Atrial fibrillation: public health implications

The Bidirectional Relationship Between Obstructive Sleep Apnea and Atrial Fibrillation: Pathophysiology, Diagnostic Challenges, and Strategies - A Narrative Review

Atrial fibrillation (AF), is an irregular heart rhythm disorder that increases the risk of stroke, heart failure, and death. Obstructive sleep apnea is typified by intermittent airway blockages which results in low oxygen levels and disrupted sleep. These two conditions often coexist, with each worsening the other. Understanding this connection is critical to improve diagnosis and treatment. The relationship between atrial fibrillation and obstructive sleep apnea appears bidirectional. Obstructive sleep apnea increases the risk of atrial fibrillation through various mechanisms which are arrhythmogenic. Conversely, patients with atrial fibrillation are more likely to have undiagnosed obstructive sleep apnea, complicating their treatment. Screening modalities for obstructive sleep apnea are often inadequate. Polysomnography remains the most reliable tool but is costly and not practical for routine screening of all patients which limits early diagnosis and management. Continuous positive airway pressure (CPAP) therapy is the primary treatment for obstructive sleep apnea and can reduce atrial fibrillation recurrence by decreasing oxygen deprivation and sympathetic activity. However, adherence to continuous positive airway pressure is often low due to patient discomfort. Alternative therapies, such as mandibular advancement devices and hypoglossal nerve stimulation, offer promising options for patients who cannot tolerate continuous positive airway pressure. The interplay between atrial fibrillation and obstructive sleep apnea requires an integrated approach to diagnosis and treatment. Improving screening tools, enhancing treatment adherence, and evaluating alternative therapies are critical steps to reducing the impact of these conditions and improving patient outcomes.

Factors associated with cognitive impairment in patients with atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is associated with an increased risk of cognitive impairment. Therefore, exploring factors which may be associated with cognitive impairment is important. Correspondingly, this study aimed to systematically evaluate factors associated with cognitive impairment in AF patients by synthesizing relevant evidence.

METHODS

A database search of the PubMed, Embase, Cochrane Library, Web of Science, CBM, CNKI, Wanfang, and VIP databases was conducted from inception until December 21, 2023. The effect size was expressed as a combined odds ratio (OR) and 95 % confidence interval (95 % CI). The heterogeneity was qualitatively analyzed by Cochran's Q test and quantified by the I2 statistic.

RESULTS

A total of 7,128 studies were identified from the 8 databases, and 39 studies of 3,491,423 participants were included. A meta-analysis was performed on 19 influencing factors. Advanced age (OR=1.38, 95 % CI: 1.11-1.71), female sex (OR=2.19, 95 % CI: 1.18-4.06), smoking (OR=2.44, 95 % CI: 1.24-4.80), hypertension (OR=1.61, 95 % CI: 1.27-2.03), diabetes (OR=1.42, 95 % CI: 1.20-1.67), and hearing impairment (OR=1.37, 95 % CI: 1.05-1.81) were risk factors for cognitive impairment. A higher education level (OR=0.57, 95 % CI: 0.46-0.72), oral anticoagulants (OR=0.61, 95 % CI: 0.48-0.78), novel oral anticoagulants (OR=0.63, 95 % CI: 0.54-0.73), warfarin (OR=0.55, 95 % CI: 0.39-0.79), novel oral anticoagulants relative to warfarin (OR=0.88, 95 % CI: 0.81-0.97), catheter ablation (OR=0.74, 95 % CI: 0.58-0.94) and exercise (OR=0.66, 95 % CI: 0.61-0.72) were protective factors for cognitive impairment.

CONCLUSIONS

Age, sex, education level, smoking, exercise, hypertension, diabetes, hearing impairment, anticoagulation therapy, and catheter ablation were associated with cognitive impairment in AF patients.

Wound incidence and outcomes in atrial fibrillation: Comparing catheter ablation and anti-arrhythmic drug therapy

The most prevalent form of cardiac arrhythmia is atrial fibrillation (AF), which is typically managed through catheter ablation or anti-arrhythmic drug therapy. We compared the incidence and outcomes of wound complications in patients with atrial fibrillation who were treated with catheter ablation as opposed to anti-arrhythmic drug therapy. From May to November 2023, 240 adult AF patients who were treated with catheter ablation or anti-arrhythmic medications participated in a 6-month retrospective cohort study at Sir Run Run Shaw Hospital in Hangzhou, China. An observation was made regarding 29 wound complications out of 240 patients. In comparison to drug therapy group, incidence of minor (8 vs. 11) and total complications (18 vs. 11) was greater in catheter ablation group. Significant adverse events occurred at higher rate in the catheter ablation group (6 versus 1) (p < 0.05). However, despite these patterns, there was no statistically significant difference in the rates of complications (total: p = 0.245; minor: p = 0.217; major: p = 0.128). Comparable treatment efficacy was observed across groups. In contrast to drug therapy, catheter ablation was associated with decreased probability of complications (odds ratio: 0.86), as determined by logistic regression; cardiac failure was a significant predictor of adverse outcomes. The study concluded that the risks of wound complications associated with catheter ablation and anti-arrhythmic drug therapy in patients with atrial fibrillation are comparable. Notwithstanding an elevated propensity for complications in ablation group, the statistical analysis indicated comparable safety profiles.

Comparison of phenprocoumon with direct oral anticoagulants in catheter ablation of atrial fibrillation

Aims

In patients undergoing catheter ablation for atrial fibrillation (AF), direct oral anticoagulants (DOACs) are as effective and safe as the vitamin K antagonist (VKA) warfarin. Phenprocoumon has a different pharmacokinetic profile compared with warfarin and is the most used VKA in Germany. The aim of the study was to compare DOAC with phenprocoumon.

Methods and results

In this retrospective single-centre cohort study, 1735 patients who underwent 2219 consecutive catheter ablations for AF between January 2011 and May 2017 were included. All patients were in-hospital for at least 48 h after catheter ablation. The primary outcome was defined as peri-procedural thrombo-embolic events. The secondary outcome was any bleeding according to the International Society on Thrombosis and Haemostasis (ISTH). The mean age of the patients was 63.3 years. Phenprocoumon was prescribed in 929 (42%) of the cases, and in 697 (31%) dabigatran, 399 (18%) rivaroxaban, and 194 (9%) apixaban. During hospitalization, 37 (1.6%) thrombo-embolic events occurred, including 23 transient ischaemic attacks (TIAs). Compared with the use of phenoprocoumon, the use of DOAC was significantly associated with a lower thrombo-embolic risk [16 (1.2%) vs. 21 (2.2%), odds ratio (OR)], 0.5 [95% confidence interval (CI) 0.2-0.9], P = 0.04. No statistically significant association with bleeding risk was observed [phenprocomoun: 122 (13%); DOAC: 163 (12.6%); OR 0.9 (95% CI 0.7-1.2); P = 0.70]. Interruption of oral anticoagulation (OAC) was associated with an increased risk for thrombo-embolic complications [OR 2.2 (1.1-4.3); P = 0.031], and bleeding [OR 2.5 (95% CI 1.8-3.2), P = 0.001].

Conclusion

In patients undergoing catheter ablation for AF, the use of DOAC was associated with a reduced risk of thrombo-embolic events compared with phenprocoumon. Non-interrupted oral anticoagulation (OAC) therapy was associated with a reduced risk of peri-procedural thrombo-embolic and any bleeding complications.

Rhythm control versus rate control in a contemporary ambulatory atrial fibrillation cohort: Post-hoc analysis of the IMPACT-AF Trial

Background

We examined the characteristics and outcomes in a contemporary ambulatory population of patients with atrial fibrillation (AF), comparing rate control with rhythm control.

Methods

This is a post hoc analysis of a cluster-randomized trial (Integrated Management Program Advancing Community Treatment of Atrial Fibrillation [IMPACT-AF]) in ambulatory AF patients from 2016 to 2018, which compared use of a clinical decision support tool for general practitioners to usual care. This analysis compared patients managed with rate vs rhythm control, at entry into the study. Outcomes included AF-related emergency department (ED) visits, unplanned cardiovascular hospitalizations, and bleeding events at 12 months.

Results

A total of 870 patients were included in this analysis, 99 (11.4%) in the rhythm-control group, and 40% women. In the rhythm-control group, the mean age was younger (70 ± 11.4 vs 72.7 ± 9.5 years, P = 0.03), a higher number were paroxysmal (80% vs 43%, P < 0.001), and CHADS₂ scores were lower. The rate of AF-related ED visits was higher in the rhythm-control group (17.2 vs 7.3%, P = 0.003), and repeat visits (rate ratio 3.03, 95% confidence interval [1.99-4.52], P < 0.001). The number of repeat ED visits was independently associated with female sex and being in the rhythm-control group.

Conclusions

Both rate- and rhythm-control patients have recurrent ED visits, with a higher rate in patients treated with rhythm control. These findings are observational, but taken in the context of current guidelines could help develop further therapies aimed at improving symptom burden in both rhythm- and rate-control patients to broadly improve healthcare utilization in the AF population.

Isolated left atrial cryoablation of atrial fibrillation in conventional mitral valve surgery

BACKGROUND

Recent trends of surgery for atrial fibrillation (AF) are towards more safe and effective energy sources, as well as to simplified sets of atrial lesions.

METHODS

One hundred eighteen (mean age, 67.4 ± 9.2 years) selected patients with paroxysmal/persistent AF and mitral valve (MV) disease underwent cryoablation of AF combined with conventional (not via mini-thoracotomy) MV surgery; the lesion set was limited to only the left atrium. Multivariable analyses identified predictors of cardiac rhythm at hospital discharge and follow-up.

RESULTS

There were 7 (5.9%) hospital deaths; 33 (28%) patients were discharged on AF. Higher values of preoperative left atrial volume index (odds ratio [OR] = 1.07, 95% confidence interval [95%CI]: 1.01-1.13) and mixed etiology of MV disease (OR = 4.19, 95%CI: 1.23-14.2) were predictors of hospital discharge on AF. Seventy-four (66.7%) patients were on stable sinus rhythm at follow-up (median period, 6.6 years); the 1, 5, and 10-year nonparametric estimates of adjusted freedom from AF were 98.1%, 89.2% and 45.6%, respectively. Higher values of preoperative systolic pulmonary artery pressure (hazard ratio [HR] = HR = 1.04, 95%CI: 1.01-1.08) and AF at hospital discharge (HR = 4.14, 95%CI: 1.50-11.4) were predictors of AF at follow-up.

CONCLUSIONS

During conventional MV surgery, a cryo-lesion set limited to only the left atrium may give good, immediate and long-term results. Left atrial dilation and mixed etiology of MV disease were predictors of hospital discharge on AF. Preoperative pulmonary hypertension and AF at discharge combined with an increased risk of AF at follow-up.

Awareness of atrial fibrillation-effectiveness of a pilot national awareness campaign

BACKGROUND

Although atrial fibrillation (AF) causes one-third of strokes in Ireland, studies have shown that public awareness and knowledge of AF are poor. The Irish Heart Foundation conducted a national AF awareness campaign in 2013.

AIMS

The aim of this study was to assess the effectiveness of the campaign in promoting awareness of AF in the general Irish population, by analyzing knowledge of AF at a population level pre- and post-campaign.

METHODS

Two thousand people were surveyed before the campaign to establish baseline knowledge, and the survey was then repeated in a sample of 1000 people in 2 months after the end of the campaign.

RESULTS

Awareness of AF was low, with 28% (560/2000) of those surveyed reporting they had heard of AF prior to the campaign and 30% (297/1002) after (p 0.347). Of those that had heard of the condition, 58% (174/300) in the pre-campaign group correctly identified AF as an irregular heartbeat compared with 35% (105/297) of the post-campaign group (p < 0.01).

CONCLUSIONS

Our study shows that overall public knowledge of AF in Ireland is generally poor. While this pilot national awareness campaign had no positive impact on awareness levels, there are several possible reasons for this including the limited funding allocation to the campaign. A further AF awareness campaign is planned for next year.

Implementation of an emergency department atrial fibrillation and flutter pathway improves rates of appropriate anticoagulation, reduces length of stay and thirty-day revisit rates for congestive heart failure

Objectives

An evidence-based emergency department (ED) atrial fibrillation and flutter (AFF) pathway was developed to improve care. The primary objective was to measure rates of new anticoagulation (AC) on ED discharge for AFF patients who were not AC correctly upon presentation.

Methods

This is a pre-post evaluation from April to December 2013 measuring the impact of our pathway on rates of new AC and other performance measures in patients with uncomplicated AFF solely managed by emergency physicians. A standardized chart review identified demographics, comorbidities, and ED treatments. The primary outcome was the rate of new AC. Secondary outcomes were ED length of stay (LOS), referrals to AFF clinic, ED revisit rates, and 30-day rates of return visits for congestive heart failure (CHF), stroke, major bleeding, and death.

Results

ED AFF patients totalling 301 (129 pre-pathway [PRE]; 172 post-pathway [POST]) were included; baseline demographics were similar between groups. The rates of AC at ED presentation were 18.6% (PRE) and 19.7% (POST). The rates of new AC on ED discharge were 48.6 % PRE (95% confidence interval [CI] 42.1%-55.1%) and 70.2% POST (62.1%-78.3%) (20.6% [p<0.01; 15.1-26.3]). Median ED LOS decreased from 262 to 218 minutes (44 minutes [p<0.03; 36.2-51.8]). Thirty-day rates of ED revisits for CHF decreased from 13.2% to 2.3% (10.9%; p<0.01; 8.1%-13.7%), and rates of other measures were similar.

Conclusions

The evidence-based pathway led to an improvement in the rate of patients with new AC upon discharge, a reduction in ED LOS, and decreased revisit rates for CHF.

One-year safety and quality of life outcomes in patients with atrial fibrillation on dronedarone: prospective, non-interventional study in German ambulatory care

Background and aims

The multichannel blocker dronedarone is currently indicated for the maintenance of sinus rhythm after successful cardioversion in adult clinically stable patients with paroxysmal or persistent atrial fibrillation (AF), with careful monitoring of cardiac, hepatic and renal function. We aimed to investigate patients’ quality of life (QoL) and tolerability and effectiveness of dronedarone under real life conditions.

Methods

In the 1-year prospective, non-interventional IMPULS study, 161 office-based cardiologists, general practitioners and internists throughout Germany documented 549 patients with AF who were currently or newly prescribed dronedarone (safety set, SS). Of those, 342 patients (full analysis set, FAS) provided data on QoL at baseline, 6 months and 12 months).

Results

Mean age of patients was 67.6/66.3 years; 53.0 %/57.3 % were men (SS/FAS). AF type at inclusion in the SS/FAS was paroxysmal in 71.9 %/71.3 % and persistent in 26.0 %/26.6 % (missing in 2.0 %/2.0 %). The proportion of patients in sinus rhythm increased from 44.6 % at baseline to 70.2 % (SS). The mean value on the 100-point visual analogue scale (EuroQol EQ-5D) increased from 62.3 ± 17.1 at baseline by 11.4 ± 18.7 points (FAS, p<0.0001). The AF-QoL Psychological Domain improved from 44.6 ± 22.6 at baseline by 16.0 ± 23.5 points at 1 year (p<0.0001), the AF-QoL physical domain from 49.5 ± 22.1 by 10.9 ± 22.5 points (p<0.0001), and the AF-QoL sexual domain from 61.8 ± 27.1 by 6.6 ± 28.2 points (p<0.0001). In all, 136 patients (24.8 % of all patients in the safety set) had at least one adverse drug reaction (ADR) causally related to dronedarone.

Conclusions

Various dimensions of quality of life of patients with AF were improved on dronedarone under clinical practice conditions. No previously unknown safety issues were noted.

Nonlinear and Stochastic Dynamics in the Heart

In a normal human life span, the heart beats about 2 to 3 billion times. Under diseased conditions, a heart may lose its normal rhythm and degenerate suddenly into much faster and irregular rhythms, called arrhythmias, which may lead to sudden death. The transition from a normal rhythm to an arrhythmia is a transition from regular electrical wave conduction to irregular or turbulent wave conduction in the heart, and thus this medical problem is also a problem of physics and mathematics. In the last century, clinical, experimental, and theoretical studies have shown that dynamical theories play fundamental roles in understanding the mechanisms of the genesis of the normal heart rhythm as well as lethal arrhythmias. In this article, we summarize in detail the nonlinear and stochastic dynamics occurring in the heart and their links to normal cardiac functions and arrhythmias, providing a holistic view through integrating dynamics from the molecular (microscopic) scale, to the organelle (mesoscopic) scale, to the cellular, tissue, and organ (macroscopic) scales. We discuss what existing problems and challenges are waiting to be solved and how multi-scale mathematical modeling and nonlinear dynamics may be helpful for solving these problems.

Improved detection of paroxysmal atrial fibrillation utilizing a software-assisted electrocardiogram approach

Background

Automated complexity-based statistical stroke risk analysis (SRA) of electrocardiogram (ECG) recordings can be used to estimate the risk of paroxysmal atrial fibrillation (pAF). We investigated whether this method could improve the reliability of detection of patients at risk for pAF.

Methods and Results

Data from 12-lead ECGs, 24-h Holter ECGs, and SRA based on separate 1-hour Holter ECG snips were collected from three groups: 70 patients with a history of pAF but who showed no AF episode in the 12-lead ECG at study entry; 19 patients with chronic AF (at study entry); and 100 young healthy individuals. AF episodes were detected by Holter ECG in 19 of the 70 non-chronic AF patients (27.1% overall, 18.6% in the first hour), and 37 of these 70 patients were classified as at risk for pAF by SRA (representing a sensitivity of 52.9% based on the first hour of analyzed recording). Fifty-four of the 70 patients also showed a sinus rhythm in the first hour. SRA detected pAF risk in 23 of these 54 patients (representing a sensitivity of 42.6%). The Holter data showed at least 1 AF episode and at least 1 hour of sinus rhythm in nine of the patients with pAF. For these patients, SRA classified 77.8% as being at risk in the first hour after the end of the AF episode, and 71.4% and 42.9% as being at risk in the second and third hours, respectively. SRA detected almost all cardiologist-confirmed AF episodes that had been recorded in 1-hour ECG snips (sensitivity, 99.2%; specificity, 99.2%).

Conclusions

This outpatient study confirms previous findings that routine use of SRA could improve AF detection rates and thus may shorten the time between AF onset and initiation of prevention measures for patients at high risk for stroke.

The CURE-AF trial: a prospective, multicenter trial of irrigated radiofrequency ablation for the treatment of persistent atrial fibrillation during concomitant cardiac surgery

BACKGROUND

Ablation technology has been introduced to replace the surgical incisions of the Cox-Maze procedure in order to simplify the operation. However, the efficacy of these ablation devices has not been prospectively evaluated.

OBJECTIVE

The purpose of this study was to examine the efficacy and safety of irrigated unipolar and bipolar radiofrequency ablation for the treatment of persistent and long-standing persistent atrial fibrillation (AF) during concomitant cardiac surgical procedures.

METHODS

Between May 2007 and July 2011, 150 consecutive patients were enrolled at 15 U.S. centers. Patients were followed for 6 to 9 months, at which time a 24-hour Holter recording and echocardiogram were obtained. Recurrent AF was defined as any atrial tachyarrhythmia (ATA) lasting over 30 seconds on the Holter monitor. The safety end-point was the percent of patients who suffered a major adverse event within 30 days of surgery. All patients underwent a biatrial Cox-Maze lesion set.

RESULTS

Operative mortality was 4%, and there were 4 (3%) 30-day major adverse events. Overall freedom from ATAs was 66%, with 53% of patients free from ATAs and also off antiarrhythmic drugs at 6 to 9 months. Increased left atrial diameter, shorter total ablation time, and an increasing number of concomitant procedures were associated with recurrent AF (P <.05).

CONCLUSION

Irrigated radiofrequency ablation for treatment of AF during cardiac surgery was associated with a low complication rate. No device-related complications occurred. The Cox-Maze lesion set was effective at restoring sinus rhythm and had higher success rates in patients with smaller left atrial diameters and longer ablation times.

Management of stroke prevention in canadian patients with atrial fibrillation at moderate to high risk of stroke

BACKGROUND

Many patients with atrial fibrillation who are at moderate to high risk of stroke do not receive anticoagulation with vitamin K antagonists (VKAs) in accordance with recommendations.

OBJECTIVE

To determine (1) why Canadian patients with atrial fibrillation who are potentially eligible for VKA do not receive this therapy, (2) why Canadian primary care physicians discontinue VKA therapy, and (3) why VKA therapy is perceived as difficult to manage.

METHODS

The study involved a chart review of 3 cohorts of patients with nonvalvular atrial fibrillation at moderate to high risk of stroke: patients who had never received VKA treatment (VKA-naive), those whose treatment had been discontinued, and those whose VKA treatment was considered difficult to manage.

RESULTS

Charts for 187 patients (mean age 78.4 years, standard deviation 8.9 years) treated at 39 primary care sites were reviewed (62 treatment-naive, 42 with therapy discontinued, and 83 whose therapy was considered difficult to manage). Atrial fibrillation was paroxysmal in 82 (44%) of the patients, persistent in 47 patients (25%), and permanent in 58 (31%). One patient in each of the 3 cohorts had experienced a stroke during the 6 months before study participation. Bleeding events were more frequent among patients who had discontinued VKA therapy than in the other 2 groups. Among those whose therapy was discontinued and those whose therapy was difficult to manage, the mean time in the therapeutic range was 46.3% and 56.4%, respectively. The most common reason for not initiating VKA therapy in treatment-naive patients was the transient nature of atrial fibrillation (25/62 [40%]). The most common reason for discontinuation of VKA therapy was a bleeding event (10/42 [24%]). The presence of a concomitant chronic disease was the most common reason that a patient's therapy was considered difficult to manage (46/83 [55%]).

CONCLUSIONS

VKA therapy was not initiated or was discontinued for various reasons. Multiple comorbid conditions made management of VKA therapy more difficult. These findings reflect the challenges that primary care physicians experience in managing the care of patients with atrial fibrillation.

A new decline in hospitalization with atrial fibrillation among the elderly

BACKGROUND

Recent studies of atrial fibrillation within the United States showed an increase in the number and rate of hospitalization and death from 1979 to 1999. We tested the hypothesis that the trends in hospitalization and death with atrial fibrillation would be upward and similar from 1999 to 2009.

METHODS

We examined data for 1999-2009 from the US National Hospital Discharge Survey for diagnoses of atrial fibrillation (International Classification of Diseases, 9th Revision, Clinical Modification code 427.3) among up to 7 coded diagnoses and data from the National Vital Statistics System for deaths with atrial fibrillation (International Classification of Diseases 10th revision code I45). We computed all-listed diagnosis numbers and rates per 100,000 for discharges and deaths.

RESULTS

In 2009, the estimated number of all-listed diagnoses of atrial fibrillation in the United States was 2,643,000: 1,330,000 (50%) in women, 2,155,000 (82%) at ages 65+ years, and 467,000 (18%) first-listed diagnoses. At age 65+ years, the number increased from 2,049,000 in 1999 to 2,573,000 in 2005, and then decreased to 2,155,000 in 2009 (10% higher than 1999). The rate per 100,000 increased 17% from 5984 in 1999 to 6994 in 2005, and then decreased 22% to 5445 in 2009, 9% lower than 1999. The average annual percentage change was 3.12% from 1999 to 2005 compared with -5.00% from 2005 to 2009. Rates of death with atrial fibrillation increased 2% annually throughout the period.

CONCLUSIONS

In contrast to steadily increasing rates of death with atrial fibrillation, rates of diagnoses of atrial fibrillation at hospital discharge increased from 1999 to 2005, and then decreased slightly between 2005 and 2009. Further research is needed to assess explanations for these trends.

Cardiovascular and non-cardiovascular hospital admissions associated with atrial fibrillation: a Danish nationwide, retrospective cohort study

OBJECTIVE

To examine the excess risk of hospitalisation in patients with incident atrial fibrillation (AF).

DESIGN

A nationwide, retrospective cohort study.

SETTING

Denmark.

PARTICIPANTS

Data on all admissions in Denmark from 1997 to 2009 were collected from nationwide registries. After exclusion of subjects previously admitted for AF, data on 4 602 264 subjects and 10 779 945 hospital admissions contributed to the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-stratified and sex-stratified admission rates were calculated for cardiovascular and non-cardiovascular admissions. Temporal patterns of readmission, relative risk and duration of frequent types of admission were calculated.

RESULTS

Of 10 779 945 hospital admissions, 729 088(6.8%) were associated with AF. Admissions for cardiovascular reasons after 1, 3 and 6 months occurred for 6.0, 14.3 and 28.4% of AF patients versus 0.2, 0.6 and 1.8 of non-AF patients. Admissions for non-cardiovascular reasons after 1, 3 and 6 months comprised 6.8, 16.1 and 33.3% of AF patients and 1.2, 3.2 and 9.7% of non-AF patients. When stratified for age, AF was associated with similar cardiovascular admission rates across all age groups, while non-cardiovascular admission rates were higher in older patients. Within each age group and for both cardiovascular and non-cardiovascular admissions, AF was associated with higher rates of admission. When adjusted for age, sex and time period, patients with AF had a relative risk of 8.6 (95% CI 8.5 to 8.6) for admissions for cardiovascular reasons and 4.0 (95% CI 4.0 to 4.0) for admission for non-cardiovascular reasons.

CONCLUSIONS

This study confirms that the burden of AF is considerable and driven by both cardiovascular and non-cardiovascular admissions. These findings underscore the importance of using clinical and pharmacological means to reduce the hospital burden of AF in Western healthcare systems.

Effects of pharmacologic therapy on health-related quality of life in elderly patients with atrial fibrillation: a systematic review of randomized and nonrandomized trials

This systematic review assessed the impact of atrial fibrillation (AF) and pharmacotherapy on health-related quality of life (HRQOL) in elderly patients. Highly prevalent in the elderly, AF is associated with morbidity and symptoms affecting HRQOL. A PubMed and EMBASE search (1999–2010) was conducted using the terms atrial fibrillation, elderly, quality of life, Medicare, and Medicaid. In all, 504 articles were identified and 15 were selected (studies examining pharmacotherapy [rate or rhythm control] and HRQOL in AF patients with a mean age ≥ 65 years). Information, including study design, cohort size, and HRQOL instruments utilized, was extracted. Five observational studies, 5 randomized trials comparing rate and rhythm control, 3 randomized trials investigating pharmacologic agents, and 2 trials examining HRQOL, depression, and anxiety were identified. Elderly AF patients had reduced HRQOL versus patients in normal sinus rhythm, particularly in domains related to physical functioning. HRQOL may be particularly affected in older AF patients. Although data do not indicate whether a pharmacologic intervention or single treatment strategy—namely rate versus rhythm control—is better at improving HRQOL, either of these strategies and many pharmacologic interventions may improve HRQOL in elderly AF patients. Based on reviewed data, an algorithm is suggested to optimize HRQOL among elderly patients.

[Patients suffering from atrial fibrillation in Germany. Characteristics, resource consumption and costs]

INTRODUCTION

Atrial fibrillation (Afib) is considered to be the most frequent form of cardiac dysrhythmia and is well known as a key risk factor for arterial thromboembolism. The incidence of Afib will increase in the future due to demographic changes as well as improved treatment options for acute and chronic heart diseases.

OBJECTIVE

The primary objectives of this analysis were to describe patient characteristics, to assess the resource consumption associated with Afib and to measure costs of direct treatment as well as consequential costs. A secondary objective was to identify factors that influence the costs or the type of Afib.

METHODS

The analysis is based on the representative ATRIUM register (Ambulantes Register zur Morbidität des Vorhofflimmerns, Ambulatory register on morbidity of atrial fibrillation), a prospective, multicenter cohort study in which general practitioners and family doctors documented the characteristics and resource utilization of consecutively enrolled patients. The documented resource consumption use was subsequently valued with unit costs. The presented results are focused on the baseline documentation and refer to the period 12 months before enrollment.

RESULTS

A total of 3,667 patients (mean age 72.1±9.2 years, 58% men) fulfilled all inclusion criteria and were included by a total of 730 doctors. The patients had an average of 2.4±1.0 risk factors and the most common was hypertension (84% of patients). The most commonly observed comorbidities were heart failure (43%) and coronary heart disease (CHD, 35%). Medicines for oral anticoagulation (86%) and beta blockers (75%) were the most frequently prescribed drugs. A total of 1/3 of all patients received a specific kind of Afib therapy (e. g. drug conversion, cardioversion) during the past 12 months. The disease-specific mean costs of the patients were 3,274±5,134 Euro, while the acute (inpatient) treatment represented the largest proportion of these total costs (1,639±3,623 Euro). Patients with high treatment costs were significantly younger and suffered from more concomitant diseases.

CONCLUSION

Atrial fibrillation is associated with significant patient-related attributable costs that are caused particularly by expenditures of inpatient stay. New, innovative treatment strategies seem to offer particular potential savings if they are able to reduce the number of hospitalizations due to Afib itself or subsequent cardiac events.

Antiarrhythmic drugs for the maintenance of sinus rhythm: risks and benefits

Atrial fibrillation (AF) is the most common arrhythmia seen in clinical practice, and its complications impose a significant economic burden. The development of more effective agents to manage patients with AF is essential. While clinical trials show no major differences in outcomes between rate and rhythm control strategies, some patients with AF require treatment with antiarrhythmic drugs (AADs) to maintain sinus rhythm, reduce symptoms, improve exercise tolerance, and improve quality of life. Currently available AADs, while effective, have limitations including limited efficacy, adverse events, toxicity, and proarrhythmic potential. The 6 most commonly used AADs (amiodarone, disopyramide, dofetilide [USA but not Europe], flecainide, propafenone, sotalol) have proarrhythmic effects (fewer with amiodarone). Amiodarone is the most effective AAD, but its safety profile limits its usefulness. Recent advances in AAD therapy include dronedarone and vernakalant. Dronedarone, approved by the United States Food and Drug Administration and the European Medicines Authority and others, has been proven efficacious in maintaining sinus rhythm and reducing the incidence of hospitalization due to cardiovascular events or death in patients with AF. The intravenous formulation of vernakalant is approved in the European Union, Iceland, and Norway. Oral vernakalant is currently undergoing evaluation for preventing AF recurrence and appears to be effective with an acceptable safety profile. Treatment should be individualized to the patient with consideration of pharmacologic risks and benefits according to AF management guidelines. Accumulating efficacy and safety data for new and emerging AADs holds promise for improved AF management and outcomes.

Update on the clinical management of atrial fibrillation: guidelines and beyond

In clinical practice, atrial fibrillation (AF) is the most commonly encountered arrhythmia. With the aging of the US population, the number of patients with AF that physicians encounter will increase. Atrial fibrillation management involves a combination of rate- and rhythm-control strategies with thromboprophylaxis, a complicated endeavor given side effect profiles of treatments, patient comorbidities, and anticoagulation treatment requirements. Early treatment discontinuation and poor compliance with anticoagulation treatment are frequent and result in increased mortality, a 5-fold increased risk of ischemic stroke, decreased health-related quality of life, and decreased exercise capacity. In 2006, the American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) provided guidelines for the management of patients with AF. Recently, the ACC Foundation, AHA, and Heart Rhythm Society released updates to these guidelines (January and February 2011). This article aims to assist physicians in improving the management of patients with AF by focusing on the main components of therapy as reflected in the guidelines, and by providing an update on new US Food and Drug Administration-approved treatments.

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

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

Management of atrial fibrillation by primary care physicians in Germany: baseline results of the ATRIUM registry

Background

In contrast to surveys in cardiologist settings, presentation and management of atrial fibrillation (AF) in primary care patients is less well studied.

Methods and results

The prospective ATRIUM (OutpatientRegistry Upon Morbidity of Atrial Fibrillation) collected data from patients with AF seen by 730 physicians representing a random sample of all primary care physicians in Germany. ATRIUM enrolled 3,667 patients (mean age, 72 ± 9 years; 58% male, mean CHADS₂ score 2.2 ± 1.3), 994 (27.1%) with paroxysmal, 944 (25.7%) with persistent or long-standing persistent and 1,525 (41.6%) with permanent AF (no AF type was specified in 204 patients). Mean duration since initial diagnosis of AF was 61 ± 66 months (median 42, interquartile range 14–88). Reported symptoms included palpitations (43%), shortness of breath (49%), fatigue (49%), dizziness (37%) and angina (20%). Most common concomitant conditions were hypertension (84%), heart failure (43%), coronary artery disease (345%), diabetes (35%) and chronic kidney disease (20%). Prior myocardial infarction was present in 11% of patients, prior stroke in 10% and prior transient ischemic attack in 10%. Antithrombotic medication was used by 93% of the patients (oral anticoagulants, 83%). Rate control therapy was reported in 75% and rhythm control therapy in 33%, often added to rate control. Drugs for rhythm and rate control included ß-blockers (75%), calcium antagonists (15%), digitalis (29%), sodium channel blockers of type IA (quinidine, 1.0%) or IC (flecainide or propafenone, 5%), and potassium channel blockers including amiodarone (11%). In the year prior to enrollment, 46% of the patients had been cardioverted (23% by drugs, 22% electrically), catheter ablation had been performed in 5%, and 10% received a pacemaker or defibrillator. A high proportion (44%) of the patients were hospitalized in the year prior to enrollment.

Conclusions

Patients with AF managed in primary care often receive guideline-conforming therapy including antithrombotic therapy, rate control and rhythm control (numbers given above). Despite this apparent adherence, almost half of the patients were hospitalized in the year prior to enrollment, suggesting that the therapies applied do not stabilize patients sufficiently to keep them out of hospital.

Presentation of atrial fibrillation and its management by cardiologists in the ambulatory and hospital setting: MOVE cross-sectional study

OBJECTIVE

The aim of the study was to collect comprehensive data on atrial fibrillation (AF) in ambulatory and hospital-based management in Germany.

METHODS

Consecutive patients with ECG-confirmed AF in the previous 12 months were documented in a non-interventional study in 638 physician offices (78.0%) or hospitals (12.7%).

RESULTS

Of the 3354 patients (mean age 68.9 ± 10.1 years; CHADS(2) score 1.9 ± 1.3), a total of 1136 (33.9%) had paroxysmal, 899 (26.8%) persistent, 1295 (38.6%) permanent and 24 (0.7%) unspecified AF. In the 12 months prior to documentation, pharmacological conversion was attempted in 18.2%, electric cardioversion in 17.5%, the combination of both in 31.2%, and catheter ablation of AF in 5.5%. Only 41.4% of patients met the definition of stable disease (having neither AF related intervention nor change in antiarrhythmic therapy in the previous 12 months). As treatment strategy, physicians stated rate control in 64%, rhythm control in 8%, and both in 19% (not reported: 8%). Patients received antiarrhythmic drugs of class IA in 1.3%, IC in 13.8%, II in 78.1%, III in 17.9%, IV in 9.7% and digitalis in 26.7%. Drugs for thromboembolic prevention (oral anticoagulants and/or antithrombotics) were administered in 81.5%. Hospitalisations for AF or associated diseases in the previous 12 months were reported in 34.2%. Possible limitations include the open, observational design, selection of physicians with particular interest in the field and selection of patients (i.e. underrepresentation of critically ill individuals).

CONCLUSIONS

While treatment rates with regards to the prevention of thromboembolic events were among the highest reported to date, the low proportion of stable patients and in particular, the high hospitalisation rate hint at difficulties in the management of patients with AF in clinical practice.

Thirty-day outcomes of emergency department patients undergoing electrical cardioversion for atrial fibrillation or flutter

OBJECTIVES

While the short-term (<7-day) safety and efficiency of electrical cardioversion for emergency department (ED) patients with atrial fibrillation or flutter have been established, the 30-day outcomes with respect to stroke, thromboembolic events, or death have not been investigated.

METHODS

A two-center cohort of consecutive ED patients undergoing cardioversion for atrial fibrillation or flutter between January 1, 2000, and September 30, 2007, was retrospectively investigated. This cohort was probabilistically linked with both a regional ED database and the provincial health registry to determine which patients had a subsequent ED visit or hospital admission, stroke, or thromboembolic event or died within 30 days. In addition, trained reviewers performed a detailed chart abstraction on 150 randomly selected patients, with emphasis on demographics, vital signs, medical treatment, and predefined adverse events. Hemodynamically unstable patients or those whose condition was the result of an underlying acute medical diagnosis were excluded. Data were analyzed by descriptive methods.

RESULTS

During the study period, 1,233 patients made 1,820 visits for atrial fibrillation or flutter to the ED. Of the 400 eligible patients undergoing direct-current cardioversion (DCCV), no patients died, had a stroke, or had a thromboembolic event in the following 30 days (95% confidence interval [CI] = 0.0 to 0.8% for all outcomes). A total of 141 patients were included in the formal chart review, with five patients (3.5%, 95% CI = 0.5% to 6.6%) failing cardioversion, six patients (4.3%, 95% CI = 0.9% to 7.6%) having a minor adverse event that did not change disposition, and five patients (3.5%, 95% CI = 0.5% to 6.6%) admitted to hospital at the index visit.

CONCLUSIONS

Cardioversion of patients with atrial fibrillation or flutter in the ED appears to have a very low rate of long-term complications.

Atrial antifibrillatory effects of structurally distinct IKur blockers 3-[(dimethylamino)methyl]-6-methoxy-2-methyl-4-phenylisoquinolin-1(2H)-one and 2-phenyl-1,1-dipyridin-3-yl-2-pyrrolidin-1-yl-ethanol in dogs with underlying heart failure

Drug discovery efforts have focused recently on atrial-selective targets, including the Kv1.5 channel, which underlies the ultrarapid delayed rectifier current, I(Kur), to develop novel treatments for atrial fibrillation (AF). Two structurally distinct compounds, a triarylethanolamine TAEA and an isoquinolinone 3-[(dimethylamino)-methyl]-6-methoxy-2-methyl-4-phenylisoquinolin-1(2H)-one (ISQ-1), blocked I(Kur) in Chinese hamster ovary cells expressing human Kv1.5 with IC(50) values of 238 and 324 nM, respectively. In anesthetized dogs, i.v. infusions of TAEA and ISQ-1 elicited comparable 16% increases in atrial refractory period, with no effect on ventricular refractory period or QTc interval. Plasma concentrations at end infusion for TAEA and ISQ-1 were 58.5 +/- 23.6 and 330.3 +/- 43.5 nM, respectively. The abilities of TAEA and ISQ-1 to terminate AF, with comparison to the rapidly activating component of delayed rectifier potassium current blocker (+)-N-[1'-(6-cyano-1,2,3,4-tetrahydro-2(R)-naphthalenyl)-3,4-dihydro-4(R)-hydroxyspiro(2H-1-benzopyran-2,4'-piperidin)-6-yl]methanesulfonamide] monohydrochloride (MK-499) and the class IC 1-[2-[2-hydroxy-3-(propylamino)-propoxy]phenyl]-3-phenyl-1-propanone (propafenone), were assessed in conscious dogs with heart failure and inducible AF (entry criterion). All test agents administered in i.v. bolus regimens terminated AF in at least half of animals tested; conversely no agent was universally effective. MK-499, ISQ-1, TAEA, and propafenone terminated AF in five of six, four of seven, four of six, and five of six animals at plasma concentrations of 32.6 +/- 18.7, 817 +/- 274, 714 +/- 622, and 816 +/- 240 nM, respectively. Directed cardiac electrophysiologic studies in anesthetized dogs using i.v. bolus (consistent with AF studies) plus infusion regimens with TAEA and ISQ-1 demonstrated significant increases in atrial refractory period (12-15%), A-H and P-A intervals, but no effects on ventricular refractory period, H-V, and HEG intervals. The demonstration of AF termination with TAEA and ISQ-1 in the dog heart failure model extends the profile of antiarrhythmic efficacy of Kv1.5 blockade.

In Vivo Cardiac Electrophysiologic and Antiarrhythmic Effects of an Isoquinoline IKur Blocker, ISQ-1, in Rat, Dog, and Nonhuman Primate

The cardiac electrophysiologic effects of ISQ-1, an isoquinolinone I(Kur) blocker, were characterized in vivo. In rat, ISQ-1 elicited maximal 33% to 36% increases in atrial and ventricular refractoriness at a plasma concentration of 11.5 microM. In African green monkey, ISQ-1 increased atrial refractory period (maximal 17% at plasma concentration up to 20 microM) with no effect on ventricular refractory period or ECG QTc. Likewise in dog, ISQ-1 increased atrial refractory period (maximal 16% at plasma concentration up to 2 microM) with no effect on ventricular refractory period or QTc. In contrast, studies with ibutilide in nonhuman primate and dog demonstrated concomitant increases in atrial and ventricular refractoriness and QTc. Additionally, in a dog model of atrial flutter, ISQ-1 terminated ongoing flutter at doses (2.5 +/- 0.5 mg/kg IV) that selectively prolonged atrial refractoriness (13% increase), whereas flutter termination with ibutilide occurred at doses that increased both atrial and ventricular refractoriness as well as QTc. Of note, the cardiac electrophysiologic profiles displayed by ISQ-1 in these species were similar to those reported previously by our lab with a structurally distinct I(Kur) blocker. Taken together, these results further support the inhibition of I(Kur) as an approach to terminate atrial arrhythmia.

The effect of ablation technology on surgical outcomes after the Cox-maze procedure: A propensity analysis

OBJECTIVES

Since its introduction in 1987, the Cox-maze procedure has been the gold standard for the surgical treatment of atrial fibrillation. At our institution, this procedure has evolved from the cut-and-sew technique (Cox-maze III procedure) to one using bipolar radiofrequency energy and cryoablation as ablative sources to replace most incisions (Cox-maze IV procedure). This study compared surgical outcomes of patients undergoing the Cox-maze III procedure versus those of patients undergoing the Cox-maze IV procedure by using propensity analysis.

METHODS

From April 1992 through July 2005, 242 patients underwent the Cox-maze procedure for atrial fibrillation. Of these, 154 patients had the Cox-maze III procedure, and 88 had the Cox-maze IV procedure. Logistic regression analysis was used to identify covariates among 7 baseline patient variables. Using the significant regression coefficients, each patient's propensity score was calculated, allowing selectively matched subgroups of 58 patients each. Operative outcomes were analyzed for differences. Late follow-up was available for 112 (97%) patients. Freedom from atrial fibrillation recurrence and survival was calculated at 1 year by using Kaplan-Meier analysis.

RESULTS

The Cox-maze III procedure had significantly longer crossclamp times. There was no significant difference in intensive care unit and hospital stay, 30-day mortality, permanent pacemaker placement, early atrial tachyarrhythmias, late stroke, and survival. Freedom from atrial fibrillation recurrence was greater than 90% in both groups at 1 year.

CONCLUSIONS

The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.

The Cox-Maze IV procedure for lone atrial fibrillation

Numerous devices are being used for the ablation of atrial fibrillation. All of the technologies used appropriately can be effective in the clinical situation. At our institution, we have favored bipolar radiofrequency ablation. Numerous experimental studies in our laboratory have shown that these devices provide reliable lesion transmurality and safety. We also have utilized cryosurgery at the valve annuli. These technologies have been used to replace most of the incisions of the Cox-Maze procedure. This new operation has been termed the Cox-Maze IV, and can be performed either through a median sternotomy or through a right mini-thoracotomy. This modified operation requires only two small atriotomies. The right heart ablations can be performed on the beating heart, but left atrial lesions are created on the arrested heart. The left atrial appendage is always amputated or excluded. In our hands, this procedure has been able to cure over 90% of patients, both with paroxysmal and permanent atrial fibrillation.