) with adjustment for age, socio-economic factors and relevant co-morbidities.

RESULTS

During a mean of 5.8 years (standard deviation 2.4) of follow-up, 3954 (32%) patients died (1971 (35%) women, and 1983 (30%) men). High HRs were found for congestive heart disease (CHF) and cerebrovascular diseases for all age-groups among men and women (except for the 45-64 year old women); for coronary heart disease among the oldest men; for diabetes among the 65-74 year old men and the 45-64 year old women. Low HRs were found for hypertension among women ≥75 years of age.

CONCLUSIONS

In this clinical setting, CHF and cerebrovascular diseases were consistently associated with mortality in all age-groups. The possible protective effect by hypertension among elderly women should be interpreted with caution. KEY MESSAGES We found congestive heart failure and cerebrovascular diseases to be consistently associated with mortality in both women and men. We found hypertension to be associated with lower mortality risk among women ≥75 years of age, although this finding must be interpreted with caution. Depression was found to be associated with increased mortality risk among men and women aged 65-74 years of age.

Remote Monitoring for Chronic Disease Management: Atrial Fibrillation and Heart Failure

This review aims to cover the latest evidence of remote monitoring of cardiac implantable electronic devices for the management of atrial fibrillation and heart failure. Remote monitoring is useful for early detection for device-detected atrial fibrillation, which increases the risk of thromboembolic events. Early anticoagulation based on remote monitoring potentially reduces the risk of stroke, but optimal alert setting needs to be clarified. Multiparameter monitoring with automatic transmission is useful for heart failure management. Improved adherence to remote monitoring and an optimal algorithm for transmitted alerts and their management are warranted in the management of heart failure.

Developing and Sustaining a Career as a Transdisciplinary Nurse Scientist

PURPOSE

The purpose of this article is to provide an overview of strategies to build and sustain a career as a nurse scientist. This article examines how to integrate technologies and precision approaches into clinical practice, research, and education of the next generation of nursing scholars.

DESIGN

This article presents information for shaping a sustainable transdisciplinary career. Programs of research that utilize self-management to improve quality of life are discussed throughout the article. The ongoing National Institute of Nursing Research-funded (R01 grant) iPhone Helping Evaluate Atrial Fibrillation Rhythm through Technology (iHEART) study is the first prospective, randomized controlled trial to evaluate whether electrocardiographic monitoring with the AliveCor™ device in the real-world setting will improve the time to detection and treatment of recurrent atrial fibrillation over a 6-month period as compared to usual cardiac care.

METHODS

Opportunities to sustain a career as a nurse scientist and build programs of transdisciplinary research are identified. These opportunities are focused within the area of research and precision medicine.

FINDINGS

Nurse scientists have the potential and ability to shape their careers and become essential members of transdisciplinary partnerships. Exposure to clinical research, expert mentorship, and diverse training opportunities in different areas are essential to ensure that contributions to nursing science are visible through publications and presentations as well as through securing grant funding to develop and maintain programs of research.

CONCLUSIONS

Transcending boundaries and different disciplines, nurses are essential members of many diverse teams.

CLINICAL RELEVANCE

Nurse scientists are strengthening research approaches, clinical care, and communication and improving health outcomes while also building and shaping the next generation of nurse scientists.

Risk Factor Management in Atrial Fibrillation

Atrial fibrillation (AF) is the most common clinical arrhythmia and is associated with increased morbidity and mortality. There is growing evidence that numerous cardiovascular diseases and risk factors are associated with incident AF and that lone AF is rare. Beyond oral anticoagulant therapy, rate and rhythm control, therapy targeting risk factors and underlying conditions is an emerging AF management strategy that warrants better implementation in clinical practice. This review describes current evidence regarding the association between known modifiable risk factors and underlying conditions and the development and progression of AF. It discusses evidence for the early management of underlying conditions to improve AF outcomes. It also provides perspective on the implementation of tailored AF management in daily clinical practice.

Late onset of atrial fibrillation in patients undergoing mitral valve repair for type II dysfunction

BACKGROUND

There are few reports regarding factors related to late-onset of atrial fibrillation (Af) after mitral valve repair, which can compromise long-term outcome. We analyzed the risk factors for late Af after mitral valve repair.

METHODS AND RESULTS

Between 2001 and 2015, 318 patients (214 males; median, 57.7 years) underwent mitral valve repair for degenerative mitral insufficiency (MI) without concomitant aortic valve disease in our institute. Patients with a history of paroxysmal or chronic Af preoperatively were excluded. Serial follow-up echocardiography was used to evaluate cardiac function. The follow-up rate was 99%. The mean follow-up period was 6.0±4.1 years. There was no early death and there were nine late deaths. A total of 29 (9.1%) patients developed late Af. Freedom from late Af was 94.0% at 5 years and 82.9% at 10 years. Small ring annuloplasty, left atrial diameter, and pressure half time, which were measured at follow-up echocardiography, were considered as significant (p<0.05) risk factors for late Af. Patients who had late Af developed recurrent MI more frequently than those who did not (p<0.05).

CONCLUSIONS

Remodeling of the atrium caused by functional mitral stenosis is important for late Af, as well as recurrent MI. To prevent these problems, avoiding selection of a small ring at primary mitral repair for type II dysfunction and durable repair are required.

Clinical significance of atrial high-rate episodes for thromboembolic events in Japanese population

OBJECTIVE

The clinical significance of atrial high-rate episodes (AHREs) detected by cardiac devices among patients with implantable pacemakers has recently emerged. However, the relationship between AHREs and ischaemic stroke and systemic embolism (SE) is not well understood in the Japanese population.

METHODS

This study included 343 patients with pacemakers capable of continuous atrial rhythm monitoring (167 males; mean age, 80±7 years). Atrial tachyarrhythmia detection was programmed to the nominal setting of each device, and AHRE was defined as any episode of sustained atrial tachyarrhythmia lasting for more than 6 min. Thromboembolic risk was defined based on the CHADS2 score.

RESULTS

During the follow-up period (52±30 months), 165 (48%) patients had at least one episode of AHREs, and 19 (6%) patients experienced stroke/SE. Among patients who experienced stroke/SE, 14 had AHREs before the stroke/SE. AHREs were significantly associated with stroke/SE (HR 2.87; 95% CI 1.10 to 8.90; p=0.03). Subgroup analysis conducted to investigate the impact of the CHADS2 score severity on stroke/SE revealed that AHREs were not associated with stroke/SE in patients with low or intermediate thromboembolic risk (CHADS2 score 0-2; n=217). In contrast, among patients with high thromboembolic risk (CHADS2 score>2; n=126), there was a significant association between AHREs and the incidence of stroke/SE (HR 3.73; 95% CI 1.06 to 13.1; p=0.04).

CONCLUSION

AHREs detected by pacemaker were associated with ischaemic stroke/SE in the Japanese population. However, this association was observed only in the high thromboembolic risk group.

The future of atrial fibrillation management: integrated care and stratified therapy

Atrial fibrillation is one of the major cardiovascular health problems: it is a common, chronic condition, affecting 2-3% of the population in Europe and the USA and requiring 1-3% of health-care expenditure as a result of stroke, sudden death, heart failure, unplanned hospital admissions, and other complications. Early diagnosis of atrial fibrillation, ideally before the first complication occurs, remains a challenge, as shown by patients who are only diagnosed with the condition when admitted to hospital for acute cardiac decompensation or stroke. Once diagnosed, atrial fibrillation requires chronic, multidimensional management in five domains (acute management, treatment of underlying and concomitant cardiovascular conditions, stroke prevention therapy, rate control, and rhythm control). The consistent provision of these treatment options to all patients with atrial fibrillation is difficult, despite recent improvements in organisation of care, knowledge about atrial fibrillation, and treatment options. Integrated care models that provide patient-centred care in, or close to, the patient's community while maintaining access to all specialist treatment options, emerge as the best approach to achieve consistent delivery of these chronic treatments to all patients with atrial fibrillation. Ongoing research efforts will establish when to initiate oral anticoagulation in patients with device-detected atrial high-rate episodes, quantify the prognostic effect of early and comprehensive rhythm control therapy, including atrial fibrillation ablation, and delineate optimum methods to reduce bleeding complications in patients treated with anticoagulation. Additionally, research efforts are needed to define different types of atrial fibrillation on the basis of the main causes of atrial fibrillation to pave the way for the clinical development of stratified atrial fibrillation therapy.