The Atrium and Embolic Stroke

Deep terminal negative of the P wave in V1 and incidence of ischemic stroke: The atherosclerosis risk in communities (ARIC) study

BACKGROUND

Deep terminal negative of the P wave in V1 (DTNPV1) is a marker of left atrial remodeling. We aimed to evaluate the association of DTNPV1 with incident ischemic stroke.

METHODS

The Atherosclerosis Risk in Communities study is a prospective community-based cohort study. All participants at visit 4 (1996-1998) except those with prevalent stroke, missing covariates, and missing or uninterpretable ECG were included. DTNPV1 was defined as the absolute value of the depth of the terminal negative phase >100 μV in the presence of biphasic P wave in V1. Association between DTNPV1 as a time-dependent exposure variable and incident ischemic stroke was evaluated. The accuracy of the prediction model consisting of DTNPV1 and CHA2DS2-VASc variables in predicting ischemic stroke was analyzed.

RESULTS

Among 10,605 participants (63 ± 6 years, 56% women, 20% Black), 803 cases of ischemic stroke occurred over a median follow-up of 20.19 years. After adjusting for demographics, DTNPV1 was associated with an increased risk of stroke (HR 1.96, [95% CI 1.39-2.77]). After further adjusting for stroke risk factors, use of aspirin and anticoagulants, and time-dependent atrial fibrillation, DTNPV1 was associated with a 1.50-fold (95% CI 1.06-2.13) increased risk of stroke. When added to the CHA2DS2-VASc variables, DTNPV1 did not significantly improve stroke prediction as assessed by C-statistic. However, there was improvement in risk classification for participants who did not develop stroke.

CONCLUSION

DTNPV1 is significantly associated with higher risk of ischemic stroke. Since DTNPV1 is a simplified electrocardiographic parameter, it may help stroke prediction, a subject for further research.

Pathophysiology and clinical relevance of atrial myopathy

Atrial myopathy is a condition that consists of electrical, structural, contractile, and autonomic remodeling of the atria and is the substrate for development of atrial fibrillation, the most common arrhythmia. Pathophysiologic mechanisms driving atrial myopathy are inflammation, oxidative stress, atrial stretch, and neurohormonal signals, e.g., angiotensin-II and aldosterone. These mechanisms initiate the structural and functional remodeling of the atrial myocardium. Novel therapeutic strategies are being developed that target the pathophysiologic mechanisms of atrial myopathy. In this review, we will discuss the pathophysiology of atrial myopathy, as well as diagnostic and therapeutic strategies.

Clinical Characteristics and Rhythm Outcomes in Patients With Atrial Myopathy After Successful Catheter Ablation of Atrial Fibrillation

BACKGROUND

Although successful atrial fibrillation (AF) ablation can maintain sinus rhythm and reduce the left atrial (LA) dimension, blunted LA reverse remodeling can be observed in patients with atrial myopathy. We explored the potential mechanisms and long-term outcomes in patients with blunted LA reverse remodeling after successful AF catheter ablation.

METHODS AND RESULTS

We included 1685 patients who underwent baseline and 1-year follow-up echocardiograms, had a baseline LA dimension ≥40 mm, and did not have a recurrence of AF within a year. The patients were divided into tertile groups according to the delta value of the change in LA dimension on the preprocedure and 1-year postprocedure echocardiography. After propensity score matching for age, sex, AF type, and LA dimension, 1272 patients were finally included in the analyses (424 in each group; the least/blunted, moderate, and the most reverse remodeling group). The patients in the T1 group (blunted LA reverse remodeling) were independently associated with higher left ventricular mass index (odds ratio [OR], 1.014 [95% CI, 1.005-1.022], P=0.001), change in ΔH2FPEF score (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder, filling pressure) score (OR, 1.445 [95% CI, 1.121-1.861], P=0.004), ventricular epicardial adipose tissue volume (OR, 1.010 [95% CI, 1.003-1.017], P=0.003), thinner LA wall thickness (OR, 0.461 [95% CI, 0.271-0.785], P=0.004), lower LA voltage (OR, 0.670 [95% CI, 0.499-0.899], P=0.008), and showed higher long-term AF recurrence (log-rank P<0.001) than other groups.

CONCLUSIONS

Blunted LA reverse remodeling after AF catheter ablation, which is suggestive of atrial myopathy, was independently associated with a larger ventricular epicardial adipose tissue volume and worsening of H2FPEF score. Blunted LA reverse remodeling after AF catheter ablation was also an independent predictor for higher recurrences of AF post-1-year AF catheter ablation.

Evaluation of organized atrial arrhythmias after cryptogenic stroke

Background

Long-term rhythm monitoring to detect atrial fibrillation (AF) following a cryptogenic stroke (CS) is well established. However, the burden of organized atrial arrhythmias in this population is not well defined.

Objective

The purpose of this study was to assess the incidence and risk factors for organized atrial arrhythmias in patients with CS.

Methods

We evaluated all patients with CS who received an insertable cardiac monitor (ICM) between October 2014 and April 2020. All ICM transmissions categorized as AF, tachycardia, or bradycardia were reviewed. We evaluated the time to detection of organized AF and the combination of either organized atrial arrhythmia or AF.

Results

A total of 195 CS patients with ICMs were included (51% men; mean age 66 ± 12 years; mean CHA2DS2-VASC score 4.6). Over mean follow-up of 18.9 ± 11.2 months, organized atrial arrhythmias lasting ≥30 seconds were detected in 45 patients (23%), of whom 62% did not have AF. Seventeen patients had both organized atrial arrhythmia and AF, and another 21 patients had AF only. Compared to those with normal left atrial size, patients with left atrial enlargement had a higher adjusted risk for development of atrial arrhythmias (mild left atrial enlargement: hazard ratio 1.99; 95% confidence interval 1.06-3.75; moderate/severe left atrial enlargement: hazard ratio 3.06; 95% confidence interval 1.58-5.92).

Conclusion

Organized atrial arrhythmias lasting ≥30 seconds are detected in nearly one-fourth of CS patients. Two-thirds of these patients did not have AF. Further studies are required to evaluate the impact of organized atrial arrhythmias on recurrent stroke risk.

Arterial Hypertension and Its Consequences Are the Main Predictors of Embolic Stroke of Undetermined Source

Methods

We performed a hospital-based prospective cohort study with 1,317 enrolled participants. We compared patients and healthy volunteers according to the main demographic, anthropometric parameters, stroke risk factors, comorbidities, and data of clinical and instrumental examination. In order to balance the study and the control groups for age and sex, the propensity score matching was performed. In order to generate the overall predictive model, a multivariate analysis was performed using the binary logistic regression method.

Results

The following predictors of ESUS were identified in current study: arterial hypertension (AH); increased heart rate and pulmonary arterial systolic pressure (PASP); the presence of conduction disturbance; the enlargement of left, right atrium, and left ventricle end-systolic length; increased intima-media thickness (IMT) in right and left common carotid artery (CCA); lowered Montreal Cognitive Assessment (MoСA) cognitive scale score; the presence of subcortical microbleeds; central brain atrophy; the larger size of third ventricle; and the higher medial temporal lobe atrophy (MTA) score. The following risk factors were included in the final predictive model: the presence of AH (p < 0.0005; OR = 12.98 (95% CI: 4.53-37.21)) and PASP (p=0.018; OR = 1.13 (95% CI: 1.02-1.25)) and male sex (p=0.046; OR = 2.771 (95% CI: 1.017-7.555)). The Nagelkerke's pseudo-R-squared value was 0.404 and the significance of the Hosmer-Lemeshow test was 0.733, which indicate the goodness of the final logistic regression model.

Conclusions

We propose that AH and its consequences are the main predictors of ESUS. The results of this study emphasize the importance of AH control for primary and secondary prevention of ESUS.

Left Atrial Strain and Incident Atrial Fibrillation in Older Adults

Atrial fibrillation (AF) is frequent in older adults and associated with left atrial (LA) dysfunction. LA strain (LAε) and LA strain rate (LASR) may detect subclinical LA disease. We investigated whether reduced LAε and LASR predict new-onset AF in older adults without history of AF or stroke. LAε and LASR were assessed by speckle-tracking echocardiography in 824 participants from the community-based Cardiovascular Abnormalities and Brain Lesions study. Positive longitudinal LAε and LASR during ventricular systole, LASR during early ventricular diastole, and LASR during LA contraction were measured. Cause-specific hazards regression model evaluated the association of LAε and LASR with incident AF, adjusting for pertinent covariates. The mean age was 71.1 ± 9.2 years (313 men, 511 women). During a mean follow-up of 10.9 years, new-onset AF occurred in 105 participants (12.7%). Lower LAε and LASR at baseline were observed in patients with new-onset AF (all p <0.01). In multivariable analysis, positive longitudinal LAε (adjusted hazard ratio [HR] per SD decrease 2.05, confidence interval [CI] 1.24 to 3.36) and LASR during LA contraction (HR per SD increase 2.24, CI 1.37 to 3.65) remained associated with new-onset AF, independently of LA volumes and left ventricular function. Along with positive longitudinal LAε, reduced LASR during ventricular systole predicted AF in participants with LA volume below the median value (HR 2.54, CI 1.10 to 6.09), whereas reduced LASR during LA contraction predicted AF in participants with larger LA (HR 2.35, CI 1.31 to 4.23). In conclusion, reduced positive longitudinal LAε and LASR predict new-onset AF in older adults regardless of LA size and may improve AF risk stratification.

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

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

"Pill-in-Pocket" anticoagulation for stroke prevention in atrial fibrillation

Uninterrupted anticoagulation for atrial fibrillation (AF), regardless of AF burden, is deeply rooted in practice since the early anticoagulation trials. However, uninterrupted anticoagulation is not without risks, and may not be beneficial for allcomers with a history of AF. Indeed, contemporary data that support a critical duration threshold of AF that benefits from anticoagulation, and a temporal association between stroke and multihour AF episodes, compel the study of a more targeted approach to AF anticoagulation. In this review, we discuss data that support further investigation of "pill in the pocket" anticoagulation for AF, and introduce the pivotal Rhythm Evaluation for Anticoagulation Therapy for Atrial Fibrillation (REACT-AF) trial that will robustly evaluate this strategy.

Serum NT-proBNP level for predicting functional outcomes after acute ischemic stroke

N-terminus pro-brain natriuretic peptide (NT-proBNP) has been studied and recognized as a biomarker of cardiac thrombogenicity and stroke risk. However, the association between NT-proBNP and functional outcomes following acute ischemic stroke is still debated. This study aimed to investigate whether serum NT-proBNP level is associated with functional outcomes in acute ischemic stroke individuals. This prospective cohort study included patients diagnosed with acute ischemic stroke, and serum NT-proBNP levels were measured within 72 h. At 3 months, all patients were followed up for a modified Rankin Scale (mRS), and logistic regression models were used to evaluate the association of NT-proBNP on the primary outcome, in which a score of 3-6 was classified as an unfavorable functional outcome. Sixty-seven patients were enrolled in the study, and 23 (34.3%) patients were identified with an unfavorable functional outcome. Elevated serum NT-proBNP levels (> 100 pg/mL) were observed in 57 (85.1%) patients, and the Youden index demonstrated a cutpoint estimation of poor outcomes at 476 pg/mL with 74% sensitivity and 63% specificity. Multivariate regression analysis showed an elevation of NT-proBNP above the cutpoint level was an independent predictor for unfavorable functional outcomes, odds ratio 3.77, 95% confidence interval (1.04-13.62), P = 0.04. The present study demonstrated that elevated serum NT-proBNP levels were expected among acute ischemic stroke patients and represented the risk of unfavorable functional outcomes, suggesting that NT-proBNP might be a useful biomarker for predicting prognosis after ischemic stroke.

Stroke in patients with heart failure and reduced or preserved ejection fraction

AIMS

Stroke is an important problem in patients with heart failure (HF), but the intersection between the two conditions is poorly studied across the range of ejection fraction. The prevalence of history of stroke and related outcomes were investigated in patients with HF.

METHODS AND RESULTS

Individual patient meta-analysis of seven clinical trials enrolling patients with HF with reduced (HFrEF) and preserved ejection fraction (HFpEF). Of the 20 159 patients with HFrEF, 1683 (8.3%) had a history of stroke, and of the 13 252 patients with HFpEF, 1287 (9.7%) had a history of stroke. Regardless of ejection fraction, patients with a history of stroke had more vascular comorbidity and worse HF. Among those with HFrEF, the incidence of the composite of cardiovascular death, HF hospitalization, stroke, or myocardial infarction was 18.23 (16.81-19.77) per 100 person-years in those with prior stroke vs. 13.12 (12.77-13.48) in those without [hazard ratio 1.37 (1.26-1.49), P < 0.001]. The corresponding rates in patients with HFpEF were 14.16 (12.96-15.48) and 9.37 (9.06-9.70) [hazard ratio 1.49 (1.36-1.64), P < 0.001]. Each component of the composite was more frequent in patients with stroke history, and the risk of future stroke was doubled in patients with prior stroke. Among patients with prior stroke, 30% with concomitant atrial fibrillation were not anticoagulated, and 29% with arterial disease were not taking statins; 17% with HFrEF and 38% with HFpEF had uncontrolled systolic blood pressure (≥140 mmHg).

CONCLUSION

Heart failure patients with a history of stroke are at high risk of subsequent cardiovascular events, and targeting underutilization of guideline-recommended treatments might be a way to improve outcomes in this high-risk population.

Personalized biomechanical insights in atrial fibrillation: opportunities & challenges

INTRODUCTION

Atrial fibrillation (AF) is an increasingly prevalent and significant worldwide health problem. Manifested as an irregular atrial electrophysiological activation, it is associated with many serious health complications. AF affects the biomechanical function of the heart as contraction follows the electrical activation, subsequently leading to reduced blood flow. The underlying mechanisms behind AF are not fully understood, but it is known that AF is highly correlated with the presence of atrial fibrosis, and with a manifold increase in risk of stroke.

AREAS COVERED

In this review, we focus on biomechanical aspects in atrial fibrillation, current and emerging use of clinical images, and personalized computational models. We also discuss how these can be used to provide patient-specific care.

EXPERT OPINION

Understanding the connection betweenatrial fibrillation and atrial remodeling might lead to valuable understanding of stroke and heart failure pathophysiology. Established and emerging imaging modalities can bring us closer to this understanding, especially with continued advancements in processing accuracy, reproducibility, and clinical relevance of the associated technologies. Computational models of cardiac electromechanics can be used to glean additional insights on the roles of AF and remodeling in heart function.

The pathogenesis of aging-induced left atrial appendage thrombus formation and cardioembolic stroke in mice is influenced by inflammation-derived matrix metalloproteinases

Elderly people without atrial fibrillation (AF) still have a high incidence of cardioembolic stroke, suggesting that thrombus formation within the left atrial appendage (LAA) may also occur in an AF-independent manner. In the present study, we explored the potential mechanisms for aging-induced LAA thrombus formation and stroke in mice. We monitored stroke events in 180 aging male mice (14-24 months) and assessed left atrium (LA) remodeling by echocardiography at different ages. Mice that had stroke were implanted with telemeters to confirm AF. Histological features of LA and LAA thrombi were examined, as well as collagen content, expression of matrix metalloproteinases (MMPs), and leukocyte density in the atria at different ages, in mice with or without stroke. Also, the effects of MMP inhibition on stroke incidence and atrial inflammation were tested. We detected 20 mice (11 %) with stroke, 60 % of which were within 18-19 months of age. Although we did not detect AF in mice with stroke, we detected the presence of LAA thrombi, suggesting that stroke originated from the hearts of these mice. Compared with 18-month-old mice without stroke, 18-month-old stroke mice had enlarged LA with a very thin endocardium, that was associated with less collagen and heightened MMP expression in the atria. During aging, we found that the expression of mRNAs for atrial MMP7, MMP8, and MMP9 peaked at 18 months, which closely correlated with reductions in collagen content and the time-window for cardioembolic stroke in these mice. Treatment of mice with an MMP inhibitor at 17-18 months of age reduced atrial inflammation and remodeling, and stroke incidence. Taken together, our study demonstrates that aging-induced LAA thrombus formation occurs through a mechanism involving upregulation of MMPs and breakdown of collagen, and that treatment with an MMP inhibitor may be effective as a treatment strategy for this heart condition.

Association of Left Atrial Strain With Ischemic Stroke Risk in Older Adults

Importance

The risk of ischemic stroke is higher among patients with left atrial (LA) enlargement. Left atrial strain (LAε) and LA strain rate (LASR) may indicate LA dysfunction when LA volumes are still normal. The association of LAε with incident ischemic stroke in the general population is not well established.

Objective

To investigate whether LAε and LASR are associated with new-onset ischemic stroke among older adults.

Design

The Cardiovascular Abnormalities and Brain Lesions study was conducted from September 29, 2005, to July 6, 2010, to investigate cardiovascular factors associated with subclinical cerebrovascular disease. A total of 806 participants in the Northern Manhattan Study who were aged 55 years or older without history of prior stroke or atrial fibrillation (AF) were included, and annual follow-up telephone interviews were completed May 22, 2022. Statistical analysis was performed from June through November 2022.

Exposures

Left atrial strain and LASR were assessed by speckle-tracking echocardiography. Global peak positive longitudinal LAε and positive longitudinal LASR during ventricular systole, global peak negative longitudinal LASR during early ventricular diastole, and global peak negative longitudinal LASR during LA contraction were measured. Brain magnetic resonance imaging was used to detect silent brain infarcts and white matter hyperintensities at baseline.

Main Outcomes and Measures

Risk analysis with cause-specific Cox proportional hazards regression modeling was used to assess the association of positive longitudinal LAε and positive longitudinal LASR with incident ischemic stroke, adjusting for other stroke risk factors, including incident AF.

Results

The study included 806 participants (501 women [62.2%]) with a mean (SD) age of 71.0 (9.2) years; 119 participants (14.8%) were Black, 567 (70.3%) were Hispanic, and 105 (13.0%) were White. During a mean (SD) follow-up of 10.9 (3.7) years, new-onset ischemic stroke occurred in 53 participants (6.6%); incident AF was observed in 103 participants (12.8%). Compared with individuals who did not develop ischemic stroke, participants with ischemic stroke had lower positive longitudinal LAε and negative longitudinal LASR at baseline. In multivariable analysis, the lowest (ie, closest to zero) vs all other quintiles of positive longitudinal LAε (adjusted hazard ratio [HR], 3.12; 95% CI, 1.56-6.24) and negative longitudinal LASR during LA contraction (HR, 2.89; 95% CI, 1.44-5.80) were associated with incident ischemic stroke, independent of left ventricular global longitudinal strain and incident AF. Among participants with a normal LA size, the lowest vs all other quintiles of positive longitudinal LAε (HR, 4.64; 95% CI, 1.55-13.89) and negative longitudinal LASR during LA contraction (HR, 11.02; 95% CI 3.51-34.62) remained independently associated with incident ischemic stroke.

Conclusions and Relevance

This cohort study suggests that reduced positive longitudinal LAε and negative longitudinal LASR are independently associated with ischemic stroke in older adults. Assessment of LAε and LASR by speckle-tracking echocardiography may improve stroke risk stratification in elderly individuals.

Subclinical left ventricular systolic dysfunction and incident stroke in the elderly: long-term findings from Cardiovascular Abnormalities and Brain Lesions

AIMS

Heart disease is associated with an increased risk for ischaemic stroke. However, the predictive value of reduced left ventricular ejection fraction (LVEF) for stroke is controversial and only observed in patients with severe reduction. LV global longitudinal strain (LV GLS) can detect subclinical LV systolic impairment when LVEF is normal. We investigated the prognostic role of LV GLS for incident stroke in a predominantly elderly cohort.

METHODS AND RESULTS

Two-dimensional echocardiography with speckle tracking was performed in the Cardiac Abnormalities and Brain Lesions (CABL) study. Among 708 stroke-free participants (mean age 71.4 ± 9.4 years, 60.9% women), abnormal LV GLS (>-14.7%: 95% percentile of the subgroup without risk factors) was detected in 133 (18.8%). During a mean follow-up of 10.8 ± 3.9 years, 47 participants (6.6%) experienced an ischaemic stroke (26 cardioembolic or cryptogenic, 21 other subtypes). The cumulative incidence of ischaemic stroke was significantly higher in participants with abnormal LV GLS than with normal LV GLS (P < 0.001). In multivariate stepwise logistic regression analysis, abnormal LV GLS was associated with ischaemic stroke independently of cardiovascular risk factors including LVEF, LV mass, left atrial volume, subclinical cerebrovascular disease at baseline, and incident atrial fibrillation [hazard ratio (HR): 2.69, 95% confidence interval (CI): 1.47-4.92; P = 0.001]. Abnormal LV GLS independently predicted cardioembolic or cryptogenic stroke (adjusted HR: 3.57, 95% CI: 1.51-8.43; P = 0.004) but not other subtypes.

CONCLUSION

LV GLS was a strong independent predictor of ischaemic stroke in a predominantly elderly stroke-free cohort. Our findings provide insights into the brain-heart interaction and may help improve stroke primary prevention strategies.

Left atrial late gadolinium enhancement in patients with ischaemic stroke

AIMS

To evaluate the extent of left atrial (LA) fibrosis in patients with a recent stroke without atrial fibrillation and controls without established cardiovascular disease.

METHODS AND RESULTS

This prospectively designed study used cardiac magnetic resonance to detect LA late gadolinium enhancement as a proxy for LA fibrosis. Between 2019 and 2021, we consecutively included 100 patients free of atrial fibrillation with recent ischaemic stroke (<30 days) and 50 age- and sex-matched controls. LA fibrosis assessment was achieved in 78 patients and 45 controls. Blinded to the cardiac magnetic resonance results, strokes were adjudicated according to modified Trial of Org 10172 in Acute Stroke Treatment classification as undetermined aetiology (n = 42) or as attributable to large- or small-vessel disease (n = 36). Patients with stroke had a larger extent of LA fibrosis [6.9%, interquartile range (IQR) 3.6-15.4%] than matched controls (4.2%, IQR 2.3-7.5%; P = 0.007). No differences in LA fibrosis were observed between patients with stroke of undetermined aetiology and those with large- or small-vessel disease (6.6%, IQR 3.8-16.0% vs. 6.9%, IQR 3.4-14.6%; P = 0.73).

CONCLUSION

LA fibrosis was more extensive in patients with stroke than in age- and sex-matched controls. A similar extent of LA fibrosis was observed in patients with stroke of undetermined aetiology and stroke classified as attributable to large- or small-vessel disease. Our findings suggest that LA structural abnormality is more frequent in patients with stroke than in controls independent of aetiological classification.

Correlation of microembolism risk factors with age in the ischemic stroke recovery period

Identification of the age-related features of interaction between the risk factors of microembolism can improve understanding of the mechanisms underlying the development of ischemic stroke (IS). The study was aimed to assess the effects of age and other risk factors of stroke on the biophysical characteristics of microembolic signals (MES) recorded during the ischemic stroke recovery period. Transcranial Doppler ultrasound (TCD) involving microembolus detection (MED) was performed in 515 people, the data of 28 patients having a history of ischemic stroke, among them 9 women (32%) and 19 men (68%) aged 33–78 (average age 58 ± 13 years), were included in the study. Using the mixed-effects linear model it was found that age and interaction between age and atrial fibrillation affected the power of MES. The increase in the power of the recorded MES with age is observed, that is especially evident in patients with atrial fibrillation (р < 0.0005). As for cardioembolic IS variant, the power and duration of MES turn out to be significantly higher in elderly patients (p < 0.0005). The power of MES gradually increases with age in patients with no atherosclerosis and gradually decreases in patients with atherosclerosis, while MES power in patients with atherosclerosis in general (all age groups) is significantly higher (р < 0.0005) than that observed in patients with no atherosclerosis.

Left Atrial Strain and the Risk of Atrial Arrhythmias From Extended Ambulatory Cardiac Monitoring: MESA

Background Abnormalities in left atrial (LA) function often occur before LA structural changes and clinically identified atrial fibrillation (AF). Little is known about the relationship between LA strain and the risk of subclinical atrial arrhythmias detected from extended ambulatory cardiac monitoring. Methods and Results A total of 1441 participants of MESA (Multi-Ethnic Study of Atherosclerosis) completed speckle-tracking echocardiography and cardiac monitoring during 2016 to 2018 (mean age, 73 years); participants in AF during echocardiography or during the entire cardiac monitoring period were excluded. Absolute values of LA reservoir, booster pump, and conduit strains were measured. We evaluated associations of LA strain with monitor-detected AF, premature atrial contractions, and supraventricular tachycardia. Primary analyses adjusted for demographic variables, blood pressure, diabetes, smoking, and clinical cardiovascular disease. Cardiac monitoring (median, 14 days) detected AF in 3%. Each SD (4.0%) lower (worse) LA booster pump strain was associated with 84% higher risk of monitor-detected AF (95% CI, 30%-162%), 39% higher premature atrial contraction frequency (95% CI, 27%-53%), and 19% higher supraventricular tachycardia frequency (95% CI, 10%-29%). Additional adjustment for NT-proBNP (N-terminal pro-B-type natriuretic peptide), LA volume index, tissue Doppler a' peak velocity, left ventricular ejection fraction, and global longitudinal strain had little impact on associations. Findings were similar for LA reservoir strain and null for LA conduit strain. Conclusions In a multiethnic community-based cohort, impaired LA strain was an important correlate of subclinical atrial arrhythmias, even after adjustment for conventional measures of LA structure and function.

Atrial cardiomyopathy: from cell to bedside

Atrial cardiomyopathy refers to structural and electrical remodelling of the atria, which can lead to impaired mechanical function. While historical studies have implicated atrial fibrillation as the leading cause of cardioembolic stroke, atrial cardiomyopathy may be an important, underestimated contributor. To date, the relationship between atrial cardiomyopathy, atrial fibrillation, and cardioembolic stroke remains obscure. This review summarizes the pathogenesis of atrial cardiomyopathy, with a special focus on neurohormonal and inflammatory mechanisms, as well as the role of adipose tissue, especially epicardial fat in atrial remodelling. It reviews the current evidence implicating atrial cardiomyopathy as a cause of embolic stroke, with atrial fibrillation as a lagging marker of an increased thrombogenic atrial substrate. Finally, it discusses the potential of antithrombotic therapy in embolic stroke with undetermined source and appraises the available diagnostic techniques for atrial cardiomyopathy, including imaging techniques such as echocardiography, computed tomography, and magnetic resonance imaging as well as electroanatomic mapping, electrocardiogram, biomarkers, and genetic testing. More prospective studies are needed to define the relationship between atrial cardiomyopathy, atrial fibrillation, and embolic stroke and to establish a prompt diagnosis and specific treatment strategies in these patients with atrial cardiomyopathy for the secondary and even primary prevention of embolic stroke.

Left atrial disease and left atrial reverse remodeling across different stages of heart failure development and progression: a new target for prevention and treatment

The left atrium is a dynamic chamber with peculiar characteristics. Stressors and disease mechanisms may deeply modify its structure and function, leading to left atrial remodelling and disease. Left atrial disease is a predictor of poor outcomes. It may be a consequence of left ventricular systolic and diastolic dysfunction and neurohormonal and inflammatory activation and/or actively contribute to the progression and clinical course of heart failure through multiple mechanisms such as left ventricular filling and development of atrial fibrillation and subsequent embolic events. There is growing evidence that therapy may improve left atrial function and reverse left atrial remodelling. Whether this translates into changes in patient's prognosis is still unknown.

In this review we report current data about changes in left atrial size and function across different stages of development and progression of heart failure. At each stage, drug therapies, lifestyle interventions and procedures have been associated with improvement in left atrial structure and function, namely a reduction in left atrial volume and/or an improvement in left atrial strain function, a process that can be defined as left atrial reverse remodelling and, in some cases, this has been associated with improvement in clinical outcomes. Further evidence is still needed mainly with respect of the possible role of left atrial reverse remodelling as an independent mechanism affecting the patient's clinical course and as regards better standardization of clinically meaningful changes in left atrial measurements. Summarizing current evidence, this review may be the basis for further studies.

Deep terminal negativity of the P-wave in V1 and stroke risk: The National Health and Nutrition Examination survey III

Background

Deep terminal negativity of the P‐wave in V1 (DTNPV1) was considered if the absolute value of the depth of the negative phase was >100 μV in the presence of a biphasic P‐wave in V1. In this study, we aimed to determine the association between DTNPV1, a simpler P‐wave index, and the risk of stroke.

Methods

We compared P‐wave indices between participants with and without a self‐reported history of stroke in the United States Third National Health and Nutrition Examination Survey (NHANES III). The association between DTNPV1 and stroke was quantified with logistic regression models.

Results

In total, 7732 participants were included (307 with a history of stroke). Patients with stroke had deeper terminal negativity of the P‐wave in V1 (52.3 ± 33.9 μV vs. 41.4 ± 27.0 μV, p < .001). After adjustment, DTNPV1 was associated with an increased risk of stroke (OR: 1.63, 95% CI: 1.03–2.60, p = .038). This association appeared to be stronger in people aged <75 years (interaction p = .023), and in those without heart failure (interaction p = .018) or ischemic heart disease (interaction p = .014). In contrast to the participants with 0 or ≥2 risk factors, in those with 1 risk factor, stroke prevalence was significantly different among the three categories of terminal negativity of the P‐wave (0 μV, >0 μV but ≤100 μV and > 100 μV) in V1 (2.8%, 3.3%, and 10.3%, respectively, p = .005).

Conclusion

In NHANES III, DTNPV1 was associated with a higher prevalence of stroke, suggesting that DTNPV1 might be a convenient marker to distinguish the risk of stroke.

A critical assessment of the current pharmacotherapy for the treatment of embolic strokes of undetermined source

INTRODUCTION

"Embolic stroke of undetermined source" (ESUS) is a term coined to identify non-lacunar stroke whose mechanism is likely to be embolic, and the source remains unidentified. The best antithrombotic treatment for preventing stroke recurrence in this population has not been delineated.

AREAS COVERED

The authors summarize and critically appraise the currently available evidence about the antithrombotic treatment for preventing stroke recurrence in patients with ESUS. Randomized trials addressing this topic were identified through MEDLINE (accessed by PubMed, as of November 2021, week 4).

EXPERT OPINION

Recent randomized trials have failed to demonstrate a significant benefit of direct oral anticoagulants over aspirin in reducing the recurrence of cerebral infarctions in unselected cohorts of patients with ESUS. The heterogeneity and often overlap of embolic sources may be possible explanations for the overall absence of a benefit of oral anticoagulants in ESUS as a single homogeneous entity. The results of these trials and their subgroup analyses have provided important cues to understand the pathophysiology of ESUS. They have, furthermore, increased in the interest in researchers in identifying distinct etiological phenotypes within this stroke population. There is a good rationale for ongoing and future investigations in order to tailor antithrombotic treatment according to individual features of patients with ESUS.

Frequent premature atrial contractions as a signalling marker of atrial cardiomyopathy, incident atrial fibrillation and stroke

Premature atrial contractions are a common cardiac phenomenon. Although previously considered a benign electrocardiographic finding, they have now been associated with a higher risk of incident atrial fibrillation and other adverse outcomes such as stroke and all-cause mortality. Since premature atrial contractions can be associated with these adverse clinical outcomes independently of atrial fibrillation occurrence, different explanations have being proposed. The concept of atrial cardiomyopathy, where atrial fibrillation would be an epiphenomenon outside the causal pathway between premature atrial contractions and stroke has received traction recently. This concept suggests that structural, functional and biochemical changes in the atria lead to arrhythmia occurrence and thromboembolic events. Some consensus about diagnosis and treatment of this condition have been published, but this is based on scarce evidence, highlighting the need for a clear definition of excessive premature atrial contractions and for prospective studies regarding antiarrhythmic therapies, anticoagulation or molecular targets in this group of patients.

Atrial cardiopathy and non-stenotic intracranial complicated atherosclerotic plaque in patients with embolic stroke of undetermined source

OBJECTIVE

To assess (1) the association between atrial cardiopathy (AC) and non-stenotic intracranial complicated atherosclerotic plaque (NICAP) in patients with embolic stroke of undetermined source (ESUS) or small-vessel disease (SVD), and (2) the performance of previously proposed biomarkers to identify AC as the underlying aetiology in ESUS.

METHODS

Based on our high-resolution MRI (HR-MRI) cohort, 403 subjects (243 ESUS and 160 SVD) were enrolled in the final analysis. All patients underwent intracranial HR-MRI to assess the presence of ipsilateral NICAP. Biomarkers of AC (ie, P-wave terminal force in lead V1 (PTFV1) on ECG, N-terminal probrain natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T and left atrial diameter) were collected within 24 hours after admission.

RESULTS

Among patients without ipsilateral NICAP, we found an association between the presence of AC (adjusted OR (aOR): 4.76, 95% CI 2.48 to 9.14), increased PTFV1 (aOR: 5.70, 95% CI: 2.43 to 13.39) and NT-proBNP (aOR: 1.65, 95% CI: 1.16 to 2.35) with ESUS. This association was not evident among patients with ipsilateral NICAP. The discrimination between ESUS versus SVD by AC/AC-related biomarkers was significantly improved after excluding ipsilateral NICAP. Similarly, the discrimination between ESUS and SVD by ipsilateral NICAP was notably augmented after excluding AC, PTFV1 and NT-proBNP.

INTERPRETATION

AC is more prevalent in patients who had ESUS without ipsilateral NICAP compared with patients with, implying that AC and ipsilateral NICAP are two distinct, competing aetiologies of ESUS. Among the AC biomarkers studied in this analysis, PTFV1 seems to be the most informative.

Clinical impact of left atrial enlargement in Korean patients with atrial fibrillation

We sought to evaluate the clinical implication of LAE based on left atrial anterior–posterior (LA AP) dimension or LA volume index (LAVI) in Korean patients with atrial fibrillation (AF). We enrolled 8159 AF patients from the CODE-AF registry. The primary outcome was rate of stroke or systemic embolism (SSE). The prevalence of mild, moderate, and severe LAE by LA AP dimension was 30.6%, 18.5%, and 21.4%, and by LAVI (available in 5808 patients) was 15.7%, 12.5% and 37.8%, respectively. Compared with no or mild LAE, patients with significant LAE (moderate to severe LAE, n = 3258, 39.9%) were associated with a higher rate of SSE (2.5% vs. 1.4%, P = 0.001). Multivariable analysis suggested presence of significant LAE by LA AP dimension was associated with a higher risk of SSE in the overall population (HR 1.57, 95% CI: 1.14–2.17, P = 0.005) and in patients using anticoagulants (n = 5836, HR 1.79, 95% CI: 1.23–2.63, P = 0.002). Patients with significant LAE by LAVI were also at higher risk of SSE (HR 1.58, 95% CI: 1.09–2.29, P = 0.017). In conclusion, significant LAE by LA dimension or LAVI was present in 39.9% and 50.2% of AF patients, respectively, and was associated with a higher rate of SSE.

Diagnosis and Treatment of Intracardiac Thrombus

ABSTRACT

Intracardiac thrombi can occur in a variety of locations and are frequently encountered in clinical practice. Yet evidence-based guidance for clinicians managing patients with intracardiac thrombi is often limited. This review summarizes what is known regarding the prevalence of intracardiac thrombus, diagnostic strategies, clinical relevance, and treatment options, focusing on four specific types of thrombus for which recent research has shifted clinical understanding and treatment decisions: (1) left atrial appendage thrombus, (2) cardiac implantable electronic device lead thrombus, (3) bioprosthetic aortic valve thrombus, and (4) left ventricular thrombus. Additional studies, ideally prospective, randomized, and head-to-head in design, are needed to better inform best practices in patients with intracardiac thrombi.

Cardiac mechanics and incident ischemic stroke: the Cardiovascular Health Study

Recent evidence indicates that our understanding of the relationship between cardiac function and ischemic stroke remains incomplete. The Cardiovascular Health Study enrolled community-dwelling adults ≥ 65 years old. We included participants with speckle-tracking data from digitized baseline study echocardiograms. Exposures were left atrial reservoir strain (primary), left ventricular longitudinal strain, left ventricular early diastolic strain rate, septal e’ velocity, and lateral e’ velocity. The primary outcome was incident ischemic stroke. Cox proportional hazards models were adjusted for demographics, image quality, and risk factors including left ventricular ejection fraction and incident atrial fibrillation. Among 4,000 participants in our analysis, lower (worse) left atrial reservoir strain was associated with incident ischemic stroke (HR per SD absolute decrease, 1.14; 95% CI 1.04–25). All secondary exposure variables were significantly associated with the outcome. Left atrial reservoir strain was associated with cardioembolic stroke (HR per SD absolute decrease, 1.42; 95% CI 1.21–1.67) and cardioembolic stroke related to incident atrial fibrillation (HR per SD absolute decrease, 1.60; 1.32–1.95). Myocardial dysfunction that can ultimately lead to stroke may be identifiable at an early stage. This highlights opportunities to identify cerebrovascular risk earlier and improve stroke prevention via therapies for early myocardial dysfunction.

Association of Rare Genetic Variants and Early-Onset Atrial Fibrillation in Ethnic Minority Individuals

Importance

Although rare variants in cardiac ion channels, transcription factors, and myocardial structural proteins are associated with early-onset atrial fibrillation (AF) in White individuals of European descent, it remains unclear whether genetic variation also contributes to the cause of AF in those of minority ethnicity.

Objectives

To assess the prevalence of rare and novel pathogenic variants in candidate genes in ethnic minority probands with early-onset AF and determine genotype-phenotype associations.

Design, Setting, and Participants

In this cohort, family-based study, probands of African and Hispanic descent with early-onset AF (defined as AF occurring in individuals aged ≤66 years) prospectively enrolled in a clinical and genetic biorepository underwent sequencing of 60 candidate genes. Recruitment took place from July 1, 2015, to June 30, 2019. Data were analyzed from February 1 to February 28, 2020.

Exposures

Rare and novel variants categorized as pathogenic or likely pathogenic.

Main Outcomes and Measures

The prevalence of rare and novel pathogenic variants in African American and Hispanic/Latinx probands with early-onset AF and genotype-phenotype associations.

Results

Among 227 probands with early-onset AF, mean (SD) age at onset of AF was 51.0 (9.9) years, 132 probands (58.1%) were men, 148 (65.2%) were African American, and 79 (34.8%) were Hispanic/Latinx. A family history of AF was verified in 24 probands with early-onset AF (10.6%). Sequencing 60 candidate genes identified 53 (23 rare and 30 novel) variants with 16 of the 227 (7.0%) probands harboring likely pathogenic (43.8%) or pathogenic (56.2%) variants, with most loss-of-function variants in TTN, the gene encoding the sarcomeric protein titin (46.7%). In 6 families with more than 2 affected members, variants of unknown significance in sodium channel (SCN10A), potassium channel (KCNE5), sarcomeric proteins (MYH6 and TTN), and atrial natriuretic peptide (NPPA) cosegregated with AF.

Conclusions and Relevance

In this study, likely pathogenic and pathogenic variants were identified, with most loss-of-function variants in TTN, that increase susceptibility to early-onset AF in African American and Hispanic/Latinx individuals. These findings provide further understanding toward molecular phenotyping of AF and suggest novel mechanism-based therapeutic approaches for this common arrhythmia in ethnic minority groups.

Angiotensin-Converting Enzyme 2 Activity Is Associated With Embolic Stroke of Undetermined Source

[Figure: see text].

Left atrial dimension and ischemic stroke in patients with and without atrial fibrillation

The incidence of ischemic stroke (IS) increases in patients with enlarged left atrium (LA) irrespective of whether or not the existence of atrial fibrillation (AF). In such situation, it is unclear whether the impact of LA on incidence of IS still significant in young, non-AF patients with enlarged LA who are primarily unconcerned on anticoagulation therapy. The study population consisted of 18,511 consecutive patients not receiving oral anticoagulants and undergoing echocardiography with measurement of LAD at baseline. The incidence rate of ischemic stroke was calculated in 3 groups according to left atrial dimension (LAD; < 30, 30-45 and ≥ 45 mm) in AF and non-AF patients. Further subgroup analysis was performed in stratification by elderly and young (aged ≥ 65 and < 65 years, respectively). The incidences of IS (per 100 patient-years) were 0.11 and 0.71 in non-AF and AF patients with LAD < 30 mm, respectively, which increased to 0.58 and 1.35 in LAD ≥ 45 mm (adjusted hazard ratios [HRs]; 1.95 [95% confidence intervals, CIs: 0.76-5.01] and 1.22 [95% CIs: 0.27-5.58], interaction P was 0.246). In non-AF patients, the incidences of IS were 0.30 and 0.04 in elderly and young patients with LAD < 30 mm, which increased to 0.67 and 0.48 in LAD ≥ 45 mm (adjusted HRs; 1.34 [95% CIs: 0.43-4.15] and 4.21 [95% CIs: 0.77-23.12], interaction P was 0.158). The incidence of IS significantly increased with increase of LAD in non-AF, especially in non-AF and young patients, although the difference was not independent of other clinical factors. The impact of LAD on IS was numerically larger in non-AF than in AF, and larger in young and non-AF than in elderly counterpart, although a significant interaction was not observed in this small population. Further studies with large population are necessary to judge whether these population with enlarged LA need antithrombotic therapy.

Echocardiographic predictors of cardioembolic stroke due to underlying atrial fibrillation: Reliable left atrial remodeling signs in acute stroke

INTRODUCTION

Atrial remodeling due to high-burden atrial fibrillation (AF) is associated with cardioembolic stroke (CES). As not all CESs is caused by AF, we analyzed the diagnostic values of each echocardiographic parameter to distinguish likely AF-related CES in acute stroke patients while in non-AF rhythm.

METHODS

The data of consecutive patients with acute ischemic stroke in sinus rhythm between 2012 and 2015 were obtained. The echocardiographic parameters of patients with CES due to underlying AF (n = 61) and control patients (n = 319) with either large artery atherosclerosis or small-vessel occlusion were compared using receiver operating characteristic curves and logistic regression analyses. Each parameter was reassessed in acute stroke patients through a validation study using the same database with different periods of generalization.

RESULTS

CES patients with underlying AF showed a significantly larger left atrial volume index (LAVi), higher mitral inflow E wave (E), and lower A wave (A) than the controls. The area under the curve (AUC) (95% confidence interval) for diagnosing CES due to underlying AF was significantly higher for LAVi/A than for LAVi (0.785 versus 0.696, P < 0.01). Among patients aged >60 years, the E/A ratio had the highest AUC (0.857) of the parameters. The cut-off values were ≥ 0.70 (sensitivity, 55.7%; specificity, 90.9%) and ≥ 0.82 (sensitivity, 71.4%; specificity, 84.1%) for LAVi/A and the E/A ratio, respectively, in patients >60 years. The cut-off values of all parameters showed similar trends in a validation study.

CONCLUSION

LAVi/A is a useful indicator for distinguishing CES patients with underlying AF regardless of age, and the E/A ratio is reliable among patients aged >60 years in evaluation during acute stroke admission.

Relation of Left Atrial Enlargement to Subsequent Thromboembolic Events in Nonvalvular Atrial Fibrillation Patients With Low to Borderline Embolic Risk

The current thromboembolic risk stratification of non-valvular atrial fibrillation (NVAF) does not include parameters from transthoracic echocardiography (TTE). We hypothesized that left atrial enlargement (LAE) on TTE could discriminate who require anticoagulation therapy among NVAF patients with low/borderline clinical embolic risk. This single-center cohort study included 6,602 patients with NVAF (median age, 56 years, 70.0% male) with a low to borderline clinical embolic risk (CHA₂DS₂-VASc score: 0 to 1 in males, 1 to 2 in females). LAE was classified as mild (≥41 mm in males; ≥39 mm in females) or moderate-severe (≥47 mm in males; ≥43 mm in females). The main study outcome was thromboembolic event (ischemic stroke and systemic embolism). Mild and moderate-severe LAE was diagnosed in 26.1% and 32.9% of the cohort, respectively. The patients with moderate-severe LAE showed a higher prevalence of baseline comorbidities and valvular heart disease and had a higher incidence of thromboembolic events than patients with mild or no LAE at 2 years of follow-up (2.5% vs 1.3% vs 1.1%, respectively, p < 0.001). After multivariable adjustment, patients with moderate-severe LAE were at a higher risk of thromboembolic event (hazard ratio, 2.54; 95% CI, 1.65 to 3.90; p < 0.001) compared to those with no LAE. This result persisted in a subgroup analysis of anticoagulant-naïve patients. The rate of thromboembolic events in patients with low clinical embolic risk and moderate-severe LAE was not different to those with high clinical embolic risk without LAE. In conclusion, Moderate-severe LAE on TTE was a significant predictor of thromboembolic events in NVAF patients at low/borderline clinical embolic risk.

Postoperative Atrial Fibrillation and Long-Term Risk of Stroke in Patients Undergoing Liver Transplantation

BACKGROUND AND PURPOSE

Postoperative atrial fibrillation (POAF) is the commonest cardiovascular complication following liver transplantation (LT). This study sought to assess a possible association of POAF with subsequent thromboembolic events in patients undergoing LT.

METHODS

A retrospective cohort study of consecutive adults undergoing LT between 2010 and 2018 was undertaken. Patients were classified as POAF if atrial fibrillation (AF) was documented within 30 days of LT without a prior history of AF. Cases of ischemic stroke or systemic embolism were adjudicated by a panel of 2 independent physicians.

RESULTS

Among the 461 patients included, POAF occurred in 47 (10.2%) a median of 3 days following transplantation. Independent predictors of POAF included advancing age, postoperative sepsis and left atrial enlargement. Over a median follow-up of 4.9 (interquartile range, 2.9-7.2) years, 21 cases of stroke and systemic embolism occurred. Rates of thromboembolic events were significantly higher in patients with POAF (17.0% versus 3.1%; P<0.001). After adjustment, POAF remained a strong independent predictor of thromboembolic events (hazard ratio, 8.36 [95% CI, 2.34-29.79]). Increasing CHA₂DS₂VASc score was also an independent predictor of thromboembolic events (hazard ratio, 1.58 [95% CI, 1.02-2.46]). A model using POAF and a CHA₂DS₂VASc score ≥2 alone yielded a C statistic of 0.77, with appropriate calibration for the prediction of thromboembolic events. However, POAF was not an independent predictor of long-term mortality.

CONCLUSIONS

POAF following LT is associated with an 8-fold increased risk of thromboembolic events and the use of the CHA₂DS₂VASc score may facilitate risk stratification of these patients. Prospective studies are warranted to assess whether the use of oral anticoagulants can reduce the risk of thromboembolism following LT.

Atrial Myopathy Underlying Atrial Fibrillation

While AF most often occurs in the setting of atrial disease, current assessment and treatment of patients with AF does not focus on the extent of the atrial myopathy that serves as the substrate for this arrhythmia. Atrial myopathy, in particular atrial fibrosis, may initiate a vicious cycle in which atrial myopathy leads to AF, which in turn leads to a worsening myopathy. Various techniques, including ECG, plasma biomarkers, electroanatomical voltage mapping, echocardiography, and cardiac MRI, can help to identify and quantify aspects of the atrial myopathy. Current therapies, such as catheter ablation, do not directly address the underlying atrial myopathy. There is emerging research showing that by targeting this myopathy we can help decrease the occurrence and burden of AF.

A New Therapeutic Framework for Atrial Fibrillation Drug Development

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia and cause of significant morbidity and mortality. Its increasing prevalence in aging societies constitutes a growing challenge to global healthcare systems. Despite substantial unmet needs in AF prevention and treatment, drug developments hitherto have been challenging, and the current pharmaceutical pipeline is nearly empty. In this review, we argue that current drugs for AF are inadequate because of an oversimplified system for patient classification and the development of drugs that do not interdict underlying disease mechanisms. We posit that an improved understanding of AF molecular pathophysiology related to the continuous identification of novel disease-modifying drug targets and an increased appreciation of patient heterogeneity provide a new framework to personalize AF drug development. Together with recent innovations in diagnostics, remote rhythm monitoring, and big data capabilities, we anticipate that adoption of a new framework for patient subsegmentation based on pathophysiological, genetic, and molecular subsets will improve success rates of clinical trials and advance drugs that reduce the individual patient and public health burden of AF.