Hypertension and Atrial Fibrillation: Doubts and Certainties From Basic and Clinical Studies

Ambulatory blood pressure and risk of new-onset atrial fibrillation in treated hypertensive patients

The aim of this study was to evaluate the influence of clinic and ambulatory blood pressure (BP) on the occurrence of new-onset atrial fibrillation (AF) in treated hypertensive patients. We studied 2135 sequential treated hypertensive patients aged >40 years. During the follow-up (mean 9.7 years, range 0.4-20 years), 116 events (new-onset AF) occurred. In univariate analysis, clinic, daytime, nighttime, and 24-h systolic BP were all significantly associated with increased risk of new-onset AF, that is, hazard ratio (95% confidence interval) per 10 mm Hg increment 1.22 (1.11-1.35), 1.36 (1.21-1.53), 1.42 (1.29-1.57), and 1.42 (1.26-1.60), respectively. After adjustment for various covariates in multivariate analysis, clinic systolic BP was no longer associated with increased risk of new-onset AF, whereas daytime, nighttime, and 24-h systolic BP remained significantly associated with outcome, that is, hazard ratio (95% confidence interval) per 10 mm Hg increment 1.09 (0.97-1.23), 1.23 (1.10-1.39), 1.16 (1.03-1.31), and 1.22 (1.06-1.40), respectively. Daytime, nighttime, and 24-h systolic BP are superior to clinic systolic BP in predicting new-onset AF in treated hypertensive patients. Future studies are needed to evaluate whether a better control of ambulatory BP might be helpful in reducing the occurrence of new-onset AF.

Coronary heart disease and atrial fibrillation: a vicious cycle

The population suffering from coronary heart disease (CHD) complicated by atrial fibrillation (AF) is rising rapidly. A strong correlation between the two diseases has been reported, and the many common risk factors they share may play prominent roles in their development. In addition, CHD can directly promote the progression of AF by affecting reentry formation, focal ectopic activity, and neural remodeling. At the same time, AF also affects CHD through three aspects: 1) atherosclerosis, 2) the mismatch of blood supply and oxygen consumption, and 3) thrombosis. In conclusion, CHD and AF can aggravate each other and seem to form a vicious cycle. For patients with CHD complicated by AF, principal studies and guidelines have focused on antithrombotic treatment and rhythm control, which are paramount for these patients. Of note, our review sheds light on the strategies to break the cycle of the two diseases, which may be fundamental to treat these patients and optimize the benefit.

Association between clustering of unhealthy lifestyle factors and risk of new-onset atrial fibrillation: a nationwide population-based study

We aimed to investigate the association between the combination of unhealthy lifestyle and risk of AF. Subjects aged 66 years who underwent health examination from 2009 to 2015 were included. The cohort was divided into 8 groups by the combination of unhealthy lifestyle including current smoking, heavy drinking (> 30 g/day), and lack of regular exercise, and followed up for new-onset AF till December 31, 2017. Among 1,719,401 subjects, 47,334 had incident AF (5.5 per 1000 person-years) during a 5-year mean follow-up period. Lack of regular exercise was the most powerful factor to be associated with a higher risk of AF as a single factor (adjusted hazard ratio 1.11, 95% confidence interval 1.08–1.13). Amongst combinations of two unhealthy lifestyle factors, current smoking with heavy drinking, lack of regular exercise with heavy drinking, and lack of regular exercise with current smoking were associated with a 6%, 15%, and 20% higher risks of AF, respectively. A cluster of three unhealthy lifestyle components was associated with a 22% higher risk of AF. Increased numbers of unhealthy lifestyle factors were associated with a higher risk of incident AF. These findings support the promotion of a healthy lifestyle to lower the risk of new-onset AF.

Dynamics of Atrial Fibrillation Mechanisms and Comorbidities

Atrial fibrillation (AF) contributes to morbidity and mortality of millions of individuals. Its molecular, cellular, neurohumoral, and hemodynamic pathophysiological mechanisms are complex, and there is increasing awareness that a wide range of comorbidities can contribute to AF-promoting atrial remodeling. Moreover, recent research has highlighted that AF risk is not constant and that the temporal variation in concomitant conditions contributes to the complexity of AF dynamics. In this review, we provide an overview of fundamental AF mechanisms related to established and emerging comorbidities or risk factors and their role in the AF-promoting effects. We focus on the accumulating evidence for the relevance of temporally dynamic changes in these risk factors and the consequence for AF initiation and maintenance. Finally, we highlight the important implications for future research and clinical practice resulting from the dynamic interaction between AF risk factors and mechanisms.

Inflammation and adiposity: new frontiers in atrial fibrillation

The aetiology of atrial fibrillation (AF) remains poorly understood, despite its growing prevalence and associated morbidity, mortality, and healthcare costs. Obesity is implicated in myriad different disease processes and is now recognized a major risk factor in the pathogenesis of AF. Moreover, the role of distinct adipose tissue depots is a matter of intense scientific interest with the depot directly surrounding the heart—epicardial adipose tissue (EAT) appearing to have the greatest correlation with AF presence and severity. Similarly, inflammation is implicated in the pathophysiology of AF with EAT thought to act as a local depot of inflammatory mediators. These can easily diffuse into atrial tissue with the potential to alter its structural and electrical properties. Various meta-analyses have indicated that EAT size is an independent risk factor for AF with adipose tissue expansion being inevitably associated with a local inflammatory process. Here, we first briefly review adipose tissue anatomy and physiology then move on to the epidemiological data correlating EAT, inflammation, and AF. We focus particularly on discussing the mechanistic basis of how EAT inflammation may precipitate and maintain AF. Finally, we review how EAT can be utilized to help in the clinical management of AF patients and discuss future avenues for research.

What Is the Ideal Blood Pressure Threshold for the Prevention of Atrial Fibrillation in Elderly General Population?

Intensive blood pressure (BP) lowering in patients with hypertension at increased risk of cardiovascular disease has been associated with a lowered risk of incident atrial fibrillation (AF). It is uncertain whether maintaining the optimal BP levels can prevent AF in the general elderly population. We included 115,866 participants without AF in the Korea National Health Insurance Service-Senior (≥60 years) cohort from 2002 to 2013. We compared the influence of BP on the occurrence of new-onset AF between octogenarians (≥80 years) and non-octogenarians (<80 years) subjects. With up to 6.7 ± 1.7 years of follow-up, 4393 incident AF cases occurred. After multivariable adjustment for potentially confounding clinical covariates, the risk of AF in non-octogenarians was significantly higher in subjects with BP levels of <120/<80 and ≥140/90 mm Hg, with hazard ratios of 1.15 (95% confidence interval (CI), 1.03-1.28; p < 0.001) and 1.14 (95% CI, 1.04-1.26; p < 0.001), compared to the optimal BP levels (120-129/<80 mm Hg). In octogenarians, the optimal BP range was 130-139/80-89 mm Hg, higher than in non-octogenarians. A U-shaped relationship for the development of incident AF was evident in non-octogenarians, and BP levels of 120-129/<80 mm Hg were associated the lowest risk of incident AF. Compared to non-octogenarians, the lowest risk of AF was associated with higher BP levels of 130-139/80-89 mm Hg amongst octogenarians.

Psychological aspects of atrial fibrillation: A systematic narrative review : Impact on incidence, cognition, prognosis, and symptom perception

PURPOSE OF THE REVIEW

Atrial fibrillation (AF) is the most frequent arrhythmia in the general population. This review aims to provide a comprehensive overview of the psychological aspects of AF, compiling evidence from epidemiological, clinical, and basic research sources.

RECENT FINDINGS

Findings from large-scale population-based and clinical longitudinal studies reveal an association between negative affectivity (e.g. depression) and the incidence and clinical prognosis of AF. Studies investigating the impact of work stress parameters on AF onset show conflicting results. Researchers have reported the impact of AF on cognitive decline and on health-related quality of life, and have highlighted the role of interoceptive cues in the development of AF symptom burden and gender differences in psychological covariates of AF. Among biological pathways linking psychosocial factors to AF, research on autonomic regulation has yielded the most evidence so far, showing that the onset of AF is associated with simultaneous sympatho-vagal activation rather than an increase in vagal or sympathetic drive alone. Thus, modulation of the autonomic nervous system is likely to be a promising strategy for protecting the myocardium from pro-arrhythmic autonomic influences. In total, the findings show that AF is embedded as a disease condition in a psycho-societal context and is not an isolated medical problem per se. A broader perspective than a focus on the electrophysiology alone is urgently needed.

Left Atrial Size May Predict Blood Pressure Improvement After Ganglionated Plexi Ablation in Addition to Pulmonary Vein Isolation

Background

Hypertension (HTN) and atrial fibrillation (AF) commonly co-exist. An improvement in control of HTN in a subset of patients undergoing AF ablation was previously demonstrated by our group. In the present study, we aimed to assess whether left atrial (LA) size based on transthoracic echocardiography may predict the patients who demonstratebetter HTN improvement after ganglionated plexus ablation (GPA) in addition to pulmonary vein isolation (PVI).

Methods

This was a retrospective chart review of patients with AF and HTN who underwent GPA+PVI. Patients were divided into 2 groupsbased on LA size: Patients with normal LA size and patients with LA enlargement. Systolic blood pressure (SBP) levelswere compared at baseline, and 3, 6, and 12 months post-ablation. The primary endpoints of the study weremean systolic blood pressure change compared between groups from baseline to 12-months, as well as the absolute difference in systolic blood pressure at 12 months follow-up.Medical therapy for HTN was also assessed before the procedure, and at 12 months post-procedure.

Results

53 patients (37 with LA enlargement, 16 with normal LA size) met inclusion criteria. At 12 months follow-up, SBP was 136.46 ± 22.38 mmHg in patients with LA enlargementand 118.25 ± 9.81 mmHg in patients with normal LA size (estimated difference of 19.04 ± 6.98 mmHg, p = 0.01). Patients with normal LA size were on significantly fewer anti-hypertensive agents at 12 months (2.33 ± 1.49 vs. 1.44 ± 1.21, p < 0.05).

Conclusions

In patients undergoing PVI+GP ablation, normal LA size may predict HTN improvement at 12 months post-procedure. Normal LA size may identify hypertensive AF patients for whom autonomic modulation could be an effective therapy.

Changes in 24-h ambulatory blood pressure following restoration of sinus rhythm in patients with atrial fibrillation

OBJECTIVE

The interplay between atrial fibrillation and blood pressure (BP) is insufficiently studied. In symptomatic patients with persistent atrial fibrillation, electrical cardioversion (ECV) is often used to restore sinus rhythm. In this prospective study, we investigated how restoration of sinus rhythm affected 24-h ambulatory BP.

METHODS

Ninety-eight patients with persistent atrial fibrillation were examined with 24-h ambulatory BP monitoring before and approximately a week after ECV.

RESULTS

Sixty-two patients remained in sinus rhythm at the time of the second ambulatory BP monitoring (AF-SR group), whereas 36 patients had relapsed into atrial fibrillation (AF-AF group). In the AF-SR group, there was a significant increase in mean systolic 24-h BP (5.6 mmHg), a significant decrease in mean diastolic 24-h BP (-4.7 mmHg) and accordingly, a significant 25% (10.4 mmHg) increase in mean 24-h pulse pressure.

CONCLUSION

These findings may reflect the haemodynamic conditions that are prevalent in atrial fibrillation, ambulatory BP measurement bias in atrial fibrillation or a combination of both factors. From a clinical standpoint, our results suggest that an increased attention to BP is needed when sinus rhythm is restored, as underlying hypertension may be masked by BP changes during atrial fibrillation. From a general standpoint, it may be speculated that BP, as indicated by the relatively large difference in pulse pressure, may be inherently different in atrial fibrillation and may therefore not be interpretable in the equivalent manner as BP in sinus rhythm.

Effect of combined renal denervation and pulmonary vein isolation in atrial fibrillation recurrence in hypertensive patients: A meta-analysis

BACKGROUND

Atrial Fibrillation (AF) is the most common cardiac arrhythmia and hypertension is the most common risk factor associated with AF. The addition of renal sympathetic nerve denervation (RSDN) to pulmonary vein isolation (PVI) in AF patients with hypertension has been reported to improve clinical outcomes.

METHODS

A systematic search was performed for studies on patients with AF and hypertension that compared RSDN with PVI versus PVI-alone. Risk ratio (RR) for categorical variables and mean difference (MD) for continuous variables with 95% confidence intervals were used.

RESULTS

Seven studies with a total of 734 patients were included. A total of 340 patients were in the RSDN + PVI group (46.32%) and 394 (53.67%) in the PVI group. A total of 608 patients had paroxysmal AF (83%) while 126 patients had persistent AF (17%). At 12 months follow-up, RSDN + PVI decreased the overall risk of AF recurrence in hypertensive patients with RR 0.60 [95% CI 0.50-0.72, P < .00001]. A subgroup analysis performed in patients with drug-resistant hypertension showed a similar reduction in AF recurrence with RR 0.61 [95% CI: 0.47-0.79, P = .0002). Procedure duration MD + 28.05 min [95% CI: 18.88-37.23, P < .00001] and fluoroscopy duration MD + 5.59 min [95% CI: 3.31-8.19, P < .00001] were significantly longer with the RSDN + PVI group. There was no significant difference in complications between the two groups.

CONCLUSION

The addition of RSDN to PVI in patients with AF and hypertension appears safe and decreases AF recurrence. Similar results were observed in patients with drug-resistant hypertension. Larger trials are needed to confirm these results.

Blood pressure measurement in atrial fibrillation: review and meta-analysis of evidence on accuracy and clinical relevance

: Atrial fibrillation (AF) often coexists with hypertension in the elderly and multiplies the risk of stroke and death. Blood pressure (BP) measurement in patients with AF is difficult and uncertain and has been a classic exclusion criterion in hypertension clinical trials leading to limited research data. This article reviews the evidence on the accuracy of BP measurement in AF performed using different methods (office, ambulatory, home) and devices (auscultatory, oscillometric) and its clinical relevance in predicting cardiovascular damage. The current evidence suggests the following: (i) Interobserver and intra-observer variation in auscultatory BP measurement is increased in AF because of increased beat-to-beat BP variability and triplicate measurement is required; (ii) Data from validation studies of automated electronic BP monitors in AF are limited and methodologically heterogeneous and suggest reasonable accuracy in measuring SBP and a small yet consistent overestimation of DBP; (iii) 24-h ambulatory BP monitoring is feasible in AF, with similar proportion of errors as in individuals without AF; (iv) both auscultatory and automated oscillometric BP measurements appear to be clinically relevant in AF, providing similar associations with intra-arterial BP measurements and with indices of preclinical cardiac damage as in patients without AF, and predict cardiovascular events and death; (v) Screening for AF in the elderly using an AF-specific algorithm during routine automated office, home or ambulatory BP measurement has high diagnostic accuracy. In conclusion, in AF patients, BP measurement is important, reliable, and clinically relevant and should not be neglected in clinical research and in practice.

Serum osteoprotegerin level is independently related to subclinical left atrial mechanical function in patients with hypertension and diabetes

OBJECTIVES

Previous studies showed that subclinical abnormal left atrial (LA) function could be diagnosed with LA speckle tracking evaluation long before chamber enlargement. Osteoprotegerin (OPG) is a member of the tumor necrosis factor (TNF) receptor superfamily and was recently found to be an indicator for adverse cardiovascular outcomes and a risk factor for new onset atrial fibrillation. The authors hypothesized that OPG values could predict LA mechanical dysfunction and LA remodeling assessed by two-dimensional speckle tracking echocardiography (2D-STE) in patients with hypertension (HT) and diabetes mellitus (DM).

METHODS

A single center study was conducted including consecutive patients presenting to the authors' outpatient clinic. Enrolled patients needed to have been treated for HT and DM for at least 1 year.

RESULTS

The study included 80 patients (mean age, 57.5 ± 8.3 years). Patients in the impaired LA strain group were older (p = 0.035), had lower low density lipoprotein (LDL) cholesterol (mg/dl) (p = 0.021), and higher OPG (pmol/l) (p = 0.004) values than patients in the normal LA strain group. Univariate logistic regression analysis demonstrated that age (p = 0.039), LDL cholesterol (mg/dl) (p = 0.025), and OPG (pmol/l) (p = 0.008) values were associated with impaired LA strain. Backward multivariate logistic regression analysis showed that LDL cholesterol (mg/dl) (OR: 0.982, CI 95% 0.964-0.999, p = 0.049) and OPG (pmol/l) (OR: 1.438, CI 95% 1.043-1.983, p = 0.027) were independently associated with impaired LA strain.

CONCLUSION

In hypertensive and diabetic patients, higher OPG values were associated with impaired LA function assessed by 2D-STE. In this high-risk patient group, serum OPG can be used as a risk predictor for LA mechanical dysfunction.

Identification of patients with embolic stroke of undetermined source and low risk of new incident atrial fibrillation: The AF-ESUS score

Background and aims

Only a minority of patients with Embolic Stroke of Undetermined Source (ESUS) receive prolonged cardiac monitoring despite current recommendations. The identification of ESUS patients who have low probability of new diagnosis of atrial fibrillation (AF) could potentially support a strategy of more individualized allocation of available resources and hence, increase their diagnostic yield. We aimed to develop a tool that can identify ESUS patients who have low probability of new incident AF.

Methods

We performed multivariate stepwise regression in a pooled dataset of consecutive ESUS patients from three prospective stroke registries to identify predictors of new incident AF. The coefficient of each independent covariate of the fitted multivariable model was used to generate an integer-based point scoring system.

Results

Among 839 patients (43.1% women, median age 67.0 years) followed-up for a median of 24.3 months (2999 patient-years), 125 (14.9%) had new incident AF. The proposed score assigns 3 points for age ≥ 60 years; 2 points for hypertension; −1 point for left ventricular hypertrophy reported at echocardiography; 2 points for left atrial diameter >40 mm; −3 points for left ventricular ejection fraction <35%; 1 point for the presence of any supraventricular extrasystole recorded during all available 12-lead standard electrocardiograms performed during hospitalization for the ESUS; −2 points for subcortical infarct; −3 points for the presence of non-stenotic carotid plaques. The rate of new incident AF during follow-up was 1.97% among the 42.3% of the cohort who had a score of ≤0, compared to 26.9% in patients with > 0 (relative risk: 13.7, 95%CI: 5.9--31.5). The area under the curve of the score was 84.8% (95%CI: 79.9--86.9%). The sensitivity and negative predictive value of a score of ≤0 for new incident AF during follow-up were 94.9% (95%CI: 89.3--98.1%) and 98.0% (95%CI: 95.8--99.3%), respectively.

Conclusions

The proposed AF-ESUS score has high sensitivity and high negative predictive value to identify ESUS patients who have low probability of new incident AF. Patients with a score of 1 or more may be better candidates for prolonged automated cardiac monitoring.

Clinical trial registration

URL: https://www.clinicaltrials.gov / Unique identifier: NCT02766205.

Atrial remodeling and atrial fibrillation in acquired forms of cardiovascular disease

Atrial fibrillation (AF) is prevalent in common conditions and acquired forms of heart disease, including diabetes mellitus (DM), hypertension, cardiac hypertrophy, and heart failure. AF is also prevalent in aging. Although acquired heart disease is common in aging individuals, age is also an independent risk factor for AF. Importantly, not all individuals age at the same rate. Rather, individuals of the same chronological age can vary in health status from fit to frail. Frailty can be quantified using a frailty index, which can be used to assess heterogeneity in individuals of the same chronological age. AF is thought to occur in association with electrical remodeling due to changes in ion channel expression or function as well as structural remodeling due to fibrosis, myocyte hypertrophy, or adiposity. These forms of remodeling can lead to triggered activity and electrical re-entry, which are fundamental mechanisms of AF initiation and maintenance. Nevertheless, the underlying determinants of electrical and structural remodeling are distinct in different conditions and disease states. In this focused review, we consider the factors leading to atrial electrical and structural remodeling in human patients and animal models of acquired cardiovascular disease or associated risk factors. Our goal is to identify similarities and differences in the cellular and molecular bases for atrial electrical and structural remodeling in conditions including DM, hypertension, hypertrophy, heart failure, aging, and frailty.

Incidence and Implications of Atrial Fibrillation/Flutter in Hypertension: Insights From the SPRINT Trial

We evaluated the impact of intensive blood pressure control on the incidence of new-onset atrial fibrillation/flutter (AF) and the prognostic implications of preexisting and new-onset AF in SPRINT (Systolic Blood Pressure Intervention Trial) participants. New-onset AF was defined as occurrence of AF in 12-lead electrocardiograms after randomization in participants free of AF at baseline. Poisson regression modeling was used to calculate incident rates of new-onset AF. Multivariable-adjusted Cox proportional hazard models were used to evaluate the risk of adverse cardiovascular events (composite of myocardial infarction, non-myocardial infarction acute coronary syndrome, stroke, heart failure, or cardiovascular death). In 9327 participants, 8.45% had preexisting AF, and 1.65% had new-onset AF. The incidence of new-onset AF was 4.53 per 1000-person years, with similar rates in the standard and intensive treatment arms (4.95 versus 4.11 per 1000-person years; adjusted P=0.14). Participants with preexisting AF (adjusted hazard ratio, 1.83 [95% CI, 1.46-2.31]; P<0.001) and new-onset AF (adjusted hazard ratio, 2.45 [95% CI, 1.58-3.80]; P<0.001) had a greater risk for development of adverse cardiovascular events compared with those with no AF. Participants with preexisting AF who achieved blood pressure <120/80 mm Hg at 3 months continued have a poor prognosis (adjusted hazard ratio, 1.88 [95% CI, 1.32-2.70]; P=0.001) compared with those with no AF. Intensive blood pressure control does not diminish the incidence of new-onset AF in an older, high-risk, nondiabetic population. Both preexisting and new-onset AF have adverse prognostic implications. In participants with preexisting AF, residual cardiovascular risk is evident even with on-treatment blood pressure <120/80 mm Hg. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01206062.

Effect of Intensive Blood Pressure Lowering on the Risk of Atrial Fibrillation

It remains uncertain whether intensive control of blood pressure (BP) results in a lower risk of atrial fibrillation (AF) in patients with hypertension. Using data from SPRINT (Systolic Blood Pressure Intervention Trial), which enrolled participants with hypertension at increased risk of cardiovascular disease, we examined whether intensive BP lowering (target systolic BP [SBP] <120 mm Hg), compared with standard BP lowering (target SBP<140 mm Hg), results in a lower risk of AF. This analysis included 8022 participants (4003 randomized to the intensive arm and 4019 to standard BP arm) who were free of AF at the time of enrollment and with available baseline and follow-up electrocardiographic data. AF was ascertained from standard 12-lead electrocardiograms recorded at biannual study examinations and an exit visit. During up to 5.2 years of follow-up and a total of 28 322 person-years, 206 incident AF cases occurred; 88 in the intensive BP-lowering arm and 118 in the standard BP-lowering arm. Intensive BP lowering was associated with a 26% lower risk of developing new AF (hazard ratio, 0.74 [95% CI, 0.56-0.98]; P=0.037). This effect was consistent among prespecified subgroups of SPRINT participants stratified by age, sex, race, SBP tertiles, prior cardiovascular disease, and prior chronic kidney disease when interactions between treatment effect and these subgroups were assessed using Hommel adjusted P values. In conclusion, intensive treatment to a target of SBP <120 mm Hg in patients with hypertension at high risk of cardiovascular disease has the potential to reduce the risk of AF. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01206062.

Efficacy and safety of renal denervation in addition to pulmonary vein isolation for atrial fibrillation and hypertension-Systematic review and meta-analysis of randomized controlled trials

Introduction

This systematic review and meta‐analysis aimed to assess the latest evidence on the use of renal denervation (RDN) + pulmonary vein isolation (PVI) compared to PVI alone for treating atrial fibrillation (AF) with hypertension.

Methods

A systematic literature search from several electronic databases was performed up until January 2020. The primary outcome was AF recurrence defined as AF/atrial flutter (AFL)/atrial tachycardia (AT) ≥30 seconds at 12‐month follow‐up and the secondary outcome was procedure‐related complications.

Results

There were 568 subjects from five studies. AF recurrence was 90/280 (32.1%) in the RDN + PVI group and 142/274 (51.8%) in the PVI group. RDN + PVI was associated with a lower incidence of AF recurrence (RR 0.62 [0.51, 076], P < .001; I²: 0%). Pooled analysis of HR showed that RDN + PVI was associated with reduced AF recurrence (HR 0.51 [0.38, 0.70], P < .001; I²: 0%). Complications were 7/241 (2.9%) in the RDN + PVI group and 8/237 (3.4%) in the PVI group. The rate of complications between the groups was similar (RR 0.87 [0.33, 2.29], P = .77; I²: 0%). In the subgroup analysis of paroxysmal AF, RDN + PVI was shown to reduce AF recurrence (RR 0.64 [0.49, 0.82], P < .001; I²: 0% and HR 0.56 [0.38, 0.82], P = .003; I²: 0%) compared to PVI alone. RDN + PVI has a moderate certainty of evidence in the reducing AF recurrence with an absolute reduction of 197 fewer per 1000 (from 254 fewer to 124 fewer).

Conclusion

RDN in addition to PVI, is associated with reduced 12‐month AF recurrence and similar procedure‐related complications compared to PVI alone.

Etiology, Pathology, and Classification of Atrial Fibrillation

Atrial fibrillation (AF) is a disorganized tachyarrhythmia with significant public health importance due to high morbidity, mortality, and health-care costs. Incidence rate of AF is on the rise and there are several modifiable and nonmodifiable risk factors that are responsible. Exact mechanisms and pathogenesis of AF are still poorly understood, yet they still have great implications in management. The aim of this article is to summarize the epidemiology, major risk factors, and their role in the pathogenesis of AF. Finally, we have reviewed the classification of AF as per professional society guidelines.

Differences in Epidemiology and Risk Factors for Atrial Fibrillation Between Women and Men

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is one of the most frequent cardiovascular diseases among both women and men. Although age-adjusted AF incidence and prevalence is larger among men, women are older at the time of AF diagnosis and have larger risk for AF-associated adverse outcomes such as morality and stroke. Based on evidence from epidemiological studies, elevated body mass index seems to confer a higher risk of AF among men. However, evidence regarding sex differences in the association between diabetes mellitus, elevated blood pressure, and dysglycemia with AF remains conflicting. While men with AF have larger burden of coronary artery disease, women with AF tend to have a larger prevalence of heart failure and valvular heart disease. Recently, several women-specific risk factors including pregnancy and its complications and number of children have been associated with AF. Earlier age at menopause, despite being a strong marker of adverse cardiometabolic risk, does not seem to be associated with increased risk of AF. To reduce the AF burden in both genders, better understanding of the differences between women and men with regard to AF is central. Large-scale studies are needed to separately investigate and report on women and men. Besides observations from epidemiological and clinical studies, to improve our understanding of sexual dimorphism in AF, sufficiently large genome-wide association studies as well as well-powered Mendelian randomization studies are essential to shed light on the sex-specific nature of the associations of risk factors with AF.

The Pathogenic Role of Very Low Density Lipoprotein on Atrial Remodeling in the Metabolic Syndrome

Atrial fibrillation (AF) is the most common persistent arrhythmia, and can lead to systemic thromboembolism and heart failure. Aging and metabolic syndrome (MetS) are major risks for AF. One of the most important manifestations of MetS is dyslipidemia, but its correlation with AF is ambiguous in clinical observational studies. Although there is a paradoxical relationship between fasting cholesterol and AF incidence, the benefit from lipid lowering therapy in reduction of AF is significant. Here, we reviewed the health burden from AF and MetS, the association between two disease entities, and the metabolism of triglyceride, which is elevated in MetS. We also reviewed scientific evidence for the mechanistic links between very low density lipoproteins (VLDL), which primarily carry circulatory triglyceride, to atrial cardiomyopathy and development of AF. The effects of VLDL to atria suggesting pathogenic to atrial cardiomyopathy and AF include excess lipid accumulation, direct cytotoxicity, abbreviated action potentials, disturbed calcium regulation, delayed conduction velocities, modulated gap junctions, and sarcomere protein derangements. The electrical remodeling and structural changes in concert promote development of atrial cardiomyopathy in MetS and ultimately lead to vulnerability to AF. As VLDL plays a major role in lipid metabolism after meals (rather than fasting state), further human studies that focus on the effects/correlation of postprandial lipids to atrial remodeling are required to determine whether VLDL-targeted therapy can reduce MetS-related AF. On the basis of our scientific evidence, we propose a pivotal role of VLDL in MetS-related atrial cardiomyopathy and vulnerability to AF.

Risk factors for recurrence of atrial fibrillation

OBJECTIVE

Atrial fibrillation (AF) is a progressive disease, associated with increased risk of mortality, stroke, heart failure, and worsens quality of life. There is a high incidence of AF recurrence despite the treatment. The aim of the study was to assess the time to recurrence of AF after sinus rhythm restoration with electrical or pharmacological cardioversion and to identify the risk factors.

METHODS

This study included 101 patients with AF (56% females) at a mean age of 68.02±7 years, after sinus rhythm restoration in a clinical observation of 1-year placebo-controlled treatment with spironolactone (1: 1). The patients were analyzed on the basis of AF recurrence, hospitalization, demographic parameters, comorbidities, embolic risk, and value of biomarker galectin-3 (Gal-3).

RESULTS

The average number of AF recurrences was1.62 per patient per year. The median time of occurrence of at least one new episode was 48 days, 95% confidence interval (CI) 14.24-81.76. Female patients experienced significantly more recurrences than male-53.3% vs. 28.6% hazard ration (HR) =1.76, 95% CI 1.02-3.03, p=0.036. The recurrences were more common with increased age, although not significantly. Patients with arterial hypertension had a threefold risk of recurrences than those without hypertension (p=0.025), independently of the treatment. CHA2DS2-VASc score was significantly associated with AF recurrent episodes. Patients with gout had a twofold increased risk, without statistical significance (p=0.15). There was no difference in the AF episodes according to treatment with spironolactone. The levels of Gal-3 did not affect the number of AF recurrences (p=0.9).

CONCLUSION

AF is associated with frequent recurrences after restoration of sinus rhythm in the majority of the patients. Most of them occurred within the first 3 months. Female sex, arterial hypertension, and CHA2DS2-VASc score were significant predictors of AF recurrence. Spironolactone did not reduce AF recurrences.

Effect of oral L-citrulline on brachial and aortic blood pressure defined by resting status: evidence from randomized controlled trials

Background

Experimental evidence indicates that oral L-citrulline (L-Cit) may reduce resting blood pressure (BP) as well as BP responses to exercise and cold exposure (non-resting). However, results from human intervention trials are inconsistent. This study aims to summarize the clinical evidence regarding the effects of L-Cit supplementation on brachial systolic blood pressure (SBP), brachial diastolic blood pressure (DBP), in addition to aortic SBP and aortic DBP at rest and non-resting conditions.

Methods

Multiple databases including PubMed, Embase, Cochrane library, Web of Science, and Clinical Trials were searched systematically. Randomized controlled trials of human participants were quantitatively meta-analyzed.

Results

Fourteen trials contained in eight studies were available for quantitative syntheses for brachial BP. Results showed that L-Cit supplementation significantly reduced both brachial SBP (− 4.490 mmHg, 95% CI: − 7.332 to − 1.648, P = 0.002) and brachial DBP (− 3.629 mmHg, 95% CI: − 5.825 to − 1.434, P = 0.001). Nine of the trials were meta-analyzed for aortic BP which showed that L-Cit intervention significantly reduced aortic SBP (− 6.763 mmHg, 95% CI: − 10.991 to − 2.534, P = 0.002), but not aortic DBP (− 3.396 mmHg, 95% CI: − 7.418 to 0.627, P = 0.098). The observed reducing effects of L-Cit appeared stronger for non-resting than for resting brachial SBP (P for difference = 0.044).

Conclusion

L-Cit supplementation significantly decreased non-resting brachial and aortic SBP. Brachial DBP was significantly lowered by L-Cit regardless of resting status. Given the relatively small number of available trials in the stratified analyses and the potential limitations of these trials, the present findings should be interpreted cautiously and need to be confirmed in future well-designed trials with a larger sample size.

Impact of pre-existing hypertension and control status before atrial fibrillation onset on cardiovascular prognosis in patients with non-valvular atrial fibrillation: A real-world database analysis in Japan

Hypertension is an important risk factor for non-valvular atrial fibrillation (NVAF) and its prognosis. However, there is no study to clarify the impact of pre-existing hypertension and BP control status before the onset of AF on the prognosis after the onset of AF. This retrospective real-world cohort analysis used data from the Japan Medical Data Center Co., Ltd database. The presence of NVAF and hypertension, plus the occurrence of adverse events, was based on ICD-10 codes in the database. The primary composite AF-related cardiovascular event end point included ischemic stroke, hemorrhagic stroke, and acute myocardial infarction. Of the 21 523 patients identified as having new-onset NVAF between January 2005 and June 2016, 7885 had blood pressure (BP) data before the onset of NVAF available and were included in the analysis (4001 with pre-existing hypertension and 3884 without pre-existing hypertension). The rate of primary composite end point events was 10.3 and 4.4 per 1000 patient-years in patients with and without hypertension, respectively (P < .001). In addition, lower systolic BP (<120 mm Hg) before the onset of NVAF was associated with a lower incidence of cardiovascular events after the development of NVAF (P < .001). This highlights the importance of earlier and tighter 24-hour BP control before the onset of NVAF in patients with hypertension, not only for reducing the occurrence of new-onset of NVAF, but also for reducing both hemorrhagic and ischemic cardiovascular events after the onset of NVAF.

Novel Oral Anticoagulants for the Prevention of Stroke in Patients with Atrial Fibrillation and Hypertension: A Meta-Analysis

INTRODUCTION

Hypertension is associated with increased risk of stroke and bleeding in patients with atrial fibrillation (AF). In the present study, we aimed to investigate the influence of hypertension status in patients with AF receiving treatment with non-vitamin K antagonist oral anticoagulants (NOACs).

METHODS

PubMed, Embase, and Cochrane Library were searched from the inception of each database to November 2017. Randomized controlled trials (RCTs) that evaluated NOACs versus warfarin in patients with AF and hypertension were identified. A meta-analysis was performed using random- or fixed-effects models according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Five trials (72,967 patients, including 51,378 patients with hypertension) were enrolled. NOACs significantly reduced the risk of stroke and systemic embolism (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.81-0.94, n = 51,378 patients), hemorrhagic stroke (HR 0.55, 95% CI 0.41-0.74, n = 28,818 patients), death from any cause (HR 0.91, 95% CI 0.85-0.97, n = 43,101 patients), major bleeding (HR 0.78, 95% CI 0.74-0.83, n = 51,378 patients) and intracranial bleeding (HR 0.50, 95% CI 0.38-0.67, n = 27,185 patients). The benefits of NOACs in comparison with warfarin were consistent in AF patients with or without hypertension (P_interaction for all outcomes > 0.05).

CONCLUSIONS

Our findings suggest that NOACs can be recommended for the prevention of stroke or systemic embolism in patients with AF and hypertension.

Cognitive Function and Atrial Fibrillation: From the Strength of Relationship to the Dark Side of Prevention. Is There a Contribution from Sinus Rhythm Restoration and Maintenance?

Atrial fibrillation (AF) is the most common chronic cardiac arrhythmia with an increasing prevalence over time mainly because of population aging. It is well established that the presence of AF increases the risk of stroke, heart failure, sudden death, and cardiovascular morbidity. In the last two decades several reports have shown an association between AF and cognitive function, ranging from impairment to dementia. Ischemic stroke linked to AF is a well-known risk factor and predictor of cognitive decline. In this clinical scenario, the risk of stroke might be reduced by oral anticoagulation. However, recent data suggest that AF may be a predictor of cognitive impairment and dementia also in the absence of stroke. Cerebral hypoperfusion, reduced brain volume, microbleeds, white matter hyperintensity, neuroinflammation, and genetic factors have been considered as potential mechanisms involved in the pathogenesis of AF-related cognitive dysfunction. However, a cause-effect relationship remains still controversial. Consequently, no therapeutic strategies are available to prevent AF-related cognitive decline in stroke-free patients. This review will analyze the potential mechanisms leading to cognitive dysfunction in AF patients and examine the available data on the impact of a sinus rhythm restoration and maintenance strategy in reducing the risk of cognitive decline.

Risk Factors for Atrial Fibrillation in People With Type 1 Diabetes: An Observational Cohort Study of 36,258 Patients From the Swedish National Diabetes Registry

OBJECTIVE

This study identified variables associated with increased risk of atrial fibrillation in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We performed a cohort study of people with type 1 diabetes from the Swedish National Diabetes Registry followed up between 1 January 2001 and 31 December 2013. Median follow-up was 9.7 years (interquartile range 5.2-13.0). The association between potential risk factors and incident atrial fibrillation was investigated using adjusted Cox regression. To compare the impact of each risk factor, the gradient of risk per 1 SD was estimated.

RESULTS

In this cohort of 36,258 patients with type 1 diabetes, 749 developed atrial fibrillation during follow-up. Older age, male sex, renal complications, increased BMI and HbA_1c, coronary artery disease, heart failure, and heart valve disease increased the risk of atrial fibrillation. Age, signs of renal dysfunction with macroalbuminuria, and decreasing estimated glomerular filtration rate were associated with the highest gradient of risk for atrial fibrillation. High blood pressure, severe obesity (BMI >35 kg/m²), and elevated levels of HbA_1c (>9.6%) were associated with increased risk, but no associations were found with hyperlipidemia or smoking.

CONCLUSIONS

The most prominent risk factors for atrial fibrillation in people with type 1 diabetes were older age, cardiovascular comorbidities, and renal complications, while obesity, hypertension, and hyperglycemia had more modest affects.

Prevalence of atrial fibrillation in the Italian elderly population and projections from 2020 to 2060 for Italy and the European Union: the FAI Project

Aims

To estimate prevalence of atrial fibrillation (AF) in a representative sample of the Italian elderly population, projecting figures for Italy and the European Union.

Methods and results

A cross-sectional examination of all subjects aged 65+ years from three general practices in Northern, Central, and Southern Italy started in 2016. Participants were administered a systematic and an opportunistic screening, followed by clinical and electrocardiogram confirmation. The study sample included 6016 subjects. Excluding 235 non-eligible, among the remaining 5781 participation was 78.3%, which left 4528 participants (mean age 74.5 ± 6.8 years, 47.2% men). Prevalence of AF was 7.3% [95% confidence intervals (CI) 6.6–8.1], higher in men and with advancing age (6.6% from systematic plus 0.7% from opportunistic screening). Using prevalence figures, Italian elderly having AF in 2016 were estimated at ∼1 081 000 (95% CI 786 000–1 482 000). Considering stable prevalence, this number will increase by 75% to ∼1 892 000 in 2060 (95% CI 1 378 000–2 579 000). European Union elderly having AF in 2016 were estimated at ∼7 617 000 (95% CI 5 530 000–10 460 000), increasing by 89% to ∼14 401 000 in 2060 (95% CI 10 489 000–19 647 000). In 2016, subjects aged 80+ years represented 53.5% of cases in Italy and 51.2% in the European Union; in 2060, 69.6% and 65.2%, respectively.

Conclusions

Our findings indicate a high burden of AF in coming decades, especially among the oldest-old, who carry the higher AF-related risk of stroke and medical complications.

Improving performance of 3D speckle tracking in arterial hypertension and paroxysmal atrial fibrillation by using novel strain parameters

The function of left atrium (LA) is closely related to LA remodeling and one of the most important mechanisms is an increased deposition of fibrous tissue that often is the basis for LA electro-mechanical changes before the onset of atrial fibrillation (AF). This study evaluated LA shape and function, by investigating standard and novel strain parameters calculated by a new approach based on homologous times derived from 3D speckle tracking echocardiography (3DSTE) in hypertensive (HT) and paroxysmal atrial fibrillation (PAF) patients with or without left ventricular hypertrophy (LVH), compared to control (C) subjects. LA function was assessed using homologous times to compare strain variables among different individuals, acquired at different physiological time periods. Standard global longitudinal (GLS) and circumferential (GCS) strains were measured at peak of atrial diastole, while longitudinal and circumferential strains (GLSh, GCSh), strain rate (GLSr, GCSr), volume (Vh) and volume rate (Vr) were measured during the atrial telediastolic phase (fifth homologous time) and atrial pre-active phase (tenth homologous time). Using ANOVA, we found an impaired LA deformation detected by standard, interpolated strains and strain rates in both HT and PAF groups compared to C. We also performed ROC analysis to identify different performances of each parameter to discriminate groups (GLSr10 + GCSr10: C vs PAF 0.935; C vs PAF_LVH 0.924; C vs HT_LVH 0.844; C vs HT 0.756). Our study showed anatomical and functional LA remodeling in patients with PAF and HT. 3D strains and strain rates derived from the homologous times approach provide more functional information with improved performance to identify among the explored groups, in particular PAF patients.

Electrocardiography for diagnosis of left ventricular hypertrophy in hypertensive patients with atrial fibrillation

Left ventricular (LV) hypertrophy at electrocardiography (ECG) predicts incident atrial fibrillation (AF). However, the diagnostic performance of ECG for diagnosis of LV hypertrophy in patients with AF is still not well characterized.

We analyzed 563 hypertensive patients enrolled in the Umbria-Atrial Fibrillation (Umbria-FA) registry, an ongoing prospective observational registry in patients with AF. All patients underwent ECG and standard echocardiography at their entry in the Register. Mean age was 74 years and 43% of patients were women. Prevalence of ECG-LV hypertrophy, defined by Perugia criterion corrected for body mass index, was 23%. Echocardiographic LV mass was the reference standard. Sensitivity, specificity and diagnostic accuracy of ECG-LV hypertrophy were 37.4% (95% confidence interval [CI]: 31.6–43.4), 90.0% (95% CI: 86.0–93.2) and 64.5% (95% CI: 60.4–68.3), respectively. Performance was comparable in patients with AF or sinus rhythm at ECG recording. The area under the receiver-operating characteristic (ROC) curve was 0.622 (95% CI: 0.580–0.664) in the group with AF and 0.662 (95% CI: 0.605–0.720) in that with sinus rhythm (p ​= ​0.266 for comparison). These data suggest that standard ECG is reliable for diagnosis of LV hypertrophy in patients with a history of AF, regardless of the presence of AF or sinus rhythm at the time of ECG recording.

Angiotensin II Induces Automatic Activity of the Isolated Guinea Pig Pulmonary Vein Myocardium through Activation of the IP₃ Receptor and the Na⁺-Ca2+ Exchanger

The automaticity of the pulmonary vein myocardium is known to be the major cause of atrial fibrillation. We examined the involvement of angiotensin II in the automatic activity of isolated guinea pig pulmonary vein preparations. In tissue preparations, application of angiotensin II induced an automatic contractile activity; this effect was mimicked by angiotensin I and blocked by losartan, but not by PD123,319 or carvedilol. In cardiomyocytes, application of angiotensin II induced an increase in the frequency of spontaneous Ca²⁺ sparks and the generation of Ca²⁺ transients; these effects were inhibited by losartan or xestospongin C. In tissue preparations, angiotensin II caused membrane potential oscillations, which lead to repetitive generation of action potentials. Angiotensin II increased the diastolic depolarization slope of the spontaneous or evoked action potentials. These effects of angiotensin II were inhibited by SEA0400. In tissue preparations showing spontaneous firing of action potentials, losartan, xestospongin C or SEA0400 decreased the slope of the diastolic depolarization and inhibited the firing of action potentials. In conclusion, in the guinea pig pulmonary vein myocardium, angiotensin II induces the generation of automatic activity through activation of the IP₃ receptor and the Na⁺-Ca²⁺ exchanger.

Obesity and Atrial Fibrillation: Epidemiology, Pathophysiology and Novel Therapeutic Opportunities

Obesity is already a major global public health issue, implicated in a vast array of conditions affecting multiple body systems. It is now also firmly established as an independent risk factor in the incidence and progression of AF. The rapidly rising morbidity, mortality and healthcare costs associated with AF despite implementation of the three pillars of AF management — anticoagulation, rate control and rhythm control — suggest other strategies need to be considered. Compelling data has unveiled novel insights into adipose tissue biology and its effect on arrhythmogenesis while secondary prevention strategies targeting obesity as part of a comprehensive risk factor management programme have been demonstrated to be highly effective. Here, the authors review the epidemiological basis of the obesity—AF relationship, consider its underlying pathophysiology and discuss new therapeutic opportunities on the horizon.

Transient outward K+ current can strongly modulate action potential duration and initiate alternans in the human atrium

Efforts to identify the mechanisms for the initiation and maintenance of human atrial fibrillation (AF) often focus on changes in specific elements of the atrial "substrate," i.e., its electrophysiological properties and/or structural components. We used experimentally validated mathematical models of the human atrial myocyte action potential (AP), both at baseline in sinus rhythm (SR) and in the setting of chronic AF, to identify significant contributions of the Ca2+-independent transient outward K+ current ( Ito) to electrophysiological instability and arrhythmia initiation. First, we explored whether changes in the recovery or restitution of the AP duration (APD) and/or its dynamic stability (alternans) can be modulated by Ito. Recent reports have identified disease-dependent spatial differences in expression levels of the specific K+ channel α-subunits that underlie Ito in the left atrium. Therefore, we studied the functional consequences of this by deletion of 50% of native Ito (Kv4.3) and its replacement with Kv1.4. Interestingly, significant changes in the short-term stability of the human atrial AP waveform were revealed. Specifically, this K+ channel isoform switch produced discontinuities in the initial slope of the APD restitution curve and appearance of APD alternans. This pattern of in silico results resembles some of the changes observed in high-resolution clinical electrophysiological recordings. Important insights into mechanisms for these changes emerged from known biophysical properties (reactivation kinetics) of Kv1.4 versus those of Kv4.3. These results suggest new approaches for pharmacological management of AF, based on molecular properties of specific K+ isoforms and their changed expression during progressive disease. NEW & NOTEWORTHY Clinical studies identify oscillations (alternans) in action potential (AP) duration as a predictor for atrial fibrillation (AF). The abbreviated AP in AF also involves changes in K+ currents and early repolarization of the AP. Our simulations illustrate how substitution of Kv1.4 for the native current, Kv4.3, alters the AP waveform and enhances alternans. Knowledge of this "isoform switch" and related dynamics in the AF substrate may guide new approaches for detection and management of AF.

Acute Tachycardia Increases Aortic Distensibility, but Reduces Total Arterial Compliance Up to a Moderate Heart Rate

Background: The differential effects of rapid cardiac pacing on small and large vessels have not been well-established. The objective of this study was to investigate the effect of pacing-induced acute tachycardia on hemodynamics and arterial stiffness.

Methods: The pressure and flow waves in ascending aorta and femoral artery of six domestic swine were recorded simultaneously at baseline and heart rates (HR) of 135 and 155 beats per minutes (bpm) and analyzed by the models of Windkessel and Womersley types. Accordingly, the flow waves were simultaneously measured at carotid and femoral arteries to quantify aortic pulse wave velocity (PWV). The arterial distensibility was identified in small branches of coronary, carotid and femoral arteries with diameters of 300–600 μm by ex vivo experiments.

Results: The rapid pacing in HR up to 135 bpm reduced the total arterial compliance, stroke volume, systemic pulse pressure, and central systolic pressure by 36 ± 17, 38 ± 26, 29 ± 16, and 23 ± 12%, respectively, despite no statistical difference of mean aortic pressure, cardiac output, peripheral resistance, and vascular flow patterns. The pacing also resulted in a decrease of distensibility of small muscular arteries, but an increase of aortic distensibility. Pacing from 135 to 155 bpm had negligible effects on systemic and local hemodynamics and arterial stiffness.

Conclusions: There is an acute mismatch in the response of aorta and small arteries to pacing from basal HR to 135 bpm, which may have important pathological implications under chronic tachycardia conditions.